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EXTINCTION OF NEANDERTHALS
Gorhams Cave at Gibraltar,
one of the last places where Neanderthals lived The last of the Neanderthals are thought to have died out around 28,000 to 24,000 years ago, but it is unclear what role – if any – modern humans played in their demise. The last known Neanderthal remains — a woman's skull found with some flaked tools and bones from an ibex — were found in cave in the rock of Gibraltar and some caves near Zafarraya, Spain. The bones date back to 33,000 years ago. In 2006, some tools dated to 28,000 years ago –- that may be as recent as 24,000 years old — thought to belong to Neanderthals were found, . meaning that Neanderthals stuck it out longer than people had previously thought and died out relatively recently.
No one knows why Neanderthals disappeared. Many believe it was climate that did them in. Scientists theorize that Neanderthals became extinct because they were too highly specialized — adapted to survive the frigid temperatures of Ice Age Europe but not suited for warmer conditions. When climate conditions changes, one scientist said “highly specialized creatures are at a tremendous disadvantage." Some scientists have theorized climate change altered their arboreal environment into a more open and grassy one, making their thrusting weapons (see Below) obsolete.
The teeth of 43,000-year-old Neanderthals found at El Sidron cave in Spain showed signs of nutritional stress. By that there may not have been many Neanderthals and a severe disease outbreak or drought could have been enough to wipe them out. The most likely possibility is that the Neanderthal population became fragmented and scattered and they succumbed to a variety of pressures. Between 30,000 and 23,000 year ago the ice age entered Iberia, where the last evidence of Neanderthals was found, and turned much of the peninsula into a steppe. Perhaps, the last remaining weakened and scattered groups of Neanderthals succumbed to a drought, a landslide or a flash flood.
Websites on Neanderthals: Neandertals on Trial, from PBS pbs.org/wgbh/nova; The Neanderthal Museum neanderthal.de/en/ ; Hominins and Human Origins: Smithsonian Human Origins Program humanorigins.si.edu ; Institute of Human Origins iho.asu.edu ; Becoming Human University of Arizona site becominghuman.org ; Hall of Human Origins American Museum of Natural History amnh.org/exhibitions ; The Bradshaw Foundation bradshawfoundation.com ; Britannica Human Evolution britannica.com ; Human Evolution handprint.com ; University of California Museum of Anthropology ucmp.berkeley.edu; John Hawks' Anthropology Weblog johnhawks.net/ ; New Scientist: Human Evolution newscientist.com/article-topic/human-evolution
Neanderthal Decline
For Neanderthals things began to change between 50,000 and 40,000 years ago. Rebecca Wragg Sykes wrote in Time magazine: Rather than a single cause for their dying out, it’s looking as if Neanderthals were caught in a many-angled vise. Intensifying climate chaos was part of that. And there probably was something qualitatively different in their H. sapiens contemporaries, potentially better hunting technologies and greater social connectivity, which crowded them out. Perhaps, even as the last hybrid babies were being conceived, something else more dangerous was exchanged. [Source: Rebecca Wragg Sykes, Time, October 28, 2020]
Or it might all however have come down to nothing more dramatic than a slow fading away, and whatever the details, the Neanderthals’ end undoubtedly unfolded in different ways across their huge geographic realm, from France to Central Asia and beyond. By 30,000 years ago, there were no more Neanderthals. Nor were there any of the other ancient hominin species who had populated Eurasia. From the Cape of Good Hope to the Blue Mountains of Australia, our H. sapiens ancestors were alone on Earth.
A vital piece of information necessary to unravel the mystery of what caused the Neanderthals to die out is determining exactly when they reach puberty. This provides insights into brain development and life span. Analysis of a 100,000-year-old tooth of an eight-year-old Neanderthal found in Scadina cave in Belgium, indicated that individual was in track to mature several years earlier than his human contemporary and presumably has a shorter life span than modern humans.
Jon Mooallemjan wrote in the New York Times magazine: Clive Finlayson, director the Gibralter Museum “described the petering out of Neanderthals on the Rock with unnerving pathos. Gibraltar, with its comparatively stable climate, would have been one of their last refuges, he explained, and he likened the population there to critically endangered species today, like snow leopards or imperiled butterflies: living relics carrying on in small, fragmented populations long after they’ve passed a genetic point of no return. “They became a ghost species,” Finlayson said. [Source: Jon Mooallemjan, New York Times magazine, January 11, 2017]
Why Did Neanderthals Become Extinct
No one knows why Neanderthals disappeared. Many believe it was climate that did them in. Scientists theorize that Neanderthals became extinct because they were too highly specialized---adapted to survive the frigid temperatures of Ice Age Europe but not suited for warmer conditions. When climate conditions changes, one scientist said “highly specialized creatures are at a tremendous disadvantage." Some scientists have theorized climate change altered their arboreal environment into a more open and grassy one, making their thrusting weapons (see Below) obsolete.
