Why are there still apes?
The reason there are still apes is simple yet complex. As Donna quite rightly states it is thought that there were many species of hominids covering a huge evolutionary timescale. Some developed into modern day apes, monkeys and lemur type animals whilst others evolved into Homo sapiens. Although scientists have found fossils for some of these creatures there are huge gaps remaining. So the exact family tree has many blanks. Here is an interesting article explaining this
http://www.pbs.org/wgbh/evolution/humans/humankind/low_bandwidth.html
All creatures can adapt or evolve to different environments and lifestyles. Therefore over a lengthy period IE millions of years some of the adaptions are remarkable and some modern animals bear little or no resemblance to their forefathers. Just to compound things some animals that have a striking resemblance to others are a completely different species with a different family tree.

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