Homo sapiens facts for kids

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Homo sapiens
Temporal range: Pleistocene - Present
General idea of an early modern European male
Conservation status
Scientific classification
Kingdom: Animalia
Class: Mammalia
Order: Primates
Family: Hominidae
Subfamily: Homininae
Genus: Homo
Species: Homo sapiens
Subspecies

Homo sapiens sapiens
Homo sapiens idaltu
Homo neanderthalensis
Homo rhodesiensis

Homo sapiens (Latin: "wise man") is the binomial nomenclature (also known as the scientific name) for the human species.

Homo is the human genus, which also includes Neanderthals and many other extinct species of hominid; H. sapiens is the only surviving species of the genus Homo. Modern humans are sometimes called "anatomically modern humans". Homo sapiens considers itself the most influential species on the planet, but many species of life, mostly plants and protists, have had a much greater effect on the outside of Earth and its air.

Origin

Homo-Stammbaum, Version Stringer-en
Schematic representation of the emergence of H. sapiens from earlier species of Homo. The horizontal axis shows geographic location; the vertical axis shows time in millions of years ago.
Blue areas show presence at a given time and place.
Early modern humans spread from Africa across the globe. They may have interbred with other descendants of Homo heidelbergensis, namely Neanderthals, Denisovans, and unknown archaic African hominins (top right).

The recent African origin of modern humans is the mainstream model describing the origin and dispersal of anatomically modern humans. The hypothesis that humans have a single origin was published in Charles Darwin's The Descent of Man (1871). The concept is supported by a study of present-day mitochondrial DNA, and with evidence based on physical anthropology of fossil humans. According to genetic and fossil evidence, older versions of Homo sapiens evolved only in Africa, between 200,000 and 100,000 years ago, with members of one branch leaving Africa by 60,000 years ago and over time replacing earlier human populations such as Neanderthals and Homo erectus.

The recent single origin of modern humans in East Africa is the near-consensus position held within the scientific community. However, recent sequencing of the full Neanderthal genome suggests Neanderthals and some modern humans share some ancient genetic lineages. The authors of the study suggest that their findings are consistent with Neanderthal admixture of up to 4% in some populations. But the study also suggests that there may be other reasons why humans and Neanderthals share ancient genetic lineages. In August 2012, a study by scientists at the University of Cambridge has questioned this conclusion, hypothesising instead that the DNA overlap is a remnant of a common ancestor of both Neanderthals and modern humans.

Evolution

Further information: Human evolution

The time frame for the evolution of the genus Homo out of the last common ancestor is roughly 10 to 2 million years ago, that of H. sapiens out of Homo erectus roughly 1.8 to 0.2 million years ago.

Scientific study of human evolution is mostly concerned with the development of the genus Homo, but usually involves studying other hominids and hominines as well, such as Australopithecus. "Modern humans" are defined as the Homo sapiens species, of which the only living subspecies is known as Homo sapiens sapiens.

Homo sapiens idaltu, the other known subspecies, is now extinct. Homo neanderthalensis, which became extinct 30,000 years ago, has sometimes been classified as a subspecies, "Homo sapiens neanderthalensis"; genetic studies now suggest that the functional DNA of modern humans and Neanderthals diverged 500,000 years ago.

Similarly, the discovered specimens of the Homo rhodesiensis species have been classified by some as a subspecies, but this classification is not widely accepted.

Anatomically modern humans first appear in the fossil record in Africa about 195,000 years ago, and studies of molecular biology give evidence that the approximate time of divergence from the common ancestor of all modern human populations was 200,000 years ago. The broad study of African genetic diversity found the ǂKhomani San people had the greatest genetic diversity among the 113 distinct populations sampled, making them one of 14 "ancestral population clusters". The research also placed the origin of modern human migration in south-western Africa, near the coastal border of Namibia and Angola.

The forces of natural selection have continued to operate on human populations, with evidence that certain regions of the genome show selection in the past 15,000 years.


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