The teeth of 43,000-year-old Neanderthals found at El Sidron cave in Spain showed signs of nutritional stress. By that there may not have been many Neanderthals and a severe disease outbreak or drought could have been enough to wipe them out. The most likely possibility is that the Neanderthal population became fragmented and scattered and they succumbed to a variety of pressures. Between 30,000 and 23,000 year ago the ice age entered Iberia, where the last evidence of Neanderthals was found, and turned much of the peninsula into a steppe. Perhaps, the last remaining weakened and scattered groups of Neanderthals succumbed to a drought, a landslide or a flash flood.
Paleoanthropologist Rick Potts, director of the Smithsonian Institution’s Human Origins Program, told Discover magazine: “ Whenever glacial habitats invaded Europe and Asia, it appears that the Neanderthals moved south, into Iberia and the Italian peninsula, to take advantage of the warmer places. Overall, their bodies show evidence of cold adaptation. Yet during one cold period, when the Neanderthals retreated, populations of Homo sapiens began to infiltrate the cold regions. How could they do this, especially since these populations were dispersing from tropical Africa? The difference is that these early populations of our species had developed the ability to invent new tools, like sewing needles that were useful in producing warm, body-hugging clothing. Preserved beads and stones suggest that they, but not the Neanderthals, maintained social networks over vast areas. My guess is that in Africa, Homo sapiens evolved better ways of adjusting to the arid-moist fluctuations—the key to adaptability—than the Neanderthals did to the cold-warm fluctuations in their part of the world. There are a lot of scientists interested in testing these ideas with new fossil and archaeological evidence. In the end, despite the adaptable features they inherited, the Neanderthals ended up as more habitat specialists than we did. Their options were more limited. As a result, our species ended up all over the world while theirs vanished.” [Source: Jill Neimark. Discover, February 23, 2012]
“There may not have been a single cause of Neanderthal extinction," Chris Stringer, a paleoanthropologist at Britain’s Natural History Museum, told The Guardian. "They may have disappeared in different regions for different reasons, but the background cause is clear. They didn't have the numbers."
Did a Small Population and Inbreeding Cause the Neanderthal’s Extinction
The study published in November 2019 in PLOS ONE by researchers from Eindhoven University of Technology, the Netherlands, suggests that small populations, inbreeding, and random demographic fluctuations could have caused the Neanderthal extinction around 40,000 years ago, according to paleoanthropologists. This findings exonerate humans from being behind the Neanderthal’s disappearance and argues that “the species demise might have been due merely to a stroke of bad, demographic luck.” [Source: Mohammed El-Said, Daily News Egypt, November 27, 2019]
Mohammed El-Said wrote in the Daily News Egypt: In this study, the authors used population modelling to explore whether Neanderthal populations could have vanished without external factors such as competition from modern humans. Krist Vaesen, associate professor of the philosophy of innovation at the department of Philosophy and Ethics, Eindhoven University of Technology told Daily News Egypt that his research suggests that scientists might have been too quick in attributing the demise of Neanderthals to the invasion of our species, Homo sapiens. “Relying on models from conservation biology, we conclude that the downfall of Neanderthals may have been the result of their small population size alone,” he said.
In the new study, the team used data from contemporary hunter-gatherer populations as parameters, the authors developed population models for simulated Neanderthal populations of various initial sizes (50, 100, 500, 1,000, or 5,000 individuals). After that, researchers simulated for their model, the effects of inbreeding Allee effects -which is a phenomenon in biology where reduced population size negatively impacts individuals’ fitness- and annual random demographic fluctuations in births, deaths, and the sex ratio, to see if these factors could bring about an extinction event over a 10,000-year period.
Vaesen further explained that the team used a set of mathematical and computer models from conservation biology to represent Neanderthal populations. And then let these populations undergo three processes that small populations are particularly vulnerable to: inbreeding, difficulties in mate-finding, and random fluctuations (in mortality and reproduction). “To our own surprise, we found that even if Neanderthals had been fully identical to modern humans, they faced, over time, a considerable risk of extinction, and this merely due to their small population size,” Vaesen added. This suggests that no invasion of another species, let alone a superior species, was needed for them to vanish from the face of the earth. Neanderthals might simply have been unfortunate to have lived in small numbers.
