Neandertal demise may be the result of interbreeding, assimilation, not early modern human superiority
An analysis of the archaeological records of Neandertals and their modern human contemporaries has found that complex interbreeding and assimilation may have been responsible for Neandertal disappearance 40,000 years ago, in contrast to many current theories, according to results published April 30, 2014, in the open access journal PLOS ONE by Paola Villa from the University of Colorado Museum and Wil Roebroeks from Leiden University in the Netherlands.
Neandertals thrived in Eurasia for more than 300,000 years but vanished around 40,000 years ago, around the same time that modern humans entered Europe. Archaeologists have developed many theories to explain their disappearance, and many of these suggest that modern-day humans were superior in a wide range of ways, including weaponry and subsistence strategies. This superiority may have eventually led to the demise of Neandertals. However, new evidence, including genetic data, suggest that differences between Neandertals and modern humans in Africa may not be so clear as previously thought.
In this study, scientists systematically tested the strength of some of the archaeologically derived explanations for Neandertal extinction, such as the Neandertals’ supposed lack of complex language, inferior capacity for innovation, inferior hunting ability, and smaller social networks, as well as other environmental explanations, including harsh climate or volcanic eruptions that occurred at the time of their decline.
If the Neandertal record is compared to that of African Middle Stone Age human contemporaries, instead of the modern humans that succeeded them, the differences between them and humans in their capacities, like weaponry, subsistence, and use of symbols are too small to explain their demise in terms of cognitive or behavioral inferiority. Instead, the authors argue, genetic data recently obtained from Neandertal skeletal remains suggest that complex and drawn-out processes of interbreeding and assimilation may have been responsible for the disappearance of the specific Neandertal morphology from the fossil record.
The extinction of any species be it big or small, is a tragic event but such is the way of life. As Darwin’s theories tell us; the strongest survive and the weakest fall away into the history books. The story of the Neanderthals does however, contain much uncertainty. Due to limitations in our dating abilities, scientists are unsure of the exact time of the extinction of the Neanderthals which is a very important factor as this could determine whether or not our ancestors came into contact with and interbred with the Neanderthal population. I for one, believe that the extinction of the Neanderthals was as a result of a number of factors, such as competition over food and space with our ancestors, assimilation with other humans resulting in the breed of humans present today, as well as environmental factors and diseases. Hopefully in time when we have developed better technologies, we will be able to analyse the evidence we have collected so far more effectively allowing us to form a better picture and maybe discover once and for all what happened to our cousins the Neanderthals.
I agree with u14115761’s comment. It is not only the inbreeding that can cause the extinction of certain species; the external factors do play a big role. But according to Darwin’s theory of natural selection, the Neanderthals could have survived if they chose partners and DNA with stronger surviving abilities. By choosing the same type of ability over and over again, it will start diminishing inside of the DNA chains, and that could cause a total failure of the survival cycle. If lion wants the mating partner it will go for the partner with the best hunting skills and those babies will again choose a partner with the best eyesight etc. and so it will start to become a “super-lion” after the fourth or fifth generation, because of all the different abilities it has entwined in its DNA chain.
I agree that interbreeding between the Neanderthals could play a role in their extinction, but I think it is more realistic to argue that a combination of factors played a role over several thousands of years that eventually caused their extinction.
It is said that the Neanderthals thrived some 300 000 years ago. It is difficult to determine how big the population was, but for them to exist for thousands of years, we must assume it was substantial.
My theory is that the population of the Neanderthals diminished over the years due to a combination of several reasons. Factors like parasites and pathogens, climate changes, interbreeding and so forth could be some of those reasons causing their numbers to decrease.
Research indicates that there was a time when the Modern Day Human and the Neanderthal specie co-existed about 30 000 to 40 000 years ago. During this time the Modern Day Human had a competitive advantage over the Neanderthals due to their higher intellect which led to the ultimate extinction of the Neanderthal specie.
Although research also indicates that there could have been interbreeding between the two species, I am of the opinion that the modern day human simply hunted and killed the Neanderthals as they saw them as a threat for their existence.
I did further reading on the Neanderthals, according to various sources about 55000 years ago, the climate fluctuated from extreme cold to extreme heat. Studies have been done and it showed that the Neanderthals where better suited to live in the colder climates. The great fluctuation in the climate caused an ecological imbalance making it near to impossible for the Neanderthals to adapt.
Further studies have shown that the Neanderthals needed a significantly larger energy intake to survive, compared to the modern day human. Due the rapid changing climate, food resources became scarce and this could have also played a lead role in the Neanderthal extinction.
I did further reading on the Neanderthals, and according to Wikipedia about 55000 years ago, the climate fluctuated from extreme cold to extreme heat. Studies have been done and it showed that the Neanderthals where better suited to live in the colder climates. The great fluctuation in the climate caused an ecological imbalance making it near to impossible for the cold climate Neanderthals to adapt.
Further studies have shown that the Neanderthals needed a significantly larger energy intake to survive, compared to the modern day human. Due the rapid changing climate, food resources became scarce and this could have also played a lead role in the Neanderthal extinction.
The comments on this topic have highlighted some interesting aspects regarding the demise of the Neanderthals and the numerous possible causes for their downfall.
I would like to add on to what u14369878 commented. We have to accept that, yes, the possible explanations offered in the article could not be the only factors leading to the disappearance of the Neanderthals. Based on my previous knowledge, and using Darwin’s theory of evolution, it is evident that environmental factors and changes do have a large impact on the ability of a species to ensure that their species survive and maintain a healthy gene pool. 14127807 mentioned the possibility of decreased levels of immunity as a result of inbreeding. This is a very good point to be made. As we know, the genome of a species evolves to a large extent when there is a flow of genes from one population into another. This means that more defence mechanisms are introduced to a single gene-line, resulting in better adapted individuals within the species.
