Explain the evolution of human beings.

Explanation

In human beings, there is a great diversity in forms and features across the planet.
`rarr` For a long-time, we used to consider these human forms as human races.
`rarr` Our belief was based on skin colour i.e., yellow, black, white or brown, etc. Over recent years, the evidence has become very clear. There is no biological basis to the notion of human races. All humans are a single species.
The earliest members of the human species, Homo sapiens can be traced from Africa. Our genetic footprints can be traced back to African roots.

A couple of hundreds and thousands of years ago some of the ancestors of the mankind strayed in Africa and some of our ancestors left Africa and gradually spread to Western Asia, Central Asia, Southern Asia and Eurasia. Some of the migrants from Africa reached Indonesian islands and from Phillipines to Australia and they crossed the Bering land bridge to the America. They did not go in a single line, so they were not travelling for the sake of travelling. They went forwards and backwards, with groups sometimes separating from each other, sometimes coming back to mix with each other, even moving in and out of Africa.
Thus, like other species of living organisms, the human beings have also been the accidental product of evolution.