Neanderthal roots can be traced back more than 250,000 years with the Neanderthal anatomy becoming firmly established about 125,000 years ago and geographically restricted to Eurasia, specifically between western Europe and NearEast.
The brain size of Neanderthals was equal to or slightly greater than modern average man.
Neanderthals were skeletally very robust and heavily muscled, but were characterized by an extremely protruding mid-facial region-as if someone had taken a face made of rubber and pulled on the nose.
Several explanations have been advanced for the Neanderthal mid-facial architecture:
A more complete specimen in 1987 from Israel found that the pelvic canal is not unusually large, merely that the pelvic bone is extraordinarily long.
This and several other features not seen in human pelves supports the increasingly popular conclusion that Neanderthals represent a dead end in human evolution, not a stage on the way to Homo sapiens.
On this basis there is argument for removing the Neanderthals from the subspecies status of Homo sapiens neanderthalensis and instead reverting to the Homo neanderthalensis.
According to last appearances in the fossil records, Neanderthals disappeared in a wave flowing east to west between 50,000 and 32,000 years ago.
- An adaptation for warming inhaled frigid air as it passed through the enlarged nasal cavities; a mean of condensing and conserving moisture in exhaled breath; and a secondary consequence in the facial region of severe chewing pressures centered at the front of the jaw.
- The Neanderthal pelvis also seems to be highly characteristic, so much that in incomplete specimens the pelvic canal appeared to be unusually large, prompting Erik Trinkaus to postulate that gestation was prolonged in this species, the infant at birth therefore being larger than in modern humans.
Most believe this disappearance to be extinction as a result of replacement-at least in the west-by incoming anatomically modern humans, whose overall anatomy is characteristic of equatorial adaptation, not cold adaptation.
Complete replacement of one population by another need not be as dramatic a process as might be envisaged.
A subsistence advantage of just 1% by modern humans in competition with Neanderthals could result in complete replacement within 30 generations or a millennium.
The fossil evidence most immediately relevant to the origin of modern humans is to be found throughout Europe, Asia, Australasia, and Africa and goes back in time as far as 300,000 years.
Most of these fossils which are crania of varying degrees of incompleteness look like a mosaic of Homo erectus and Homo sapiens and are generally termed archaic sapiens.
Neanderthals are a form of archaic sapiens.
It is among such fossils that signs of regional continuity are sought, being traced through to modern populations.
Milford Wolpoff and Alan Thorne argue for such regional anatomical continuities among Australasian populations and among Chinese populations.
Citing different characters, Fred Smith believe a good case can be made for regional continuity in Central Europe and North Africa.
Proponents of a replacement model argue in most of these cases, the anatomical characters being cited as indicating regional continuity are primitive and therefore cannot be used uniquely to link specific geographic populations through time.
If the archaic sapiens population were not part of a general phyletic transformation toward Homo sapiens, what were they?
It is possible that they represent several different species.
Molecular biological evidence from mapping and sequencing nuclear DNA yields 2 main conclusions:
The amount of genetic variation throughout all modern human populations is surprisingly small and implies a recent origin for the common ancestor of us all.
The argument that genetic variation among widely separated populations has been homogenized by gene flow (interbreeding) is not tenable.
Shahin Rouhani calculates it would require almost half a million years for an advantageous gene to travel from South Africa to China by the normal process of gene flow.
He point out that in general population genetic theory does not support the notion of phyletic transformation in population as widespread as those of hominids in the Middle Pleistocene.
Although genetic variation among the world’s population is small overall, it is greatest in African populations implying they are the longest established.
Data on B-goblin gene cluster implies that the anatomically modern humans who migrated out of Africa went through a population bottleneck.
One consequence of placing the origin of Homo sapiens at 100,000 years or earlier is an apparent uncoupling of modern anatomy from modern behavior.
Modern tool technology-Upper Paleolithic in Europe, Late Stone Age in Africa occurs between 40,000 and 10,000 years ago, long after the origin of the species responsible for it.
- Addresses the depth of our genetic routes,
- The possible location of the origin of anatomically modern humans.