Episode Transcript
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1:00
Light the fireworks and blow the trumpets.
1:03
It's the 100th episode of Big
1:05
Biology. That's a hecta episode for
1:07
those of you who tend to invoke Greek prefixes
1:09
unnecessarily. Okay, it's going to be that
1:11
kind of show, huh? Even episode 100? Have
1:14
you no respect, man? We considered
1:16
many options for our 100th episode, but in
1:18
the end, we decided that it would be fun to pick
1:20
out just one theme and piece together
1:22
how different guests have approached it.
1:24
We picked agency. A totally
1:26
non-controversial topic, right, Cam? Cam?
1:30
Cam? Yeah, we'll hear from Cam
1:32
later in the show. Let's just say he has different
1:34
opinions on agency than me and Marty. But
1:37
why did we choose agency? We chose it because
1:39
many past guests have convinced us that we really
1:41
should be paying it a lot more attention in our own
1:43
research. And all of that unintended cajoling
1:46
worked. We've come to think a lot more about
1:48
agency and its implications for the work we do. For
1:50
instance, it's really helped me to think about how epigenetic
1:53
marks like DNA methylation might enable
1:55
organisms to respond plastically and invade
1:57
new areas. And it's helped me design better
1:59
experiments. on niche construction and thermal
2:01
regulation in insects. Also agency,
2:04
or at least one of its core elements, information,
2:06
has so resonated with us that we've profoundly
2:09
changed the way we think about stress in animals.
2:11
Art and I have been interested in the topic for years,
2:13
and after talking about information and agency
2:16
to many guests on big biology, we've
2:18
changed our approach to this topic big time. But
2:20
in the broadest sense, we chose to focus on agency
2:23
in the 100th Big Biology episode, because
2:25
it illustrates why so many biologists
2:27
have called for updates to the modern synthesis.
2:29
Even extended evolutionary synthesis, some have called
2:32
it. They want a more complete theory of life. Unfortunately,
2:34
the message of the extended synthesis crowd
2:37
often came across as the original modern
2:39
synthesis was incomplete or wrong. Which
2:41
is not just off-putting, it misses the point.
2:44
The major innovation of the modern synthesis was to take
2:46
statistical shortcuts and thus make
2:48
tractable that which until then had
2:50
been out of reach. It made the complex
2:53
simple. Darwin's ideas about population
2:55
change over time were first merged mathematically
2:57
with the principles of inheritance that Mendel gleaned
2:59
from his pea plants. Then Fischer, Haldane,
3:02
Wright, and others invented concepts like
3:04
gene types, populations, and
3:06
relative fitness to predict genetic evolution
3:09
and voila, a lot of biology became
3:11
intelligible. And predictable. Based on
3:13
a few simplifying assumptions. Here's
3:15
Dennis Walsh, our guest from episode 62 explaining
3:18
the modern synthesis. The modern synthesis
3:20
is a really abstract
3:22
theory. You
3:25
take these abstract entities,
3:27
gene types, and you construct
3:29
an abstract entity, a population,
3:31
and an assemblage of gene types, and
3:34
then you apply to
3:36
the gene types this very abstract
3:39
para parameter, growth rate,
3:41
relative growth rate. You can track
3:43
the dynamics of these abstract populations
3:46
in this very, very powerful way. And
3:49
the- While skipping over the organisms. Exactly.
3:51
Exactly. Leaving them out. Right.
3:54
So, how does this parameter fitness or growth rate-
3:57
all those biological things-
4:00
packed into them. It can accommodate
4:02
any amount of biology. But
4:04
I think what the defenders of the modern synthesis
4:07
don't do is they don't acknowledge
4:10
or realize the level of abstraction
4:13
at which this theory actually works.
4:14
It's not about the
4:17
nuts and bolts biology. It's basically
4:20
identifying a universality
4:23
phenomenon that we find in
4:25
thermodynamics. Any time you have
4:28
an assemblage of differentially growing
4:31
or changing entities, you're going to have
4:33
this change
4:35
in the population of the ensemble
4:39
that's expressible at a really high
4:41
level of abstraction. And I think that's
4:44
the core of the modern synthesis.
4:45
That's what makes it so powerful. But
4:48
it's not a theory of
4:51
the metaphysics of evolution, or
4:54
as I say in the book, what happens when evolution
4:56
happens. It's a very poor account
4:58
of what happens when evolution happens.
5:01
In this light, it's strange to say that the
5:03
modern synthesis needs an update because it
5:05
always rested on what William James
5:07
called vicious abstraction. By
5:10
intentionally leaving out many of the details that
5:12
make life life, we learned
5:14
things we never knew and made all sorts of progress
5:16
in animal husbandry, improvements in crop
5:19
productivity, and even in human medicine.
5:21
That said, we empathize with calls
5:23
by some for an extended synthesis. We
5:25
agree that biology is more complex than the modern synthesizers
5:28
imagined. And we think it's time to strive
5:31
for a more inclusive and cohesive theory of
5:33
life, one that captures its origins, its
5:35
adaptive operations, and its
5:37
evolution. To channel Sarah Walker, guest
5:40
on episodes 9 and 93,
5:42
we need a model of life that focuses more
5:44
on the alive parts of life.
5:46
In my mind, life is a dynamical
5:48
process. And it's one where you have a
5:51
particular informational patterns that are like
5:53
structuring physical systems across space and time.
5:56
People get mad that I think a computer is life
5:58
or a screwdriver is life.
5:59
but those things literally would not be created without
6:02
information. Yeah, it was consistent. That's okay. And
6:05
then alive is the systems that
6:07
are actively constructing things. They're the ones doing
6:09
the information processing to actually build those
6:11
things and use internalized information
6:13
to actually do the construction. The modern synthesis
6:15
took shape at a time in history when inheritance
6:18
was just coming to be understood, and the
6:20
molecular revolution, including the discovery
6:22
of DNA, was just getting underway. Progress
6:24
via synthesis thinking was great, but it
6:26
also led many subfields of biology to forget about
6:28
the original vicious abstraction. Most
6:31
egregiously, genes came to take on
6:33
causal powers they simply can't have,
6:35
including the culmination of this forgetfulness,
6:38
the selfish gene concept. To Richard
6:40
Dawkins, George Williams, Arvid Oggren, a
6:42
guest on episode 73, and many
6:44
others, willow
6:45
catkins blowing from trees are literally
6:48
DNA rain. To their way of thinking, one
6:50
need only understand how the DNA from
6:52
one willow generation gets into the next.
6:55
That's it. That's all. Biology done.
6:57
Nuh-uh.
6:58
Can't be. The modern synthesis can't
7:00
be the main paradigm for understanding
7:02
life if it doesn't explain most of how
7:05
life is alive, how complex systems
7:07
emerge and come to be resilient, how homeostasis
7:10
works, and how collections of sub-entities
7:12
are integrated into working holes. One
7:14
of our very first guests, Massimo Piliucci
7:16
from episode 7, beautifully laid out
7:18
the limits of the modern synthesis. But
7:21
to be fair, he was using Dick Lewington's analogy.
7:23
So he said, look, imagine you're
7:26
building a house,
7:27
and instead of in the United States where most
7:29
houses are built of wood, which is why they
7:32
don't last, you
7:34
build it the old-fashioned way, the European
7:36
way, with bricks and lime. So
7:39
you say, okay, so you start putting
7:41
the
7:42
first layer of bricks and
7:44
then lime on it, and then bricks and lime
7:46
and bricks and lime. Now, once you get the final
7:48
house,
7:50
you could, if you wanted, ask the
7:52
very quantitative question, well, what
7:55
is the weight of the house in bricks?
7:57
And what's the weight of the house in lime? And
8:00
there is an answer to that question. And I'm sure it will be
8:02
something like 98% bricks and 2% line. That
8:07
tells you precisely nothing about how to build
8:09
a house. Because it isn't
8:11
about, you're not going to come up with 98 bricks
8:14
and then two little pieces of line
8:17
and then you say, oh, I got the house. No, you
8:19
get the house by the specific patterning
8:22
of the bricks and the line. And so the
8:24
idea there is that even if you could
8:26
show that, let's say 90% of
8:28
variation in phenotypes
8:31
in a particular human trait is the result of genetic
8:34
influences,
8:35
that still doesn't mean the way
8:38
in which is usually interpreted. Oh, so
8:40
genes do all the work and the environment is not important.
8:43
You take out that 10% in that specific
8:45
patterning, you get nothing, absolutely nothing.
8:48
Because genes by themselves don't do crap. And
8:50
yes, you can buy that on a bumper sticker
8:53
in the big biology store. Massimo was
8:55
talking here about the importance of phenotypic plasticity,
8:58
but his point applies more broadly. The
9:00
modern synthesis focuses on changes in the
9:02
fraction of variation that things, either
9:04
genes or environments, explain. But that
9:06
kind of model doesn't capture much of what we wanted
9:09
to understand in the first place. How
9:11
the house comes to take the form it does, and
9:13
how the house doesn't fall apart soon after
9:15
being built.
9:16
Can we come up with another theory of life? A
9:18
simple one, but also one that better captures
9:20
the key things that distinguish life from non-life.
9:23
We think we can. And we think at its core
9:25
will be the concept of agency.
9:27
A system's propensity to maintain its integrity
9:30
by either changing the disruptive external forces
9:33
it experiences,
9:34
or adjusting its internal makeup to better
9:36
suit those challenges and opportunities. Or
9:39
to blend the words and ideas of a bunch of past
9:41
guests, agency is the intentionally
9:43
cognitive set of activities that a living
9:45
system uses to achieve dynamic
9:47
stability. The architecture and updates
9:49
of the Bayesian Priors and its Markov blanket
9:52
model of the world.
9:53
In this 100th episode of Big Biology, we focus
9:55
on agency with input from a subset
9:57
of our past guests to try to forecast where
9:59
biology might be.
9:59
be going and what values lie
10:02
in the conceptual transformation. And in the
10:04
last third of the show, Art and I will talk with the newest
10:06
host of Big Biology, Cam Gallimbor, on
10:09
his thoughts and skepticism about agency. I'm
10:11
Art Woods, and I'm Marty Martin, and this
10:13
is Big Biology Episode 100!
10:29
To make a case for agency, let's start at the literal
10:32
beginning, life's origins. In Episode 49,
10:34
we talk with Nick Lane about this topic and his
10:36
book, The Vital Question.
10:38
Most origins of life scientists, at least historically,
10:41
identify with one of two camps, the
10:43
RNA first world or the metabolism first
10:45
world.
10:46
Nick has feed in both worlds with heavy
10:48
doses of systems and thermodynamics
10:50
thinking. The old idea of a primordial
10:53
soup, it's not gone away.
10:55
Darwin's warm pond is probably still
10:57
the dominant idea in the origin of life
11:00
field, except when we would now call it terrestrial geothermal
11:02
systems. And
11:05
a lot of that chemistry works quite well.
11:08
You start with cyanides or cyanosetylene,
11:10
you use UV radiation, and you're able to make
11:12
all the building blocks of life. And
11:15
the problem for me with all of that
11:17
is
11:18
beautiful chemistry that works well, but
11:20
it doesn't look anything like biochemistry. And
11:22
so you're still left with this question, okay, so we've got all
11:25
these all these monomers floating around in
11:27
solution.
11:28
What happens next? How do they invent life
11:30
from there? As you can hear, Nick wonders
11:32
whether particular conditions on young Earth led
11:35
to the appearance of simple but self-sustaining
11:37
complex systems. Data from his and
11:39
other labs show that proto-life processes
11:41
were originally possible because of the availability
11:44
of particular forms of matter and energy in
11:46
particular places. Many sites on early
11:48
Earth would not have supported lifelike systems, but
11:51
some might have been just rich in resource dense
11:53
enough for those systems to maintain their integrity
11:55
and eventually reproduce.
11:57
One way, perhaps the way, that these systems
11:59
were able to...
