Did Homo Sapiens Drive Neanderthals to Extinction?

Check out this answer from Consensus:

The extinction of Neanderthals is likely the result of a combination of factors, including economic pressures from Homo sapiens’ migration, genetic interactions, and environmental changes. While Homo sapiens may have played a role in creating conditions that were challenging for Neanderthals, the evidence does not support the idea of a violent extermination. Instead, it appears that a complex interplay of factors led to the eventual disappearance of Neanderthals.

The extinction of Neanderthals, our closest evolutionary relatives, has been a subject of intense debate and research. Various hypotheses have been proposed to explain their disappearance, ranging from direct competition with Homo sapiens to environmental factors. This article aims to explore whether Homo sapiens played a significant role in driving Neanderthals to extinction by examining the latest research findings.

The Survival Trap Hypothesis

One of the prominent models proposed to explain the extinction of Neanderthals is the “survival trap” hypothesis. This model integrates multiple conjectures, suggesting that neither individual nor combined hypotheses are sufficient to explain the Neanderthals’ extinction. Instead, it posits that economic incentives related to Homo sapiens’ migration played a crucial role. This model implies that the migration patterns and economic strategies of Homo sapiens created a survival trap for Neanderthals, leading to their eventual demise1.

Neanderthals: Intelligent and Social Beings

Contrary to earlier views that depicted Neanderthals as brutish and unintelligent, recent research has shown that they were highly social, clever, and adaptable. Neanderthals exhibited behaviors and technologies similar to those of Homo sapiens, including cave art and intentional burials. The extensive gene exchange between the two species suggests that their interactions were likely peaceful rather than violent. This evidence casts doubt on the notion that Homo sapiens violently exterminated Neanderthals2.

Genetic Interactions and Cohabitation

It is well-documented that Homo sapiens and Neanderthals cohabited for a period, during which they exchanged genetic material. Modern humans carry approximately 2% Neanderthal DNA, indicating that there was significant interbreeding between the two species. This genetic exchange suggests that the relationship between Homo sapiens and Neanderthals was more complex than simple competition or conflict3.

Climate Change and Environmental Factors

Another critical factor to consider is the impact of climate change on Neanderthal extinction. Neanderthals were not particularly adapted to cold climates, and significant climatic shifts could have adversely affected their survival. The changing environment, combined with the arrival of Homo sapiens, may have created conditions that were unfavorable for Neanderthals, contributing to their extinction2.

 

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Did Homo sapiens drive Neanderthals to extinction?

Chris Hunt has answered Uncertain

An expert from Liverpool John Moores University in Palaeoecology, Evolutionary Biology

I don’t think there’s strong evidence either way. Material culture is not very distinctive of species so we can’t safely use it as a marker of change between Neanderthals and H. sapiens. DNA studies of sediment might in the future tell us but sediment DNA preservation in many sites is still to be explored.

Other interpretations are possible, for instance that climate change finished off the Neanderthals, or disease, and ecological issues around food procurement strategies or reproduction rates and genetic swamping.

In some European caves there is a period of non-occupation between the last Neanderthals and the first Homo sapiens. This might suggest that H. sapiens was not a direct cause of Neanderthal extinction. I think we have to concentrate effort on sites where it looks as if there was no gap between Neanderthals and H. sapiens. It then requires very high-resolution dating to demonstrate that the gap between one and the other was very short, and a careful exploration of the evidence about what Neanderthals and H. sapiens were doing on the site, how they lived, the ecology and climate of the time and so forth. Before lockdown we were exploring these questions at Shanidar Cave (Iraq) and we hope to go back after thepandemic to continue our work there with our colleagues in the Kurdish Antiquities Service.

 

Did Homo sapiens drive Neanderthals to extinction?

