Transcription: So gradually, over time, genes mutate. Organisms acquire new characteristics and those creatures that find the going just too tough quietly disappear. They go extinct. Species can go extinct for all kinds of reasons. Their habitat might be destroyed or the environment might get a bit nastier. Say somewhere really cold suddenly became really hot for some weird reason. Then many species that live there would just find it too hot, they'd die out. Think about this. Less than 1% of all species that have ever lived are still around. Over 99% are now extinct, so in a way extinction is just the normal ...
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