Modern human's occupation of Europe
Modern Man (Homo sapiens sapiens) arrived relatively late arrival in Europe (35 000 - 40 000 years ago) compared to colonization that occurred in South East Asia and Australia which date back to 55 000 years ago. One of the first arrivals of Homo sapiens sapiens are referred to as Cro Magnon, but they were not the first humans to have arrived in Europe.
The oldest non-African hominid date back to 1.8 million years ago and are based on three fossil finds in Georgia (an ex state of the former USSR) representing what appears to be a series of evolutionary sequences from Homo habilis-like to increasingly Homo erectus-like. [http://www.talkorigins.org/faqs/homs/d2700.html].
These fossils question the commonly held belief that homo erectus/ Homo ergasta was the first hominid to hot-foot it out of Africa, however, skeptics are of the opinion these fossils represent shrunken Homo erectus, which would make it a close relative of the diminutive Homo floresiensis. Nevertheless these skulls have been named Homo georgicus, and were only 1.5 m in stature and possessing a cranial capacity as low as 600cc [http://en.wikipedia.org/wiki/Homo_georgicus].
Fast forward nearly a million years and Homo cepranensis or “Ceprano Man” is found in Italy and appears to be an intermediate between Homo erectus and more advanced Homo heidelbergensis. Skipping across to Spain (Gran Dolina) we find Homo antecessor which is only slightly more recent at 780 000–500 000 years old, whose cranium had more advanced features like a full litre capacity. More gruesomely there were cuts on many of the bones indicating either cannibalism [http://en.wikipedia.org/wiki/Homo_antecessor], or a ritual defleshing of the body. Homo antecessor may be the same species or a proto Homo heidelbergensis, who inhabited Europe from 600,000 to 250,000 years ago, was tall (1.8m) and muscular (91 kg for adult male) and large brained (1100-1400 cc cf modern human average 1350cc).
Homo antecessor tools (Acheulian ) were similar to Homo erectus, Some Homo antecessor bones are anatomically similar to the East African (Turkana Boy) Homo ergaster which date back 1.9 to 1.4 million years ago. However, Homo heidelbergensis is more closely related to southern African Homo rhodesiensis which was the likely ancestor of Homo sapiens idaltu (Herto Man) who was the ancestor of Homo sapiens sapiens.
This evolutionary line is the evolutionary background for the “Out of Africa” hypothesis describing a single species origin for all of the World’s people. In Europe Homo heidelbergensis probably evolved into the shorter, but even more heavily built Homo neanderthalensis - an ice-age specialist.
So when modern humans decided to rather look west than east while pondering their future in a rather cold Central Asia they would have found Europe already occupied by Homo neanderthalensis, who had separated from the main evolutionary line some 500 000 years ago. About 40 000 years ago the Central Asian steppes would have extended from China to Europe (Germany) with an abundance of migrating herd animals that would be available “padkos” (literal road food from Afrikaans) on virtually any trek they wished to make. Why had modern humans not explored Europe earlier? About 10 000 years previously they had fully colonized Australia which required at least a 100 km boat trips across the Wallace line? Most anthropologist present the Ice Age and the extensive Saudi Arabian deserts as their main argument for modern man not seeking an occidental homeland. The opening up of the “Fertile Crescent” about 40 000 years is the key to the European colonization according to other anthroplogists.
Somehow, I find this difficult to accept, that deserts were more of a barrier than oceans - given the number of humans that can survive in the desert regions (e.g. the San of the Kalahari). Ecologically human populations could have worked their way around to Europe by beach-combing the south eastern shores of the Mediterranean. Further both Homo habilis and Homo egaster/errectus had managed to arrive in Europe. Further the molecular data suggests that Homo sapiens and Homo neanderthalensis have a common ancestor some 500 000 years ago, with the closest candidate colonizer being a more modern version of Homo errectus or Homo rhodesiensis which has been dated in Africa to between 125,000 and 600,000 years. Was there any hybridization between Homo antecessor and these more recent ancestors of Homo erectus from Africa? Was there one or several “Out of Africa” leaps prior to our modern explanation for the the populating of the world?. Homo heidelbergensis had already got to the UK with the fossil finds at Boxgrove dating back to between 478,000 and 524,000 years ago, but seems to be most similar to the fairly modern Homo rhodesiensis.