Paul Pettitt has answered Unlikely

An expert from Durham University in Palaeoanthropology

Neanderthal populations seem to have been declining numerically since a peak in Europe around 80,000 years ago towards their extinction around 40,000. They were not the only large bodied mammal to become extinct around the same time (several did, including a species of rhino and hyaenas in Europe). They seem to be part of a wider set of events, possibly tied either directly or indirectly into climatic oscillation in the period. Genetic evidence suggests that relatively small amounts of gene exchange occurred and hence, that the two groups did come in to contact on occasion, althought this was probably at the edges of their ranges, i.e. in western and central Asia, and not in their European core. There, the archaeological proxies for their presence suggest that when Homo sapiens groups arrived in a given region, Neanderthals had already disappeared. In most areas of Europe, therefore, Homo sapiens seems to have dispersed first into a vacant hominin niche, rather than ousted the Neanderthals. Larger populations of Homo sapiens, and more questionably some behavioural ‘innovations’ may have made us better able to cope with fluctuating Pleistocene climate, but generalisations of this nature are based not on the archaeology of our earliest appearance in Europe, i.e. the Initial Upper Palaeolithic, but on much later Upper Palaeolithic material. There is, therefore, no evidence that we had some kind of advantage. Thus, while contact obviousy did occur from time to time, and that such contact could have been violent, if this did occur it was exceptional, and certainly nowhere near enough to cause, or probably even contribute in a minor way, to Neanderthal extinction.

 

Did Homo sapiens drive Neanderthals to extinction?

Joshua Akey has answered Uncertain

An expert from Princeton University in Genetics, Evolutionary Biology

The role that modern humans played in the disappearance of Neanderthals remains controversial. Although it’s plausible modern humans outcompeted Neanderthals leading to their extinction, other explanations remain. For example, the population size of modern humans was larger than Neanderthals and we know some admixture occurred. Thus, perhaps Neanderthals didn’t go extinct so much as they were absorbed in to the modern human gene pool. Another explanation is that Neanderthals simply went extinct because of their small population size. There was a nice recent summary of these different possibilities (https://www.nature.com/articles/s41598-021-84410-7) and my own opinion is that these are not mutually exclusive factors, and therefore a number of reasons likely explain why the Neanderthal lineage ended ~30,000 years ago.

 

Did Homo sapiens drive Neanderthals to extinction?

Jérémy Duveau has answered Unlikely

An expert from Musée de l’Homme in Palaeoanthropology

Actually, we do not yet know the precise reasons that led to the extinction of the Neandertals, whose last representatives lived in Western Europe between 40,000 and 30,000 years ago. This extinction was gradual, taking several thousand years.

During the various studies carried out for more than a century on this subject, many factors have been considered to have caused or participated in the disappearance of Neandertals: climate (climate instability or extreme phenomena such as volcanic eruptions in Italy), demography (Neandertal populations becoming too small), genetics (Neandertal descendants would have become progressively less fertile), or indeed conflicts with Homo sapiens who arrived in Europe more than 40,000 years ago. However, although such conflicts may have occurred when the two taxa coexisted in the same region and at the same time, they were not a generality and there is no evidence of such widespread conflict. Indeed, we have known for several years now through paleogenetic analyses that Neandertals and Homo sapiens reproduced together, part of the genome of modern populations having a Neandertal origin. 

Therefore, a single and conscious action undertaken by Homo sapiens that would have led to the extinction of the Neandertals is very unlikely. Although there is no real consensus as to the reasons for the disappearance of the Neandertals, it is possible that, as in many other disappearances, several factors had an impact and not just one. 

On this subject, an article was recently published in the journal Scientific Reports. In this article, Vaesen and colleagues conducted a survey among 216 paleoanthropologists about the causes leading to the disappearance of Neandertals. According to this survey, the emerging consensus among paleoanthropologist seems to be that demography had a significant impact on this disappearance. However, this study does not meet with unanimous approval in the scientific community and no doubt other studies will soon highlight the impact of other factors.

 

Did Homo sapiens drive Neanderthals to extinction?

Francisco José Espejo has answered Likely

An expert from Spanish National Research Council  in Palaeoclimatology

Modern humans inherited DNA from Neanderthals, so, at least their DNA is not extinct yet. Neanderthals populations suffered contraction (local extinction) and expansions associate to climate variations, and modern humans co-existed with them during more than 100 kyr in the Levant and other regions. In most case when we describe “Neanderthal” or “Modern humans” presence, we are talking about tools or technocomplexes that we assume are relate with Neanderthals, but this assumption could change in the future, and in few case Neanderthals and Modern humans used same technologies. Extreme climatic conditions during the last glacial periods and population dynamics (e.g., endogamy) was affecting negatively to the last Neanderthals populations, in addition low numbers and interbreeding with Modern humans along generations could be the reason for “dilution” of Neanderthal DNA in Homo populations. More and more studies point that they similar cognitive capacities than “Modern Humans” and the low number of both modern and Neanderthals during this period likely avoided direct violent conflicts.

 

Did Homo sapiens drive Neanderthals to extinction?

