Thursday, July 30, 2009

Chimpanzee

Chimpanzee, sometimes colloquially chimp, is the common name for the two extant species of ape in the genus Pan where the Congo River forms the boundary between the native habitat of the two species:

* Common Chimpanzee, Pan troglodytes: the better known chimpanzee lives primarily in West and Central Africa.
* Bonobo, Pan paniscus: also known as the "Pygmy Chimpanzee", this species is found in the forests of the Democratic Republic of the Congo.

Chimpanzees are members of the Hominidae family, along with gorillas, humans, and orangutans. Chimpanzee are thought to have split from human evolution about 6 million years ago and thus the two chimpanzee species are the closest living relatives to humans, all being members of the Hominini tribe (along with extinct species of Hominina subtribe). Chimpanzees are the only known members of the Panina subtribe. The two Pan species split only about one million years ago.

Human evolution

Human evolution, or anthropogenesis, is the part of biological evolution concerning the emergence of Homo sapiens as a distinct species from other hominins, great apes and placental mammals. It is the subject of a broad scientific inquiry that seeks to understand and describe how this change occurred. The study of human evolution encompasses many scientific disciplines, most notably physical anthropology, primatology, archaeology, linguistics and genetics.

The term "human", in the context of human evolution, refers to the genus Homo, but studies of human evolution usually include other hominins, such as the Australopithecines. The Homo genus diverged from the Australopithecines about 2 million years ago in Africa. Scientists have estimated that humans branched off from their common ancestor with chimpanzees—the only other living homininis—about 5–7 million years ago. Several species of Homo evolved that are now extinct. These include Homo erectus, which inhabited Asia, and Homo neanderthalensis, which inhabited Europe.

Archaic Homo sapiens evolved between 400,000 and 250,000 years ago. The dominant view among scientists is the recent African origin of modern humans (RAO) that H. sapiens evolved in Africa and spread across the globe, replacing populations of H. erectus and H. neanderthalensis. Scientists supporting the alternative hypothesis on the multiregional evolution (ME) view modern humans as having evolved as a single, widespread population from existing Homo species, particularly H. erectus. The fossil evidence is insufficient to resolve this vigorous debate,. Studies of haplogroups in Y-chromosomal DNA and mitochondrial DNA have largely supported a recent African origin, while some researchers argue that evidence from nuclear genes supports a multiregional origin.

Biological anthropology

Biological anthropology, or physical anthropology is a branch of anthropology that studies the mechanisms of biological evolution, genetic inheritance, human adaptability and variation, primatology, primate morphology, and the fossil record of human evolution.

Physical anthropology was developed in the 19th century, prior to the rise of Alfred Russel Wallace's and Charles Darwin's theories of natural selection and Gregor Mendel's work on genetics. Physical anthropology was so called because all of its data was physical (fossils, especially human bones). With the rise of Darwinian theory and the modern synthesis, anthropologists had access to new forms of data, and many began to call themselves "biological anthropologists."

Some of the early branches of physical anthropology, such as some of the early studies in anthropometry, have been criticised. Metrics such as the cephalic index were often used to derive behavioral characteristics.



* Primatology, the study of primates,
* Human adaptation, the study of human adaptive responses (physiological, developmental, and genetic) to environmental stress and variation (see biomedical anthropology, human biology).
* Human biology, an interdisciplinary academic field of biology, biological anthropology, nutrition and medicine which focuses on international, population-level perspectives on health, and on human evolution, adaptation, and population genetics rather than individual diagnosis (see also biomedical anthropology ).
* Human evolution including:
o Paleoanthropology, the study of fossil evidence for human evolution.
o Human behavioral ecology, the study of behavioral adaptations such as foraging, reproduction, and ontogeny from an evolutionary ecological perspective (see also behavioral ecology).
* Neuroanthropology, the study of the evolution of the human brain, and of culture as a neurological adaptation of the species to its environment.

The study of human evolution often involves other specializations:

* Human osteology, the study of skeletal material. Experts in osteology are able to apply their skills and knowledge to other areas:
o Paleopathology, which studies the traces of disease and injury in human skeletons
o Forensic anthropology, the analysis and identification of human remains in the service of coroners or medical examiners. This research often provides law enforcement with important evidence.