The population model showed that inbreeding alone was unlikely to have led to extinction which has happened only in the smallest model population. However, reproduction-related Allee effects through which 25 percent or fewer Neanderthal females gave birth within a given year (as is common in modern hunter-gatherers) could have caused extinction in populations of up to 1,000 individuals. In conjunction with demographic fluctuations, Allee effects plus inbreeding could have caused extinction across all population sizes modelled within the 10,000 years allotted.
Did Diet Play a Role in Neanderthal’s Extinction?
Neanderthals died out about 25,0000 years ago. Dan Vergano wrote in National Geographic: Conventional wisdom holds that boiling to soften food or render fat from bones may have been one of the advantages that allowed Homo sapiens to thrive, while Neanderthals died out.” [Source: Dan Vergano, National Geographic, April 30, 2014]
“Some researchers have suggested that the Neanderthals' meat-centric diet may have left them open to extinction when they were forced to compete for resources after other omnivorous early modern humans entered their territory, bringing more complex tools with them. [Source: Dan Vergano, National Geographic, June 25, 2014 |]
That story looks a little too simple now, even if Neanderthals did have a "meat-dominated" diet, according to the study. MIT geoarchaeologist Ainara Sistiaga, suggests that Neanderthal digestion worked with the help of bacteria similar to the ones at work in our own guts.The coprolites also revealed that the Neanderthals apparently had parasites, such as hookworms and pinworms, similar to the ones afflicting modern and other ancient people. We were told that people with [as] many parasites as we saw [in the samples] would be very sick’” |
Ruth Schuster wrote on haaretz.com, “Why the Neanderthals eventually went extinct is not known. They ate whatever herbivores they could catch, not only giant animals. But among the many theories is that their demise is related to the extinction of the megafauna, which disappeared just before they did, around 50,000 years ago. We don’t know precisely why the megafauna went extinct either but one postulation is that the climate changed in ways they found uncomfortable, and they were hunted to death. If so, that may have doomed the Neanderthals in their turn.” [Source: Ruth Schuster, haaretz.com, May 21, 2016]
Did Neanderthal’s Massive Eyes Play a Part in Their Extinction
Some scientists have theorized that Neanderthal’s massive eyes might have led to their demise. Neanderthals have larger eyes than modern humans. Based on this fact, Eiluned Pearce of the University of Oxford to suggest that their massive eyes meant that a large part of the Neanderthal’s brain was devoted to vision and body control, leaving less brain to deal with other functions, like developed social skills needed to survive in changing environments. [Source: Paul Jongko, Listverse, May 14, 2016]
Robin McKie wrote in The Guardian: “Eiluned Pearce and Robin Dunbar of Oxford University compared the skulls of 32 Homo sapiens and 13 Neanderthals, finding the latter had eye sockets that were significantly larger. These larger eyes were an adaptation to the long, dark nights and winters of Europe, they concluded, and would have required much larger visual processing areas in Neanderthal skulls. |=|
“By contrast, modern humans, from sunny Africa, had no need for this adaptation and instead they evolved frontal lobes, which are associated with high-level processing. "More of the Neanderthal brain appears to have been dedicated to vision and body control, leaving less brain to deal with other functions like social networking," Pearce told BBC News. |=|
Stringer said: "Neanderthal brains were as big as modern humans' but the former had bigger bodies. More of their brain cells would have been needed to control these larger bodies, on top of the added bits of cortex needed for their enhanced vision. That means they had less brain power available to them compared with modern humans." |=|
“Thus our ancestors possessed a fair bit of enhanced cerebral prowess, even though their brains were no bigger than Neanderthals'. How they used that extra brain power is a little trickier to assess, though most scientists believe it maintained complex, extended social networks. Developing an ability to speak complex language would have been a direct outcome, for example. |=|
Paul Jongko wrote for Listverse: “Not all scientists are convinced with Pearce’s theory and have even contradicted it. One of them is John Hawks of the University of Wisconsin-Madison. Together with his colleagues, Hawks examined 18 living primate species, and he discovered that “big eyes actually indicate bigger social groups.” Hawks asserts that the size of the eyes has nothing to do with the formation of social networks. Furthermore, he believes that the reason why Neanderthals had bigger eyes is that they were slightly larger than our ancient ancestors, and that their eyes had to be proportional to their bodies.”
Less Brain Space for Social Networking Killed the Neanderthals?