Finally looking at the distribution of the various Haplogroups present in European populations as presented on the National Geographic Genographic website ( https://www3.nationalgeographic.com/genographic/atlas.html ) suggests multiple lines for both Mitochondial DNA and Y Chromosome genes, not all of which included a detour through Central Asia. I will conclude this introduction by suggesting that Europe has seen at least two or multiple invasions of Out of Africa hominids, with the last colonization starting almost 40 000 years ago. For the rest I will explore firstly the Y Chromosome and then the Mitochondrial DNA, since both are carried by one sex only and do not get cut and diced during meiosis (I will ignore the strange case of an individual inheriting most of their mitochondrial DNA through the paternal line that has been published recently).
Before I go into the details of each lineage of modern human occupation, it is important to examine the climate, and more particularly the position of the Ice Caps. Compared to even the fairly recent geological past, the present climate is unusually warm. In essence most living organisms and ecosystems are adapted to cooler climates, this is is especially the case during the evolution and spread of modern humans. Consequently some 200 000 years ago the world was cooler and the polar ice caps rather larger and spread over most of North America and Western Europe, leaving eastern Asia, even at high latitudes relatively ice free (Figure 1)
Figure 1 The postulated extent of the the Polar Ice Cap 200 000 years ago. Mean global temperatures would have been about seven degrees C lower than present and a major extinction of tropical hominids is thought to have occurred. At 140 000 years the lowest temperatures would have been eight degrees C lower than present but then started to warm until it was about three degrees C warmer than present 130 000 years ago. The Sahara was a grassland with freshwater lakes and allowed the first modern humans to leave Africa via the Middle East and would have been tracking the movement of the great ungulate herds. it then started cooling and at 65 000 years was back at seven degrees C lower than present and the modern human populations that had left Africa had succumbed to extinction.
Conditions got really severe about 60 000 years ago (possibly even earlier), making Africa cooler, but more importantly drier and this caused herds of game to possibly move out of Africa with human hunters in hot pursuit. The hypothesized route is a southern one around present day Yemen (Aden) and eventually on to Australia via the Southeast Asian islands. Much of their geographical journey would have been along a coastline long since submerged by rising sea levels, so the only evidence is that carried in the genes of indigenous people. The very first exodus out of Africa carried the (M Haplogroup) and is present in about 20% of eastern Africa’s population but is largely missing from indigenous Indian and Southeast Asians. This mystery is due to either M-individuals living in East Africa being replaced and/or a bi-directional movement of people between the Arabian peninsular and African mainland which diluted the M .
The postulated extent of the the Polar Ice Cap 55 000 to 60 000 years ago
The postulated extent of the the Polar Ice Cap 45 000 to 50 000 years ago
The postulated extent of the the Polar Ice Cap 40 000 to 45 000 years ago
The postulated extent of the the Polar Ice Cap 35 000 to 40 000 years ago
The postulated extent of the the Polar Ice Cap 25 000 to 30 000 years ago
The postulated extent of the the Polar Ice Cap 10 000 to 15 000 years ago
The postulated extent of the the Polar Ice Cap 10 000 years ago to present
The oldest and most widespread Y chromosome genes in Europeans today appear to be M89 (Haploid F) and is found in 90-95% of all non-African males and dates back to 45 000 years ago
A. Vekua, D. Lordkipanidze, G. P. Rightmire, J. Agusti, R. Ferring, G. Maisuradze, et al. (2002). “A new skull of early Homo from Dmanisi, Georgia”. Science, 297:85–9.
A cranium for the earliest Europeans: Phylogenetic position of the hominid from Ceprano, Italy
G. Manzi,*†‡ F. Mallegni,*§ and A. Ascenzi*¶ available from http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=55569