11:59
maintain integrity was by instantiating
12:02
information into their structural elements,
12:04
which include the nucleic acids that became
12:07
today's RNA and DNA. Now it remains
12:09
a mystery how lifelike systems came alive,
12:12
from this point of being just a dynamically stable
12:14
system to the complex homeostatic modulus
12:17
systems that resemble modern microbes. Probably
12:19
there was no bright line between these stages anyway.
12:22
An early step in this process must have entailed
12:24
a separation of internal and external states,
12:27
some sort of physical boundary like what would become
12:29
a cell
12:29
membrane. Exactly what that first membrane
12:32
would have been, much less how the inside
12:34
came to take on such diversity, is
12:36
to put it lightly, a work still in progress.
12:39
Nevertheless, according to Carl Friston, our
12:41
guest in episode 70, all viable
12:43
complex systems have what mathematicians call
12:45
Markov blankets. The first barrier
12:48
must have provided a clear demarcation between outside
12:50
and in. And to
12:51
be clear, Carl isn't referring to Markov's
12:53
blanket as the thing he slept under during particularly
12:56
cold Russian winters. Rather Markov blankets
12:58
are relatively simple interconnected sets of states
13:00
whereby complex systems shield themselves
13:03
from entropy. At its simplest, a Markov
13:05
blanket is just a way
13:08
of partitioning the states
13:11
of a universe into
13:14
a system of interest, say
13:17
you or me or the virus or the vegan
13:19
and everything else.
13:21
More specifically, it's
13:23
a partition, a dividing
13:26
into three sets
13:29
of states, those states that are internal
13:31
to a system,
13:33
those states that are external
13:35
to the system, and then some intervening
13:37
states that mediate the exchange
13:40
between the inside and the outside.
13:42
So if you were a physicist
13:45
or if you go back to your schoolboy
13:47
physics, the Markov blanket enshrouds
13:50
the internal states. If you're a biologist,
13:53
then you can think of this as the cell surface.
13:55
It's the thing that sort of together with the internal
13:58
states constitutes the unit
14:00
of description of discussion
14:04
and is responsible for mediating
14:07
the reciprocal, the two-way
14:10
causal exchange between the inside and
14:12
the outside. Mathematically, it
14:14
inherits from the work of Pearl
14:18
in Bayesian networks and is defined
14:21
operationally in terms of what's called conditional
14:23
independence, which means that quite
14:25
simply,
14:26
if I wanted to know how my
14:29
internal states are going to change
14:32
in the future, in
14:34
the immediate future, then I only
14:37
need to know
14:38
the Markov blanket states, the surrounding
14:41
states. I don't need to know the rest of the universe.
14:43
Carl says that Markov blankets are the key elements
14:46
in his free energy principle. The idea
14:48
that all enduring complex systems, including
14:50
living ones, must resist entropy
14:52
by minimizing surprise.
14:55
Carl's surprise here is mathematically
14:57
defined. He means how unexpected
14:59
information gleaned from the environment, internal
15:01
or external, is related to a set of Bayesian
15:04
priors. These are ineffective parameters that
15:06
comprise the Markov blanket. Here's Carl
15:08
on surprise
15:08
and free energy minimization, ideas
15:11
he attributed to Richard Feynman. So he was dealing
15:13
with a problem of trying to characterize
15:16
the behavior of small
15:18
particles in quantum electrodynamics, trying
15:22
to understand the probability distributions
15:24
or the beliefs about different paths
15:26
that particles could take,
15:29
realize and describe it properly.
15:32
He had to turn what was an impossible
15:34
integration problem, marginalization
15:37
problem, into an optimization
15:39
problem that he could then solve using
15:41
standard techniques. That's a key
15:43
move. What that does is it
15:46
creates, it takes a
15:49
system that can be described probabilistically,
15:51
in this instance, quantum mechanics,
15:54
and converts it into an
15:56
object that can be understood
15:59
in terms of
15:59
of optimization. And that
16:02
means you've now got a normative, theological
16:06
gloss on describing how this
16:08
system works, because it looks as if something
16:10
is being minimized or maximized.
16:13
So what is that thing? Well, the thing
16:16
is the variation for energy. So it
16:19
is exactly the same construct
16:21
that is using machine learning and high
16:23
end deep learning like variational autoencoders,
16:26
where the negative
16:29
physics Feynman variational free energy
16:31
is known as an evidence lower bound and an elbow.
16:35
So in
16:36
that name, in that acronym,
16:38
you have the key thing, which
16:41
is evidence. So what
16:43
we are talking about now is a
16:46
generic mathematical way of
16:48
describing the
16:50
probabilistic dynamics or evolution
16:52
of any system in a normative
16:55
sense, in a theological sense, as trying
16:58
to optimize
17:01
a bound on evidence. So what
17:03
is evidence? It's just the probability
17:06
of some outcomes,
17:08
given some model
17:10
or hypothesis or construct
17:13
explanation that
17:15
you consider generated
17:18
those outcomes. If Carl's
17:20
hypothesis that all complex systems have
17:22
Markov blankets, all the way down,
17:24
as he likes to say, lifelike systems have
17:26
to make choices to endure. They must
17:29
either push back on the world to make it what they need it
17:31
to be, or they must update their models
17:33
of the world. If their models become sophisticated enough
17:35
that they can come to plan about how to push back,
17:38
they
17:38
by definition have agency.
17:40
Given enough time and the right contexts, one
17:43
should expect such systems to become common.
17:46
One more time. Here's Carl. If you
17:48
believe that the universe is
17:50
essentially a random dynamical
17:52
system, what you are saying is that the
17:56
variables and states of the universe evolve,
17:58
which means that a trajectory.
18:01
If they have a trajectory, then
18:04
if you want to understand that
18:06
trajectory in a normative sense, it's
18:08
basically doing some form of gradient descent,
18:11
some sort of either hill climbing or hill descending,
18:13
which gives you this sort of teleological optimization
18:16
perspective. But in so doing, even
18:19
an elementary particle
18:22
is in effect selecting
18:24
a path to pursue.
18:26
So in that elemental sense, there has
18:28
to be agency because there's time, you
18:30
can't have dynamics without time. And
18:32
if there's time, then there are trajectories.
18:35
If there are trajectories, then I go over there
18:37
and I don't go over there. So I
18:39
agree entirely that you can't
18:42
move away from or deny an
18:45
agentual aspect even to elementary
18:47
particles. Having said that, I
18:50
think there is a fundamental difference between
18:52
agency that involves planning and
18:55
agency that is just an expression of
18:57
density dynamics. So my favorite
19:00
example is the difference between a virus and a vegan.
19:02
The virus certainly
19:05
has attained
19:07
a non-equilibrium steady state. It's a beautiful
19:09
little model of its eco-nish.
19:13
It's milieu in which it survives. It does
19:15
all the right things entailed
19:17
in its sort of
19:20
molecular structure and kinetics
19:22
are all the right
19:25
substrates to be interpreted
19:27
as a model of the kind of inputs and outputs
19:30
in the world, the intracellular world usually
19:32
that it inhabits. And
19:35
one could say the same as a vegan, but a vegan
19:38
of course can do a lot more than a
19:40
virus. And if you can plan, then
19:43
by definition you must have a generative
19:45
model
19:46
of the consequences of your action in
19:48
the future. And of course in the
19:51
future now says well
19:53
you've got a generative model with the temporal depth
19:55
with the horizon. So then you
19:57
can ask well how far into the future can you go?
19:59
I see? Well,
20:01
in a sense, a virus could probably see a few
20:03
nanoseconds or milliseconds into the future simply
20:05
by committing to a particular trajectory. But
20:08
of course, a vegan
20:09
can not only see a few milliseconds
20:11
into the future, she can see
20:15
minutes, hours, days, months in
20:17
terms of- Half a century, yeah. Half
20:19
a century, exactly.
20:26
Okay, so combining Nix and Carl's thinking
20:28
so far, the first forms of life on
20:30
Earth must have been self-sustaining systems. Or
20:33
autocatagletic sets, in the words of Stuart
20:35
Kaufman. Appearing in one or more places conducive
20:38
to persisting.
20:39
To avoid succumbing to entropy, the Markov
20:41
blankets of successful systems would have become
20:43
more and more complex. If they couldn't
20:45
change their external states, they'd
20:47
instead update the parameters of their internal
20:50
states, eventually instantiating information
20:52
about past successes into nucleic acids
20:55
and probably many other structures. Paul
20:57
Davies, guest on episode 33, and
20:59
author of many books, including the focus
21:02
of our chat, Demon and the Machine, said that this
21:04
use of information, in the sense Carl talked about,
21:06
is one of the things that distinguishes life
21:08
from non-life. I think everybody
21:11
thinks about the world about them will realize
21:13
that life stands out. Living things
21:16
are in a class apart. They perform
21:18
the most amazing feats.
21:20
They seem to be different in
21:22
a very fundamental way, and not just difference
21:25
in degree, but difference in principle
21:27
from non-living systems. They are
21:30
very, very odd. Now, biologists
21:32
tend to not
21:34
find their subject matter quite so
21:36
odd, because of course they're dealing with it every day. Life's
21:38
what they study, so they sort of take it for granted. Of course, of course
21:40
we know what it is. To a physicist, it looks
21:42
like magic. It really does.
21:44
I remember thinking, when I
21:47
suppose, if you take a living organism,
21:50
it's made up of normal atoms
21:52
doing normal physics things.
21:55
How is it that a collection of
21:57
these stupid atoms, blundering
21:59
around just for
21:59
following the rules of physics, can collectively
22:03
combine to produce some,
22:05
what looks like magic, some form of magic. How
22:08
can that happen? And it is a very,
22:10
very profound mystery. To Paul, whereas
22:13
we're taught from our first biology classes that
22:15
DNA encodes
22:16
information, what that really means
22:18
is incredibly important for understanding life.
22:21
Without doubt, some kind of information is in DNA,
22:24
but information is everywhere in life.
22:26
What's in DNA is not all of it. And even
22:28
in DNA, the information that resides in
22:30
the sequence isn't necessarily even the most
22:33
important bit. Here's Paul again. You're
22:35
absolutely right that the information
22:38
contained in DNA, the genetic information,
22:41
is something that people are familiar with,
22:44
but it doesn't
22:46
stop there. So genes rarely act
22:48
in isolation.
22:49
They can switch each other on and off,
22:51
and they can form networks sometimes of great
22:54
complexity, and information swirls
22:56
around these networks. And sometimes
22:59
they're very much like components
23:01
in some electronic system.
23:04
They form modules, and these modules,
23:06
in turn, couple to each other, form
23:08
bigger networks. And we're
23:11
talking here, unlike in electronics,
23:13
about components
23:15
being wired together chemically, not electrically.
23:18
But the same principles apply, that
23:20
these are logical operations that
23:23
these components can carry out, and they can
23:26
compute and regulate and
23:29
fulfill many of the functions of modern electronics
23:32
and computing. But they're doing it with
23:36
a chemical basis. And so genes
23:38
form networks, but it
23:41
doesn't stop there because cells themselves
23:44
can form communities. They can signal each
23:46
other chemically. So we're using this information
23:49
language all the time. We talk about
23:51
cell-cell signaling cooperation
23:53
among colonies of cells. Even bacteria
23:57
can form communities that
23:59
can carry out coherent tasks.
24:03
And then when we come up to multicellular
24:06
organisms, take social insects for
24:08
example, one of the really fascinating
24:10
areas of study here at Arizona State University
24:13
is with ants and ant communication.
24:15
And they form colonies and they engage
24:18
in collective decision making.
24:20
You can see these pictures where ants
24:22
are sort of clustering around, you know,
24:24
having a little conference and you're
24:26
wondering, you know, what are they talking about. And
24:30
we're beginning to understand now, there's
24:33
no sort of chief ant that
24:35
says, you know, okay
24:38
lads and it's not lads because they're all female gals,
24:43
you know, we're off to a new nest. It's one of these things
24:45
that is done collectively, it's distributed
24:47
across them and it's done through information
24:50
exchange through all sorts of chemical
24:52
and physical cues. And it goes on all
24:54
the way up. We've talked about the brain, this
24:57
is the biggest information processing system
24:59
that we know. But again,
25:01
it doesn't stop there. It really encompasses the
25:04
entire planet.
