Here is a good time table based on primate fossils available.
First primate-like mammals appear perhaps 66 million years ago.
First true primates appear about 52 million years ago. These
animals resemble modern lemurs and galagos in some respects.
First anthropoid primate (monkey and ape group) appear about 35 million
First true apes emerge in the late Oligocene/early Miocene, about 28
million years ago.
First hominids (humans) appear 6 million years ago.
Homo habilis 2.4 million years ago
Homo erectus 1.6 million years ago
Homo sapiens (early archaic forms) 200,000 years ago
Modern Homo sapiens, say 35,000 years ago.
Enough gene flow has been maintained between human populations to
prevent speciation from occurring. Human adaptation is primarily
though culture these days and not biology. For this reason,
biological evolution is less diversifying. Amerindians have been
separated from other human populations no more than 10000 years
Philip Nicholls "To ask a question,
Department of Anthropology you must first know
SUNY Albany most of the answer."