There was a show on the Discovery Channel about Oliver, a chimp who walks upright like a human. Oliver was born in the wild and was raised in a family in America. He behaved like a human, shook hands, washed his hands after using the bathroom, and sat in chairs. He prefferred the company of humans over his fellow chimps.Oliver has less hair, a smaller chin, a smaller and rounder cranium, and pointed ears than do chimps.
There was some research done in Japan in the 70's that showed that some of his cells had 48 chromosomes (the same number as chimps) and some had 47 (humans have 46 chromosomes. It was thought that Oliver was a human and chimp, a hybrid.
Later research in America showed that Oliver had 48 chromosomes, in fact he is a chimp. However, when you look at Oliver's DNA and compare ti to a control chimp's DNA, Oliver is indeed different.
This absolutly amazed me and I was staring at the screen the whole hour. If you want to see it, it will be on again May 15, 2004 at 1:00 PM.
Here is a link from Rotten about Oliver, it uses some colorful language, but is very interesting.