http://www.physorg.com/news94753229.html

It seems that most genetic studies are saying that modern humans did not interbreed with other homo species. The fossil record keeps popping up evidence of interbreeding. Is there a historical bias skewing results? (i.e. scientists were fearful to publish findings about the "nature vs nurture" debate b/c of its unpopular implications that genetic superiority could exist) Is it possible that what we used to consider genetic junk in our DNA are actually primitive traits, making this a phenotype problem? When it comes to interbreeding are we to believe right now that the jury is still out? This feels like one of those huge mistake areas in science is brewing around the topic and we are still mad about the last one (i.e. we were wrong and lets re-organize the food pyramid because we gave people wrong advice about how to eat)

The whole "out of Africa" thesis happened developed largely because of the Leakeys and the fact that most digging for hominid remains has taken place there. I have no doubt that we'll get a much more nuanced paradigm for hominid evolution as we look harder elsewhere.

New analysis shows three human migrations out of Africa.

http://www.physorg.com/news10534.html

A new, more robust analysis of recently derived human gene trees by Alan R. Templeton, Ph.D, of Washington University in St Louis, shows three distinct major waves of human migration out of Africa instead of just two, and statistically refutes — strongly — the 'Out of Africa' replacement theory. That theory holds that populations of Homo sapiens left Africa 100,000 years ago and wiped out existing populations of humans. Templeton has shown that the African populations interbred with the Eurasian populations — thus, making love, not war.

"The 'Out of Africa' replacement theory has always been a big controversy," Templeton said. "I set up a null hypothesis and the program rejected that hypothesis using the new data with a probability level of 10 to the minus 17th. In science, you don't get any more conclusive than that. It says that the hypothesis of no interbreeding is so grossly incompatible with the data, that you can reject it." "Not only does the new analysis reject the theory, it demolishes it," Templeton said. In 2002, Templeton analyzed ten different haplotype trees and performed phylogeographic analyses that reconstructed the history of the species through space and time. Three years later, he had 25 regions to analyze and the data provided molecular evidence of a third migration, this one the oldest, back to 1.9 million years ago. "This time frame corresponds extremely well with the fossil record, which shows Homo erectus expanding out of Africa then," Templeton said. Another novel find is that populations of Homo erectus in Eurasia had recurrent genetic interchange with African populations 1.5 million years ago, much earlier than previously thought, and that these populations persisted instead of going extinct, which some human evolution researchers thought had occurred.

The new data confirm an expansion out of Africa to 700,000 years ago that was detected in the 2002 analysis. "Both (the 1.9 million and 700,000 year) expansions coincide with recent paleoclimatic data that indicate periods of very high rainfall in eastern Africa, making what is now the Sahara Desert a savannah," Templeton said. "That makes the timing very amenable for movements of large populations through the area." Templeton said that the fossil record indicates a significant change in brain size for modern humans at 700,000 years ago as well as the adaptation and expansion of a new stone tool culture first found in Africa and later at 700,000 years expanded throughout Eurasia.

"By the time you're done with this phase you can be 99 percent confident that there was recurrent genetic interchange between African and Eurasian populations," he said. "So the idea of pure, distinct races in humans does not exist. We humans don't have a tree relationship, rather a trellis. We're intertwined."

The dates for the fossils in question by Big Tone were after the first two waves of emigration. There is no fossil discrepancy!

I find the idea strange that many species of humanity started in Africa and no where else. It would suggest that our ancestors never left Africa and spread elsewhere which is highly unlikely. In times when such beings would form into small tribes or family groups and deliberately avoid others who may desire conflict by moving further afield. It seems likely that they would spread out, out of Africa.

Big Tone....
I don't know where u get the idea that the fossil record confirms "inter-breeding"...

evolutionary theory actually discounts this concept...
isolation and restricted populations normally produce evolution/adaptation...
species normally diverge when inter-breeding is restricted....

It seems everyone believes that my initial post was making assumptions based on things that I believe, read, or have evidence for (I don't own any fossils). If my previous post reads that way, then I apologize. I was simply trying to state that this general area seems controversial and I was asking (repeat ASKING!) if it had been resolved. Thus, I have no assumptions or pre-concieved notions about the answer. After reading the - I don't always trust but sometimes find to be a great resource - wikipedia - on the subject of "Neanderthal", I found considerable differences of opinion and became frustrated. The article above and many others suggest interbreeding linked to fossil evidence - that is them talking - not me - I have no expertise or opinion in the area. I was curious if someone "in the know" that likes this forum within the scientific community could provide answers and insights into the questions of: did different species of hominid interbreed? if so, what species and when? and most interesting to me... did modern man interbreed?

I don't care if the answers (or best guesses) include fossils, DNA, and/or cultural artifacts - I just wanted to know the opinion of latest scientific work in the area.

I don't feel as though I need to post any quotes here to backup that this breeding debate is alive and well - I also hope that it is now clear that I have no position nor am making any assumptions.

If primative man is anything like modern man, a pretty girl is a pretty girl no matter what her background. If the females had a breeding season, the females would also have invited the mysterious dude's advances. What is more romantic for a modern female than a sweet talking foreigner. In their case, the intriguing strange male with his different colored hairy back.

Besides, modern human culture did not form until 6-10K years ago, so there was little social stigma connected to maintaining ethnic purity. That type of social stigma is way too modern. We are talking about prehumans, something between natural animals and almost human enough to form civilization. The intermediate state of mind leading toward civilization would have induced the need to attempt extending the population density beyond just one family tribe into a more metropolian way of life. Maybe this was only possible during breeding season.

I realize that everyone wants data to support conclusions. But when it come to prehistory, the data is sparse and appears quantum due to being sparse. The result is continuing speculation. Say for example, a dad writes a detailed journal about his son, with dailly entries for ten years. This data set will give one a good feeling for what constitutes his ten year old son. After he is done, he lets his little three year old daughter (unbiased) pick one or two data points from each year. Would that be enough to determine the nature of his son, (fossils are random and not purposely place by nature as examples of key events).