It is not simply the case that they share the same insertion points.Byblos wrote: Where are these scientific evidences you keep referring to, Angel? I haven't seen any just yet. What you've shown is that two distinct species have something in common. Out of some 98,000 insertion points, there happens to be 7 common ones between humans and chimps. Out of this observed commonality you conclude a common ancestor. I know analogies most often fail miserably but I will offer one anyway. Uncle Bob has 6 toes on his right foot and uncle Tom has six toes on his right foot. Therefore, uncle Bob and uncle Tom must be twins. Except they're 10 years apart and not even brothers (from 2 different parents, one on my mother's side and the other on my father's). That is the argument you are forwarding re common retroviral insertion points and common descent. I believe it is called the fallacy of the undistributed middle.
ERV's are the result of viral insertions. When a virus successfully inserts its genetic material into a host cell the cell will begin mass producing copies of the virus untill the host cell is full of viral particles. At this point tthe host cell will burst releasing the new viral particles to infect other host cells.
Now sometimes the viral insertion does not lead to this. If this genetic material somhow finds itself in germ cells the next generation will have this genetic material in all of their bodies cells. It has now become an ERV(endogenous retrovirus) We identify ERV's by their genetic sequence, certain proteins are known to be used specifically by retro viruses to enter their host cells. For ERV's these genes are identifiable but they are also decayed versions. Random mutations have scrambled up the sequence somewhat. Not only do closely related species share the same viral insertion points the genetic sequence of the ERV's are mostly identical. So it's not only insertion point but also shared sequence.
If it were found that guinnea pigs and humans shared an ERV which was not found in chimpanzees, it would be powerful evidence against common descent.
Scientists would have to show the section of DNA in chimpanzees which would have contained the ERV has been removed. If they were to find the section intact sans the ERV then common descent would be in trouble.
ERV's more often than not have no function in the host genome. In some cases the viral proteins have been coopted as in the case of placental development in human babies. Retroviruses are beleived to be a vehicle for horizontal gene transfer. If this mechanism of gene transfer played a large part in the development of life on earth, then ERV's become even more important in decrypting the tree of life.
The better analogy would thus be Uncle Tom and Uncle Bob both have six toes on their right foot. Their children also have six toes. The trait must be genetic. Uncle Bob and Uncle Tom are related and must have gotten this trait from a shared relative.
Although it is possible that they each got this mutation independantly the chances are low. So we will investigate, to see if the mutations are the result of independent activity. There are multiple known mutations which will cause the development of a sixth toe.
After analysis of mutations the sequences of the mutation are identical. It is most likely that they both received this genetic material from a common relative.
After a thorough search a distant relative is found in the Ural mountains. This very kind Russian gentlemen also has six toes on his right foot. The genetic sequence was determined. It is an identical sequence. The mutation cannot have occurred independently in the same manor in five separate individuals. The most likely explanation is that these men all shared a common ancestor.