The demise of the Neanderthals was most likely the overall result of complex interactions between the individuals and their surroundings (including other members of the population).
In my studies I have learnt a fair deal about evolution of the modern day humans and about the extinction of Neanderthals. There are a lot of different theories as to how they became extinct that I have heard of in detail. The theory stated in this article ‘’that inbreeding may have caused extinction’’ is not a theory I have heard of. As with all the other theories this one does have its advantages and disadvantages above the other theories. Interbreeding can lead to recessive genes being expressed. These recessive genes can code for characteristics that are detrimental to the Neanderthal race, making it difficult to adapt to a new and changing world. If the gene pool was larger, these recessive genes would carry less weight and adaptation could have been easier. I do agree with 14127807 that without today’s technology we would find it hard, if not impossible, to adapt to a changing climate.
I do agree with what 14369878 is saying, but we must take into consideration that one of the reason that human and animals in the modern time are adapting is because we humans have the means to adapt, as well as have the means to help other species to adapt to the rapid changing environment.
The Neanderthals could be call the dinosaurs of the homo sapiens. The dinosaurs became extinct due a rapidly changed environment. I must admit that if I faced the rapid changing environment head-on, and I did not have the various technological advancements we have available now, I would to perish.
The Neanderthals is indeed a very interesting topic. I have heard about them on the various television channels in the past, but I must admit that the topic never interested me. When I stared to read up and do a little research on the topic my curiosity took over. The fact that inbreeding could be the result of the extinction of this species is an interesting point. Inbreeding does cause the daughter human genome to become less exposed to various pathogens that the parenting genome of another bloodline could have already experienced. Thus reducing immunity when inbreeding has occurred. The Neanderthals clearly wanted to keep there bloodline pure, and not having the various medical advancements that we have available today, they did not realize the result inbreeding could have on their population.
These reasons given in the passage can not be the only reasons for the Neanderthals to become extinct.
I believe they couldn’t handle the change in the earth as it developed into a new world, as we know the world was once known as one large continent and several years later the world had divided into seven different continents.
So if the Neanderthals would wanted to survive they should have adapted to their new environments and learn new skills to move along with the new world. They could have done it because the Neanderthals were smart creatures.
It was not impossible for them to adapt because in every day life we and other animals are adapting as our world is still changing!!!!
This is fascinating to read. It has been a long serving assumption of mine that Neanderthals were inferior to humans in their intelligence. They were in fact very complex thinkers with good problem solving skills. They would participate in premeditated group hunting expeditions and use tactics such as rushing much larger prey (woolly mammoths) into sinkholes, thus leading them to their death. The presence of Neanderthals was mostly concentrated across Europe and Asia, and their participation in the fossil record tapers down to an end, as early human navigated north of Africa.
The fact that early humans and Neanderthals could interbreed is astounding. The first offspring would have a 50:50 split of the DNA, but as interbreeding continued natural selection favoured the genes of the early humans leading to what is known as the “extinction” (on a gentic, molecular level) since the male offspring were more often than not infertile.
This is not to say that the Neanderthals genes were not of use. It is believed that our immune system owes its strength to them.
Most of the Archaeologists and Paleontologists of our time has to `understand` and `comprehend` the fundamentals of `biology` and `genetics` and “evolution” in `molecular terms` first , they have been more like `artisans` to classify `Morphological ` differences what they see as evidence with their “eyes” and completely ignore the ` EVER CHANGING VARIABILITY OF GENES AND MOLECULES IN TIME AND SPACE(ENVIRONMENT) ` , continuously changing variability as a function of time and space(environment) within the same species ; never ever `rings any bell ` on them . They are fixated with ` the Spots –time frames- in the past ` of the same species in the past , they look them as if they were different species . Unfortunately this ` artificial morphological classification of ` Neanderthals and `Denisovans` are one of their(archaeologists and paleontologists` handy work of `classifications` still being discussed today .
Well ; first we know for sure that they so called (Neanderthals) did NOT disappeared 40,000 years ago since up to % 3 of our genes and particularly the most important ones that help boost our immunity to survive as Modern Human came from them , second our ancestors did not discriminated one way or other against them and successfully interbred with them as the opportunity arise obviously thanks to the Genetics and Molecular level investigational -real sciences- of our time . Certain part of their genes are eliminated by natural selection over time . First interbred offspring surely shared successfully % 50 %50 of their genes from the start with as Modern Humans and so called Neanderthals , the frequency of each alleles at a given time over 40,000 years dependent to the interbreeding frequency and its continuity between two different gene pools(populations) of course but there was no `genetic or molecular or physiological ` impediment to interbreed successfully whatsoever in between them .
In `genetics` molecular term of “extinction” is complete elimination of unique genes`from the face of the earth of a “ completely different species that can not interbreed successfully with the closely similar other species “ – there is a fine line of distinction of other species here – as the natural selection process , since those beneficial Genes of Neanderthals still within us it means they are living with us as we do , so they were not different species from the start . Looking at the minor overall phenotypic paleontological remains `fossils` and measurements and their morphologic differences “variability ` does not itself allow the description of a new `different species` BUT morphologically different `variant` of the SAME species as long as they successfully interbreed for generations to come , so the Neanderthals were the `variant` representatives of different frequencies of different genetic alleles and phenotypes who had surely shared the MRCA (Most Recent Common Ancestor) with late arrival of the same species at the same geography later on ; somehow we call –Modern Humans- only difference was the frequencies of certain genes but they were able to interbreed effectively .
I fail to see them most likely reason listed – higher dependence on animal protein, while H.Sap was more of a generalist omnivore and could survive lean times better.