The development of behavioural complexity and intricate judgment were once only thought to be characteristics possessed by modern humans.
However, the archaeological record emphasises distinctive bone structure which makes Neanderthals anatomically adept to climatic hardship. Many bone features are also portrayed, which assists in vigorous movements and in occupying cold, harsh environments.
In addition, Neanderthals exhibit significant leaps in behavioural modification, being among the first hominids to bury their dead or utilise language. These modern examples of behaviour display the development of social stratification and the rise of ritualistic and symbolic mannerisms representing advances that are anything but inferior.
Part I: Evolution of Structural Distinctiveness
The time in which Neanderthals inhabited the earth vastly overlaps with the first documentation in the appearance of modern humans. Research has unbraced the theory that we evolved from Neanderthals and has exposed that these two species evolved from a common ancestor within the last 500-600ka (O’Connell, 2006).
The oldest pre-Neanderthal fossils have been dated to over 300ka, whereas “classic” Neanderthal deposits can be dated to less than half that and are confined to the boundaries of Eurasia (Feder, 2006). Comparatively, deposits of modern humans are dispersed over much larger areas and are thought to have evolved from around the same time as these “classic” Neanderthals. Through applying the Argon/Argon dating the Omo remains found in 1967 are firmly dated to 195ka, thus proving them to be the oldest known specimen of modern humans.
This illustrates that moderns and Neanderthals occupied the earth around the same time (Feder, 2006). It is unsure what lead Neanderthals to their demise, but the main postulation is that it was the growth and advance of modern humans out-competed other pre-modern species. However, their reign throughout Eurasia for over 100ka can still enable them to be labelled successful, as they provide a unique example of some of a highly adapted species showing levels of behavioural complexity and cumulative learning that had yet to be seen in hominid species (Langley et al. 2004).
The most striking characteristics that distinguish Neanderthals from other hominids can be argued to be the facial bones (Jolly & White, 1995). Although some bones resemble adaptations to the cold, others are merely seen as ancient features which bear a resemblance to primitive hominids. An attribute that has been labelled a ‘Neanderthal feature’ refers to cheek teeth appearing smaller than earlier hominids and are set forward in the jaw (Villa & Giacobini, 2005). Other facial features are representations of adaptations to the cold, paying particular attention to the large nasal aperture in the cranium.
Neanderthals used this evolutionary trait to warm and moisten the inhaled air on the passage to the lungs. However, it is more likely that instead of moistening the air for the lungs, this adaptation benefits the brain as it is in danger of chilling through inhaled air (Villa & Giacobini, 2005). This is due to the nasal passages that are in close proximity to the artilleries that feed the blood to the brain. In addition, triangular peninsulas of bone projecting into the nasal opening from both sides of the nasal margin are properties not seen in modern humans. These peninsulas aid in increasing surface area for mucus-producing nasal membranes, aiding in humidifying the cold air breathed in (Feder, 2006).
Adaptation to the colder, harsher European environment continues from the head down as Neanderthals skeletal structure is essentially modern, although shows some crucial differences. One key morphological adaptation is their smaller, robust stature (average 150cm in height) with short extremities (Jolly & White, 1995). This general body form is associated with cooler climates, as it retains heat efficiently in comparison with a body that has longer extremities and a smaller torso (Feder, 2006). These adaptations are consistent with the Neanderthal population escalating over the time of the glacial maximum, therefore adopting these key characteristics resembling that of a modern Inuit (Eskimo) (Feder, 2006).
Through the study of the hallux, also dubbed the ‘big toe’ there is an indication of the walking abilities of the Neanderthal man. Trinkaus’s examination of the toes in the anatomy of the Shanidar specimens, found in modern day Iraq, show that the big toe is closely aligned with the other toes (Trinkaus & Shipman, 1993). It is also showed the presence of fully developed arches and short toes, which shows a greater resemblance to modern humans and lacks similarity to apes.
Through further examination of Neanderthal bones in their feet, it was concluded that the robustness of their stature was also present in their toes. This was thought to be an adaptation to assist Neanderthals with field running while barefoot, in which the toes must grip onto the rugged terrain. Their stout stature, including their arms, has also been seen to have a mechanical advantage, having the ability to leverage different muscles (Trinkaus & Shipman, 1993). Locations at which these muscles are attached to those bones shows enhancement of the power; the bicep muscles bending the elbow with the forearm muscles located the hand into the motion of thrusting a spear (Trinkaus & Shipman, 1993).
The wide birth canal that is seen in the bones of female Neanderthals reflects an important reproductive difference between Neanderthals and modern humans. An excavation of the Kebara Cave found Neanderthal bones dated to 50-55ka, which presented for the first time a completely intact inlet. The superior pubic ramus is extremely long, typical in Neanderthal bones (Rak & Arsenburg, 2005). The studies of the pelvic bones in females indicate that they could reproduce with offspring that have a larger head 15-25 % bigger than modern offspring (Trinkaus & Shipman, 1993). This suggests that offspring were in the womb for a longer gestation period of 12 months. As the gestation of modern humans is shorter, the brains are still developing for, approximately, a further 12 months after birth (Trinkaus & Shipman, 1993).
This is not seen in Neanderthal communities. Due to having a shorter gestation period, modern humans have the ability to reproduce at a faster rate then Neanderthals. It has therefore, been suggested that Neanderthals were replaced by modern humans due to the ability to reproduce at a faster rate and populate immense areas over less time (Trinkaus & Shipman, 1993). Although Neanderthals may have had a disadvantage with reproducing at a slower rate, it can be also understood that there was more development through pregnancy. It can, therefore, be argued that Neanderthal offspring were born more capable needing less maternal attention and nourishment after birth.
The skeletal variation of Neanderthals from other hominid species indicates that they were specifically adapted to the colder, harsher climate in Europe as climatic reconstructions are echoed in the anatomical features that are unique to their species. Furthermore, their remains signify that they were bipedal and maybe had a more effective reproduction system than ours….
Does this indicate that they were skeletally better adapted than modern humans? Most probably. Therefore, why did they become extinct during a time when modern population’s sky rocketed? Is it possible they fell short in other areas which are detrimental to the success of modern humans, such as the adaptation of intricate thought and/or behavioural complexity?
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Image Credit : Luna04