25:05
When we look at ecosystems,
25:07
there's a lot of information flow. There
25:09
are mobile genetic elements, things like
25:12
viruses that get around the environment, couple
25:15
widely separated systems together. So
25:17
I like to say that the biosphere
25:19
is the original world wide web. The problem with
25:21
adding information to our theory of life is that
25:24
it's a very abstract concept. So
25:26
we've had a hard time measuring it. In the 1950s, for
25:29
instance, cybernetics was all the rage
25:31
and many scientists argued that by studying information,
25:34
the mysteries of life
25:35
would soon be solved. Wrong. Although
25:37
in some context, information theory was really fruitful.
25:40
We're looking at you neuroscience. In most
25:42
biological sub-disciplines, it just never delivered.
25:45
Information was truly a bad idea or was too
25:48
diffusely defined, leading people to talk past
25:50
each other, or it was just never really measured
25:52
well in any of its possible forms. Several
25:55
guests now feel that the tides have turned and
25:57
that information will in fact be integral
25:59
to biology's future.
26:00
For instance, Carl Friston thinks that the information
26:03
geometry of a system will be what distinguishes
26:05
a stone from a virus.
26:07
Sarah Walker, on her second visit in
26:10
episode 93, seemed to agree. She
26:12
and collaborator Lee Cronin proposed that something
26:14
called the Assembly Index will be useful
26:16
to finding extraterrestrial life. These
26:18
indices can be calculated in principle for
26:21
anything, and inherently they represent
26:23
the kind of thing Carl meant about information
26:25
geometry. Sarah used Harry Potter's Hogwarts
26:28
Castle, one made of Lego, that is, as
26:30
an example.
26:31
Sarah thinks that the higher the Assembly Index
26:33
is of a thing, the more likely it was produced
26:36
by non-random processes, namely life. Only
26:39
information rich things like life could
26:41
build high Assembly Index structures.
26:43
So, with Hogwarts Castle, for example,
26:46
imagine I had just put the Legos on the table, and
26:48
I didn't give you the instructions. And maybe
26:50
you're a child that never read Harry Potter,
26:53
and I said, make Hogwarts. What is
26:55
the likelihood of you even being
26:57
able to build that object? So, the
26:59
fact that you could even imagine the experiment probably
27:01
means that you have some cultural
27:03
association with my cultural background. But
27:06
there was a goal in mind, and you can imagine building
27:08
toward that goal, and probably you were assuming you had the
27:11
Lego instructions in front of you to build it. So,
27:13
Hogwarts has a very high Assembly Index. The
27:16
minimal path to make Hogwarts by randomly
27:19
constructing it, just by joining operations, is
27:21
quite large. You know, if I had said,
27:23
let's just stick three blocks together, red, blue,
27:26
red, you know, that would be pretty easy
27:28
for you to randomly assemble. And
27:30
so, the idea is that everything can be tiered by
27:32
this minimal path, which we call
27:33
the Assembly Index, and the things that have
27:35
a larger depth in time, require
27:37
more minimal steps, more memory to produce them, are more
27:40
evolved objects. They require more evolution
27:42
to get to them, more knowledge, more learning.
27:44
If you heard that episode, you could probably
27:46
tell that I was skeptical about Sarah's Assembly
27:48
Index as Panacea. Or I'm too dense to understand
27:50
her. Yeah, she's way smarter than you. abstraction
28:01
extinguished the fire of life. It's dynamism.
28:03
I understood that even life processes like metabolism
28:06
could be captured by the assembly index,
28:08
but it wasn't convinced that an idea developed to identify
28:11
alien life was sufficient to explain
28:13
living life. I
28:14
mentioned this to Sarah and she said assembly theory
28:16
accounted for it, but I just couldn't quite accept her explanation.
28:19
Well, for once you're in good company, Marty, as
28:22
this very thing is what motivated Dan Nicholson,
28:24
guest on episode 82, to co-edit
28:26
the book Everything Flows. To Dan,
28:28
a key trait of life is its dynamic equilibrium.
28:31
It's for this reason that we titled his episode,
28:34
Organisms are Not Machines. In
28:36
other words, life is more a river than
28:38
a riverboat.
28:39
Organisms are, from a physical perspective, these
28:42
systems, okay, they're systems that have
28:45
to maintain their organization by
28:47
constantly bringing in matter and energy from the environment
28:49
so that they attain this steady state. If they lose
28:51
the steady state, they die. It's an irreversible
28:53
process and that you can think of everything
28:56
that organisms does ultimately
28:58
is being reducible to that, even if that in practice may
29:00
not necessarily be helpful, but you know at
29:02
least that whatever else organisms
29:05
are, what can't be denied is that they're self-organizing
29:08
systems. I mean, it's puzzling to me because it
29:10
isn't something that often comes
29:12
up in biology. If you really press a
29:14
biologist, that's like, well, of course, and yet it
29:16
doesn't usually feature in the way biologists
29:19
explain certain phenomena. It's a reminder
29:22
that you can provide a physical
29:25
explanation for certain
29:26
capacities that organisms have in
29:28
a way that shouldn't be controversial, shouldn't
29:30
be problematic, and yet it's a way of thinking
29:33
about them physically that is very different from the
29:35
traditional mechanistic, reductionistic, deterministic
29:38
view that has dominated the biological
29:40
discourse since the 17th century. So it's saying,
29:42
okay, I'm giving you an alternative and
29:44
I'm going to anticipate your
29:48
protest that is not scientific by saying I'm grounding
29:50
it in physics and I'm going to show
29:52
to you that
29:53
this grounding leads to really interesting
29:56
implications for how you should think about biology.
29:58
Then push so hard against like... as things,
30:01
namely machines, because this metaphor
30:03
has so biased the field. Machines
30:05
like cars don't get tired, they don't rebuild
30:07
their own tires when the old ones wear down, and they
30:10
don't make baby cars. Organisms
30:12
do all of these things, and when we abstract organisms
30:15
into simpler systems like machines
30:17
or worse, genetic blueprints, we
30:19
miss the main points about life. We
30:21
want a simple model of life, because a too
30:24
complex model defeats the purpose. Okay,
30:26
first, before we dive into agency, we
30:28
have to say that, yeah,
30:29
we know, we get it, that agency
30:32
is a taboo topic to many biologists. It
30:34
smacks of some god of the gaps, some
30:37
form of soul, or a spooky force
30:39
galvanizing ourselves.
30:41
Historically, though,
30:41
agency and other vitalistic ideas
30:44
didn't leave the bad taste that they now do. Claude
30:47
Bernard, Louis Pasteur, and many
30:49
others had much more sophisticated and nuanced
30:52
ideas of agency than the simplistic negative
30:54
one that's
30:55
so common now. Hopefully by this point in the episode,
30:57
you can tell that the agency we mean is not
30:59
a mystical spiritual one. We see no
31:01
room for such things in life, and we're both
31:04
fairly staunch atheists. However, we and
31:06
the many guests we quoted earlier do think
31:08
that agency, or something like it, promises
31:11
the chance to truly and fully integrate
31:13
biology. Maybe not all the details,
31:16
but all the major elements. So
31:18
let's get after it with help from past guests,
31:21
starting with Dennis Walsh. Dennis' book,
31:23
Organisms, Agency, and Evolution, had a huge
31:25
effect on us. To Dennis, for life to
31:27
sustain itself and evolution to occur,
31:30
agents must seek out resources, avoid
31:32
danger, and generally expose themselves
31:34
or not to selective pressures. Some things
31:37
are inherited. Memory tokens, as Scott
31:39
Turner called them, and these factors plus
31:41
DNA affect change over generations.
31:44
But what happens within generations, organisms
31:46
struggle for existence, is what Dennis thinks
31:49
needs a lot more attention than it gets. In
31:51
other words, if organisms didn't have agency,
31:53
they'd never succeed in this struggle. Organisms
31:56
as systems, always at risk
31:58
of breaking down, must have agency. to
32:00
explain what Dennis calls affordances.
32:03
So I think the affordance concept is really
32:05
important. It helps us
32:07
to explain the external
32:10
dynamics of organisms, how they move through their
32:13
environments and why. But
32:15
they're internal dynamics too. Why the parts
32:18
are integrated in the way they are. Why
32:21
organisms synthesize these very
32:23
materials out of which they're made. Because
32:25
they're conducive to the pursuit
32:28
of the organisms' goals and the exploitation
32:30
of their affordance. And they also create
32:32
affordances. The
32:35
structures or capacities confer
32:38
on
32:39
organisms capacities to
32:41
capabilities to pursue their
32:43
lives in this particular way. So
32:45
we should understand the integration of organisms
32:48
and their movement through their environment in terms
32:50
of the creation and exploitation
32:53
of affordances. And affordances
32:55
are dynamic. As you respond to an affordance,
32:58
other affordances open up.
33:00
So there's this constant
33:02
creation and exploitation of affordances
33:04
going along. So my thought
33:06
about agency was we should start there. See that
33:09
knowledge that this is what organisms are like. This is
33:11
the kind of defining feature of life. And
33:14
see how working from the
33:16
taking the affordance notion is basic.
33:20
Transforms our understanding of the dynamics
33:22
of evolution. One of our other repeat
33:25
guests on Big Biology, episodes 39 and 65, is
33:27
Mike Levin. In
33:29
our first chat with Mike, we talked about the inheritance
33:31
of body form in multicellular organisms.
33:34
Convention, of course, has it that a developmental program
33:36
somehow resides in the genes, one
33:38
that unfolds over some period of time to
33:40
produce a mature body plan.
33:42
But not always true. At least not in flatworms
33:44
and frogs. Inheritance of their body plans
33:47
has to do with, believe it or not, electrical
33:49
fields. But that's for you to go here in episode 39
33:51
if you like. Our chat with Mike on episode 65
33:54
focused on agency, or more accurately,
33:57
something he called cognition and agendas.
33:59
and was largely based on a 2020 article
34:02
that he co-authored with Dan Dennett in Eon
34:04
magazine, called Cognition All
34:06
the Way Down. The main point of the article was
34:08
that only agents can have agendas.
34:11
Put a mouse and a ball on the top of a very steep
34:13
hill, and both might initially resist rolling
34:15
down the slopes. But shake that hill enough, and
34:17
only one system stays in place. Or
34:19
it climbs back to the top. Mike and Dan realize
34:22
that any system with an agenda also
34:24
requires a form of cognition, some
34:26
way to identify options and choose among
34:28
them to remain in the same state or to
34:30
exploit another one. This choosing of options is
34:32
what Mike means when he says cognition. And
34:35
cognition is core to what agents do. Here's
34:37
Mike talking about a molecular reaction, arguing
34:40
that in some sense even molecules have
34:42
simple forms of cognition. People
34:44
sometimes say to me, especially, let's say molecular
34:46
biologists, will sometimes say, look, you're
34:49
talking as if this thing made decisions, whatever.
34:52
But that's just the metaphor, right? You don't really mean
34:54
that. You know, I make decisions. This thing is just chemistry.
34:57
And I think it's very important. I think
34:59
that's a major mistake that you and I think
35:01
it's really important to get
35:04
from the get-go that I think agency
35:07
and cognition are a continuum or
35:09
a spectrum. To Mike,
35:10
cognition can and should be broadly defined.
35:13
The most conspicuous form involves the brain,
35:15
but really any system that has an information
35:17
geometry can be understood as cognitive.
35:20
So subsequently, even simple systems like
35:22
molecules and rocks can be cognitive in
35:24
that their interactions with other entities can lead
35:26
to predictable changes in their form. For me, agency
35:29
is a kind of center of gravity for
35:32
things like decisions, preferences, memories,
35:35
and in the more advanced implementation, sometimes things
35:37
like blame and credit and other
35:40
things like that.
