麻豆社

Looking at the adult chimps in a reserve in Cameroon, Steve Leonard reflects that it's easy to see how amazing human hands are. All these chimps have been rescued from the bush meat trade. They鈥檙e now looked after by Dieudonne who has a very special relationship with them. The chimps have been playing with Dieudonne鈥檚 shoelaces for years. There seems to be an element of competition here. The chimps never give up, they tie themselves in knots trying to get it right. But however hard they practise, and for however many years, they can鈥檛 compete. Learning to tie your shoelace is more complicated than it looks and chimps just don鈥檛 have what it takes. So why do humans beat chimps at tying shoelaces hands down? We can control our hands with more precision than any other creature can because of our thumbs. Human thumbs are really long and very mobile compared to a chimp鈥檚. They can鈥檛 actually move their thumbs and knuckles very much - whereas we can move ours right across the palm making our hands expert tools for handling small and delicate objects. It was this precise touch that was crucial in making us what we are today and we couldn鈥檛 have done it if we were still using our hands for walking.