The neanderthal problem regarding its phylogenetic status has been circulating for many years and some of the major questions are these: What is the evolutionary position of the western European Neanderthals? Were they too specialised to be in our evolutionary lineage? How does one interpret the intrapopulation and interpopulation variability? In which areas of the world did Homo sapiens sapiens evolve?
Although some answers to these questions are becoming clearer with the discovery of new forms and the re-examination of others; other questions are becoming more difficult to answer. Earlier the term Neanderthal was originally applied to, and designed to describe, forms from Western Europe only, but now it is used to describe a wide array of fossils, many of which barely resemble the original material.
There are conflicting view points concerning the taxonomic placement of the western European Neanderthals. Some designate them as a separate species, Homo neanderthalensis; most others refer to them as Homo sapiens neanderthalensis. A major reason for this disagreement is the recognition of transitional forms that cannot be satisfactorily assigned to either the Neanderthal or archaic Homo sapiens sapiens.
Concerning the various interpretations of the Neanderthal material, the unilinear school advocated by Hrdlicka (1927) was first to be proposed. This theory argues that modern Homo sapiens sapiens arose directly through a number of evolutionary stages, including the Neanderthals. It eliminates extensive side branching and discounts most cases of argued extinction and vigorously argues that the Neanderthal population, as typified in western Europe, formed a large part and parcel of the genetic ancestry of modern Homo sapiens.
The two other view points, Preneanderthal and Presapiens (A theory suggesting that Homo sapiens is a distinct, completely separate line from that leading to the Neanderthals) school (Keith, 1925, Nallois, 1958) have much in common. Both spilt the main stem of human evolution back to the time of Steinheim man and Swanscombe man. Both consider western European Neanderthals to be dead ends in human evolution, becoming extinct as the climatic conditions to which they were adapted ameliorated.
- The Presapiens school, suggest that modern Homo sapiens originated as distinct lineage, completely separate from the line leading to the Neanderthals. Unlike the Preneanderthal school, the Presapiens school holds that this divergence occurred before the Eeemian Interglacial, if not before the Mindel glacial. Both schools employ the same evidence but differently. Some adherents of the Presapiens school argue that Steinheim man led to the Neanderthal population and that Swanscombe man, through Fontechevade man, led to modern Homo sapiens.
- Adherents of the Preneanderthal school view Steinheim man and Swanscombe man as leading to another interglacial stem, for example, Ehringsdrof man, of a basically Neanderthal nature. In this view, there was a broad and varying population, one segment of which was an isolated European cold-adapted group (the western European Neanderthals): the other segment inhabited the Near East and become modern Homo sapiens. There are three morphological bases for the Preneanderthal schools the so-called “overspecialisation” Neanderthals into “modern” Upper Palaeolithic populations within a short time, and the coexistence in other parts of the world of more modern-looking populations. The factors appearance of more modern-looking humans in other parts of the world is essentially correct.
It is now generally recognised that the Neanderthals were a worldwide grade intermediate between the earliest Homo sapiens and the earliest Homo sapiens sapiens samples. The Neanderthal ancestors , Homo sapiens sapiens were forms possessing modern-size brains coupled with an archaic-looking skull. The time span of this group was from about 75,000 or perhaps 100,000 to 35,000 years ago. The earliest possible ancestors of the European Neanderthals may be represented by the Saccopastore and Krapina samples. These skulls show some typical Neanderthal facial features, although the most complete specimens are small brained compared to the later Neanderthals.
Recent redating of the Mousterian (Cultural assemblage commonly associated with the Neanderthals) stone tool assemblage has not only doubled the time span of the Mousterian but also expanded the time span of the Mousterian tool manufactures, the Neanderthal man. The redating suggests that the period between the last Neanderthals and emergence of Homo sapiens sapiens was long enough for the evolution of Homo sapiens neanderthalensis into Homo sapiens sapiens.
This calls into question the view that the Neanderthals disappeared after immigration of modern Homo sapiens into Europe. The redating also suggest that Mousterian industries remained virtually unchanged over a long time period, in marked contrast to the speed with which modern Homo sapiens tool industries advanced during the Upper Palaeolithic times. This suggests fundamental differences in Neanderthals and modern Homo sapiens societies that make it more difficult to see how one could have evolved into the other.
Phylogentic status -IGNOU
Although less numerous remains were discovered from East and Central Europe than from Western Europe, nevertheless they are very important. New fossil finds from this area have filled some of the geographical and chronological gaps in the fossil record. They have also blurred the boundary between classical European Neanderthals and fully modern Homo sapiens populations. Major eastern and central European materials come from Czechoslovakia and Hungry. Some refer to them as transitional specimens, between modern and Neanderthal populations.
Taxonomically speaking the transitional status of these materials suggests that hominid evolution in eastern and central Europe was proceeding towards modern Homo. The transitional forms are important since they display many traits found in anatomically modern populations to varying degree. Chronologically, it extend to the time period in which the oldest finds of fully modern Homo sapiens appear even forms designated fully modern Homo sapiens exhibit some cultural and morphological links to the past.
Such findings indicate that the appearance of Homo sapiens sapiens in Central and Western Europe need not be explained in terms of a sudden east to west migration but rather as local evolution in Neanderthal populations sharing basic traits but differing in intensity and detail. As far as the Middle Eastern (Progressive) Neanderthal are concerned some of the Middle Eastern populations appear to be transitional. Middle Eastern forms are considered to be the members of a late non-cold adapted Neanderthal group imperceptibly grading into fully modern Homo sapiens sapiens. The most complete finds come from Israel and Iraq; other remains come from six caves listed below.
- Zuttiya near the Sea of Galilee
- Tabun and Skhul at Mount Carmel
- Jebel Gafza near Nazareth.
- Shukba, 17 miles northwest of Jerusalem
- Amud near Lake Tiberias.
Although from the same geographical area and dating from approximately the same time period, the skulls differ from one another. The richest and deepest fossil sites are in areas where vegetation and game were most abundant. They can be seen at two major sites at Mount Carmel viz., the Cave of et-Tabun (Cave of the oven) and Cave of es-Skhul (Cave of the Kids). It is difficult to generalise about the skeletal characteristics of Near Eastern and Central Asian Populations contemporaneous with the Neanderthals of Europe.
Some specimens’ like-Tabun, Shanidar and Amud shared more features with western Neanderthals than did Skhul. It has been suggested that physical differences in the populations of the Near East and Central Asia may be of the order of subspecific (or) racial variation. These populations constitute one part of the species range that had more ties with the western European Neanderthals and another variety with closer ties with populations in the direct line to Upper and post-palaeolithic Homo sapiens.
The results of experiments on the effect of cold on the skin temperature suggest that reduced frontal sinus area and an exposed nose and streamlined malar region all Neanderthal features, act to reduce the effects of chilling. Relatively short limbs are also features of modern human populations adapted to cold climates. The broad anterior teeth, combined with reduced size of the cheek teeth and lung, strongly buttressed cranium of the Neanderthals have been proposed as unified response to the use of teeth for holding and fixing objects during tool manufacture and food preparation.