35:41
Agents
35:44
are things that can make mistakes. Chemistry
35:46
and physics doesn't make mistakes. It just sort of does what
35:48
it does. But agents are, and I
35:50
think this is a point that Dan has made before, that
35:52
agents are capable of making mistakes.
35:55
And so there is a
35:57
kind of a whole spectrum of
35:59
different. different levels of sophistication
36:01
that different agents can achieve.
36:04
So the thing with
36:07
the ball and the mouse on top of a hill is
36:09
just an example of this. If you've got
36:11
a ball at the top of a hill, you can use
36:14
equations that will tell you what it's going to do. And
36:16
those equations have almost no
36:19
reference whatsoever to information processing, to
36:21
memory, to learning, to preferences. You don't need
36:23
any of that. You have a much simpler model that does
36:25
pretty much everything you want to do to predict
36:27
what that system is going to do. If you've got a mouse
36:30
at the top of a hill, Newton's equations
36:32
about what it's going to do with it, where it rolled
36:34
down the gravity well, unless the mouse is dead,
36:37
are almost useless because
36:39
now if you really want to understand what that system is
36:41
going to do or modify it and
36:43
make the mouse go somewhere else, you have
36:46
no hope other than through a
36:48
model that takes seriously what
36:50
that system actually is. And it's a system with preferences,
36:53
with memories, with all kinds of internal states
36:55
that are going to determine what happens later
36:57
on. Okay, so now that we've laid out what agency
37:00
is, let's confront the elephant in the room.
37:02
Does it matter? Do
37:04
we have any evidence that agential thinking will
37:06
contribute new and important things to biology?
37:09
Because we started the show today by highlighting the vicious abstraction
37:11
at the heart of the modern synthesis, let's start
37:13
there with the evolutionary implications
37:15
of agency. Specifically, let's flesh out the
37:17
roles that agency plays in what's become a hot
37:20
topic in evolutionary physiology. Thermal
37:23
regulation. Boo, how do your boys
37:25
put up with those terrible jokes? They love
37:27
me. Ectotherms often
37:29
use behavior to get body temperatures they want.
37:32
And recent thinking on this topic is
37:34
focused on something called the Bogart Effect,
37:36
which is named after the American herpetologist
37:38
Charles Bogart.
37:39
In the 1940s and 50s, Bogart studied
37:42
lizard thermoregulation and found something
37:44
surprising. Lizards in many different geographic
37:46
localities, living under many different prevailing
37:48
thermal regimes, had body temperatures that
37:50
varied little, primarily because
37:53
many of those lizards were such good behavioral
37:55
thermoregulators. Bogart wondered whether
37:57
behavioral thermoregulation could blunt the effect of the human's behavior.
37:59
of selection on other aspects of their thermal
38:02
biology, specifically their upper thermal
38:04
tolerances. And indeed, it can.
38:07
Here's Martha Munoz in episode 81 explaining
38:09
her work on the Bogart Effect.
38:10
Ray Huey, in collaboration with Paul
38:12
Hertz and Barry Senervo, wrote
38:15
a really impactful, conceptual
38:18
paper
38:19
taking Bogart's qualitative ideas
38:21
and creating a quantitative hypothesis
38:24
testing framework with which to put them to
38:26
the test.
38:27
If we take Bogart's argument
38:29
at the broadest possible level, what the
38:31
argument says is that when
38:34
any kind of regulatory homeostatic
38:36
behavior is at play, that has the capacity
38:39
to reduce environmental variation across
38:42
some environmental gradients, and that that
38:44
buffering should limit physiological
38:47
divergence and or slow
38:49
the rate of evolution.
38:51
Ray Huey and so Ray
38:53
and colleagues effectively
38:55
just gave this a new name,
38:57
the Bogart Effect, and devised a series
39:00
of approaches for testing it. And
39:03
what they did was basically
39:04
develop two premises that should be
39:06
true under the Bogart Effect. The first is that
39:09
regulatory behavior is occurring.
39:11
That, while it seems quite obvious,
39:14
is very complicated to actually demonstrate
39:16
in the field. It requires understanding
39:18
the
39:19
environment that's available to organisms.
39:21
So you need a null distribution of temperatures
39:23
that organisms, if you're doing thermal regulation, that
39:26
organisms could theoretically play with. Then you
39:28
need to demonstrate that
39:30
body temperatures are actually
39:32
in a mean and range that
39:34
is so separate from what's available
39:37
in the environment that our metrics indicate
39:39
that they're regulating. And so the null distribution
39:41
tells you what the environment is, and then you can
39:44
compare that to observed body temperatures
39:46
and through a series of metrics
39:49
basically quantify the degree
39:51
of thermal regulation that organisms are engaging
39:54
in. And this is step one. So
39:56
the second premise that should be true under
39:58
the Bogart Effect is that thermal regulation should
40:00
be associated with limited physiological
40:02
divergence or weaker selection on
40:04
physiology. The short version of Martha's
40:06
work to put a fine point on it? I've
40:09
discovered that lizards from tropical
40:11
islands tend to thermal regulate more than
40:14
lizards from the Latin American mainland.
40:16
And we discovered that the rate of heat tolerance
40:19
evolution is about three and a half times
40:21
slower on islands than on the
40:23
mainland.
40:24
Get that? 3.5 times slower evolution
40:26
on islands because island lizards do
40:28
so much more thermoregia regulation.
40:30
Their physiology is shielded from selection.
40:33
Although Martha didn't explicitly use the word agency
40:36
when she talked to us, we think it fits well into
40:38
the arguments we're making in the episode. To recast
40:40
Martha's work explicitly in this language, we
40:42
would say that lizards are agents, moving
40:45
around in their environments and exploiting affordances.
40:48
By which I mean choosing microclimates that give
40:50
high body temperatures when it's otherwise cool, and
40:53
microclimates that give low body temperature when
40:55
it's otherwise hot.
40:57
The outcome of this agency is remarkable
40:59
differences in the macroevolutionary trajectories
41:01
of lizard physiology in different lineages.
41:04
Martha's not nearly the only biologist that feels this
41:06
way. And perhaps not surprisingly, the biggest
41:08
proponents of agency as an important biological
41:10
force tend to be the physiologist, especially
41:13
those focused on homeostasis, how a system
41:15
maintains stability. Think thermostats.
41:18
Scott Turner from episode 36 said
41:20
that adaptations generally don't
41:22
really make sense except in the light of agency.
41:24
What we so liked about Scott's approach is
41:26
that he weaves
41:27
together adaptation and physics
41:29
with homeostasis as his threat. To Scott
41:32
and to Claude Bernard, a contemporary of Darwin
41:34
and the father of modern experimental medicine, homeostasis
41:37
is the process that distinguishes life
41:39
from non-life.
41:40
The very persistence of an organism's form
41:42
is itself a form of homeostasis.
41:45
And that, of course, is maintained by
41:47
this enormous complex of adaptive barriers
41:50
that separates us from the environment, the
41:53
lightings of lung, the lightings of the intestine,
41:56
the sensory interfaces, and
41:59
those kinds of things. all of which are mediated
42:01
by epithelium-like
42:04
structures. And you can take some
42:06
fairly simple aspects of
42:12
conservation of mass and thermodynamics to
42:15
be able to extend
42:19
adaptive boundaries outward from
42:21
the organisms. And in the
42:23
case of the termites, of course, these
42:26
are the African termites that build these
42:28
massive mounds as
42:30
infrastructure for their sub-training colonies.
42:34
What these mounds are is they are a big, massive,
42:37
adaptive boundary that has been
42:39
constructed between the termites themselves and the
42:41
environment, which
42:43
they are, of course, totally unsuited to be living
42:46
on their own. And the more
42:48
I studied them, the more I
42:50
came away impressed with just
42:52
how extensive this reach was, you know. So
42:55
it extends not only to managing the
42:59
atmospheric composition within the nest, but
43:01
it also co-ops
43:04
the physical environment, the entire
43:06
hydrology of the environment over
43:08
a fairly extensive range
43:10
to be able to
43:12
enable termites to live in a
43:15
dry environment, but because they
43:17
reconstruct their environment to manage water flow through
43:19
it, they can survive in those
43:22
kinds of environments. Cortescott's thesis
43:24
is that organisms and perhaps other levels
43:26
of biological organization have to be intentional.
43:29
Here he talks about how mole crickets actively
43:32
modify their burrows to get just
43:34
the sound they want so they can attract mates. In
43:36
some cases, like in humans, consciousness
43:38
can come into play and be an aspect
43:40
of intentionality. But intentional
43:42
behavior need not be conscious. It
43:45
just needs to be directed at something in the environment based
43:47
on some pre-existing model in
43:49
the brain or elsewhere in the body about expected
43:52
outcomes and current needs. Again,
43:54
states of a Markov blanket.
43:56
So what is it that we do
43:59
when we...
44:00
have an intention. You know, well,
44:02
we, there's a conscious part
44:04
of it, definitely. Kind of want to stay away from
44:07
that a little bit, but, you
44:09
know, this intentionality
44:12
can be framed
44:13
in a way that links the cognitive
44:15
interpretation of the environment with the connection
44:18
to the engines,
44:20
if you will, that can modify the environment.
44:23
And so, when you look
44:25
at the burrows
44:28
of, the tuned burrows of mall
44:30
crickets, for example, you know, these
44:35
creatures build a burrow, it ends
44:37
up in the shape of an exponential horn, this
44:39
helps project the
44:41
sound of the call much further than
44:43
it would otherwise. And if you look at what's
44:46
happening during the construction of that burrow,
44:48
the cricket burrows a little
44:50
bit, emits a chirp,
44:53
listens to it, and if it's not quite right,
44:55
it continues to modify its burrow
44:58
until it gets the chirp that it wants.
45:00
Again, I'm putting up scare quotes here, that
45:02
it wants. Yeah, right. And
45:05
that's kind of an intentionality, isn't it?
45:08
And so, if we want to try to develop
45:10
a concept of what intentionality is
45:13
that can be kept
45:15
independent from the kind
45:17
of mysticism that
45:20
tends to trip this up, then to
45:22
me, the simplest
45:23
definition is coupling
45:27
modification of the environment with the
45:29
cognitive interpretation of the environment.
45:40
Before wrapping our story, we think it's important
45:42
to point out the practical reasons for understanding
45:44
agency. One more time, here's Mike Levin on
45:47
just two such reasons. First,
45:49
our health. So imagine in the next 10 years,
45:51
we solved two things. We're
45:53
going to solve genome editing. So somebody
45:55
will have come up with a nice clean way
45:58
of making genetic edits.
45:59
where you want it and nowhere else. For perfect editing.
46:02
Yeah, yeah, yeah. Forget all that. Let's say you
46:04
get totally perfect editing. And let's say, and by
46:06
the way, let's also say that stem cell biology
46:08
gets solved so that from a stem cell, you
46:10
can get any other single cell type that you want. Okay.
46:13
So now you have all this. And
46:15
so now that means that you're going to solve some
46:17
really nice low hanging fruit. So
46:20
single gene diseases of which there are
46:22
some and single cell
46:24
diseases, you know, Parkinson's maybe things
46:27
like that.
46:28
But then, then you're going to reach
46:31
the much, much deeper question. Okay. Somebody's
46:33
missing their hand. Let's say there was an accident or birth defect
46:36
or whatever or an eye.
46:38
And now what? Because the point
46:41
isn't to be able to edit the genome cleanly.
46:43
The point is what in the world would you edit? So
46:45
if you don't believe, you know, if we
46:47
don't have a good account of
46:49
morphogenetic agency
46:52
and competency, if we don't have
46:53
a reverse engineering of this kind of software
46:56
of life that enables it to have modularity
46:58
and so on,
46:59
you're talking about micromanaging at the
47:01
molecular level,
47:03
all of the steps that go on to making a complex
47:05
organ. That is not going to happen. Nevermind
47:07
our lifetime. You know, I don't know how many years it's going to be before
47:09
that's even feasible. If it even is at all feasible,
47:12
that kind of micromanagement. Second, here's Mike
47:14
on rapid advances in our technology.
