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  However, it is not as if the older designs are inefficient. So many of the older and
                       simpler designs still survive.
                     In fact, one of the simplest life forms – bacteria – inhabit the most inhospitable
                       habitats like hot springs, deep-sea thermal vents and the ice in Antarctica.
                     In other words, human beings are not the pinnacle of evolution, but simply yet
                       another species in the teeming spectrum of evolving life.

               HUMAN EVOLUTION
                     Evolution has created a huge biodiversity.
                     Natural selection, genetic drift, and speciation – all these factors shaped the
                       biodiversity.

                     The new species have never left a choice to mate with the previous ones.

                     Each species had to reproduce in their own way with their own group members.
                     This leads to the branching of species i.e., a common ancestor diverges into two
                       or more different lineages.

                     Human evolution also has the same story. If we talk about human evolution, the
                       first thing which comes to mind is a chimpanzee.

                     Even though human evolution is not from chimpanzees, they share a common
                       ancestor.

                     Both the species of human and chimpanzee evolved in their own way from a
                       common ancestor as per their living conditions.
                     Nowadays, we can trace the evolutionary relationships between species easily
                       by using fossils, DNA sequences, and paleontological excavation, etc.

                     It is said that human evolution began in Africa. The earliest genus of Homo to be
                       ever discovered is Homo habilis, which lived nearly 1.75 million years ago.
               → Although there is great diversity of human forms all over the world, yet all humans
               are a single species.
               → All humans come from Africa. The earliest members of the human species, Homo
               sapiens, can be traced there. Our genetic footprints can be traced back to our African
               roots.
               → The residents spread across Africa, the migrants slowly spread across the planet
               from Africa to West Asia, then to Central Asia, Eurasia, South Asia, East Asia. They
               travelled down the islands of Indonesia and the Philippines to Australia, and they
               crossed the Bering land bridge to the Americas.
               → They did not go in a single line.
               → Sometimes came back to mix with each other. so they were not travelling for the
               sake of travelling, obviously.
                 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.

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