**Credit** [History of the Earth](https://yewtu.be/watch?v=PDkvrWt7qN8)
[vostfr ](https://www.youtube.com/watch?v=PDkvrWt7qN8)
> Researched and Written by Leila Battison
Narrated and Edited by David Kelly
Art by Khail Kupsky
Thumbnail Art and Art by Ettore Mazza
Music from Epidemic Sound and Artlist.
> If you like our videos, check out [Leila's youtube channel](https://yewtu.be/channel/UCXIk7euOGq6jkptjTzEz5kQ):
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**References:**
https://www.nature.com/scitable/topicpage/the-origins-of-viruses-14398218/​
https://www.frontiersin.org/articles/10.3389/fmicb.2019.00523/full​
https://www.ft.com/content/8009dad5-9665-4602-b61c-2a294f781568​
https://www.pbs.org/wgbh/nova/article/endogenous-retroviruses/​
https://www.ancient.eu/Antonine_Plague/​
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https://elifesciences.org/articles/12704​
http://www.bbc.co.uk/history/historic_figures/galen.shtml​
http://sitn.hms.harvard.edu/flash/2012/issue127a/​
http://www.bristol.ac.uk/alspac/external/presentations/The-human-genome-and-what-we-do-with-it.pdf​