47:16
We are going to see cyborgs
47:18
and hybrids and, you know,
47:21
every kind of combination of biology,
47:23
technology, artificial intelligence and
47:25
software and hardware merges
47:28
of, of living tissue with, with
47:30
engineered, you know, all kinds of things. What
47:32
that means is the older categories,
47:35
things like
47:36
what is a robot? What is a machine?
47:39
How do we recognize agency?
47:41
What is, what is something that was evolved
47:43
versus design? Does it matter for
47:46
these things? We have to start wrestling
47:49
with this now because in the olden
47:51
It was very easy to tell.
47:54
And even then, of course, we made all kinds of
47:56
mistakes with various kinds of humans and
47:58
animals. We made all sorts of terrible mistakes.
47:59
But generally speaking, you
48:02
could do this. You would sort of knock on something.
48:04
And if you hear a metallic sound, you would say, oh
48:06
yeah, you can do whatever you want with this. And if
48:08
it was squishy and sort of warm
48:10
and furry, you would say, if
48:13
you do certain things with this, you're going to jail,
48:15
right? You have to be nice to this one. It's a
48:17
horse or a dog, whatever. And
48:19
that was easy because you could rely on two
48:21
things. You could rely on the thing
48:23
it's made, what it's made of.
48:25
And you could rely on an origin story. You
48:27
could say, well, this thing evolved.
48:29
And this thing was created in the lab. And that makes
48:32
all the difference. Those categories are gone.
48:34
I think even now these categories are no good.
48:36
And they're absolutely going to be no good going forward.
49:05
Let's suppose that Darwin had remained in the
49:07
clergy, that Fisher failed out of math,
49:09
and Mendel flew kites instead of growing peas. Suppose
49:11
that Lamarck, Shannon, Cannon, Waddington,
49:14
and McClintock got more positive attention
49:16
or just weren't excluded by others in their
49:18
fields. Suppose Lysenko was honest or
49:20
was just ignored. Suppose that Williams, Franklin,
49:23
Watson, and Crick had access to the computing
49:25
power of the average smartphone. Or
49:27
suppose that Dennis Noble, Yuri alone, or other
49:29
systems biologists had been working in the early
49:31
1900s. Suppose that biomedicine
49:34
hadn't become a barotting capitalistic behemoth.
49:36
If these counterfactuals were true,
49:38
biology today would probably be a discipline much
49:41
less focused on genes and much more
49:43
focused on life, is what Stuart Newman
49:45
calls active matter. Let's make
49:47
it so.
50:09
And
50:09
before we go, as promised, here's a quick
50:11
exchange between Cam, Marty, and me on agency.
50:14
Clearly Cam views agency differently than
50:15
we do.
50:19
Okay, we've got the three of us here in a room. It's
50:22
me, Marty, and Cam, and we're going to talk
50:24
for a little while about agency. We have a divergent
50:26
set of points of view about the importance
50:29
and utility of agency and sort
50:31
of bigger or broader issues in biology,
50:33
like how much does
50:35
the modern synthesis need updating. So,
50:38
Cam, why don't you go first and
50:40
have at it. So I want to start off
50:42
by saying that I don't deny that
50:45
organisms are complex systems
50:47
and that agency
50:49
exists. I absolutely
50:52
agree that living systems have evolved to
50:54
be robust, to
50:56
exhibit homeostasis, to
50:58
be flexible, to be plastic,
51:01
to be self-regulating, that
51:03
they interact with their environments in
51:05
complex ways. And
51:08
you can see this at different sort of
51:10
levels of biological organization.
51:13
But what I'm struggling with is, I guess
51:15
like my first question for you is, can
51:17
you have agency
51:20
without natural selection?
51:22
Yeah, sure. Can
51:24
you give me an example of that? Okay,
51:27
so this is where it gets interesting and yet
51:29
maybe complicated and off page. Immediately.
51:32
Yeah, we just first question and it's already off
51:34
the rails.
51:36
By natural selection, I'm assuming that you mean
51:38
the one that Darwin pointed to,
51:40
the one that Darwin popularized,
51:42
or you mean something broader.
51:44
Is there another version of natural selection
51:47
aside from the one that Darwin coined? So
51:50
natural selection, what I'm saying is
51:52
that evolution can happen independent of life.
51:55
None of us would argue that, I think.
51:57
You don't have to have living systems to evolve.
51:59
to have complex systems that
52:02
change through time, one of which is life.
52:04
So Darwin didn't bother to talk about any other kind
52:06
of complex system. He was only interested in the one with
52:08
fins and feathers and such.
52:10
But Marty, I think I may disagree with
52:12
you on this point. So do you think you can
52:15
have agency without selection
52:17
no matter how you define a selection? Like to me, it doesn't actually
52:19
really matter how we define selection. Let's just
52:22
take it as
52:23
Darwin's kind of natural selection and
52:25
then try to use that to answer Cam's question.
52:28
Can you get agency without that
52:30
form of selection operating? I
52:33
don't know that I can answer the question that way because I have it
52:35
in my head in such a different way. Let me just
52:37
try really briefly to articulate what it is
52:39
that I mean and why I'm pushing back on the natural selection
52:42
that's not Darwinian.
52:43
You're inevitably, any time you get at the existence
52:45
of a complex system, where you get a system that
52:48
comes to sustain itself through time,
52:51
the process by which that happens,
52:53
as long as sustaining happens for long enough, if you ever
52:55
get to a point of replication, you're gonna have the instantiation
52:58
of information such that the future generation to
53:00
that system are different than the last ones. That's
53:02
evolution by natural selection of any system living
53:05
and non-living. That's what I'm talking about.
53:07
So Darwin happened to pick
53:09
on
53:10
living systems,
53:12
but that process
53:14
should apply to any kind of system
53:16
that persists in time.
53:18
So you would say, for example, that like, we
53:21
talked to Tim Linton about this, and he
53:23
had this idea of say, grasslands
53:25
being a complex system, that
53:27
have a lot of different components that are interacting in
53:29
the grasslands, because of the
53:32
way grasses affect fire dynamics and grazing
53:34
dynamics, and the interaction between
53:36
grasses and trees, those systems are
53:38
complex, and they're self-sustaining
53:41
over long periods of time. So
53:43
would you say that that ecosystem
53:45
has agency?
53:47
I, yeah, I have a hard time with that. I
53:49
think just because of my bias about organisms,
53:51
based on everything that I've said, and most of
53:54
the people that we talked to, including Tim, I think they
53:56
would say yes, that has agency.
53:58
Because agency in the most...
53:59
generic sense is the Carl
54:02
Friston one
54:04
of an updatable set of Markov blanket
54:06
states, right? And so as long
54:08
as you have one that reifies
54:10
itself because of the way that it's updated,
54:12
it states that should mean that it has agency.
54:15
I suppose I could accept that, although it
54:17
seems a lot more likely to me that it's,
54:19
you know, individual organisms and
54:22
parts within those organisms that are going to actually
54:24
develop sophisticated forms
54:26
of agency
54:27
because that agency itself is
54:29
going to be shaped by natural selection.
54:32
Well, yeah, now natural selection, you mean a Darwinian
54:34
one?
54:35
I do. Yeah. So, I mean,
54:37
I agree with you, but I'm uncomfortable
54:40
and fully agreeing with you only because I can't get
54:42
my head around why that should fundamentally be different,
54:45
organismally and suborganismally than
54:48
at the level of what Tim was talking about.
54:50
Well, I'm still
54:52
a little bit confused by
54:54
non-Darwinian selection.
54:56
I mean, I think in the general
54:58
sense, when we talk about evolution
55:01
by natural selection, we're referring
55:04
to a
55:05
set of conditions that when those
55:07
conditions are met, then there
55:09
is some predictable outcome. And those
55:11
conditions are simply just that there's variation.
55:14
Some of that variation is heritable. And
55:18
if some of that variation is associated
55:21
with differential survival or
55:24
reproduction,
55:25
then those individuals
55:28
that, you know, have higher fitness become
55:30
more represented in a population.
55:33
And so in
55:34
the most general sense, that
55:37
can apply, you know, if we think about
55:39
it as a levels of selection problem,
55:42
something like a transposable element
55:44
is a selfish
55:47
bit of DNA. It doesn't have
55:49
like a heritable component in
55:51
the same way that a multicellular
55:53
organism would have. But
55:56
if there is an
55:58
element that tries to propagate
56:00
and make more copies of itself, then
56:03
in within the environment
56:05
that it lives in inside that genome, it
56:07
has higher fitness, and
56:09
it will propagate and increase.
56:12
That's
56:12
what happens. That's true.
56:15
But I think what we're talking about is a different kind
56:18
of thing. It's a much more inclusive thing
56:20
than the sort of temporal
56:23
changes in lineages like transposable
56:25
elements. Well, but I guess
56:28
that still confuses me because
56:31
you could think of a computer program as also
56:33
something that could evolve. It has some sort
56:36
of information. It's not living,
56:38
but it still conforms to
56:40
the same principles of
56:44
Darwinian natural selection.
56:45
Even though it's not a living
56:48
organism, it's still those
56:51
programs that have higher fitness
56:54
increase, those that have lower fitness
56:57
decrease. It's
56:59
the same general concept. That's why I guess
57:01
I'm struggling with
57:02
why that's different from
57:04
any other kind
57:07
of system that might evolve.
57:09
There's two big things in
57:12
the example that
57:14
you're using that stick out for me. One of them is
57:16
that when we say
57:18
that evolution by natural selection from
57:20
Darwin is those big three, heritability,
57:23
variation, and differential survival
57:25
and reproduction. That's all true,
57:27
but
57:28
it doesn't drive home what
57:31
Scott Turner really emphasized, where
57:33
Darwin was really coming from and a lot of people around
57:35
his time. It doesn't capture the
57:37
struggle for existence component
57:39
nearly well enough, meaning that it over
57:42
simplifies
57:43
how hard it is to be alive. Before
57:45
you even get to the heritability and variation, it's
57:48
just plain old, what is it to be
57:50
alive that will allow any of those other three
57:52
things to make a difference? The second
57:54
piece that I think is really important in this same
57:56
space
57:57
is why people traditionally pick on...
58:00
traditional thinking of evolutionary biology, we don't
58:02
have ideas about the origins of variation.
58:05
We just say that there's variation,
58:06
but coming from an agential homeostatic
58:09
complex systems mindset, immediately
58:12
for free, when you start talking about minimizing
58:14
surprise and entropy reproduction or entropy
58:16
exporting,
58:17
you end up with an explanation for not just
58:19
how much variation, but the sources and
58:22
kinds and variety of information that so
58:24
many people wanna know. So it's just
58:26
a richer landscape.
58:28
I mean, it just does work that isn't
58:30
offered by modern theory,
58:32
but I'd be interested to hear what Art says about that.
58:34
I think I agree with what you just
58:36
said. I was hung
58:39
up on thinking about the
58:41
computer software program that Cam was just
58:44
mentioning. And I was thinking maybe of a similar
58:46
sort of analogy last night when I was anticipating
58:49
this conversation. And I was
58:51
trying to think about like, what
58:53
would be a fair way to characterize
58:56
the difference between maybe
58:57
a modern synthesis view
59:00
and something that took a broader stance.
59:03
And this comes from, I think the comments
59:05
that you've made, Cam, about this
59:08
conversation in our writings to each other and
59:10
what I've heard from other people.
59:12
And that is, I think you could say, well, this
59:15
agency stuff is all really interesting and
59:18
yeah, physiology interesting, but that's
59:20
not what the modern synthesis was designed
59:23
to do. It was designed to provide a very
59:25
simplified quantitative statistical way of
59:27
understanding how variation and
59:30
filters on that variation is translated into
59:32
micro and macro evolutionary change over time.
