Evolutionary History of Humans
Created | Updated Feb 19, 2007
Ancestorial Species
Humans are thought1 to have decended from a common ancestor of modern day chimpainzes about 6 million years ago. This idea is based on fossil evidence of now extinct species2 of hominids3 found around the world. Not all Hominids are direct ancestors of modern humans. Some are thought to have branched off of the evolutionary timeline and then died out. Some of these branches lived at the same time and had cultures that may have interacted with each other. Several theories as to what environmental variable was key in the evolution of hominids have been set forth. The most widely accespted one is that climatic cooling between 2.5 and 6 million years ago triggered the split from early primates.Other Genera4
These are species not in the genra Homo that are related in some way to the evolution of man.
- australopithecines (species: Australopithecus)
- gracile australopithecines:
- A. afarensis (The famous "Lucy") 5 to 3 million years ago
- A. anamensis 4.2 to 3.9 million years ago
- A. ramidus (misnamed see Ardipithecus) 3.6 to 2.9 million years ago
- A. africanus 3.5 to 2.0 million yeas ago
- A. garhi
- robust australopithecines: (sometimes put in genus Paranthropus)
- A. robustus 2.5 to 1.0 million years
- A. boisei 2.5 to 1.0 million years
- A. robustus 2.5 to 1.0 million years
- gracile australopithecines:
- Gorilla
- G. gorilla (Gorilla) Close primate relative that shares common ancestor.
- Pan
- P. troglodytes (Chimp) Close primate relative that shares common ancestor.
- Kenyanthropus
- K. platyops about 3.5 million years ago, a disputed possible replacement for A. afarensis as ancestor.
Direct line decent
This may be misleading as no complete line of decent has been established. In fact, most scientists can not agree as to whether something is a sperate species or not, much less which is a direct line decendant. The consensus, as far as it goes, is as follows:
- H. sapiens
200,000 to 250,000 years ago - H. heidelbergensis
- H. erectus
1.8 to 1.9 million years ago Widely believed to be direct ancestor of H. sapiens - H. antecessor
Theorized ancestor of erectus and neanderthalensis - H. ergaster
an ancestor of erectus or perhaps the same species - H. rudolfensis
If H. habilis isn't an ancestor of H. sapiens than this one is. It is unclear which one it is. - H. habilis
believed by Louis Leakey to be the direct ancestor of H. sapiens, but not widely accepted as such. - An unknown species of early Homo probably existed 2.3 million years ago
- A. garhi
most likely ancestor of genus Homo - A. africanus
probable ancestor of garhi - A. afarensis
probable ancestor of africanus - Some unknown common ancestoial primate
Dead end Branches
Several species of homonid are not ancestorial lines of H. sapiens at all but parallel branches of evolution that are now extinct.
- H. neanderthalensis The neanderthal, alive at the sme time as Cro-magnon5 but died out about 30,000 years ago. Probably split from H. heidelbergensis about 100,000 years before H. sapiens did. Previously thought to be an ancestor before DNA testing.
- H. erectus Some believe that H. heidelbergensis evolved from H. ergaster and that H. erectus is not an ancestor of H. sapiens at all but a dead branch.
- H. habilis and H. rudolfensis, one of these may be a dead branch while the other is not.
1By Evolutionists anyway, by a process called evolution2A Taxonomy classification.3The family of humans4Plural of genus5An early H. sapiens