John Shea has answered Extremely Unlikely

An expert from Stony Brook University in Archaeology

Simple answer = No.

Other than tiny amounts of “Neanderthal DNA” is some living humans, there’s no conclusive evidence Neanderthals and humans (Homo sapiens) ever set eyes on one another. They were probably aware of one another, for both were large mammals with large foraging areas, but much as different species of African apes do when they bump into one another, they probably mostly left one another alone.

If they were in conflict, we would expect to find their fossils in the same places and at the same time. When paleontologists find Neanderthal and human fossils at separate sites in the same region, those fossils date thousands or even tens of thousands of years apart. In the very few instances where Neanderthal and human fossils occur in the same levels of a site, those levels are sedimentary deposits that accumulated over thousands of years. Most such finds are teeth or small bones that have a way of moving around in soft cave sediments before those sediments become compacted.

If these hominins encountered one another, one would expect to find evidence of cultural exchanges or imitation. Archaeologists have yet to find evidence of any way of making tools that appears earlier among humans and later among Neanderthals, or vice versa.

So why are Neanderthals extinct?

Bottom line: The were unable to reproduce themselves in numbers above their standing population.

First, one needs to appreciate that extinction is common. It is not an unusual event.

Second, one needs to recognize that Neanderthals were already a “high-risk” population. They lived in some of the coldest habitats that primates ever occupied. Primates are tropical-temperate animals. We can see signs of cold stress in Neanderthals’ body shape (barrel chests, wide hips, short forearms, lower legs -these evolved characteristics reduce body surface area, conserving heat.  Cold had already begun overwhelming such social and technological “insulation” they had agains cold.

Third, Neanderthals’ last appearance dates across much of Europe and Western Eurasia cluster around 45,000 years ago. This is also the date of the Heinrich H5 Event, a several thousand-years long shift from already very cold conditions to even colder conditions that we think was caused by a slowing of the North Atlantic thermohaline circulation current.  The H5 event probably wiped out most of them, and swiftly, for such events happen fast. The survivors might have lived on it pockets along the Mediterranean, where their numbers dwindled. 

Finally, humans’ arrival in Europe and montane western Asia after 45,000 years ago might have made these late-surviving Neanderthals lives more complicated, but there is no convincing evidence humans made systematic efforts to exterminate Neanderthals. Doing so would have required them to divert vast amounts of time and energy against Neanderthals that were already nearly extinct and away from those humans’ efforts at reproducing themselves in, again, some of the most risky habitats in which primates ever lived.

 

Did Homo sapiens drive Neanderthals to extinction?

John Stewart has answered Unlikely

An expert from Bournemouth University in Palaeoecology

This particular topic, the cause of Neanderthal extinction, is not one that I would characterise as requiring fact checking in so much that scientists read the facts in different ways to derive widely differing conclusions. My personal take on it is that Neanderthals went extinct at a time when a lot of other ecological things were happening. There were extinctions of a number of large mammals during this general time including the cave bear and the cave hyaena. In fact it is interesting that the Neanderthals, while being large mammals that went extinct at this time, are still discussed as separate from the other megafaunal extinctions. There were also episodic local extinctions at this time of populations of animals like collared lemmings from NW Europe. In fact the Neanderthals went extinct in NW Europe at a time before modern humans had arrived. So for this region modern humans can not be considered to have a role. It is also interesting that Neanderthals seem to be most prevalent during the warmer intervals in Europe and retreat southwards as temperatures drop which speaks of a sensitivity to climate. The temperatures in Europe were becoming increasingly harsh while at the same time oscillating wildly between warm and cold. The warm associations of Neanderthals is backed up by their hunting styles and the faunas they are associated with. It is interesting, that with all the ecological phenomena taking place, which are thought to be caused by climate, it is only the Neanderthals that considered to have been affected by modern humans. Competition between closely related species in nature does not necessarily cause extinction. And when there are so many other ecological things taking place due to climate, it is highly likely that they too were affected by and eventually driven to extinction by climate.

 

Did Homo sapiens drive Neanderthals to extinction?

