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How the placenta evolved from an ancient virus

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Re: How the placenta evolved from an ancient virus

#21

Post by vbezhenar »

chrisma0 wrote: post #7

Retroviruses and our coexistence with them is fascinating to me. Fun fact: "About 8 percent of human DNA comes from viruses inserted into our genomes in the distant past, in many cases into the genomes of our pre-human ancestors millions of years ago." https://newsroom.uw.edu/news/genes-%E2%80%98fossil%E2%80%99-... Endogenous retrovirus Wiki page: https://en.wikipedia.org/wiki/Endogenous_retrovirus

Just a wild thought: if aliens wanted to change a genome of some species, what are the chances they would construct viruses to do that? AFAIK CRISP uses something similar.

Re: How the placenta evolved from an ancient virus

#22

Post by irjustin »

vbezhenar wrote: post #21
chrisma0 wrote: post #7

Retroviruses and our coexistence with them is fascinating to me. Fun fact: "About 8 percent of human DNA comes from viruses inserted into our genomes in the distant past, in many cases into the genomes of our pre-human ancestors millions of years ago." https://newsroom.uw.edu/news/genes-%E2%80%98fossil%E2%80%99-... Endogenous retrovirus Wiki page: https://en.wikipedia.org/wiki/Endogenous_retrovirus

Just a wild thought: if aliens wanted to change a genome of some species, what are the chances they would construct viruses to do that? AFAIK CRISP uses something similar.

Ah is that what's in the black goo?

Re: How the placenta evolved from an ancient virus

#23

Post by [deleted] »

chrisma0 wrote: post #7

Retroviruses and our coexistence with them is fascinating to me. Fun fact: "About 8 percent of human DNA comes from viruses inserted into our genomes in the distant past, in many cases into the genomes of our pre-human ancestors millions of years ago." https://newsroom.uw.edu/news/genes-%E2%80%98fossil%E2%80%99-... Endogenous retrovirus Wiki page: https://en.wikipedia.org/wiki/Endogenous_retrovirus

[deleted]

Re: How the placenta evolved from an ancient virus

#24

Post by shellfishgene »

andrewflnr wrote: post #6

I'm just realizing that several shark and snake species also give birth to live young, but I don't know whether they have placentas or similar structures. I'm sure they couldn't be homologous to mammal placentas, right? (Certainly not if this article is right about the timeline.) To what extent do viviparous animals converge when it comes to the mother/child interface? So some sharks have placentas, as mentioned in t…

Seahorses are also interesting in this regard, not only do they also have internal pregnancy and a placenta-like structure, it's also the males that get pregnant.

Re: How the placenta evolved from an ancient virus

#26

Post by shellfishgene »

rocqua wrote: post #10

Wait, so placenta's existed before this virus gave us the ability for them to work? I would have guessed that the virus imparted the DNA at some earlier point, and that DNA helped a placenta evolve.

More specifically, the gene that enables syncytiotrophoblasts to do what they do enabled placentas to be compatible with an adaptive immune system. So the evoution of the placenta needs to be seen in the immune system context, a more simple immune system may not have a problem with a non-self embryo in the body. So the virus gene could be one of the factors that enabled a proto-placent to evolve along an adaptive immune system. [Note this is pure speculation, I haven't read up on the evolutionary timescales of either.]

Re: How the placenta evolved from an ancient virus

#27

Post by xattt »

hypertele-Xii wrote: post #4
buran77 wrote: post #3

Earlier quoted context omitted.

Unfortunately trying to get something useful from a viral infection is almost like trying to get bitten by a radioactive spider in order to get superpowers. The problem is that as useful as those new "features" may be, they always need many generations and many more mutations to be integrated and turn into something practically useful. In the meantime you would at best have to live with a painful spider bite and some…

The best time to plant a tree is 20 years ago.

The best time to get retroviral gene integration is hundreds of millions of years ago.

Re: How the placenta evolved from an ancient virus

#28

Post by mrunkel »

TeMPOraL wrote: post #16
johnnujler wrote: post #9

Every thing about life is so fascinating. I have always wondered how viruses have persisted for so long if they need a host to survive and it took us millions of years to go from single celled to multicellular. I wish there was a way to know everything and become good at everything. :/

Viruses are ultimately bits of genetic code wrapped in a shell and injection mechanism. IANAB, so this is pure conjecture, but: it wouldn't surprise me if it turned out that viruses are a kind of degenerative state - something evolution may just spit out as it makes mistakes trying to improve on cells. If that's the case, then viruses may exist simply because they are a waste product of natural selection of more comp…

This implies that evolution has a goal and that we are that goal. This shows a fundamental misunderstanding of evolution of natural selection that is common.

Who is to say that viruses won't be the end result of life on the planet earth?

Complex life more evolved life. It's just differently evolved.

Re: How the placenta evolved from an ancient virus

#30

Post by jgilias »

It is also being researched how endogenous retroviruses are part of aging. The very rough idea being that at some point long in past a retrovirus became endogenous and provided a pathway for aging increasing the evolutionary rate of that organism, which would then out-compete most of the immortal organisms with time.

Something like:

https://pubmed.ncbi.nlm.nih.gov/20346965/

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