Neanderthal
The neanderthal adaptations were substantial - enough to place them well outside any of the norms for other homo ssp. These included:
- extremely stocky build, with lower leg bones shorter than thigh bones, as is the case with most apes. The broad build lowers the body surface area, preventing heat loss. Some other arctic dwellers, such as some Saami individuals, have the same leg proportions.
- very strong. Other apes are much stronger than sapiens, who are relatively light-bodied. Male gorillas are estimated to be 8-15 times as strong as humans, but fortunately they are peaceful vegetarians. Even chimpanzees can exert about eight times the pull of a human of similar weight. We do not know the strength of a Neanderthal, but they were far more heavily muscled than we are, and probably were at least twice as strong. Scholars are divided on whether they could throw better than humans.Sexual dimorphism in the subspecies was about the same as in sapiens, so the females were also strong.
- large nose. Thought be some to be a cold adaptation; also a feature of Europeans who later occupied the same area. But it is doubtful that this is useful in the cold.
- fair skin Mutations in genes associated with skin colour suggest they had similar fair and red-headed colouring to modern people dwelling around the Baltic. Reduced melanin levels are necessary to allow Vitamin D production under low light conditions, especially when fish are absent from the diet. Some well known recent depictions of Neanderthals have suggested they were red-haired and freckled.
- highly inbred The DNA of Neanderthals in a single location barely varies, and both strands of the X-X chromosome in a recent study were almost identical. It appears that Neanderthals travelled and mated in small family groups - which would accentuate their differences and accelerate evolution.
- brain and eyes. Brain size at 1500-1800 cc was significantly larger than sapiens. The occupital bun" or protruding back of the skull implies that it was the occupital lobe that expanded in Neanderthals, rather than the frontal lobe. This expanded occupital lobe is very peculiar and not known in other mammals. The occupital lobe contains the primary visual cortex and is used for visual perception and colour recognition.
It appears that neanderthal had much better eyesight, adapted to low light conditions in the far north and probably to the arctic winter. The larger eyes also suggest better night vision, so perhaps they were partly nocturnal. It also suggests why they stopped their expansion at about 30-35 degrees of latitude, probably because the light was too bright and the weather too warm for comfort.
Although neanderthal must have been slow on its feet, it might have compensated by having faster eye-hand co-ordination reflexes, making it into a super-warrior.
The bun appears in some European humans as a sign of admixture:
Aggressive behaviour The high proportions of fractures in neanderthal bones, similar to rodeo riders, suggests frequent contact with large combative mammals, suggests they may have leaped upon their prey. It appears they were highly combative; stab and club wounds are also frequent, and there are signs of cannibalism. Intraspecies competition and their aggressive hunting methods using direct contact probably accounts for adaptive selection in favour of superior strength.
Social behaviour. Like erectus before it, neanderthalus was an apex predator, very capable of hunting the largest and fastest creatures on open plains or in forest. They appear to have had a reasonably complex social organization but probably travelled in smaller bands than sapiens - 5-10 individuals as opposed to 20-30. It is thought they kept to small areas and rarely ventured forth. Injured individuals were nursed back to health - something that erectus had been doing for more than a million years. They maintained the same basic toolmaking practices of flaking sophisticated, very sharp stone implements for a variety of purposes for several hundred thousand years until they ran into sapiens; which suggests they were probably better at observational learning than at creating new methods (as indeed are most modern humans). They conducted burials and included funerary objects in graves, though these are less elaborate than those of sapiens.
Language Their hunting tactics probably required spoken language. Although scholars initially thought that this must be very limited, various genes and facial bones associated with speech seem to be identical in the two subspecies.
Numbers It is thought they were never very numerous, perhaps numbering no more than 10 000 individuals - which might have contributed to their lack of technological progress and to their ultimate defeat. Given the large range they occupied - all over Europe and into Siberia in the east and Israel in the south - it is hard to know why their populations were not greater, unless they had a low birthrate or the constant losses from feuding kept numbers down.
Location It is rather tempting to think that given the many special adaptations of the Neanderthal, they originally developed in an isolated location such as an island. The one that springs most readily to mind is Fennoscandia
- large nose. Thought be some to be a cold adaptation; also a feature of Europeans who later occupied the same area. But it is doubtful that this is useful in the cold.
- highly inbred The DNA of Neanderthals in a single location barely varies, and both strands of the X-X chromosome in a recent study were almost identical. It appears that Neanderthals travelled and mated in small family groups - which would accentuate their differences and accelerate evolution.
- brain and eyes. Brain size at 1500-1800 cc was significantly larger than sapiens. The occupital bun" or protruding back of the skull implies that it was the occupital lobe that expanded in Neanderthals, rather than the frontal lobe. This expanded occupital lobe is very peculiar and not known in other mammals. The occupital lobe contains the primary visual cortex and is used for visual perception and colour recognition.
It appears that neanderthal had much better eyesight, adapted to low light conditions in the far north and probably to the arctic winter. The larger eyes also suggest better night vision, so perhaps they were partly nocturnal. It also suggests why they stopped their expansion at about 30-35 degrees of latitude, probably because the light was too bright and the weather too warm for comfort.
Although neanderthal must have been slow on its feet, it might have compensated by having faster eye-hand co-ordination reflexes, making it into a super-warrior.
The bun appears in some European humans as a sign of admixture:
"There are still many human populations which often exhibit occipital buns. A greater proportion of early modern Europeans had them, but prominent occipital buns even among Europeans are now relatively infrequent."Ear The skulls of neanderthal are so different from sapiens that even the small bones of the ear can be readily distinguished. This may relate to more detailed pitch modulation by sapiens necessary to distinguish some aspects of speech,
Aggressive behaviour The high proportions of fractures in neanderthal bones, similar to rodeo riders, suggests frequent contact with large combative mammals, suggests they may have leaped upon their prey. It appears they were highly combative; stab and club wounds are also frequent, and there are signs of cannibalism. Intraspecies competition and their aggressive hunting methods using direct contact probably accounts for adaptive selection in favour of superior strength.
Social behaviour. Like erectus before it, neanderthalus was an apex predator, very capable of hunting the largest and fastest creatures on open plains or in forest. They appear to have had a reasonably complex social organization but probably travelled in smaller bands than sapiens - 5-10 individuals as opposed to 20-30. It is thought they kept to small areas and rarely ventured forth. Injured individuals were nursed back to health - something that erectus had been doing for more than a million years. They maintained the same basic toolmaking practices of flaking sophisticated, very sharp stone implements for a variety of purposes for several hundred thousand years until they ran into sapiens; which suggests they were probably better at observational learning than at creating new methods (as indeed are most modern humans). They conducted burials and included funerary objects in graves, though these are less elaborate than those of sapiens.
Language Their hunting tactics probably required spoken language. Although scholars initially thought that this must be very limited, various genes and facial bones associated with speech seem to be identical in the two subspecies.
Numbers It is thought they were never very numerous, perhaps numbering no more than 10 000 individuals - which might have contributed to their lack of technological progress and to their ultimate defeat. Given the large range they occupied - all over Europe and into Siberia in the east and Israel in the south - it is hard to know why their populations were not greater, unless they had a low birthrate or the constant losses from feuding kept numbers down.
Location It is rather tempting to think that given the many special adaptations of the Neanderthal, they originally developed in an isolated location such as an island. The one that springs most readily to mind is Fennoscandia
No comments:
Post a Comment