Andrew Sorensen has answered Likely

An expert from Leiden University in Archaeology, Palaeoanthropology

Technically, the answer should be “Uncertain” regarding the influence of anatomically modern humans (AMHs; i.e. Homo sapiens) on the demise of the Neandertals, because we still don’t know for sure which factors were most important in driving their disappearance. But I chose “Likely” because the general consensus in the field of Palaeolithic Archaeology is that the arrival of AMH into Eurasia ~50,000 years ago from Africa in one way or another tipped the scales against the Neandertals, whose existence was already quite precarious (e.g. low population numbers, erratically shifting climate around this period). So to be clear, I am not at all saying that AMHs wiped out the Neandertals through interpersonal violence (there is virtually no evidence for this in the archaeological record). What I am saying is that the introduction of this new group of people would have created added pressures on the Neandertal populations living in Eurasia related primarily to demography (the study of populations). This inflow of peoples from Africa would have increased competition for food resources, and these new peoples would have occupied spaces at the peripheries and between Neandertal groups, reducing mobility and genetic flow between segregated populations, thereby reducing genetic diversity, which can then negatively affect Neandertal birth rates. So this would have been a slow, gradual process of intrusion and exclusion that, over a few thousand years, would have contracted the territories of the Neandertals as AMHs spread, ultimately causing a complete collapse of the remaining Neandertal populations. And all this without any concerted effort by the AMHs to actively “wipe out” the Neandertals through genocidal violence, as is sometimes assumed by the public. An interesting open access article on the very subject of consensus among Palaeolithic Archaeologists and Palaeoanthropologists surrounding the disappearance of Neandertals was just recently published by Vaesen et al. in Scientific Reports, which you can access here if you’d like to read more on this topic: https://www.nature.com/articles/s41598-021-84410-7.

 

Did Homo sapiens drive Neanderthals to extinction?

Jeffrey Schwartz has answered Unlikely

An expert from University of Pittsburgh in Paleobiology

Based on my understanding of the fossil record of other animals, “drive to extinction” isn’t a conception I would invoke to explain the disappearance of species in general. There are aspects of the physical world – such as polarity reversals, volcanic eruptions, asteroids – that have geographically large-scale affects on large numbers of species, and others that are more local, affecting fewer species. The time period “Anthropocene” was recently coined to recognize the impact of human agency on the world, which would include the disappearance of species, which is ongoing. What we know about present-day and near-recent (e.g. Bronze Age and later) humans is that we are bellicose animals. So one might think that humans that were contemporaneous with Neanderthals killed them off. There are some Neanderthal skeletal remains that present evidence of trauma, but nothing that would be considered lethal. Some colleagues have suggested that humans drove Neanderthals into refuges (as represented by sites in Spain and Croatia), but that wouldn’t explain their ultimate disappearance. Indeed, until the advent of permanent settlements, humans were likely nomadic, traveling in small groups. As indicated by settlement sites in the “Fertile Crescent”, human populations did not expand greatly until after 14,000 years ago – coinciding with increasing evidence of physical conflict. Basically, I’m at a loss to invoke human activity as the direct cause of Neanderthal extinction. Every other species of human relative went extinct, and there is no reason to believe it was the result of a battle of “survival of the fittest”. Neanderthals did exist for some hundreds of thousands of years. So, perhaps, their “time was up”.

 

Did Homo sapiens drive Neanderthals to extinction?

DANIEL GARCÍA MARTÍNEZ has answered Uncertain

An expert from CENIEH in Paleobiology, Evolutionary Biology

From the archaeological, paleontological and biological facts discovered during the last decades, it is true that Neanderthals and sapiens interacted, both for the bad and the good. However, I think the genetic and ecological evidence for the Neanderthal extinction are stronger compared to the competitiveness with H. sapiens.

 

Did Homo sapiens drive Neanderthals to extinction?

Oren Kolodny has answered Uncertain

An expert from The Hebrew University of Jerusalem in Ecology, Evolutionary Biology, Behavioural Science

The driver(s) of Neanderthal extinction have been hotly debated for decades, and the debate is far from being settled. Their demise was no doubt close in timing to the spread of Moderns (H. sapiens) throughout Eurasia, but whether the competition (direct or indirect) between these populations was a major driver of Neanderthal extinction or rather it was more a situation in which moderns arrive just in time to deliver the final blow, is an open question. Even if it were moderns that were a major force in driving Neanderthals to extinction (and not, as has been suggested, epidemics, climate change, or other environmental factors), there is no agreement regarding what might have been the factor that determined the outcome in the competition between the two species: it could have been some factor that provided moderns with an advantage (candidates are differences in cognitive capacity, rate of bearing young, hunting techniques, relatively lower inbreeding depression, and many others), or perhaps each species was as capable and adept in pretty much everything as the other, and the outcome was simply a result of random drift.