Robin McKie wrote in The Guardian: “Having extended networks of clans would have been a considerable advantage in Europe, which was then descending into another ice age. When times got hard for one group, help could be sought from another. Neanderthals would have less backup. This point is supported by studies of the flints used for Neanderthal tools. These are rarely found more than 30 miles from their source. By contrast, modern humans were setting up operations that saw implements transported 200 miles. |=|
“Cultural life became increasingly important for humans. Research by Tanya Smith of Harvard University recently revealed that modern human childhoods became longer than those of Neanderthals. By studying the teeth of Neanderthal children, she found they grew much more quickly than modern human children. The growth of teeth is linked to overall development and shows Neanderthals must have had a much reduced opportunity to learn from their parents and clan members. |=|
“"We moved from a primitive 'live fast and die young' strategy to a 'live slow and grow old' strategy and that has helped make humans one of the most successful organisms on the planet," said Smith. Thus Neanderthals – who already lived in sparse, small populations across Europe – were fundamentally ill-equipped to deal with the newcomers who had arrived from Africa. |=|
Pearce told AFP that “among living primates and humans, the size of an individual's social network is constrained by the size of specific brain areas, she said. The larger these areas are, the more connections an individual can maintain. The archaeological record seems to support the theory that Neanderthals were cognitively limited to smaller groups - they transported raw materials over shorter distances and rare finds of symbolic artefacts suggest a limited ability to trade. [Source: Mariette La Roux, AFP, March 13, 2013 \*//]
“The ability to organise a collective response would have been a key to survival when times turned harsh, like during the Ice Age, Pearce told AFP. "If Neanderthals knew fewer people in fewer neighbouring groups, this would have meant fewer sources of help in the event of, for example, local resource failure,'' she said. "Smaller groups are also more liable to demographic fluctuations, meaning a greater chance of a particular group dying out. Smaller groups are less able to maintain cultural knowledge, so innovations may be more likely to be lost. "Overall, if Neanderthals had smaller groups/social networks, this could have led to their extinction along a variety of pathways.'' \*//
Did a Volcanic Eruption in Italy Play a Part in Neanderthal Extinction
One idea that is not taken too seriously is that a volcanoic eruption in Italy — devastating eruption of the Campi Flegrei volcano west of Naples 39,000 years ago — played a part in the Neanderthal’s extinction Robin McKie wrote in The Guardian: Recent studies have shown this eruption was much more destructive than previously recognised. More than 60 cubic miles of ash were blasted into the atmosphere and covered a vast area of eastern Europe, North Africa and western Asia. This layer gives scientists a precise means of dating for this period and, combined with the new radiocarbon dating, shows there seem to be no Neanderthal sites anywhere in Europe 39,000 years ago, a date 10,000 years earlier than previous estimates. It is a significant shift in our thinking about our nearest evolutionary cousins. [Source: Robin McKie, The Guardian, June 2, 2013]
“Some researchers have even suggested that Campi Flegrei – the biggest volcanic eruption in Europe for more than 200,000 years – would have had a catastrophic impact. Vast plumes of ash would have blotted out the sun for months, or possibly years, and caused temperatures to plummet. Sulphur dioxide, fluoride and chloride emissions would have generated intense falls of acid rain. Neanderthals may simply have shivered and choked to death. |=|
“The Campi Flegrei eruption not only gives us a date for the Neanderthals' disappearance, it may provide us with the cause of their extinction, though Stringer sounds a note of caution. "Some researchers believe there is a link between the eruption and the Neanderthals' disappearance. But I doubt it," he said. "From the new radiocarbon dating and the work carried out by Reset scientists, it looks as if the Neanderthals had probably already vanished. A few may still have been hanging around, of course, and Campi Flegrei may have delivered the coup de grace. But it would be wrong to think the eruption was the main cause of the Neanderthals' demise."” |=|
Did an Inability to Hunt Rabbits Kill Off the Neanderthals?
