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8% of Your DNA Comes From a Virus
An anonymous reader writes "About 8 percent of human genetic material comes from a virus and not from our ancestors, according to an article by University of Texas at Arlington biology professor Cédric Feschotte, published in the Jan. 7, 2010 issue of Nature magazine."
Is any of that DNA in use or are those parts dormant? What effect do these modifications have on us beyond the initial use of replication and further propagation of viruses?
The real news here doesn't appear to be that endogenization has occured through our past (OK, maybe the 8% number is news; I don't know about the numbers...) but instead that a virus, bornavirus, is displaying this property. This is news because bornaviruses are not retroviruses (previously the only know virus-types to produce endogenous copies.) Furthermore, the article seems to suspect that this virus may have ties to the schizophrenia and mood disorders...
Demented But Determined.
Google for placenta and endogenous (as in endogenous virus). The placenta uses a lot of viral code, to the extent that it might be more virus than anything else. It also sheds a lot of viruses. The placenta is almost a different life form.
BTW, the Wikipedia entry shows that the "8%" number was known as long as 6 years ago.http://en.wikipedia.org/wiki/Endogenous_retrovirus
To be pedantic, the difference between humans and animals is usually called reason, but in fact it's probably more specific if less poetic to call it 'problem solving'. Animals don't 'live in equilibrium' per se because that implies that they know what they're doing, as though they're thinking 'oh... I'll eat exactly this much and no more because that will mess things up!' Pfff I'll bet somewhere there's some green whackjobs who think that's exactly the romantic notion going through the brains of animals. (In fact, there are predators that kill even after they are full, just to kill. I remember watching a documentary about sea turtles and watching them hatch and try to make their way to the sea, and predatory birds were attacking them, first to eat them, but even after that they just kept killing and leaving the dead baby turtles there to rot.) Anyway, I'm rambling, point is, animals expand as far as they can. They consume as much as they can, whenever and where-ever they can, and reproduce as often as possible. What determines their numbers ultimately are things like the rate at which their consumed resources replenish and the rate at which they otherwise die from predation/disease/accidents/age, not some kind of instinctive population control.
So the contrast is, an animal, insofar as it thinks, thinks 'I will eat x' and then when x is scarce it thinks 'oh shit there isn't enough x!' Then depending on luck, it dies. Whereas humans think 'I like to eat x' and when x becomes scarce humans think 'well, this sucks, there isn't enough x anymore. Maybe I can eat something else? How about this? Ew. No, not that. How about this other thing? Meh, it's ok. Maybe I can cook it? What things could I do, or do in concert with others, that might restore the natural abundancy of x and/or allow x to be produced in an environment I control?' Yeah. That's why human population keeps growing, moving, adapting, and animals just have to suck it up. They can't solve resource problems creatively.
(Viruses aren't creative either, they and other micro-organisms just have such fast life cycles that it allows them to find mutations that positively affect their survival at a higher rate. In other words they adapt quickly by chance, humans adapt quickly by decisions.
I support the Slashcott and will not be reading or commenting from 2/10/14 to 2/17/14. Beta is steaming pile of dog shit
There are 4^3000 (about 1.5*10^1806) different 3000 letter works (if you only have 4 characters). The odds of finding your specific one in a 3 trillion collection of random letters is so small, you can't even imagine how small it is. (approx 1 in 2*10^1794)
But let's try anyway. Imagine playing the universal lottery. You are supposed to pick one subatomic particle in the entire universe, and if you choose the correct one you get 1 nickle, the odds of winning is about 1 in 10^80, if you were to enter that lottery a billion trillion times a second (10^21) by the time all protons in the universe would have decayed the likelyhood that you would have won even once would be so small that you could not even imagine. Never the less.
Now imagine playing that lottery one time for each billion trillion times times you look through a different set of random characters (with each set being 3 trillion characters). After having won that lottery, not once, but enough times to build a tower of your nickles 1000 times longer than the circumference of the entire universe the likelyhood of you having found a matching set to your 3000 character set would be so close to 0, that you still can not even imagine how small it is.
So my guess would be that this virus dna didn't just appear by chance in the dna of humans.