Common Descent: the tale of the tape

[supersport]

Originally Posted by souper genyus

Humans have 23 pairs of chromosomes and all the other great apes have 24. At first glance, the implications of this do not look good for evolution. It would be impossible for humans to survive if an entire chromosome pair was simply lost. So, evolutionary biologists made a prediction, an extremely risky prediction. They predicted that for human-ape common ancestry to be true, they would need to find evidence of two primate chromosomes fusing together to form one human chromosome. If they didn't find it, they would have to admit that human-ape common ancestry is false.

They knew what they would have to see, as well. Chromosomes have two types of markers, centromeres (at the center), and telomeres (one at each end). It looks like this (C=centromere, T=telomere):

T====C====T

So, if two primate chromosomes fused to form one human chromosome, it would look like this (C=centromere, T=telomere, c=inactive centromere):

T====C====T________T====C====T
\________________/
T====C====TT====c====T

And, of course, the prediction was correct. When scientists sequenced human genome (as well as primate genomes), they realized that human chromosome 2 was two primate chromosomes fused together. Scientists have located the fusion site down to the exact base pair!

So, that was a big win for evolution. Scientists were willing to put evolution to the test, and it passed with flying colors. This is why the TOE is so remarkably accepted by people who know anything about it. It is tested repeatedly, and if one of the tests falsifies evolution, evolution is dead, or at least needs revision. The same happened with genetics. It could have blew evolution out of the water, but instead, it supported it exclusively.

You can watch a video on it here.

and what does this chromosome have to do with making a human human or an ape an ape? why would this change be selected? What do chromosome numbers have anything to do with making an animal what it is? A human has 23 chromosomes. One of the vegetables has 11...does that make the vegetable half a human (or there abouts)? It must, considering your logic. And why would the chromosome change? for fun? what selective benefit did it offer?