Even if this point were accurate, what does it prove? Does it prove that chimps and man have a similar ancestor, that they are different branches off of the same evolutionary trunk, or does it indicate that both chimps and man have the same designer who simply created man as a variation on an existing theme?
"or does it indicate that both chimps and man have the same designer who simply created man as a variation on an existing theme?"
So God looked and said about the chimp "It's no good and I can do better" and zap a little tweak here and a tuck there and we have Patrick Henry?
BTW and FYI, the coding portions of the chimp and human genome are 99% identical.
It proves common descent -- not that we and chimps had a similar ancestor, but that we share a common ancestor. How do we know this? Well, for one of many reasons, because DNA mutates at a remarkably constant rate. Now some parts of DNA code for things that we select for on a daily basis -- someone born with no arms is less likely to live than someone with two arms, so a mutation that codes for no arms quickly dies out. But most mutations have no effect on an individuals ability to survive, and those survive, and are measurable. By comparing the mutations present in both human and chimp DNA, we can tell just how long it was we branched off (imagine a genetic stop watch) -- and amazingly, the date we get is exactly what we find in the fossil record.