# What caused the Pleistocene/Holocene extinction? Human hunters, or climate change? **URL:** \ **Category:** Great Debates\ **Created:** [April 20, 2006, 12:32am UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398 "2006-04-20T00:32:00Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [April 20, 2006, 10:41pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/21 "2006-04-20T22:41:53Z")
> [@Ale](#): > > It would be a compelling case to the (mostly) human caused extintion if it can be stablished that a sizable proportion of the extinct animals fit within the group of animals humans hunted; mammoths, some species of large deer and moas fit the bill in that aspect. This is the case. There is evidence for hunting of many of the extinct species; and most of them would have been expected to be game animals anyway, being large herbivores. In the case of the carnivores that became extinct, like Sabre-toothed Cats, it is postulated that they may have either been killed directly, as threats or competitors, or become extinct after humans had killed off their prey base. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [April 20, 2006, 10:44pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/22 "2006-04-20T22:44:12Z")
> [@spoke-](#): > > And the same point could be made about mammoths, which also were surprisingly adaptable. Their remains have been found as far south as [Guatemala](http://www.unesco.org/culture/latinamerica/html_eng/chapter12/chapter4.htm), which would have been warm and lush even during glacial periods. And there were several other species of elephants, the gomphotheres (a kind of mastodont), in South America. They were known to be hunted by Paleoindians. ---
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [April 22, 2006, 12:42pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/23 "2006-04-22T12:42:58Z")
> [@Colibri](#): > > Your conclusion seems to be the opposite of what the evidence suggest. If horses can survive in a variety of climates, and if they today can thrive in an area where they were formerly wiped out (the western US), then how could climate change have caused their extinction? One would think that some other factor must have been involved. > > This has been proposed, but there is little evidence for it, and it seems unlikely due to the taxonomic diversity of animals involved (which included not only a great variety of mammals but also large birds and reptiles). Excuse me, but are horses easily hunted? I can understand slow lumbering animals like the mammoths becoming prey for humans (likewise the giant sloths). But horses are fast, and naturally wary animals. I don’t see how a few bands of humans, equipped with stoneheaded spears, could actually hunt and kill enough horses to wipe them out. ---
**Author:** ![E-Sabbath](https://avatars.discourse-cdn.com/v4/letter/e/e19adc/32.png) [@E-Sabbath](https://boards.straightdope.com/u/E-Sabbath)\ **Post date:** [April 22, 2006, 1:53pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/24 "2006-04-22T13:53:50Z")
Humans have three advantages over most other animals. First, the brain. Second, the hands. Third, the ability to run, for long distances, longer than any other animal can or will. Horses can run faster, but humans can, in fact, eventually run them into the ground. ---
**Author:** ![bittersweet](https://avatars.discourse-cdn.com/v4/letter/b/c57346/32.png) [@bittersweet](https://boards.straightdope.com/u/bittersweet)\ **Post date:** [April 22, 2006, 1:58pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/25 "2006-04-22T13:58:28Z")
Actually, it was my fault. So was Chernobyl. Sorry. I won’t do it again. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [April 22, 2006, 5:36pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/26 "2006-04-22T17:36:50Z")
> [@E-Sabbath](#): > > Humans have three advantages over most other animals. > > First, the brain. > > Second, the hands. > > Third, the ability to run, for long distances, longer than any other animal can or will. > > Horses can run faster, but humans can, in fact, eventually run them into the ground. While cursorial hunting should work against horses, I’d think that it would be more effective to use the sorts of techniques that Plains Indians used on bison, which are also much faster than humans: chase herds into makeshift corrals or over steep drops, and then kill them. ---
**Author:** ![holmes](https://avatars.discourse-cdn.com/v4/letter/h/e95f7d/32.png) [@holmes](https://boards.straightdope.com/u/holmes)\ **Post date:** [April 22, 2006, 5:55pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/27 "2006-04-22T17:55:04Z")
The thing I never understood about the run 'em off a cliff technique is, wouldn’t you end up with a lot game you couldn’t eat and would end up rotting? It would seem to be a waste of potential game to me. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [April 22, 2006, 6:29pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/28 "2006-04-22T18:29:53Z")
> [@holmes](#): > > The thing I never understood about the run 'em off a cliff technique is, wouldn’t you end up with a lot game you couldn’t eat and would end up rotting? It would seem to be a waste of potential game to me. So? If it’s the easiest way to hunt, that’s what people are going to do. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [April 22, 2006, 6:31pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/29 "2006-04-22T18:31:49Z")
The drops I’ve seen aren’t actually cliffs, just steep embankments. (That’s not particularly important, just thought I’d share.) As for the wastefulness: 1. So? Stone age hunter-gatherers aren’t conservationists. Why would they care if a lot of carcasses rotted? 2. Yes, exactly. You’re not going to manage to overhunt a species to the point of extinction without putting a little effort into it. 3. Not so much as you’d think. First you gorge yourself for a week, eating everything your digestive system can handle before the meat turns. And second, the Plains Indians at least preserved a lot of the meat. They dried it and made it into pemmican, a mix of dried meat and berries which could be stored for months. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [April 22, 2006, 6:46pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/30 "2006-04-22T18:46:47Z")