Regardless, it is worth noting that the two species interbred, and that the majority of living humans carry in their genes some 1%-2% of DNA sequence that originates in Neanderthals, so in some sense they never went extinct at all.

 

Did Homo sapiens drive Neanderthals to extinction?

Lior Weissbrod has answered Uncertain

An expert from Israel Antiquities Authority in Archaeology

Homo sapiens may have played an indirect role in Neanderthal extinction by increasing demographic pressure on limited resources. Testing this hypothesis is extremely challenging.

 

Did Homo sapiens drive Neanderthals to extinction?

Iosif Lazaridis has answered Uncertain

An expert from Harvard University in Genetics, Palaeoanthropology

Neanderthals disappeared within a few thousand years after the appearance of modern humans across Eurasia, even though they had lived there across diverse climatic conditions for hundreds of thousands of years. So it seems likely that modern humans had something to do with it. This could have been adversarial, but also just a matter of demography (e.g. many more modern humans than Neandertals). Direct evidence for this and the alternative hypotheses is hard to come by though.

 

Did Homo sapiens drive Neanderthals to extinction?

Steven Churchill has answered Uncertain

An expert from Duke University in Biological Anthropology

There are lines of evidence from both archeology and ancient DNA studies that indicate that Neanderthals lived at low population densities in Europe and western Asia, that is, that they were vulnerable to extinction for much of their time on Earth. The evidence also suggests that during downturns in the climate (as glacial episodes waxed), Neanderthals may have become “locally extinct” across large parts of Europe, with most of their numbers concentrated in refugia along the Mediterranean coasts of Europe and the somewhat warmer climates of the Near East. Given this situation, any number of factors (such as climatic variability or competition with modern humans) may have tipped the scales towards extinction. While the extent of the interactions that may have occurred between Neanderthals and modern humans is an open question, it is certainly possible that ecological competition with modern humans may have contributed to the extinction of the Neanderthals.

 

Did Homo sapiens drive Neanderthals to extinction?

Antonio Rodríguez-Hidalgo has answered Unlikely

An expert from Complutense University of Madrid in Palaeoanthropology, Anthropology

The extinction of Neanderthals is probably a complex and multi-causal event. Modern humans probably drove them to extinction, but if it were their ultimate cause, it would be evident in the fossil record and would not be a controversial topic.

 

Did Homo sapiens drive Neanderthals to extinction?

Hila May has answered Unlikely

An expert from Tel Aviv University in Biological Anthropology

There are numerous hypotheses regarding the extinction of Neanderthals, some are related to modern humans, environmental condition, or the demographic characteristics of the Neanderthals themselves.

The hypothesis that humans has some part in Neanderthals extinction derived from the fact that they lived at the same time and place for a while and had some level of interaction between them as demonstrated by DNA and material culture.

Since we are here and they are not, we can assume that humans better adapted to their changing environment than Neanderthals. Whether it is related to differences in these groups genetic composition, indirect activity of humans, or intentionally is awaiting to be uncovered.

 

Did Homo sapiens drive Neanderthals to extinction?

Fereidoun Biglari has answered Uncertain

An expert from National Museum of Iran in Archaeology, Palaeoanthropology

To answer this question, many factors, such as climatic conditions, technology, and other adaptive capabilities of these two human groups must be considered. The population of Neanderthals seems to have been declining since about 70,000 years ago. When the populations of Homo sapiens settled in Europe, West Asia, and some other parts of this continent between 50,000 and 40,000 years ago, Neanderthals lived in smaller and scattered groups. The reason or reasons for this relatively gradual population decline are not clear. But for whatever reason, this explanation makes sense that their population became very vulnerable when modern human groups dispersed into their territories. Larger populations of Homo sapiens and their higher reproduction rates gave them a significant advantage over other human populations such as Neanderthals. 

Although genetic evidence suggests some contacts between the two groups, this occasional interbreeding contributed little to the modern human gene pool. If we accept that modern human populations played a role in the extinction of the Neanderthals, this role was probably as coup de grâce, as Neanderthals were on the verge of extinction because of their small population and lower average fertility rate that was coincided with rapid temperature and vegetation changes between 50-40 thousand years ago.

Finally, based on the present demographic, genetic, and archeological datasets, we can say that a combination of different factors contributed to Neanderthal extinction, among which demographic factors, especially population decline among Neanderthal has been one of the most effective factors.

