Because evolution was not the mechanism by which this country was formed - actually there is no relationship at all.
Not only have apes evolved, they have evolved at least as much as humans have evolved.
Do you have any supporting evidence for this claim?
Actually, there is a considerable analogy here. When two populations become reproductively isolated (much as the US and England were socially and politically isolated), they grow apart via genetic drift and may grow to occupy different niches. At some point, they grow so far apart that they cannot reproduce easily. At a further point, they will be unable to reproduce entirely. But that doesn't mean that only one descendent species can exist.
o you have any supporting evidence for this claim?
Sure! Well, for one, we share more genetic material in common with chimpanzees than chimpanzees share with other apes. That certainly suggests what I'm talking about. I'll try to find a recent paper that shows that.