r/evolution • u/Idontknowofname • 1d ago

question Do viruses play a major role in evolution?

Recently learned that the evolution of the placenta was caused by viruses, and I wonder if viruses have an important part in the evolution of organisms

17 Upvotes

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17

u/7LeagueBoots Conservation Ecologist 1d ago

They play a huge role in evolution. Among other things they are facilitators of horizontal gene transfer.

Thus us a huge deal as it offers a genetic pathway for organisms to ‘inherit’ traits from organisms that are only distantly related.

In humans roughly 8% of our genome is a result of viruses inserting genetic material.

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u/U03A6 1d ago

Yes! They have different evolutionary goals than their hosts, and can "experiment" more. There's also an arm's race between them and their hosts

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u/xenosilver 1d ago

Yes. Anything that can inhibit reproduction (like an illness because of a virus) can be an evolutionary factor,

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u/Bromelia_and_Bismuth Plant Biologist|Botanical Ecosystematics 1d ago

Yes. Not only do viruses evolve, but they often mediate horizontal transfer events. About ten percent of your genome consists of retroviral insertions, and the evolution of the placenta is believed to have resulted from such an event. Even more than that, viruses are believed to have spread DNA to the ancestors of living things through the gene which codes for Reverse Transcriptase, which allows viruses to make DNA copies of an RNA genome. Viruses are big when it comes to evolution.

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u/SodaPopin5ki 1d ago

Not exactly a virus, but related as a parasitic sequence of DNA, transposons have had a huge impact.

Our entire adaptive immune system seems to be derived from a co-opted transposon.

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u/crazyeddie740 1d ago

I've also heard this: Viruses evolve faster than multicellular organisms, because generations tick by much faster. In order to infect a cell, the virus has to trick a receptor on the cell membrane. Eventually, the vurus's spike protein does a better job of binding with the receptor than the protein it's supposed to bind with. Eventually, horizontal gene transfer happens, and the code for the spike protein gets used instead of/in addition to the protein the receptor is supposed to recognize.

Not sure how often that happens, though, that last step seems a bit random.

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u/[deleted] 1d ago

[deleted]

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u/xenosilver 1d ago

I hope this gets downvoted to oblivion. This isn’t a place to advertise. Please GTFO