Thursday, January 10, 2013
"Decoding Neanderthals" on PBS NOVA: we are all "black", and we are all Neanderthal
PBS Nova presented a revised documentary about the Neanderthals, “Decoding Neanderthals” which seems to update an earlier documentary “Becoming Human: Last Human Standing” Nov. 17, 2009.
Researchers, largely in the Netherlands and Germany, compared the genomes of homo sapiens and Neanderthals in detail. They found a common gene thought to be related to language. They are fairly certain from art work left that the Neanderthals could communicate verbally. They also discovered that the Neanderthals had been amazingly resourceful in working with flint to make spearheads and in making the glue and poles for their weapons. We still can’t replicate how they cracked their flint into such effective shapes.
Researchers compared commonality of genes among Europeans, Africans, and Orientals. They found that Africans have the lowest percentage of Neanderthal genes, less than 2%, that Orientals an Asians are in the middle (about 3%), and Europeans the most (5%), with the largest percentage in Tuscany (northern Italy). That seems presumptive evidence that homo sapiens mated with Neanderthals and created fertile offspring, which makes Neanderthals part of our species (as a subspecies). However, homo sapiens and Neanderthals don’t share maternally passed mitochondrial DNA. It seems as though Neanderthal, dating back to 800000 BC, were gradually absorbed by the newer humans that had come from Africa after 100000 BC. The newer forms of humans seemed to have a slight advantage in innovation and passing it along to descendants in culture, which may be why the newer form dominated.
Some specific Neanderthal genes (and perhaps epigenes), however, seemed to contribute advantages in cellular immune function, particularly in the way HLA antigens work and maybe even in the way T-helper cells function. It sounds conceivable that this could help explain why HIV has been so readily transmitted by bi-directional heterosexual activity in Africa but much less so in the western world, a fact that would have “political” significance in the 1980s.
The opening scene of the film shows a handsome and slender European young man (almost breathtaking to look at, as far as “gay values” go), compared to a bulky Neanderthal. In fact, however, we (not just our president) are all “black” because we are all descended from Africa about 100000 years ago (or more) and benefit from some genetic changes that improved cognition (related to problem-solving and innovation and teaching) that we all know happened in Africa, as an adaption to complex food-gathering requirements. We also all are a little bit Neanderthal, which may have strengthened our resistance to some infections and particularly some cancers. Maybe we’ll find out we’re all Martians, or that we all came from Gliese 581G.
Certainly, all the new research tears all of the Nazi racial theories of the 1930s to shreds.
Did we acquire any appearance characteristics from the Neanderthals? The lighter skin of Europeans is thought to be an adaptation to less sunlight, and the need to make vitamin D. The heavier body hair (which had been sacrificed in Africa in order to remain cool during daytime hunting) may have come back in colder climates starting as an accident, and then become a secondary sexual characteristic to help men seem more desirable to female mates. No one in science has said whether this could have come from Neanderthals, although some sci-fi movies form the 50s maintain that.
The link for the film is here.
Another film for comparison is Herzog’s “Cave of Forgotten Dreams”, Jan. 23, 2013, movies blog.
Picture: No, that's a gorilla from the DC zoo, March, 2007.