Cross Breeds

Do you think that there is a possibility that Neanderthals and Cro-Magnons mated and created cross-breeds?

Neanderthals were human also. I know that they were a different species of human, and any child produced by such mating would be sterile and not able to reproduce ( like mules ). My question is : There are very strange human fossils that have been found. Could they be the offspring of the two species of humans?

Public Comments

1. Most likely they did have sex with each other. They may have even been able to produce offspring. Whether the offspring were viable or not is up for discussion. If the human species in question (Neanderthal and Cro-Magnon) had the same amount of chromosomes, then it's possible that they could have produced viable offspring. ==========================================================
2. Track with me: The Neanderthal genome has been established (We know their DNA) The Neanderthal DNA shows that they are a "cousin" species. It's possible that we both developed from Homo heidelbergensis or Homo erectus but Homo sapiens didn't evolve from Neanderthals. There's enough difference in the Neanderthal and Human DNA structure to pretty much rule out crossbreeding. All supposed "Hybrids," found so far, fit within the physical range of one or the other of the two species. Given that Neanderthals range was pretty much limited to Europe, any results of crossbreeding would show up in today's European population and to a much lesser extent in the populations of Asia and Africa. Research has shown this isn't the case. While it's OK to consider the "possibility" or cross breeding, there's no evidence. To put forth the idea as a theory means a lot of physical evidence must be produced to support it. Say about as much as required to support the "Battlestar Galatica" population landing here 50,000 years ago.
3. Yes, it is quite possible that such hybrids were produced - though they were most likely infertile, as you have already suggested. Modern human skeletal remains (possibly those of a child) with 'Neanderthal traits' were found in 1999 in Lagar Velho (Portugal) and can be interpreted as evidence of extensively admixed populations. The following (full-text) article by Ian Tattersial explores this case in greater detail: http://www.pnas.org/content/96/13/7117.full.pdf See also the article entitled 'More Human-Neandertal Mixing Evidence Uncovered' in ScienceDaily | Nov. 6, 2006 that discusses a re-analysis of older fossils found in Romania in the 1950's: http://www.sciencedaily.com/releases/2006/11/061103083616.htm While there do seem to be possible cases of interbreeding, they not have seem to have made much of an impact in either of our genomes as recent molecular studies seem to indicate. The first draft of the Neanderthal genome published earlier this year, (Feb 2009) suggests that no significant mixing occurred between the two genomes. (Although interbreeding cannot be ruled out completely as this is just the first pass on the sequence and accounts for about only 60% of the genome.) Thus, pending more detailed molecular analysis, one could tentatively conclude that the above mentioned hybrids were most likely non-viable in some way or largely infertile. For more info see: http://news.nationalgeographic.com/news/2009/02/090212-neanderthal-genome.html
4. As far as science has been able to determine at this time, the modern human genome does not contain any neanderthal DNA, so while it is certainly possible that the two species interbred, none of the potential resulting offspring contributed to the modern population, so the most likely explanation is that if there were offspring produced by such encounters, they were infertile.
5. I think if anything, we would have murdered the males and absorbed the females.