Sunday, November 24, 2013

The Neanderthal


Who were the Neanderthals? The Neanderthals were archaic people who colonized Europe and some parts of the Middle East as long ago as 400,000 years. They co-existed with the first modern humans from about 80,000 to 30,000 years ago when they became extinct.

What were they like?
Neanderthals were hunter-gatherers. They made and used flint and stone tools for day to day operations. But they also built shelters and were active in fire control operations. They were highly carnivorous  yet there is limited evidence of plant foods that they operated with and which survives in the archaeological record. Their locations puts them in Mediterranean regions such that they went after marine resources such as shellfish and seals. However, their use of aquatic foods was more limited than that of modern humans.

Quick Facts

Scientific nameHomo Neanderthalensis

Genus: Homo

Height(Male, Adult) 164 – 168 cm [5.3 – 5.5 ft.] (Female, Adult) 152 – 156 cm [4.9 -5.1 ft.]

Mass(Adult, Male) 77.6 kg [171 lb.] on average; (Adult, Female) 66.4 kg [146 lb.] on average

The Humanoid Subspecies
The Neanderthals are an extinct species of the genus Homo, possibly a subspecies of Homo sapiens. They are closely related to modern humans. That means that between 1% and 4% of the Eurasian human genome seems to come from Neanderthals. Furthermore, they differ in DNA by only 0.3% with that of Homo sapiens genome structure.

Their Appearance
Neanderthals looked much like modern humans only shorter, more heavily built and much stronger, particularly in the arms and hands. Their facial feature which included large nose and strong double-arched brow ridge distinguished them from modern humans. Their skulls show that they had no chin and their foreheads sloped backwards. The brain case was lower but longer housing a slightly larger brain than that of modern humans. Because they were largely carnivorous, both male and female Neanderthals hunted prey. The evidence of a huge number of injuries, like those sometimes seen with today's rodeo riders, suggests that hunting involved dangerously close contact with large prey animals.

Are the Neanderthals a different species?

No, the fact that they interbred with modern humans shows they were not a separate species. Modern humans are classified as Homo sapiens. Most scientists today view Neanderthals as a sub-species or hominid sister group of all present-day humans. Homo sapiens and Neanderthals are believed to have a common ancestor who lived about 500,000 years ago in Africa. The common ancestor? Homo heidelbergensis.

Eye Size and its impact on Human social connections
One study of Neanderthal skulls suggests that they became extinct because they had larger eyes than our Home sapiens species.  In fact, one research team explored the idea that the ancestor of Neanderthals that left Africa and had to adapt to the longer, darker nights and murkier days of Europe. The result was that Neanderthals evolved larger eyes and a much larger visual processing area at the backs of their brains.

To prove this a scientific researcher, Eiluned Pearce of Oxford University, checked this theory. She compared the skulls of 32 Homo sapiens and 13 Neanderthals. She found that Neanderthals had significantly larger eye sockets, usually by as much as an average of 6mm from top to bottom.

So what was the impact of the larger eyes? How did affect them? One of the results of this was that their social connection to other Neanderthals was not as significant as the connection that Homo sapiens use with other humans. This is in contrast to the humans that stayed in Africa who  continued to live with bright days and so had no need to make weather adaption. As a result our Homo sapien ancestors, evolved their frontal lobes, associated with higher-level thinking, before they spread across the globe.  Because the Neanderthals were not the socially connected species, as Homo sapiens were, they were not able to advance as a species, not because of their preferences, but because their brain biology had a preference for visual operations, not thinking operations.
One thing to point out is that research on primates has shown that eye size is proportional to the amount of brain space devoted to visual processing. Given that prognosis scientist researchers have made the assumption that this would also be true of Neanderthals.

Thus it is hypothesized that Neanderthals had a smaller cognitive part of the brain and this would have limited them, including their ability to form larger groups. The idea is that if you live in a larger group, you need a larger brain in order to process all those extra relationships. This may also have had another consequence resulting from their more visually-focused brain structure which was that this focus affected their ability to adapt and innovate to the ice age that was thought to have contributed to their demise.
On their extinction

Although they had survived for hundreds of thousands of years and mastered the cold climates of the last Ice Age, Neanderthals had a tendency to be over-specialized meaning that they weren’t the dynamic race that would easily or necessarily change to meet environmental features. Moreover, they were never very populous to begin with. They were eventually edged out by Homo sapiens, but not before hybridization had occurred. Hybrid vigor due to Neanderthal admixture may have played a role in what human populations best succeeded at during the changing climate of Europe. But in a sense, Neanderthals never became totally extinct. Their genes live today on in hybrid populations.