Jim Beaux
01-30-2010, 09:16 AM
New Scientist has published an interesting article about how the human genome contains many sequences of ancient viruses, and why they continue.
In brief, some viruses add nothing to their host, in the sense that they don't get passed on by incroporating into DNA passed on in host reproduction. However, some do get passed on incorporated into DNA host reproduction, suggesting that they confer some kind of benefit.
Human DNA has ancient viruses in 'junk' sections - pieces once thought to have no function.
However, human DNA also has ancient viruses in active genes. The article notes a couple that are essential for formation of the human placenta.
In other words, we have taken something that once attacked us and found a useful function for it as we evolved.
Human DNA shows signs of several wipe-outs (bottlenecks) due to ancient bacteria.
As for HIV, there is animal evidence in primates showing that the virus is being passed on in DNA host transmission, raising the possibility that this may happen in humans.
Anyone who is up to a more scientific explanation will find the article at http://www.newscientist.com/article/mg20527451.200-i-virus-why-youre-only-half-human.html
In brief, some viruses add nothing to their host, in the sense that they don't get passed on by incroporating into DNA passed on in host reproduction. However, some do get passed on incorporated into DNA host reproduction, suggesting that they confer some kind of benefit.
Human DNA has ancient viruses in 'junk' sections - pieces once thought to have no function.
However, human DNA also has ancient viruses in active genes. The article notes a couple that are essential for formation of the human placenta.
In other words, we have taken something that once attacked us and found a useful function for it as we evolved.
Human DNA shows signs of several wipe-outs (bottlenecks) due to ancient bacteria.
As for HIV, there is animal evidence in primates showing that the virus is being passed on in DNA host transmission, raising the possibility that this may happen in humans.
Anyone who is up to a more scientific explanation will find the article at http://www.newscientist.com/article/mg20527451.200-i-virus-why-youre-only-half-human.html