Homo neanderthalensis and Homo sapiens
Is there a connection?
Read the blurbs, follow the links, and see what you think. There's no final decision yet either way, so you can make up your own mind on this one.
(In the interest of full-disclosure, I want to say that I personally believe that while there may have been cross-breeding Neanderthals are not ancestors of modern humans. I've tried to include arguments for both sides on this page.)
"What if we could actually compare our mtDNA with mtDNA of a distant ancestor? This, in fact, has been done, with mtDNA from the bones of Neanderthals. Comparing mtDNA of these Neanderthals to mtDNA of living people from various continents, researchers have found that the Neanderthals' mtDNA is not more closely related to that of people from any one continent over another.
"This was an unwelcome finding for anthropologists who believe that there was some interbreeding between Neanderthals and early modern humans living in Europe...; these particular anthropologists instead would have expected the Neanderthals' mtDNA to be more similar to that of modern Europeans than to that of other peoples. Moreover, the researchers determined that the common ancestor to Neanderthals and modern Homo sapiens lived as long as 500,000 years ago, well before the most recent common mtDNA ancestor of modern humans. This suggests (though it does not prove) that Neanderthals went extinct without contributing to the gene pool of any modern humans."
"Analysis of ancient DNA extracted from the original Neanderthal skeletal remains found in the Neander Valley, Germany, in 1856, indicates that Neanderthals did not interbreed with modern humans. This remarkable achievementthe oldest DNA ever extracted from a hominid remainswas accomplished in 1997 by scientists at the University of Munich in Germany.
"Their unprecedented genetic findings imply that Neanderthals were not our ancestors but a distinct species who split off from the hominid line at a much earlier date than modern humans and reached their evolutionary end about 35,000 years ago."
"A Washington University anthropologist claims that the characteristics of a 24,500-year-old Neanderthal skeleton of a four-year-old boy show that Neanderthals and early humans cohabited and produced children. If the skeleton is indeed evidence of interbreeding, it contradicts the dominant hypothesis among scientists that Neanderthals were a separate branch of the evolutionary line from early modern humans....
"The child's skeleton was found on a hillside in the Lapedo Valley north of Lisbon, Portugal, in December 1998. It possesses characteristics of both species, such as the stocky trunk and sturdy leg bones of Neanderthals and the prominent jaw and small teeth of modern humans. Radiocarbon dating of the skeleton in 1999 confirmed that the child lived 4,000 years after the arrival of early modern humans (Cro-Magnons) on the Iberian Peninsula where Neanderthals already resided-offering possible evidence that the two groups intermixed, interbred, and produced offspring over several millennia.
"If this extensive interbreeding did occur, then Neanderthals may not have been a separate species after all. Neanderthals may have disappeared not because they were wiped out from war, but because their traits may have eventually been 'bred out.' This would also mean that their human descendantsuscarry a little bit of Neanderthal in our gene pool."
"In July 2002, an international team...announced the discovery of a humanlike skull that may be up to seven million years old, twice as old as any others found. The previously unknown ape species, named Sahelanthropus tchadensis, was found in Chad, in central Africa. The remarkably complete skull was nicknamed 'Toumai,' which means 'hope of life' in the Goran language. Compared to the famous four-million-year-old 'Lucy,' Toumai looks more modern and less chimplike, with a shorter, flatter face and smaller canine teeth.
"Is Toumai a direct ancestor of later hominids, perhaps even modern humans? While some scientists support this theory, others believe that Toumai was one of various hominids that once walked, perhaps upright, on the African continent. In this model, evolution looks less like a tree, with humans and apes branching from a single common ancestor, than a bush in which various hominids evolved and became extinct. Meanwhile, some rival anthropologists think the skull is that of an ancient female 'proto-gorilla.'"
Also from the BBC, in December 2003, an article addresses the "fierce debate" by saying: "Remains of early modern humans from Central Europe often display Neanderthal traits, say the researchers. But these features are no longer as common in present-day European populations." It says that maybe Neanderthals and Cro-Magnon were interbreeding, or maybe they were just evolving in the same direction because they lived in the same climate.
"Three fossilized skulls discovered near the Ethiopian village of Herto in 1997 have now been identified as the oldest known remains of modern humans. Assigned to a new human subspecies called Homo sapiens idaltu (idaltu means elder in the Afar language of Ethiopia), the skulls are estimated to be about 160,000 years olda good 50,000 years older than any previously discovered Homo sapiens.
"The Herto discovery helps resolve two major debates in paleontology: whether humans are related to Neanderthals and whether all modern humans originated in Africa or developed simultaneously in other regions of the world. These skulls suggest that modern humans existed thousands of years before the Neanderthals evolved in Europe, which would confirm that Homo sapiens neanderthalis was not a rung on the evolutionary ladder leading to Homo sapiens sapiens (that's us) but an entirely separate offshoot of hominid that eventually went extinct."
"The study found that the differences measured between modern humans and Neanderthals were significantly greater than those found between subspecies or populations of the other species studied. The data also showed that the difference between Neanderthals and modern humans was as great or greater than that found between closely related primate species."
Articles on CBS (www.cbsnews.com/stories/2004/01/26/tech/main596026.shtml) and MSNBC (http://msnbc.msn.com/id/4063766/) covering the study and citing the same AP article said:
This of course led me to read a little more about the last, which was a study by Dr. Alan Templeton. The CBC (Canada's answer to the BBC) wrote: