Roger, feel free to post this on the Wiki. It is a summary of hominin evolution which I have posted at http://www.antiquityofman.com/hominin_e ... mmary.html . These are various page links within the summary (see the original)
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Summary of hominin evolution
by Mikey Brass
Despite the abundance of quality "coffee-table" archaeological books on the market, the public in general display a remarkable ignorance (intentional and unintentional) of the basic fundamentals of the history of our own lineage, let alone the intricacies of past and current theories, paradigms and debates.
This is true in my birthland of South Africa: only really since 1997 have bookshops been stocking archaeological books of good quantity and, equally importantly, good quality. Sadly I have found, through bitter experience, this occurrence to be equally common in many towns, cities and countries across the globe; the worst case is, ironically, America with its appalling scientific education system and the powerful, idiotic, fundamentalist, religious right. Regrettably, universities are not much better at providing information on their websites, although the time passed since this website was launched has seen a vast improvement. Although there are Internet courses offered by some universities in archaeology, many people either cannot afford them or do not have the time to study, or in other cases both.
To this end a site like Talk Origins fills the blank on the Internet informatively, with its particular emphasis on debunking the pseudoscientific myths of creationism. It is weaker in outlining some of the debates presently argued in academic circles and in scholarly journals, as well as summarising a determined selection of current research paradigms and the results generated from the earliest hominins right down to the present.
A combination of the genetic and fossil evidence point to the last common ancestor of humans and chimpanzees living in East Africa between 8 - 6 million years ago (mya). The currently oldest classified hominin fossil in the published literature is that of Sahelanthropus tchadensis at 7.4 - 6.4 mya (millions of years ago). The two next oldest hominins are Ardipithecus ramidus kadabba, dated at 5.6 mya, Ardipithecus ramidus at 4.4 mya and Orrorin tugenensis at 5.7 - 6 mya. For the next three million years australopiths occupied various ecological niches in East, Central and Southern Africa. At roughly 2.5 million years ago the first stone tools (termed the "Oldowan Industry") are evident in the archaeological record. This coincides with the appearance of the disputed Homo habilis. The new skill was copied by their australopith contemporaries. Homo erectus is descended from Homo habilis and, around 1.8 mya, migrated first into the Near East, then into Asia and finally later from the Near East up into Europe.
The modern debate surrounding the origins of anatomically modern humans has traditionally been associated, in the public's eyes, with two models: the Multiregional and the strict Out-of-Africa. Less commonly known are the Assimilation (Fred Smith) and mild Out-of-Africa (Brauer) models. The strict Out-of-Africa model is contradicted by anatomical and genetic data; although still espoused by some scholars (for example, Paul Mellars), it is generally regarded as flawed. There are also questions marks over the validity of the form of Multiregionalism as espoused by Wolpoff, Hawkes and others. The main difference between Brauer and Smith's models is the degree of postulated interbreeding. To me it is clear from the available evidence that late archaic hominins interbred. Eric Trinkaus concluded his recent survey of the genetic and anatomical data in the 2005 issue of the Annual Review of Anthropology by stating that "the issue has increasingly become whether one can perceive the ancestry of non-African late arcahic humans (especially of the Neandertals) in the biology of living humanity. This is not a question addressing the evolutionary processes involved in the emergence of modern human biology. This is a question regarding the evolutionary purity of living humanity. This...confuses the human population dynamics of 30-100 millennia ago with the complex human population history of the past 30 millennia. Given the human demographic dynamics associated, minimally, with the climatic and ecozonal changes of the last glacial maximum (OIS 2), the development of food-producing societies, the rise and interaction of complex societies, and the globalization of the human population during the past two millennia, it remains curious how one can even pose the...question. The only justification would be a macroevolutionary approach in which all past and present "modern" humans are perceived as the same; such a perspective is typological and irrelevant to the populational processes involved in the establishment of modern humanity... Two dozen years ago, human paleontologists suggested that modern humans originated in equatorial Africa and subsequently expanded into at least western Eurasia, variably absorbing regional late archaic human populations in the process. After two decades of debate, the field has come to the concensus that modern humans originated in equatorial Africa and subsequently expanded into Eurasia and the remainder of Africa, variably absorbing regional late archaic human populations in the process. This is known as the assimilation model. Versions of the assimilation model have remained contenders for the interpretation of modern human phylogenetic emergence, if frequently overshadowed by the more polarized regional contintuity (with gene flow) and (out of Africa with) replacement scenarios. The last two interpretations are finally intellectually dead. Both are contradicted by available evidence, and it is time for the discussion to move on... The question can therefore be rephrased to ask, to what extent can the early modern human paleontological record and other data help refine the regional biological, behavioral, and chronological details of the assimilation model?"
It is, literally, the exploration of a lifetime.