Anthropology , Human evolution , and Timeline of human evolution The genus Homo evolved and diverged from other hominins in Africa, after the human clade split from the chimpanzee lineage of the hominids great apes branch of the primates. Modern humans, defined as the species Homo sapiens or specifically to the single extant subspecies Homo sapiens sapiens, proceeded to colonize all the continents and larger islands, arriving in Eurasia ,—60, years ago,   Australia around 40, years ago, the Americas around 15, years ago, and remote islands such as Hawaii, Easter Island , Madagascar , and New Zealand between the years and The gibbons family Hylobatidae and orangutans genus Pongo were the first groups to split from the line leading to the humans, then gorillas genus Gorilla followed by the chimpanzees genus Pan.
The splitting date between human and chimpanzee lineages is placed around 4—8 million years ago during the late Miocene epoch. Each of these species has been argued to be a bipedal ancestor of later hominins, but all such claims are contested. It is also possible that any one of the three is an ancestor of another branch of African apes, or is an ancestor shared between hominins and other African Hominoidea apes.
The question of the relation between these early fossil species and the hominin lineage is still to be resolved. More recently, however, in , stone tools , perhaps predating Homo habilis, have been discovered in northwestern Kenya that have been dated to 3.
During the next million years a process of encephalization began, and with the arrival of Homo erectus in the fossil record, cranial capacity had doubled. Homo erectus were the first of the hominina to leave Africa, and these species spread through Africa, Asia, and Europe between 1. One population of H.
It is believed that these species were the first to use fire and complex tools. The earliest transitional fossils between H. These descendants of African H. The earliest fossils of anatomically modern humans are from the Middle Paleolithic , about , years ago such as the Omo remains of Ethiopia and the fossils of Herto sometimes classified as Homo sapiens idaltu. The most significant of these adaptations are 1. The relationship between all these changes is the subject of ongoing debate.
The earliest bipedal hominin is considered to be either Sahelanthropus  or Orrorin , with Ardipithecus , a full bipedal,  coming somewhat later. It is possible that bipedalism was favored because it freed up the hands for reaching and carrying food, because it saved energy during locomotion, because it enabled long distance running and hunting, or as a strategy for avoiding hyperthermia by reducing the surface exposed to direct sun.
However, the differences between the structure of human brains and those of other apes may be even more significant than differences in size. The reduced degree of sexual dimorphism is primarily visible in the reduction of the male canine tooth relative to other ape species except gibbons.
Another important physiological change related to sexuality in humans was the evolution of hidden estrus. Humans are the only ape in which the female is fertile year round, and in which no special signals of fertility are produced by the body such as genital swelling during estrus. These changes taken together have been interpreted as a result of an increased emphasis on pair bonding as a possible solution to the requirement for increased parental investment due to the prolonged infancy of offspring.
Archaic human admixture with modern humans , Early human migrations , Multiregional origin of modern humans , Prehistoric autopsy , and Recent African origin of modern humans By the beginning of the Upper Paleolithic period 50, BP , full behavioral modernity , including language , music and other cultural universals had developed.
Since , evidence for gene flow between archaic and modern humans during the period of roughly , to 30, years ago has been discovered. This includes modern human admixture in Neanderthals, Neanderthal admixture in modern humans,   Denisova hominin admixture in Melanesians  as well as repeated admixture from unnamed archaic humans to Sub-Saharan African populations.
They inhabited Eurasia and Oceania by 40, years ago, and the Americas at least 14, years ago. History of the world The rise of agriculture, and domestication of animals, led to stable human settlements. Until about 12, years ago the beginning of the Holocene , all humans lived as hunter-gatherers , generally in small nomadic groups known as band societies , often in caves. The Neolithic Revolution the invention of agriculture took place beginning about 10, years ago, first in the Fertile Crescent , spreading through large parts of the Old World over the following millennia, and independently in Mesoamerica about 6, years ago.
Access to food surplus led to the formation of permanent human settlements , the domestication of animals and the use of metal tools for the first time in history.
Agriculture and sedentary lifestyle led to the emergence of early civilizations the development of urban developent , complex society , social stratification and writing from about 5, years ago the Bronze Age. The Scientific Revolution , Technological Revolution and the Industrial Revolution up until the 19th century resulted in independent discoveries such as imaging technology , major innovations in transport, such as the airplane and automobile; energy development , such as coal and electricity.
The bright lights signify both the most densely inhabited areas and ones financially capable of illuminating those areas.