This happened after Homo sapiens migrated out of Africa and began living alongside their more primitive cousins in Europe. Genetically different from both modern humans and Neanderthals, this is the finding of a new species of early human. The oldest known tools are flakes from West Turkana, Kenya, which date to 3.3 million years ago. During the 1960s and 1970s, hundreds of fossils were found in East Africa in the regions of the Olduvai Gorge and Lake Turkana. The foramen magnum migrated under the skull and more anterior. Up until the genetic evidence became available, there were two dominant models for the dispersal of modern humans. Because of that, having a durable facial structure that can withstand a punch was a useful anatomical quality.
 Homo habilis is the first species for which we have positive evidence of the use of stone tools. Modern day human’s predecessors were able to harness the use of fire to keep themselves warm using this essential element. , The immediate survival advantage of encephalization is difficult to discern, as the major brain changes from Homo erectus to Homo heidelbergensis were not accompanied by major changes in technology.  Encephalization may be due to a dependency on calorie-dense, difficult-to-acquire food. Initial divergence occurred sometime between 7 to 13 million years ago, but ongoing hybridization blurred the separation and delayed complete separation during several millions of years. This migration and origin theory is usually referred to as the "recent single-origin hypothesis" or "out of Africa" theory. Between 40,000 to 30,000 BP, the first flutes appear in Germany, Japan, and Hong Kong become settled, and cave paintings in Spain show up. Discovered in Northwest Spain, the blue eyes were paired with a dark skin tone, similar to that of modern Sub-Saharan Africans. On the other hand, our brains are shrinking.  The Sahara pump theory (describing an occasionally passable "wet" Sahara desert) provides one possible explanation of the early variation in the genus Homo. Richard Wrangham suggests that the fact that Homo seems to have been ground dwelling, with reduced intestinal length, smaller dentition, "and swelled our brains to their current, horrendously fuel-inefficient size", suggest that control of fire and releasing increased nutritional value through cooking was the key adaptation that separated Homo from tree-sleeping Australopithecines..
Culturally-driven evolution can defy the expectations of natural selection: while human populations experience some pressure that drives a selection for producing children at younger ages, the advent of effective contraception, higher education, and changing social norms have driven the observed selection in the opposite direction.
Most people hate to hear that they have a slow metabolism, but it could help us live longer than most other animals.
The question then of the relationship between these early fossil species and the hominin lineage is still to be resolved. Get access risk-free for 30 days, Early humans didn’t really have the hunting skills that we imagine they did.
Trepanation, or in simpler terms, drilling a hole in a person’s skull, has been done for various reasons for over 10,000 years, but it might not have always been that crazy of idea.  Linnaeus and other scientists of his time also considered the great apes to be the closest relatives of humans based on morphological and anatomical similarities. Now imagine prehistoric brain surgery. In their seminal 1967 paper in Science, Sarich and Wilson estimated the divergence time of humans and apes as four to five million years ago, at a time when standard interpretations of the fossil record gave this divergence as at least 10 to as much as 30 million years.  In other primates, the thumb is short and unable to touch the little finger. The closest early humans to you and me were a group called Neanderthals (pronounced nee-AN-der-thals).
It has been suggested that because of its function of sensory-motor control and learning complex muscular actions, the cerebellum may have underpinned human technological adaptations, including the preconditions of speech.
 All the evidence from autosomal DNA also predominantly supports a Recent African origin.