Radioactive carbon dating is useful for approximately
Humans also lack the fur coat that all other primates possess, and, relative to body size, human brains are nearly three times as large as those of the apes.Finally, all human groups are completely dependent on the use of language, without which they could not survive, and there is nothing comparable among their nearest nonhuman kin.
It is much less easy, however, to tell such things as whether or not the prehistoric creatures in question had lost their fur coatings yet or whether they had developed the capacity for articulate speech.
This led one scientific journalist to refer to humans as "the third chimpanzee." Despite all that is held in common, however, the differences are crucial and allow humans to be allotted their own genus and species, Homo sapiens.
Human feet have lost their grasping capabilities and clearly reflect the fact that humans are characteristically bipedal while chimpanzees and all of their other relatives are characteristically quadrupedal as well as being more clearly adapted to tree-climbing as part of their normal way of life.
At the time when Darwin was writing, there was only the most rudimentary sort of a fossil record to support his view, and he was further hindered by the use of the term man to stand for the human species as a whole.
As that word suggests, there was a tendency to conceive of males as typifying the human condition.