- Holliday, T. W., Gautney, J. R., Friedl, L. (2014). "Right for the Wrong Reasons: Reflections on Modern Human Origins in the Post-Neanderthal Genome Era". Current Anthropology. 55(6): 696-724 While (some) living humans only have 1-4% of Neanderthal genes which might be considered trivial - it turns out (some) Upper Palaeolithic humans had a larger percentage of Neanderthal genes: http://www.nature.com/nature/journal/v524/n7564/full/nature14558.html I wouldn't say 6-9% is negligible or trivial. In my view these findings seem to have falsified the Out of Africa (Recent African Origin) hypothesis. What do you think?
If anyone's confused as why (some) Upper Palaeolithic humans had considerably higher Neanderthal admixture, here's an explanation: "In the past Neandertal genes were more common in Europe than they are today. This is in line with various contentions that many if not most Neolithic populations in Europe came from western Asia. European Neolithic populations were largely a consequence of population replacement and subsequent expansion: some 70 percent of the Neolithic settlements are of Levantine origin (Chihki et al. 2002), Neolithic hunter-gatherers of northern Europe have a genetic profile that is not often found in living populations of the region, con-tinued Neolithic gene flow between farmers from western Asia and local and hunter-gatherer populations created the current pattern of genetic variation (Skoglund et al. 2012)." (Wolpoff & Caspari, 2013) So it has to do with the population-size changes, gene flow and migrations during the Neolithic.
My knowledge is that Neanderthals are offspring of humans which left africa earlier than ones which contributed the remaining 90+ percent to our genome. So, since both lines originated in africa I don't see a problem with the "out of africa" hypothesis here. The German Wikipedia page about Neanderthals supports this (the English one has no such pragaraph as it seems): https://de.wikipedia.org/wiki/Neandertaler Translation attempt: He (the neanderthal) developed in Europe, in parallel to Homo Sapiens in Africa - from a common african ancestor of the genus Homo. If this is correct, the ancestors of the Neanderthals were out of africa, too. They just left earlier. PS: Found another page that lists "Homo Erectus" as common ancestor of the neanderthals and our species: http://www.helles-koepfchen.de/gesc...mo-erectus-neandertaler-und-homo-sapiens.html Translation attempt: It came to split in human evolution: From the Homo Erectus developed the Neanderthal (Homo neanderthalensis) as well as the modern man (Homo sapiens sapiens). This also supports the "out of africa" hypthesis. Homo erectus lived in Africa.
We already know that the entire family tree of humans and our ancestors--modern, earlier and ancient--evolved from an ancestral genus, Ardipithecus, in Ethiopia around 5MYA. Two closely-related species of Ardipithecus have been found, and both are clearly spinoffs from the chimpanzee family tree. Yet they had anatomical divergences that are obvious mutations away from the rest of the apes. Most notable is the anatomy of the lower body, which has been re-engineered for full-time bipedal walking. The feet are shaped for comfortably carrying the entire weight of the creature full-time. When they had to climb into the trees to escape predators, they retained just one prehensile toe to assist in climbing, but they could not perform the arboreal gymnastics that most other primates are capable of. The ancestors of humans remained in Africa for quite a long time before they began to migrate to the other continents. Obviously the Neanderthals were among that group, as their more compact anatomy is clearly suited for colder temperatures than ours. For example, unlike us, they were not buoyant and could not have swum efficiently--an ability that would have been of little use in a region where the rivers were frozen most of the year. Other ancestral species colonized other parts of the Earth, but Homo sapiens was the last (or one of the last) to leave Africa. They reached Australia around 60KYA, one of the few places that, like Africa, had temperate weather as the rest of the planet was still at the end of an ice age. (In fact, at that time Australia was warmer than Africa. Those first explorers left precisely because the food supply in Africa was rather meager.) It was about 10,000 years later that the climate began to warm worldwide, and this is when our ancestors established colonies in Asia. Europe was one of the last places to warm up, and about 30KYA is when H. sapiens finally established a population on that continent (the Cro-Magnon people). The Neanderthals were still able to make a living there and the two species clearly got along reasonably well--there is very little evidence of battles between them. I'm sure that every community of sapiens was happy to have a couple of Neanderthals in their community to do the hard labor, and the Neanderthals would have been in awe of the weapons that our species can wield with the much greater range of motion in our arms. (The Neanderthals could never have operated a bow and arrow.) Not to mention our ability to swim in the rivers that were now liquid for half the year or longer.
The Out of Africa (OOA) theory only concerns modern humans, hence it is also called Recent African Origin (RAO). Yes, no doubt the human species originated in Africa, but this was probably up to a million years ago, long before the OOA/RAO timeline which argues there was a migration (or number of migrations) out of Africa by anatomically modern humans within the last 100,000 - 50,000 years and that these "modern" African migrants replaced all the "archaic" populations of the Old World (Europe, East Asia etc.) with negligible, to no admixture. These concepts of "archaic" and "modern" are though problematic, and hard to define. The latter issue aside, the most recent genome analyses of Upper Palaeolithic specimens like Oase seem to have falsified the OOA/RAO model because the extent of Neanderthal admixture: 6-9% is not negligible, but significant.
A way to improve an overbred species is to mix in wild forms. So I'm pretty sure the Neanderthal mixins are good for us. If it's 3%, 5% or 9% doesn't bother me much. Seeing what our explorers did to native people in the past 500 years, I'm truly amazed to see that the Nenderthals and our ancestors lived 10.000 or more years in the same region without killing each other. I'm a bit doubtful if they lived together for mutual benefit as Fraggle Rocker suggests, but while a long time a "theory of almost complete segregation" was proposed, I think the recent findings that interbreeding has happened, are much more believable. My personal believe is that both, our ancestors and the Neandethals were quite clever people, so they sure were able to see the benefits of mixed settlements, making use of the different skillsets for mutual benefit. I'd not be surprised if it happened exactly like Fraggle Rocker suggested.
It makes more sense if Neanderthals etc. are Homo sapiens. So they are the same species, but a different subspecies: Homo sapiens neanderthalensis. I think all "archaic" humans including Heidelbergs were the same species, just with geographical subspecies variations.
caveat Genus homo is slightly older than this current ice age. Nothing destroys archaeological sites quite as thoroughly as do glaciers. And we have had dozens of glacial cycles. ergo: We really do not know (every)where that early Homo lived nor evolved. "Out of Africa" is a simple line for simple minds. alternately phrased (as a wise person in here once posted) "Absence of evidence is not evidence of absence."
[https://en.wikipedia.org/wiki/Species] There are two problems in the use of the term "species." One is that the word itself is not very well defined. The other is that even if it were, it's not easy to apply it to actual living organisms. Somewhere along the way, we decided that dogs and wolves are two subspecies of the same species: Canis lupus domesticus and Canis lupus lupus. Yet there are plenty of reasons to classify the coyote as a subspecies in that same group, but instead we classify it as a separate species: Canis latrans. Coyotes and dogs interact very much the same way that wolves and dogs interact: if food is plentiful they'll run in mixed packs and interbreed freely; but if food is scarce, a coyote will happily kill and eat a dog. Coyotes have also been observed socializing with wolves, and an entire population of coyote-wolf hybrids is slowly making its way from eastern Canada down into the eastern USA. So: How many different species do we have here?
There's a useful write up here- http://rationalwiki.org/wiki/Recent_African_Origin_hypothesis http://rationalwiki.org/wiki/Assimilation_model http://rationalwiki.org/wiki/Multiregional_hypothesis IMO a "weak" form of Multiregionalism or the Assimilation model fits best with the evidence.