59:36
And it does that quite well.
59:38
But okay, so here's this analogy that I had in mind
59:40
last night thinking about this. So imagine
59:43
we're trying to explain the evolution of flying
59:45
machines from say the Wright brothers plane
59:47
up to
59:48
modern fancy jets. What
59:51
would the modern synthesis say about that
59:54
sort of evolution and diversification
59:56
of flying machines? It would be something about
59:58
the plans,
1:00:01
the blueprints, the electronics
1:00:04
that have diversified and become
1:00:06
more complex over time.
1:00:09
And we could even draw phylogenies
1:00:11
of airplanes that were based on what we know
1:00:14
about how that information was transmitted
1:00:16
among individuals and among companies.
1:00:19
But that knowing that somehow still
1:00:22
doesn't explain that much
1:00:24
about how airplanes operate,
1:00:26
about
1:00:27
where the Bernoulli effect comes from,
1:00:29
about why the wings and the tails
1:00:31
are where they are and how you steer the plane in
1:00:34
the air. Like all this interesting stuff
1:00:36
about
1:00:37
what makes a plane a plane isn't captured
1:00:39
by that sort of theory of transmission
1:00:42
of plans. And so I mean
1:00:44
maybe this is not a good example because like
1:00:48
what I'm invoking here is not like different parts of an
1:00:50
airplane that have agency so
1:00:52
much as saying you
1:00:54
know there's this sort of narrow path that describes
1:00:56
the evolution, but we want to know a lot
1:00:58
more than that
1:00:59
because that's where a lot of the interest lies.
1:01:02
So I agree with you and I think
1:01:05
this is a little bit reminiscent of
1:01:07
some
1:01:08
debates that happened sort of
1:01:10
at the interface of ecology and evolution
1:01:13
between sort of the evolutionary
1:01:15
explanations for patterns
1:01:18
versus sort of more proximate
1:01:21
mechanistic explanations. And
1:01:23
you know during the 50s and 60s
1:01:26
I think there was a lot of debate about just
1:01:28
among ecologists to try to explain
1:01:31
the phenomenon that they saw. It
1:01:33
was very strictly a mechanistic
1:01:36
interpretation of what regulated
1:01:39
populations you know through for
1:01:41
example rainfall and they
1:01:43
viewed those explanations as very distinct
1:01:46
from any kind of evolutionary explanation
1:01:48
that like ecology and especially
1:01:51
sort of like functional ecology, ott ecology
1:01:54
was its own separate discipline and provided
1:01:56
its own set of explanations
1:01:59
for how things work.
1:01:59
And you can think about it in the same sense
1:02:02
of like a more mechanistic explanation
1:02:04
for behavior. You know, an organism
1:02:07
exhibits a certain behavior because there's
1:02:09
a stimulus from the environment
1:02:11
that causes a hormonal response,
1:02:14
which triggers some sort of neural response,
1:02:17
which then, you know, eventually through
1:02:19
various complex pathways results
1:02:22
in a certain kind of behavior.
1:02:24
Those are not evolutionary explanations.
1:02:27
The evolutionary explanation for that would
1:02:29
be that, you know, the animal does that behavior
1:02:31
because it gives it a fitness advantage.
1:02:34
It doesn't say anything about the nuts and bolts
1:02:36
about that. And, and I think there was a lot
1:02:38
of debate about this through the fifties
1:02:40
and sixties and Ernst Meijer wrote
1:02:43
about this kind of cause and effect problem
1:02:45
in biology and, and in the end,
1:02:48
you know, the consensus was that, look,
1:02:50
we're studying the same things and these
1:02:52
approaches are not antagonistic
1:02:54
to one another,
1:02:55
they're complementary to one another. And
1:02:57
we shouldn't think of them as being opposed. We
1:03:00
should think of them as, you know, different
1:03:02
ways of understanding.
1:03:04
And so when reading Ernst
1:03:06
Meijer's descriptions of the
1:03:08
big meeting that sort of led to
1:03:11
the coining of the term modern
1:03:13
synthesis, he, he makes some comment
1:03:15
about how they invited developmental biologists
1:03:19
and physiologists to attend the meeting and nobody
1:03:21
was interested.
1:03:22
It was because they really didn't see
1:03:24
how they thought they were unrelated.
1:03:26
Yeah. They, it just, it didn't cross their minds
1:03:29
that, you know, what you study at
1:03:31
an organismal level, the mechanisms of
1:03:33
physiology and development and behavior would
1:03:36
have anything to do with, with these sort
1:03:39
of population level, evolutionary responses.
1:03:42
And so I, I wonder if
1:03:44
some of the
1:03:46
debate and disagreement over
1:03:48
the importance of agency and, and
1:03:50
some of these other mechanisms, like understanding
1:03:52
the nuts and bolts of like an airplane,
1:03:55
the physics and the mechanics and the electronics
1:03:58
are like, those are.
1:03:59
those are also very important and those are very
1:04:02
complimentary, but those aren't
1:04:04
going to be explained by a general
1:04:07
theory of population genetics
1:04:10
that is thinking about the processes
1:04:13
of genetic drift and mutation. And
1:04:15
those all become, I think what Marty
1:04:18
calls the vicious abstraction. You
1:04:20
can't see those mechanisms,
1:04:23
but you have to sacrifice. And
1:04:25
I think that one thing that
1:04:27
I know both you and Marty have talked
1:04:30
a lot about as kind of a different perspective
1:04:32
is the systems level perspective.
1:04:35
And I think systems biology
1:04:38
and systems level thinking, that
1:04:40
does offer a different perspective
1:04:43
on the sort of traditional
1:04:45
single locus, two allele
1:04:47
population genetic kind of simplification
1:04:50
model because it does bring in a lot
1:04:52
of complexity that isn't
1:04:54
necessarily in those population genetic
1:04:57
models, but people are studying
1:04:59
that. There are evolutionary biologists
1:05:01
that think about, for
1:05:03
example, the concept
1:05:06
of robustness. Robustness is not
1:05:08
a concept that is easily pulled
1:05:11
out of quantitative genetics or population
1:05:13
genetics, but it's still a type
1:05:16
of problem and phenomenon that's
1:05:18
studied within evolutionary biology.
1:05:20
I just first wanted to make a
1:05:23
comment about this idea of vicious
1:05:25
abstraction, which we talked a lot about in the
1:05:28
script that we just read and that you just brought up. And
1:05:30
to be clear, there's nothing wrong with
1:05:33
simplification in models. And in fact,
1:05:35
that gives them
1:05:36
enormous amounts of power. I mean,
1:05:39
that's essentially the philosophy of doing a model
1:05:41
is what's the minimal amount of stuff you can
1:05:43
write down to capture something that's important
1:05:45
and of essence in a system. And
1:05:49
another non-evolutionary example of that would
1:05:51
be thinking about, well, what are good
1:05:53
mathematical models of how populations fluctuate
1:05:55
over time? And there's the exponential
1:05:58
growth model, which has just... a very
1:06:00
simple equation that underlies it. There's the
1:06:02
logistic growth equation, which adds
1:06:04
in just another couple of terms
1:06:07
that allow you to incorporate density
1:06:09
dependence into an exponential
1:06:12
growth model. And those have been vastly powerful
1:06:15
precisely because they're really vicious abstractions,
1:06:18
right? And so I think the
1:06:20
way to relate that back to what you're just talking about,
1:06:22
about evolutionary theory, is that the
1:06:24
modern synthesis is based on these abstractions
1:06:26
that are super powerful because they boil it
1:06:28
down to some kind of essence that really
1:06:29
matters. And I
1:06:32
think one path would be to say,
1:06:35
this stuff about agency and physiology
1:06:37
and homeostasis is just something else.
1:06:40
And it's not what the modern synthesis
1:06:42
was designed to explain. And
1:06:44
the problem with that, I think, is that what I
1:06:47
can see glimpses of is that
1:06:49
this complex system stuff and agency
1:06:51
and homeostasis feel to me like they feed
1:06:54
back on that evolutionary process
1:06:56
in a really important way. In other words,
1:06:58
by doing the vicious abstraction, you've
1:07:00
actually lost sight of something that's
1:07:03
not tangential, but something that's really central
1:07:05
to the way lineages evolve
1:07:07
and diversify. And so it feels
1:07:10
like we need to bring that back into the main thread.
1:07:14
Yeah, that's where I would end. Because first,
1:07:16
to be fair and clear, that's not my word. I'm
1:07:18
not that creative. That was William James' particular
1:07:21
word, but it wasn't him that claimed that necessarily.
1:07:24
Vicious abstraction. Yeah, he was making a general
1:07:26
point about, when you're trying to model
1:07:28
something by its nature, you want to simplify it
1:07:30
with defeat. But I think it's at
1:07:33
core. It's been really good,
1:07:35
really generous of you to include all of this text
1:07:37
and the script and the other emails and things, Cam, because I think
1:07:39
at the bottom, we're
1:07:41
interested in different
1:07:43
things. It's not surprising to me for
1:07:45
you to say that you believe that agency
1:07:48
is real and all those sorts of things. And I think most
1:07:50
evolutionary biologists, not everyone, but
1:07:53
most of them would go along with
1:07:55
agency if agency is defined
1:07:57
in a really specific way as to be. the
1:08:00
kinds of things that help organisms not fall apart
1:08:02
or help systems not fall apart.
1:08:04
But I think that
1:08:06
the piece that's a little bit weird, what Art
1:08:08
is alluding to, it's not so much that the modern
1:08:10
synthesis was wrong. The question
1:08:12
is whether the original vicious abstraction
1:08:15
is the best, most
1:08:17
effective abstraction. And
1:08:19
I just think that it can't be exactly what
1:08:21
replaces it. Now, that's a totally fair
1:08:23
question. And I think, you know, when the people
1:08:25
are kicking the modern synthesis and people saying, what else
1:08:27
do you want? Just listing terms, niche
1:08:30
construction or epigenetics, that's not enough, because
1:08:32
that's just the laundry list. It's something else that isn't
1:08:34
necessarily incompatible. So
1:08:37
it is the responsibility of those that want
1:08:39
something different to articulate what's different. And
1:08:41
I think that's you know, that's why we did this thing with agency.
1:08:44
It seems to be because most
1:08:46
of this stuff are like they're all systems. It's
1:08:48
really interesting to me to hear you
1:08:51
say that you are cool with robustness
1:08:54
and systems thinking, but since all of this other
1:08:56
stuff gets a little bit wonky, you're drawing
1:08:58
the line in a different place than I can under I can
1:09:00
understand, because I don't think it's really all that different. But
1:09:03
but at the end of the day, wouldn't you say that we want we
1:09:06
all want a vicious abstraction, we just
1:09:08
want a different one?
1:09:09
Or is there value in a different one? Well, I
1:09:11
think that any kind
1:09:14
of model that
1:09:16
improves our understanding
1:09:19
of how things work is something that, you
1:09:21
know, who wouldn't want that everybody wants
1:09:23
that. And I think it's
1:09:26
I think that, you know, my problem
1:09:28
with a lot of the
1:09:30
people who, you know, beat up
1:09:32
the standard evolutionary theory and say
1:09:34
like, well, it doesn't include epigenetics,
1:09:37
or it doesn't include niche construction,
1:09:40
it doesn't include plasticity, even
1:09:42
though I study plasticity, and I find
1:09:44
plasticity perfectly compatible within
1:09:47
the context of, you
1:09:49
know, the standard evolutionary theory, what
1:09:52
I haven't seen articulated is
1:09:55
what changes. So at the
1:09:57
core of like what we would
1:09:59
call standard evolutionary theory are
1:10:01
certain processes. You
1:10:04
know, those include mutation,
1:10:06
genetic drift, gene flow,
1:10:09
recombination selection. And,
1:10:13
and then you can, you can study and you
1:10:15
can model and you can empirically measure
1:10:18
interplay between gene flow and selection.
