Many viruses are like bad party guests—they show up uninvited and wreak havoc. But some viruses are more cooperative guests. A virus may have even made us mammals!Read the transcript.Check out all the Quick and Dirty Tips shows.Subscribe to the newsletter for regular updates.Join the conversation on Facebook and Twitter.Links:https://www.quickanddirtytips.com/education/science/virus-mammalshttps://www.quickanddirtytips.com/podcastshttps://www.quickanddirtytips.com/subscribehttps://www.facebook.com/qdteinsteinhttps://twitter.com/qdteinstein