One of the potential regions for exploring this question is the Zagros Mountains where Late Neanderthal groups were present at the edge of their ranges until 40-45 thousand years ago (https://www.researchgate.net/publication/321683750_The_Middle_to_Upper_Paleolithic_Transition_in_the_Zagros_The_Appearance_and_Evolution_of_the_Baradostian). Some excavated sites in this region that contain archaeological sequences of both Middle Paleolithic and Upper Paleolithic periods have good potential to explore the question of Neanderthal demise and spreading of Homo Sapiens populations into the region. 

 

Did Homo sapiens drive Neanderthals to extinction?

Matteo Romandini has answered Unlikely

An expert from University of Bologna in Archaeology, Cultural Anthropology, Palaeoanthropology

Not exactly. Homo sapiens did not lead the Neanderthal to extinction..

Homo sapiens diluted the Neanderthal DNa in him. And today it is still present in some of us.

 

Did Homo sapiens drive Neanderthals to extinction?

Adrián Pablos has answered Unlikely

An expert from CENIEH in Palaeoanthropology

We have no strong evidence that they coexisted in the same time and the same region. Especially in the period when Neandertals were extinct 40-45 ka. They were found in the same area in Middle East, but in previous times (60-80 ka). On the other side a ecological competition in which Homo sapiens advance into Europe and Neandertals went back must not be discarded.

 

Did Homo sapiens drive Neanderthals to extinction?

Maxime ROTIVAL has answered Likely

An expert from Pasteur Institute in Genetics, Immunology, Genomics

The long posited scenario of an extinction driven by war and competition between humans and Neanderthals becomes less likely as evidence accumulates suggesting that Neanderthals were complex beings and had extensive cultural exchanges with modern humans.

Yet, Homo sapiens had probably an important part in the extinction of Neanderthals, albeit indirectly, and unwillingly. The most likely is that modern humans precipitated the extinction of Neanderthals by competing for the same food sources (Timmerman, Quaternary sciene Reviews, 2020), promoting the arrival of new pathogens into the Neanderthal population (GreenBaum, Nat comms, 2019) and assimilating the remaining Neanderthals (Sankararaman, Science, 2014).

Indeed, there is now widely accepted evidence of geographical and temporal overlap of humans and Neanderthals (Hublin, Nature, 2020), and of multiple events of admixture between these species (Wolf, PloS genetics, 2018). During these encounters humans and Neanderthals also likely exchanged pathogens, similar to what happened with Europeans settlers and native americans in the 16th century. We know that modern humans were genetically more diverse than Neanderthal at the time of their encounters (Juric et al, PloS genetics, 2016), which could have led them to adapt better to the newly encountered pathogens, whereas the pathogens they carried would have generated a steep decline of neanderthal populations (GreenBaum, Nat comms, 2019).

However, prior to their extinction, Neanderthals admixed with modern humans with genetic studies estimating that ~2% of DNA from present-day non-African populations is of Neanderthal origin (Petr, PNAS, 2018). Thus, in a way one could says that Neanderthals were never truly extinct they are just a part of our ancestors.

 

Did Homo sapiens drive Neanderthals to extinction?

Mayowa Adegboyega has answered Unlikely

An expert from University of California, Davis in Biological Anthropology, Osteology, Palaeoanthropology, Anthropology

Neanderthals were a species of archaic humans who lived across Eurasia from about 400,000 to 40,000 years ago. They most likely went extinct due to climatic change, disease, malnutrition, or a combination of these factors. 

Neanderthals lived during the temperate MIS 5e and the cold and arid MIS4. Their extinction coincides with a period of intense cold and dry climate causing their preferred forest landscape to give way to steppeland. This climate change may have depopulated several regions of Neanderthals, like previous cold spikes, but these areas were instead repopulated by immigrating Homo sapiens. The changes in climate and the introduction of Homo sapiens on the landscape led to even more competition for food and other resources like clothing and shelter which would have made them vulnerable to extinction.

Another factor in their demise was their already small population size. Neanderthals lived in more sparsely distributed groups of about 10 to 30 individuals, much smaller than contemporaneous Homo sapiens groups. This would have made it easier for disease, malnutrition or others factors to wipe out entire Neanderthal populations easily.

Homo sapiens arriving in Eurasia also arrived with a more sophisticated and varied technological industry. Though Neanderthals developed many sophisticated tools themselves, the modern human suite of tools was would have allowed them more control over the environment leading anthropologists to believe that Neanderthals were simply outcompeted by Homo sapiens.