1:10:21
Well, let me, let me, let me add
1:10:23
something else in here, because I guess, I think I didn't finish
1:10:25
the thought before it's, it's not
1:10:28
just that we want a model that includes
1:10:30
a vicious abstraction, because useful models have
1:10:32
to have vicious abstractions.
1:10:34
What is it that we're trying to model? What
1:10:36
I'm talking about is not the same
1:10:39
thing because modeling evolutionary change,
1:10:41
especially when the history of those kinds of models have
1:10:43
been about genetic
1:10:46
change,
1:10:47
right? This kind of mentality,
1:10:49
whatever the suspicious abstraction is going to be, will
1:10:51
be something about the viability,
1:10:54
the sort of sustainability of a system.
1:10:56
Now that can include
1:10:58
reproduction, right? And evolution
1:11:00
subsequently, but it doesn't have
1:11:02
to. So we're talking, we're coming up with a model
1:11:05
that explains the existence,
1:11:07
like the origins of life, the persistence
1:11:10
of life and variations into
1:11:12
the future on life based on
1:11:14
these markup updates and that kind of thing. But
1:11:16
it's not quite the same thing. So, you know, gene
1:11:18
flow and drift and those kinds
1:11:21
of things aren't necessarily
1:11:23
even included. And why I'm picking
1:11:25
on this, and I want to hear what you think about it, knowing
1:11:27
that this is the like, to what end are we modeling?
1:11:30
I
1:11:30
just really strongly feel that
1:11:32
even though the modern synthesis was not
1:11:35
intended to
1:11:36
have the impact on biology
1:11:38
that it has had,
1:11:40
it's time to confront the fact that it has,
1:11:43
that biomedicine, for example,
1:11:45
spends an enormous amount of money, so
1:11:47
much more money on things genetic
1:11:50
than things other,
1:11:51
right? And so practically, it's
1:11:53
time to stop living
1:11:55
in the modern synthesis world, or
1:11:58
tacitly representing it
1:12:00
as our backbone because
1:12:02
people's lives are at stake.
1:12:15
So I think part of my disagreement
1:12:17
then is holding up this
1:12:20
thing that people keep referring
1:12:22
to the modern synthesis, which
1:12:25
is, you know, it's like by it's
1:12:27
like evolutionary biology had the synthesis 50
1:12:30
years ago and nothing's happened ever since, which
1:12:33
is how it's often depicted. That's
1:12:36
unfair. That's you're right. So I think
1:12:38
a more a more productive maybe
1:12:41
way is like within kind
1:12:43
of what we would think of a standard evolutionary
1:12:46
theory, what are the explanations
1:12:48
for what I think your
1:12:50
first step that you're very interested
1:12:53
in is
1:12:53
the origin of life. Like
1:12:56
I know, for example, you've interviewed people
1:12:58
like Sarah Walker and Nick
1:13:00
Lane and you know, does RNA
1:13:02
come first or does metabolism come first?
1:13:06
The population genetic based
1:13:08
theory doesn't say anything about that. There
1:13:11
may be some other theory out there
1:13:14
that maybe invokes a role for natural
1:13:16
selection in favoring
1:13:19
one variant over another
1:13:21
variant of you know, which which
1:13:24
one may be more effective, but but
1:13:26
I think that's that's more kind
1:13:28
of a discussion for
1:13:31
biochemists and
1:13:34
chemists and and biologists.
1:13:36
This well, it you know, it's
1:13:38
certainly more at the interface. And
1:13:41
and so so then if we if we want to
1:13:43
then move beyond that to say that, you know,
1:13:45
successful systems are those
1:13:48
that
1:13:48
do a good job of replicating themselves
1:13:51
that can keep themselves
1:13:53
alive and persist entropy
1:13:56
and maybe modify their
1:13:58
environments in way that
1:14:00
ways that make them
1:14:01
survive better and more
1:14:04
suitable for themselves.
1:14:05
I think that's all fine. I think articulating
1:14:09
a model or
1:14:12
a theory for that
1:14:14
kind of process of life that's very,
1:14:17
very general.
1:14:18
That is totally fine. And I
1:14:20
think standard evolutionary theory
1:14:23
maybe can be incorporated into that to
1:14:25
talk about, you know,
1:14:27
how things go in one direction
1:14:29
versus the other or...
1:14:31
But I don't, I don't see, I see
1:14:33
that as a,
1:14:35
again, more of a complementary
1:14:37
type of theory. It's
1:14:39
maybe most evolutionary
1:14:41
biologists are focused on micro
1:14:44
evolutionary change, but, you know,
1:14:46
I can say going to like the evolution meetings,
1:14:49
you don't see people giving talks, for example,
1:14:51
or presenting posters on...
1:14:54
At least it's not very common on like, did
1:14:56
RNA come first or did metabolism
1:14:59
come first? Like, certainly that's
1:15:01
a big evolutionary question, especially,
1:15:04
you know, in the history of life.
1:15:05
But that at bottom is the thing.
1:15:08
There's a bunch of people, I think, Art
1:15:11
and I are really physiologically inclined.
1:15:13
I think we get jazzed about this
1:15:15
because the number one thing for us
1:15:17
when you talk about any living system
1:15:19
is that it's not dead. That there has to
1:15:21
be some on these days. I mean, it's... I'm
1:15:24
not dead yet. But that's the core,
1:15:26
not dead yet. But that's the core. And evolutionary
1:15:28
biologists,
1:15:30
to me, bizarrely, and I am one because my PhD
1:15:32
says it, but they don't care necessarily
1:15:36
that life resides in those equations.
1:15:39
And that's just perplexing.
1:15:41
And I don't think, and I don't think even viable in 2023.
1:15:44
But Art, what do you think? You've been quiet. Well,
1:15:46
I want to go a different direction. So what
1:15:48
I hear you guys arguing about is,
1:15:51
you know, whether we should localize this argument
1:15:54
onto a sort of more standard
1:15:56
view of how we view evolution right now among
1:15:59
living organisms. using the mechanisms that we understand,
1:16:02
versus taking this approach that Marty
1:16:04
is advocating that sort of goes beyond
1:16:08
evolution of individual populations
1:16:11
and, you know, genes and differential survival.
1:16:13
So to sort of thinking about complex
1:16:15
systems and their origin more broadly.
1:16:17
I want
1:16:18
to circle back to sort of how I feel
1:16:20
like some of these ideas affect my
1:16:23
thinking about more standard use of evolution.
1:16:25
And this comes out of just a couple days
1:16:27
ago. So Alicia Shaw
1:16:29
invited me to Kellogg Biological Station.
1:16:31
I gave a talk there a couple of days ago and did
1:16:33
a lot of thinking about how all of these
1:16:35
ideas interface with my own work on thermal
1:16:38
ecology and thermal physiology of insects.
1:16:41
And
1:16:42
I was struck again by, I think it's this
1:16:44
idea that maybe was articulated most strongly by Scott
1:16:47
Turner, that what's interesting about agential
1:16:50
thinking is that if you
1:16:52
think about how populations evolved,
1:16:54
you know, what is there? There's some kind of variation,
1:16:57
there's some kind of filter, and
1:16:59
then some subset of that
1:17:01
original variation makes it through that filter
1:17:04
and becomes the subsequent population
1:17:07
that's reproducing. And that's a very kind of micro-revolutionary
1:17:10
view. It's a standard thing that we all say in our
1:17:12
basic biology classes. And what agency
1:17:15
adds to that is that it means
1:17:17
that the organisms that have the variation
1:17:20
are also by their actions,
1:17:23
you know, creating and modifying the
1:17:25
very filter that is selecting
1:17:28
on them. And that to me feels like,
1:17:30
you
1:17:31
know, you could say that's a small thing, and we could
1:17:33
explain that as, you know, the fact we've known
1:17:35
forever that,
1:17:36
yeah, organisms interact with their environment, organisms
1:17:38
have behavior. But
1:17:40
I think that underplays this sort of
1:17:42
fundamental importance of organisms both,
1:17:44
you know, at some level creating the variation
1:17:47
and modifying and creating the very
1:17:50
filter that's doing that selection.
1:17:52
And that feels to me like a sort
1:17:54
of profound shift in thinking about where
1:17:57
variation
1:17:59
and
1:17:59
you know, potential causes of change
1:18:02
come from, discuss.
1:18:03
Yeah, so
1:18:06
I think that is a
1:18:09
more sort of rich and
1:18:12
productive way of thinking about things. But
1:18:14
again, that kind of thinking is also
1:18:17
captured, for example, within the,
1:18:20
what people call eco-evolutionary dynamics.
1:18:23
So, like the guppies that
1:18:25
I study, work by Dave Resnick,
1:18:27
John Endler and others, but Ron
1:18:30
Basser and Joe Travis recently
1:18:33
have shown, for example, that
1:18:35
when you move guppies from a river
1:18:39
that is full of predators, that
1:18:41
keeps the population density of the guppies
1:18:43
down, you get a certain life history
1:18:46
that evolves, sort of a live fast,
1:18:48
die young kind of strategy. And
1:18:51
whether guppies naturally colonize
1:18:53
or experimentally are put into
1:18:55
these streams where these predators are absent,
1:18:58
they modify their environment,
1:19:00
but not always in a good way.
1:19:02
In the absence of predators,
1:19:04
the populations grow, they
1:19:07
become, you
1:19:08
know, very high density
1:19:10
kind of populations. And you would
1:19:12
think that maybe in the absence of predators, this
1:19:15
is sort of a nice,
1:19:17
happy paradise. But in fact, it's
1:19:19
kind of a nasty place to live. You're
1:19:21
in these very small streams under a closed
1:19:24
canopy with very little productivity, and
1:19:26
the population densities are high. So
1:19:29
it's a very competitive, very nasty
1:19:31
kind of environment. And the sort
1:19:33
of previous thinking was that the evolution
1:19:36
of the sort of low, the
1:19:38
more slow life history
1:19:40
was simply just due to the absence
1:19:43
of mortality from predators. But
1:19:45
now it's appreciated that it's
1:19:47
much more driven by the density
1:19:49
dependent
1:19:51
kind of competition for food
1:19:53
and the sort of
1:19:55
nastiness that occurs in these kinds
1:19:57
of streams. So
1:19:59
And of course, that then changes how
1:20:02
the Guppies evolve, right? They
1:20:04
go from one situation to
1:20:06
the other. And I think that's where
1:20:09
the concept of agency, I
1:20:11
worry about that then becoming a bit circular.
1:20:13
Because if Guppies weren't
1:20:17
able to adapt and evolve to these new
1:20:19
set of conditions, they would go extinct. And
1:20:21
the fact that they don't go extinct means that
1:20:24
there's been some sort of compensatory evolutionary
1:20:27
change in the life history and
1:20:29
the physiology and the behavior that allows
1:20:31
them to persist.
1:20:32
And so the system, in this case,
1:20:35
the population level, persists in
1:20:37
this new environment. And it's been shown
1:20:39
that this can evolve very quickly.
1:20:42
And it's been replicated many, many times.
1:20:45
So is that kind of interaction
1:20:47
between the Guppy and its environment
1:20:50
agential? I would refer to that
1:20:52
as either density dependent evolution
1:20:54
or ecoevolutionary dynamics. We
1:20:57
could also call it agential behavior.
1:21:00
But I think all three are capturing
1:21:02
the same kind of interaction
1:21:05
between the
1:21:06
organism, the environment, changing
1:21:08
the selection pressure,
1:21:10
acting on that variation, and
1:21:12
this more kind of feedback loop,
1:21:15
rather maybe a more linear sort
1:21:17
of response. Sure, sure. I
1:21:19
mean, I think honestly, that's a super beautiful example.
