What year did the first humans appear?
The first human ancestors appeared between five million and seven million years ago, probably when some apelike creatures in Africa began to walk habitually on two legs. They were flaking crude stone tools by 2.5 million years ago. Then some of them spread from Africa into Asia and Europe after two million years ago.
Scientists do not know how life began on Earth. They do know that the early Earth's atmosphere was very different from the atmosphere now. In 1952, Stanley Miller was working with Harold C. Urey designed an experiment to see how complex organic molecules might have formed under the conditions of early Earth.
|Catalog no.||AL 288-1|
|Age||3.2 million years|
|Place discovered||Afar Depression, Ethiopia|
|Date discovered||November 24, 1974|
3.8 billion years ago
Humans first evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa. Most scientists currently recognize some 15 to 20 different species of early humans.
Anatomically modern humans arose in Africa about 200,000 years ago, and reached behavioural modernity about 50,000 years ago.
Carnivorous humans go back a long way. Stone tools for butchering meat, and animal bones with corresponding cut marks on them, first appear in the fossil record about 2.5 million years ago. Some early humans may have started eating meat as a way to survive within their own ecological niche.
Perhaps the world's most famous early human ancestor, the 3.2-million-year-old ape "Lucy" was the first Australopithecus afarensis skeleton ever found, though her remains are only about 40 percent complete (photo of Lucy's bones).
Both fossil and genetic evidence indicate that Neanderthals and modern humans (Homo sapiens) evolved from a common ancestor between 500,000 and 200,000 years ago.
Neanderthals went extinct in Europe about 40,000 years ago, giving them millennia to coexist with modern humans culturally and sexually, new findings suggest. This research also suggests that modern humans did not cause Neanderthals to rapidly go extinct, as some researchers have previously suggested, scientists added.
The oldest unequivocal evidence, found at Israel's Qesem Cave, dates back 300,000 to 400,000 years, associating the earliest control of fire with Homo sapiens and Neanderthals. Now, however, an international team of archaeologists has unearthed what appear to be traces of campfires that flickered 1 million years ago.
So far, the earliest finds of modern Homo sapiens skeletons come from Africa. They date to nearly 200,000 years ago on that continent. They appear in Southwest Asia around 100,000 years ago and elsewhere in the Old World by 60,000-40,000 years ago.
Like other humans, Neanderthals originated in Africa but migrated to Eurasia long before other humans did. Neanderthals lived across Eurasia, as far north and west as the Britain, through part of the Middle East, to Uzbekistan.
The period between the extinction of the dinosaurs and the present day is called the Age of Mammals or Cenozoic. Mammals appeared on the earth long before the extinction of the dinosaurs; in fact, dinosaurs and mammals originated within 10 million years of each other, in the late Triassic about 200 million years ago.
The earliest migrations and expansions of archaic and modern humans across continents began 2 million years ago with the out of Africa migration of Homo erectus, followed by other archaic humans including H. heidelbergensis.
1802, in William Turton's translation of Linnæus, coined in Modern Latin from Latin homo "man" (technically "male human," but in logical and scholastic writing "human being;" see homunculus) + sapiens, present participle of sapere "be wise" (see sapient).
Homo sapiens, (Latin: “wise man”) the species to which all modern human beings belong. Homo sapiens is one of several species grouped into the genus Homo, but it is the only one that is not extinct. See also human evolution. Human being (Homo sapiens), male. H. sapiens is human by definition, whereas apes are not.
The first land plants appeared around 470 million years ago, during the Ordovician period, when life was diversifying rapidly. They were non-vascular plants, like mosses and liverworts, that didn't have deep roots.
The theory of evolution by natural selection, first formulated in Darwin's book "On the Origin of Species" in 1859, is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits.
In addition to Ardi, a possible direct ancestor, it is possible here to find hominid fossils from as recently as 160,000 years ago—an early Homo sapiens like us—all the way back to Ardipithecus kadabba, one of the earliest known hominids, who lived almost six million years ago.