Theories Behind the Extinction of Neanderthals

A recent breakthrough in Neanderthal extinction study suggests that their large eyes led to their extinction. Due to the large size of their eyes, more brain power was used to process visual images rather than other functions.

About 12 km east of the city of Düsseldorf, the capital of the German state of North Rhine-Westphalia, lies a small river valley by the name Neanderthal.

During the 19th century, the valley served as a limestone quarry. In 1856, while some local workers were quarrying limestone in one of the caves in the valley, they stumbled upon several bones of what they thought was a bear that had died many years ago. The workers collected the bones, and put them together in the corner of the cave.

When a local schoolteacher saw those bones, he realized that they definitely did not belong to a bear, but looked human. The only problem with his belief was that the bones looked unusually thick and had some pretty odd shapes. About 15 pieces of bones were found, including a skullcap, and other bones of hands and feet.

After several studies regarding the source of the skeletal remains, a major breakthrough came in the year 1864, when an Irish geologist, William King studied them, and published a report saying that the bones were indeed human, but belonged to a different species of humans than the modern ones.

He named the newly identified species as Homo neanderthalensis or the Neanderthal Man, after the valley in which the bones were found.

Further researches on the subject have shed light on the fact that the Neanderthal Man was, in fact, a distant cousin of the modern race of the Homo sapiens, and is therefore, also sometimes classified as its subspecies, Homo sapiens neanderthalensis.

According to carbon-14 analysis of the oldest bones ever found, the Neanderthal man may have lived in Europe, as early as 600,000-350,000 years ago. Moreover, archaeological studies have also revealed that the species went extinct sometime about 30,000 years ago.

Since the probable dates when the Neanderthal man may have gone extinct have been put forth and widely accepted, there have been a lot of studies in order to find out possible reasons for the same. Numerous hypotheses have been postulated with respect to the Neanderthal extinction, most of which are highly disputed.

Owing to the radiocarbon date, with regards to the last appearance of the Neanderthals on earth, which is, as mentioned above, some 30,000 years ago, one hypothesis states that they may have coexisted with modern humans, the Homo sapiens, in Europe.

This is because modern humans are believed to have migrated to Europe around 40,000 to 43,000 years ago. So, this hypothesis holds a solid ground according to some researches.

According to this hypothesis, when modern humans migrated to Europe, or more precisely, encroached their territory, the Neanderthals, were forced to live in refugium due to the increasing intervention of the Homo sapiens in their original habitat.

Therefore, they may have led a concentrated existence at some isolated locations, where their population may have dwindled by the day, primarily because of their inability to compete with modern humans. This theory is highly disputed as we do not have many concrete evidences with respect to the interactions between the Neanderthals and modern humans.

This theory is largely based on the Gause's law of competitive exclusion, which states that two distinct species cannot coexist in the same ecological setup and the moment one species gains even a slightest edge over the other, that species will dominate in the long run, thus completely excluding the other species from competition.

According to French paleontologist Marcellin Boule, this precisely, might have happened with the Neanderthals, with the advent of modern humans in their competition.

• The Homo sapiens are anatomically more superior than the Neanderthals. Owing to the overall form of their body and the shortness and stoutness of their limbs, they were unable to walk or run as fast as modern humans.

• American author and scientist, Jared Diamond has proposed that the ability of modern humans to use a spoken language by producing a huge array of sounds was what gave them an edge over the Neanderthals who, according to him, were not able to produce complex speech.

• In 2006, anthropologists of the University of Arizona postulated that unlike modern humans, one of the possible causes of the Neanderthal extinction may have been the absence of the division of labor. Owing to this, both men and women performed the same tasks, and hence, they were not able to exploit their resources properly, and subsequently went extinct.

One of the major differences between the Neanderthals and modern humans was that the latter had a more developed brain than the former. This enabled modern humans to do things in a much better way and with more ease than the Neanderthals. This might definitely have resulted in the Neanderthals running out of competition with the Homo sapiens.

Jared Diamond has proposed that the extinction of the Neanderthal man may have been the result of acts of mass violence and genocide. According to him, scenarios similar to some modern ones, wherein mass murders or genocide may have occurred in case of the Neanderthals.

Moreover, some archaeologists and scientists also think that the early Homo sapiens displayed a highly cannibalistic behavior.

They may have hunted and consumed the Neanderthals, and this may also have had an adverse effect on their population. However, again, like the previous theory, this hypothesis is also not based on any solid evidence, and is therefore rejected.

The Homo sapiens had migrated to the Neanderthal mainland from other parts of the world. Jared Diamond and some others have hypothesized that in the course of their migration, they may have carried with them certain pathogens, which were foreign and completely unknown to the Neanderthal immune system.

Quite possibly, when the two species came in contact with each other, these pathogens must have spread to the Neanderthals, and because they were not able to fight the newly contracted diseases, their race may have vanished from the face of the Earth.

Furthermore, it has been established that the Neanderthals fed on the brains of the mammals, According to modern medical research, this may have been one of the causes behind their extinction as consumption of mammals can create a high risk of developing various diseases and infections related to the brain.

Partial extinction is a very interesting hypothesis that puts forth a thought that the race of the Neanderthals is not totally extinct, in fact, they may have got assimilated into the more dominant race of modern humans.

According to a 2010 press release by the Max Planck Society for the Advancement of Science, Germany, a recent research conducted on the sequencing of the Neanderthal genome yielded that, "between one and four percent of the DNA of many humans living today originate from the Neanderthals".

Therefore, the research concluded that, contrary to popular belief, it is quite evident "that some Neanderthals and early modern humans interbred". This means that complete extinction of the Neanderthals seems to be a highly improbable scenario.

However, it seems quite possible to believe that some of the last of their lot may have got absorbed into the greater race of the Homo sapiens.

Another hypothesis, with respect to the extinction of the Neanderthals, is related to the drastic change in climatic conditions during the last Ice Age, when Europe was semi-desert with sparse vegetation. The result of this was the disappearance of many species of plants and animals, which formed a major portion of the food of the Neanderthals.

One theory states that the Neanderthals suffered due to the reduction in their food resources, which subsequently led to their starvation and thus, extinction. Another theory states that even their bodies cold not adapt to the new climatic conditions, and hence they could not survive the change.

However convincing or unconvincing some of these theories may seem, one thing is for sure - it is not possible that only one of the above given factors may have been responsible for bringing about the complete downfall of a species that was once, most dominant.

The decline of the Neanderthals surely must have been a collective result of many of the above factors. However, in the absence of solid evidences, it is very difficult to ascertain as to what exactly may have happened to the Neanderthals. Researches on the subject are still going on, but unless we find a solid clue, the results will always remain obscure.