The inability of Neanderthal to shift to hunting smaller prey such as rabbits after large mammals became extinct may have been what did the Neanderthals in. “There have been some studies that examined the importance of rabbit meat to hominins”—or early human ancestors—”but we give it a new twist,” said study lead author John Fa, a biologist at the United Kingdom’s Durrell Wildlife Conservation Trust and Imperial College London. “We show in our study that [modern humans] used rabbits extensively, but Neanderthals didn’t.” [Source: Ker Than, National Geographic, March 11, 2013 ^^]
Ker Than of National Geographic wrote: “Fa and his team analyzed animal bone remains spanning a period of 50,000 years from Neanderthal and modern-human-occupied sites across Iberia, the part of Europe that includes Spain and Portugal, and southern France. They found that rabbit remains only started to became common at sites around 30,000 years ago, which is around the time that Neanderthals started to disappear and—perhaps not coincidentally—when modern humans first arrived in Europe. The authors speculate that over the course of thousands of years, as climate change or human hunting pressure whittled down populations of Iberian large animals such as woolly mammoths, rabbits would have become an increasingly important food resource. ^^
“But Neanderthals may have been unable or unwilling to “prey shift” to smaller game, the authors argue in a new study, which will be published in an upcoming issue of the Journal of Human Evolution. “Neanderthals were large mammals hunters, par excellence,” Fa said, but they “could have found it difficult to hunt the smaller, but superabundant, rabbit.” John Shea, a paleoanthropologist at Stonybrook University in New York City who did was not involved in the research, agreed. Most people underestimate how hard it is to hunt rabbits, Shea said. “If I say, ‘Let’s go hunt a mammoth,’ you’ll probably think I’m nuts and that we’re going to die. But if I say, ‘Let’s go hunt rabbits,’ then it’s a piece of cake.” ^^
“In reality, the cost and benefits for Neanderthals would have been almost reversed, Shea said. “If you have the technology to kill a mammoth when you run into it”—as Neanderthals did—”then the risk is low and the return is high. Whereas with a rabbit, the cost in killing it is negligible, but the return is tiny.” ^^
Bruce Hardy, an anthropologist at Ohio’s Kenyon College, said he’s unconvinced. “I think the data is at a very gross level and they’re drawing implications from it that are quite frankly speculative,” said Hardy, who also did not participate in the research. Hardy also finds it difficult to imagine that Neanderthals couldn’t change their hunting strategies to target rabbits when they had thousands of years to do so, or turn to other food sources, such as plants. “If they were this inflexible, why did they make it for 250,000 years?” Hardy said. It’s like saying “‘Oh, the big animal are gone. I guess I’m going to starve now.’ That doesn’t make sense for any animal, not to mention a large-brained hominin that’s very closely related to us.” ^^
“But the Neanderthals’ longevity might have been irreversibly tied to the big game they hunted, Fa said, and once those prey items disappeared, our highly specialized cousins found it difficult to adapt. “We are not saying that small prey was not part of the diet,” he said. “What we are saying is that the Neanderthals could have specialized to such an extent that [it] did not allow them to use a superabundant but more difficult to catch food source.”“ ^^
Neanderthals Lacked the Weaponry, Technology and Strategy to Hunt Small Game
Ker Than of National Geographic wrote: “The piercing spears and clubs known to have been used by European Neanderthals weren’t very well suited for catching rabbits. In contrast, early modern humans used complex projectile weapons such as spear throwers and possibly bows and arrows—both of which are better for hunting small, fast-moving prey. There are other ways to catch rabbits, however. There is evidence that Neanderthals were capable of making string, so it’s very possible that they were able to weave nets and snares to use as traps, Shea said. [Source: Ker Than, National Geographic, March 11, 2013 ^^]
“But even if Neanderthals could make such traps, they still might not have done so because of the high startup costs involved. “There’s more time and energy involved in trapping than most people think,” Shea said. “You have to set a lot of them and monitor them, because once an animal is trapped, it becomes vulnerable to predation by rival carnivores.” The process could have been too demanding for Neanderthals, who likely had higher energy requirements than modern humans. Stockier and more muscular than humans, and lacking humans’ tailored clothes, scientists estimate that Neanderthals could have needed twice as many calories to survive and stay warm. ^^
“Fa and his team speculate that most of the rabbit hunting among early modern humans may have been done by women and children, who could have stayed behind in settlements while the men went on hunting trips for larger prey. The women and children “may have specialized in hunting rabbits, by surrounding warrens with nets or smoking the rabbits out of the warren,” Fa said. ^^
“Ancient rabbit hunters may also have had help from a four-legged ally picked up during their travels from Africa: dogs. The oldest fossil evidence for dogs is only about 12,000 years old, but there is genetic evidence suggesting dogs may have split from wolves as far back as 30,000 years ago-around the time that humans were arriving in Europe. “What we are saying is that this may have occurred,” Fa said. “The domestication of the dog for hunting purposes may have been a tremendous advantage for human hunters.” ^^
Image Sources: Wikimedia Commons
Text Sources: National Geographic, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Nature, Scientific American. Live Science, Discover magazine, Discovery News, Ancient Foods ancientfoods.wordpress.com ; Times of London, Natural History magazine, Archaeology magazine, The New Yorker, Time, Newsweek, BBC, The Guardian, Reuters, AP, AFP, and various books and other publications.
Last updated April 2024