This specialization of work also involved creating specialized tools such as fishing nets, hooks, and bone harpoons.The transition into the subsequent Neolithic period is chiefly defined by the unprecedented development of nascent agricultural practices.
It remained the only mode of subsistence until the end of the Mesolithic period some 10,000 years ago, and after this was replaced only gradually with the spread of the Neolithic Revolution.
Starting at the transition between the Middle to Upper Paleolithic period, some 80,000 to 70,000 years ago, some hunter-gatherers bands began to specialize, concentrating on hunting a smaller selection of (often larger) game and gathering a smaller selection of food.
This hypothesis does not necessarily contradict the scavenging hypothesis: both subsistence strategies could have been in use – sequentially, alternating or even simultaneously.
Hunting and gathering was presumably the subsistence strategy employed by human societies beginning some 1.8 million years ago, by Homo erectus, and from its appearance some 0.2 million years ago by Homo sapiens.
Many of them reside in the developing world, either in arid regions or tropical forests.