Neanderthal and the Denisovans

The southern Iberian Peninsula near Gibralter was the last outpost of Neanderthal. They languished there until as late as 24kbp (thousand years before present). This area offered several survival elements They had warmth, seafood, and cliffs. With so much game gone at this point, they probably relied on food provided by the sea and cliffs. The cliffs also offered security from intruders. Climate had undergone drastic changes. A volcanic eruption 40kbp began a series of extremely cold seasons. This caused a loss of game animals and the calving of icebergs that also lowered temperatures. This is seen as the match that broke the camel's back for our cousins. Some researchers believe that Neanderthals couldn't make warm enough clothing, but that seems ridiculous. These were a people long used to living in colder temperatures. After all, aren't they built for the cold with their shortened arms, legs, and stocky bodies, just like Arctic people today?

Neanderthal and AMH (anatomically modern human) separated about 600kbp. By 200kbp, they had diverged completely from Homo sapiens. They survived for all of these years in glacial climates, so what happened? There are scientists who think we just walked in, and with our superior brains took over. Were our brains superior? Neanderthal has been shown, quite recently, to have made cave art and jewelry. They decorated themselves, buried their dead and probably had language (see the article on language in Vocal) Did we have better weapons and survival techniques? We are, after all, taught in biology that no two species can occupy the same niche. One loses and one wins. New research shows that aDNA (ancient) of Neanderthal exists in everyone except sub-Saharan Africans. Maybe we just interbred to the point where we absorbed them into our own species. However, the aDNA in us is on such a small scale that interbreeding them out of existence seems improbable. Why would our genes be so much more dominant than their DNA is?

More than likely, they were losing ground before AMH got to Europe. They lived in small communities, and the population of Neanderthals was apparently small. When we strolled in, it was not unlike when Europeans entered America. There were some conflicts, and our large numbers meant Neanderthal groups would have had to take more circuitous routes to meet up for mating and the exchange of goods. Eventually, the effect became untenable. Neanderthals became so isolated, they could no longer find each other. Some interbreeding took place out of desperation, which offers a clue as to what those interbreeding sessions really were. They were physically and genetically isolated.

Can you imagine being the last of your kind, eeking out an existence on the periphery of your former hunting grounds? You haven't seen another like you in a very long time, perhaps never. A lone soul looking over the sea on the cliffs of Gibraltar, the very shore of extinction.

THE DENISOVANS

A mystery on the scale of the Denisovans is alluring to all who have read about them. For the first time in history, we have fossil DNA for a people we didn't even know existed. Currently, we have literally a handful of Denisovan fossils and no skulls. We have no idea what they looked like, how they lived or the extent of their intellect. We do know where they lived because we can trace their pathway through modern DNA. This leads to more mystery. For instance, they lived in the Russian Altai Mountains - that's where what remains we have were found. Apparently, Tibetans got their ability to survive on low oxygen levels from them, but their genes do not show up in mainland Asians. It does show up in Australia and Oceania! They couldn't have gotten to those places without going through Asia.

POSSIBLE DENISOVAN ROUTE TO AUSTRALIA

Extensive research into Chinese remains dating 40kbp shows no Denisovan DNA. Australia (Aborigines) shows the highest in the world, bar none. It is possible they conquered the sea. Homo erectus seems to have gotten to similar places, and they are much older.

The divergence of AMH and Denisovans cannot be accurately determined at this time - it is anywhere from 170 kbp to 700 kbp. Denisovan DNA shows an admixture of Neanderthal and another unknown archaic. So the mysteries abound! This enigmatic DNA could be either Homo erectus or Homo heidelbergensis, we just don't know - yet. Admixture in these examples of Neanderthal, Denisovans and the unknown were male to female - again pointing to an unwillingness to mate, with male admixture offspring being weaker and possibly sterile, and females stronger and fertile. That would take an entire textbook to explain, but there are legitimate reasons to think this true. Also assumed is the fact that Denisovans had a much larger population than the Neanderthals had because their genome has much greater variability. There are some interesting choices out there for who the Denisovans might have been.

RED DEER CAVE PEOPLE

These include Red Deer Cave People, a skeleton found in the Philippines, and an unusual skeleton found in India. Who knows? Maybe they'll turn out to be connected to the unusual Andaman Island people or Homo floresiensis. There will be more to this story when more aDNA is analyzed, and more bones are found.