Because homo sapiens survived and the others did not.
Homo Sapiens beat natural selection and became more generalized instead of more specialized...for whatever reason. In fact, there is no reason, really, unless you believe the Mesopotamians (ie: we were created as work slaves).
Homo Sapiens beat natural selection and became more generalized instead of more specialized...for whatever reason. In fact, there is no reason, really, unless you believe the Mesopotamians (ie: we were created as work slaves).