Neanderthal Hybrid Essays - Human Evolution,

Neanderthal Hybrid Implications of Neanderthal-Homo Sapiens Hybrid by Abrigo do Lagar Velho. In a recent excavation at Abrigo do Lagar Velho in Portugal, Duarte et al (1999) unearthed what was later to be recognized as early human skeletal remains which pointed to interbreeding between Neanderthal and Modern Humans during the mid - upper Palaeolithic transition. The morphology of the remains, belonging to a child of approximately 3-4 years old, indicates a Neanderthal typology in post-cranial features, and more modern cranial features. The find has been cited as evidence of hybridization between the two traditionally separate human lines, and offers an explanation to the question of Neanderthal extinction. (Trinkaus 1999) Anthropologists are now offered a line of evidence pointing to the contemopranity of Moderns and Neanderthals in parts of Europe and assumptions can be made about their contact: "The discoverers...are making a ground-breaking claim, that the skeleton shows traces of both Neanderthal and modern human ancestry, evidence that modern humans did not simply extinguish the Neanderthals, as many researchers had come to think. Instead the two kinds of human were so alike that in Portugal, at least, they intermingled...for thousands of years." (Kunzig, 1999) By examining the theories of human evolution, and looking at the cultural evolution of tool technology as well as the biological transitions and differences between the two types of humans, we can see that this hybridization just might be the answer. Perhaps this find will be able to tell us what exactly did happen to the Neanderthals. Firstly, it is useful to have an overview of the different theories of human evolution, or I should say the two most widely accepted views as accepted by palaeo-anthropologists in the field. For some years now it has been the contention that the origins of modern humans stem from either a continuous evolution from archaic to modern humans in local regions from an earlier dispersal of Homo erectus, or conversely from modern humans evolved in Africa only which then dispersed to replace those hominids in said regions. These two theories are known as the Continuity or Regional model and the Replacement or Out of Africa model respectively. The fossil (skeletal) and cultural (technological) evidence thus far has pointed to convincing arguments on both sides, which proponents are quick to defend. Neanderthals can be distinguished from anatomically Modern Humans by the presence of prominent brow ridges, low forehead, occipital bun, facial prognathicism, large nasal aperture, and shorter, sturdier skeletal features most notably, distinguishing them from Moderns who were taller and had longer limbs, higher foreheads, lass prominent browridges and rounder skulls. It should be noted that the cranial capacities of both were comparable, with the Neanderthals being even slightly larger. (Klein: 1989) Many proponents of a regional theory claim that such morphological differences show a continuity and depending on how they are viewed can be seen as evidence of variation within a species, not distinct species. This would mean that the Neanderthal morphology developed as an adaptation to the colder glacial climate of Europe and elsewhere. (Wolpoff:1980) From a replacement standpoint however, these differences in morphology are too distinct to be variables on a theme and in conjunction with dates provides evidence supporting that view. (Mellars and Stringer:1989) Neanderthals occupied Europe and the Middle East during a time range usually agreed upon as ranging from roughly 130 kya - 35 kya to as recent as approx. 26kya. Modern populations are seen as early as 100kya in the Middle East and around 40 kya in Europe. At some sites in the middle east, both populations lived in very close proximity to one another for what is thought to be a time range of about 40 000 years. (Akazawa et al:1998) Recent developments in genetic studies have begun to open new lines of evidence in the relatedness of Neanderthals to current modern human populations. By studying the genes of both, we can compare the similarities and differences and calculate whether the two are close enough to say there is a relation or not. This line of research had been theory mostly because the skeletal remains on record had no organic material available from which to extract genetic material (i.e.: collagen in the bone). DNA from a Neanderthal specimen would be able to confer or oppose the " Mitochondrial Eve" theory put forth by Cann et al in 1987 (Foley and Lahr 1992: 526; Klein 1989:352) which stated that the common ancestor for modern human populations could be traced to approx. 200kya in Africa. When DNA was finally extracted from a Neanderthal specimen, this could be addressed.