1:21:22
And to me, that's a great example
1:21:25
of organisms creating the conditions
1:21:28
themselves that are then selecting back
1:21:30
on them. And density dependence is clearly an
1:21:32
example of that that happens not only in Guppies, but in
1:21:34
many other groups. But
1:21:37
to me, what's important about this idea of
1:21:39
agency
1:21:40
is that it allows me to see that
1:21:42
that kind of density dependent selection that you
1:21:44
just described is a subset
1:21:47
of a much broader
1:21:48
set of things that organisms are doing,
1:21:52
exploiting affordances in their
1:21:54
environments. And taking advantage of
1:21:56
opportunities and avoiding threats in
1:21:58
a way. And it's not just that.
1:21:59
just guppies creating dense, nasty
1:22:02
competitive streams, it feels
1:22:04
like this is a characteristic of life everywhere.
1:22:07
And that that agential thinking somehow
1:22:09
sort of unifies those various ways by
1:22:11
which organisms are interacting with their
1:22:13
environments. Yeah, I mean, it becomes very
1:22:16
specific, right? The amazing thing about agency
1:22:18
is that
1:22:19
agency is directed at something, it's for
1:22:21
something. I know to the theology, we're
1:22:23
not supposed to
1:22:25
simplify such things, but it is for
1:22:27
something, which means that the kind of things
1:22:29
that you could expect to find in populations
1:22:31
and subsequently how they're going to involve,
1:22:33
it's not just anything,
1:22:35
right? There's gonna be particular paths that lineages
1:22:37
can take because of the kind of challenges that they have.
1:22:40
Again, this variation, it
1:22:42
doesn't just become any old thing, it becomes that thing,
1:22:44
that physiological problem that
1:22:46
agency is for. Yeah,
1:22:49
and again, I mean, so like,
1:22:50
at least in the literature that I read, I
1:22:53
see people talk about how
1:22:56
contingent is evolutionary
1:22:58
change based on the past. Like
1:23:01
that is a topic that is thought
1:23:03
about, what are the constraints? What are the
1:23:05
trade-offs? How do those dictate
1:23:08
the direction that evolution
1:23:11
will go
1:23:12
go towards? Is there a
1:23:14
bias because of some kind
1:23:16
of historic
1:23:17
sort of constraint like that? And so,
1:23:19
if the concept of agency can be
1:23:22
brought into that
1:23:24
type of thinking and say like, given
1:23:26
what we know about this particular lineage,
1:23:28
for example, and
1:23:30
agency is one of the other
1:23:32
kinds of baggage that they bring with them, sometimes
1:23:36
that baggage can be not so good because
1:23:39
it really prevents you from exploiting
1:23:42
certain kinds of environments and evolving
1:23:44
in certain directions, but then
1:23:47
agency could certainly be
1:23:50
thought of as a way of, for example, facilitating
1:23:54
evolutionary change into, for
1:23:56
example, colonizing new environments because
1:23:59
of some kind of
1:23:59
something that's there, but you mentioned
1:24:02
the word teleology and teleonomy,
1:24:05
like, I think that's where a
1:24:07
lot of people get uncomfortable within
1:24:09
the evolutionary community because because
1:24:12
then it implies that there is
1:24:14
some, you know,
1:24:15
known outcome that
1:24:18
will happen. And, and I think, repeatedly,
1:24:21
the evidence suggests that, you
1:24:23
know, there isn't necessarily going
1:24:25
to be evolutionary progression
1:24:27
towards, for example, greater complexity
1:24:30
or greater agential sort
1:24:33
of behavior. I mean, we, we see,
1:24:35
for example, that there are some lineages
1:24:37
that have more or less been
1:24:40
unchanged for, you know, millions
1:24:42
and millions of years, living
1:24:44
in, in very
1:24:45
constant, usually kinds of environments
1:24:48
with no, no change. And then, you know, we've
1:24:50
seen other lineages that have like,
1:24:53
diversified and, and expanded.
1:24:56
And so, I don't think agency would
1:24:58
necessarily predict progress or complexity.
1:25:00
As long as the system remains viable, it doesn't
1:25:03
need to become anything different. If the world
1:25:05
is predictable, it remains, it maintains
1:25:07
the same old model. And I think that's totally
1:25:09
fine. But if and when the world does change, it
1:25:11
has to act back or it has to update its model. I don't
1:25:14
think that those ideas are incompatible. But bringing
1:25:16
up this idea, it reminds me
1:25:18
to ask you about something that you mentioned a couple
1:25:21
of different times. And I think it's, it's a part
1:25:23
that I feel a little bit responsible to touch. Do
1:25:25
you think that talk or where do you think in 2023,
1:25:27
the field stands with agency
1:25:30
as some kind of spooky force?
1:25:33
Like, do you feel that biologists have to be
1:25:35
extra careful about using words like
1:25:37
this because of the potential influence it has on
1:25:40
folks that are against or have different agendas,
1:25:42
like intelligent design, that kind of thing?
1:25:44
Well, I'm not an expert
1:25:47
on these kinds of ideas. And I'm sure
1:25:49
there are other people who've thought about this a lot more.
1:25:52
I can only say from my perspective, one
1:25:54
thing that makes me very uncomfortable is
1:25:57
that
1:25:58
most of the papers that I've read
1:26:00
that deal with agency are
1:26:02
funded by the Templeton Foundation.
1:26:05
And so within that group,
1:26:07
within that set of researchers and
1:26:10
philosophers
1:26:12
and biologists who are funded through
1:26:14
that agency. So
1:26:21
does that mean that it's just
1:26:23
a little bubble of people that
1:26:26
have
1:26:27
similar thinking and
1:26:29
are all in agreement with one another and
1:26:32
there's nothing more than that? That could be
1:26:34
the case. What makes me
1:26:36
uncomfortable and I think makes a lot of
1:26:38
other people uncomfortable is this
1:26:40
way of depicting evolutionary biology
1:26:43
as being somehow in crisis and
1:26:45
that there's a real problem here
1:26:47
and there's some fundamental
1:26:49
problem that needs to be corrected.
1:26:53
And whether it's what people are
1:26:55
calling the extended evolutionary synthesis
1:26:57
or using new terms like agency.
1:27:01
So within biology, I don't think this is a big
1:27:03
deal but does this open the door for the general
1:27:05
public to then say, look, biologists
1:27:08
evolutionary biology
1:27:10
is all wrong or has been
1:27:12
wrong and is
1:27:15
in this crisis mode and that
1:27:18
somehow
1:27:19
gives the perception that it
1:27:21
gets discredited, it shouldn't
1:27:23
be trusted because those guys still haven't
1:27:25
figured things out. That gives me strength
1:27:28
to push maybe
1:27:30
a creationist or intelligent design
1:27:33
kind of agenda. Those
1:27:35
are our concerns. I mean, those are, there
1:27:37
are people out there who would exploit these kinds
1:27:39
of disagreements in that kind of way. So
1:27:43
I think it's extremely healthy to,
1:27:46
we don't want everybody to have the
1:27:48
exact same views. We want people
1:27:50
to have a diversity of views. Wouldn't be science, wouldn't it? Exactly.
1:27:54
And we want to encourage that. And so, I
1:27:57
think the challenge here is articulating.
1:27:59
and incorporating a view of agency
1:28:03
that is compatible
1:28:05
with and appealing to those
1:28:08
people who are actually doing
1:28:10
evolutionary biology research and
1:28:12
how would you incorporate it into you
1:28:15
know your studying guppies
1:28:18
or insects or birds? Would
1:28:20
it fundamentally change the
1:28:22
kinds of experiments you design,
1:28:24
you know the assumptions that you're making, the interpretation
1:28:27
of your results in ways that the
1:28:29
standard theory wouldn't do? I do
1:28:31
hear your concerns, I mean and it's unfortunate
1:28:33
that you know a lot of the people talking
1:28:36
about agency are also funded by you know
1:28:38
this agency that could raise
1:28:40
some
1:28:41
some doubts. I mean I agree
1:28:43
with you there on camera. Earlier
1:28:45
you said that
1:28:47
a grassland ecosystem could have
1:28:50
agency. It's hard
1:28:52
for me to
1:28:54
see how
1:29:04
you use the term without cognition.
1:29:07
A cognition for sure because any
1:29:09
any complex system with the ability to update
1:29:11
is learning
1:29:12
so that's just that's cognition. But I
1:29:15
think you guys may differ on this meaning of cognition
1:29:17
too right? Oh probably yeah I mean the
1:29:19
last the last part of the conversation we
1:29:21
focused on the thing we just recorded was
1:29:23
with Mike Levin that was it called
1:29:25
cognition all the way down? I thought it was
1:29:28
agency all the way down. Agency all the way
1:29:30
down but cognition is the is the main word that
1:29:32
he uses in there. And the people that are invoking
1:29:34
cognition this way are I
1:29:36
think generally careful while they're rare
1:29:38
probably for a good reason and they're
1:29:40
very careful to to distinguish
1:29:42
it from consciousness right? So there's nothing about
1:29:45
cognition that that requires
1:29:47
consciousness. Awareness is secondary.
1:29:50
Yeah yeah but what so
1:29:52
guys we've been going on for a little while and
1:29:54
I've got to go in a few minutes what are the
1:29:56
like main landing points that that
1:29:58
we want to hit? Cam is there something? Well,
1:30:00
I think one thing that I wanted
1:30:02
to say was that one thing
1:30:04
that I've really appreciated about
1:30:08
big biology as a listener
1:30:10
and now joining as a co-host is
1:30:13
interviewing people with diverse opinions
1:30:16
for sure, even if I don't agree with them,
1:30:18
but also interviewing people
1:30:21
who are also interested in the
1:30:24
philosophy of biology. And
1:30:26
I think most working
1:30:29
biologists don't read
1:30:32
philosophy of the science as much
1:30:34
as they probably should. And I
1:30:36
think that's a
1:30:37
really great thing that big biology
1:30:39
has done to introduce working
1:30:41
biologists to this kind of philosophical approach.
1:30:45
But
1:30:45
having said that, I think,
1:30:48
and I know I've heard you and Art
1:30:50
ask these questions in the past is
1:30:53
it's one thing to talk about philosophical
1:30:56
ideas as they relate
1:30:58
to evolution and agency and everything.
1:31:01
It's another much more difficult
1:31:03
task to then bring those ideas
1:31:06
into sort of the working
1:31:09
nuts and bolts of what people actually
1:31:11
do in terms of their research. And
1:31:14
I know you've asked that question in the past
1:31:16
of some of the guests of like, how do I incorporate
1:31:18
that into my own research? So now you're pinning that on
1:31:21
us, I see. And so
1:31:23
now I would just say that I
1:31:25
look forward to another
1:31:28
hundred episodes engaging
1:31:30
with both of you in conversations
1:31:32
about agency and the
1:31:34
complexities of
1:31:37
life
1:31:37
and how life evolves. Yeah,
1:31:40
there's a lot of room for different ideas
1:31:43
and a lot of work that needs to be done.
1:31:45
That's a great place to wrap it up, I think. Honestly. That
1:31:47
is a good place to wrap it up. Did you see everything that you
1:31:50
needed to, Art? Yeah, I think I'm fine. Good.
1:31:53
That was fun. Together, it was fun.
1:32:03
Thanks for listening, and if you like what you hear, please tell a friend,
1:32:05
mention us on social media, or if you're feeling really
1:32:07
generous, remember we're a non-profit.
1:32:10
We always welcome donations to help support our production
1:32:12
team, and especially our student interns.
1:32:15
And a special thanks to our dedicated fans for helping us reach
1:32:17
this 100th episode. Without your support
1:32:19
and enthusiasm, we'd never have made it here. Thanks
1:32:22
to Steve Lane who manages the website, and Ruth Demry
1:32:24
for producing the episode. Thank you as well to
1:32:26
interns Dana Delec-Cruz and Kyle Smith,
1:32:28
who helped produce the episode. Kating Shamiri does our
1:32:31
awesome cover art.
1:32:32
Thanks to the College of Public Health at the University of
1:32:34
South Florida, the College of Humanities and Sciences
1:32:36
at the University of Montana, and the National
1:32:39
Science Foundation for support.
1:32:42
Music on the episode is from Poddington Bear and Tearan
1:32:44
Castello.
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