| Guybrush |
05-31-2009 11:24 PM |
Quote:
Originally Posted by Darkest Hour
(Post 669967)
if we evolved from apes, why are there still apes?
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It's about divergence and speciation. Not all higher apes became humans. Imagine millions of years back, there would be a common ancestor of orangutans, gorillas, humans, chimpanzees and bonobos ..
http://info.mcmaster.ca/~mlou/lts/im...pe_species.jpg
That common ancestor was at the very bottom. When it reached the first fork up the phylogenetic tree, that means that the species then became two species where one branched out and started evolving to what we know today as orangutans. Moving one more fork up on the tree, the species that would become gorillas diverged. This means that going back millions of years on that tree, f.ex to 6 million years ago, there were only 3 species on this chart - orangutans, gorillas and the common ancestor of humans and chimps/bonobos. Make a bigger tree and go back and you could find the common ancestor between humans and cats. Even further back, humans and birds - humans and fish and so on.
There are many factors in speciation. The most obvious and perhaps easiest way to imagine it happen is if you have one ancestor species and it spreads over a large area, then some of them become geographically isolated from others of it's species. Just imagine one population at one side of a chasm or a mountain and another population on the other side. The environmental conditions are not the same on both and the populations can't interbreed, so over time they both adapt to the conditions on their respective side and as a result, diverge and become two separate species.
In truth, there are many things that could add to speciation (doesn't have to be by isolation of populations which is called allopatric speciation) and it's a hot topic still being studied by evolutionary scientist.
Feel free to ask if there's anything else you'd like to know.
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