> [@Gorsnak](#): > > 1. Not so much as you’d think. First you gorge yourself for a week, eating everything your digestive system can handle before the meat turns. And second, the Plains Indians at least preserved a lot of the meat. They dried it and made it into pemmican, a mix of dried meat and berries which could be stored for months. I’d be wary about drawing behavioral conclusions about paleo-Indians from observed behaviors of groups like the Plains Indians. Most of what we know about the latter comes from a time when they adopted the use of horses, which only happened after the arrival of the Spanish. That altered their culture tremedously. But even before that, we would expect the Plains Indians to be technolgically advanced compared to paleo-Indians and for their bands/tribes to be larger. Some estimates for the pre-1492 popluation of the New World put it as large as 100M people. I can’t imagine that the population was even 1/10 that size 12,000 years ago, and probably not even 1/100. ---
**Author:** ![holmes](https://avatars.discourse-cdn.com/v4/letter/h/e95f7d/32.png) [@holmes](https://boards.straightdope.com/u/holmes)\ **Post date:** [April 22, 2006, 6:56pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/31 "2006-04-22T18:56:26Z")
> [@John Mace](#): > > So? If it’s the easiest way to hunt, that’s what people are going to do. I guess this is a hijack of sort, but the easiest way to hunt, means no more game tomorrow. I don’t know what the intelligence level was, but common sense would tell you; 50 rotting hunks of meat today, is 50 less hunks of good meat tomorrow. And I guess that’s what happened… ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [April 22, 2006, 7:03pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/32 "2006-04-22T19:03:48Z")
> [@holmes](#): > > I guess this is a hijack of sort, but the easiest way to hunt, means no more game tomorrow. I don’t know what the intelligence level was, but common sense would tell you; 50 rotting hunks of meat today, is 50 less hunks of good meat tomorrow. Depends on the size of the herds and how many people there are (two things that paleo-Indians probably had no way of knowing). Plus, we really don’t know how widely used that hunting technique was. > [@](#): > > And I guess that’s what happened… Not really. It’s one competing hypothesis. I doubt we’ll ever know with any degree of certainty about what caused something to happen 10,000 years ago. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [April 22, 2006, 7:17pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/33 "2006-04-22T19:17:18Z")
> [@John Mace](#): > > I’d be wary about drawing behavioral conclusions about paleo-Indians from observed behaviors of groups like the Plains Indians. Most of what we know about the latter comes from a time when they adopted the use of horses, which only happened after the arrival of the Spanish. That altered their culture tremedously. But even before that, we would expect the Plains Indians to be technolgically advanced compared to paleo-Indians and for their bands/tribes to be larger. Some estimates for the pre-1492 popluation of the New World put it as large as 100M people. I can’t imagine that the population was even 1/10 that size 12,000 years ago, and probably not even 1/100. Well sure. I believe we know that the making of pemmican considerably pre-dated contact with Europeans, though. It’s not like cutting buffalo up into thin strips and leaving it in the sun is particularly high-tech. And I agree that we can’t conclude anything about the behaviour of paleo-Indians from their millenia-removed descendants. I do think, however, that it’s reasonable to expect that paleo-Indians would have attempted to get as much use out of their kills as possible, and that would include forms of preservation if they had figured out how to do so (which, admittedly, they might not have). In any event, I was more answering **holmes** ’s question, “Isn’t running bison off a cliff wasteful?” For the pre-horse Plains cultures that we know in reasonable detail, it wasn’t. On the other hand, hypothesizing the use of drops by paleo-Indians to hunt horses is pure speculation on my part to begin with. I was just pointing out that using drops, along with using “pounds” (those would be the makeshift corrals) are techniques that we know were used to hunt bison in pre-horse Plains cultures, and that would have been far more efficient means of hunting horses than the cursorial technique suggested by **E-Sabbath**. ---
**Author:** ![E-Sabbath](https://avatars.discourse-cdn.com/v4/letter/e/e19adc/32.png) [@E-Sabbath](https://boards.straightdope.com/u/E-Sabbath)\ **Post date:** [April 22, 2006, 8:13pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/34 "2006-04-22T20:13:35Z")
Of course it was. That’s using your brain. The cursorial technique that I mentioned is simply worth noting for the fact that, given nothing but your bare hands, you can run a horse to death and kill and eat it. Everything after that, such as pack hunting, spears, intelligent use of terrain, simply makes it easier. Ralph wasn’t aware that such a technique existed. According to Wikipedia, wolves and hyenas also can do this. Which _can_ explain part of why we hunt with dogs, they can keep up with us… over the long term. It makes more intuitive sense with what I know about animals to visualize wolves chasing a deer to death, for example, but humans can do it too, and just as well to a horse. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [April 22, 2006, 8:41pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/35 "2006-04-22T20:41:17Z")
> [@ralph124c](#): > > Excuse me, but are horses easily hunted? I can understand slow lumbering animals like the mammoths becoming prey for humans (likewise the giant sloths). But horses are fast, and naturally wary animals. I don’t see how a few bands of humans, equipped with stoneheaded spears, could actually hunt and kill enough horses to wipe them out. Horses were certainly hunted by stone-age hunters in Europe: From [here](http://www.carnegiemnh.org/anthro/olsen_horse.html) > [@](#): > > Horses were hunted for their meat, skin, and bones in many areas of Eurasia by modern humans during the Ice Age. Some strategies of horse hunting have been recreated through a long-term study of the Upper Paleolithic site of Solutré, in east-central France, where over 30,000 horses were killed between 32,000 and 12,000 years ago (see Selected Publications). Local topography, modern wild and feral horse behavior, the horse remains and available prehistoric technology were examined. From these various lines of evidence it has been possible to reconstruct the likely scenario that occurred on repeated occasions at Solutré. During their spring and autumn migrations between the Saône River floodplain and the foothills of the Massif Central, bands of wild horses were detoured into a natural corral created by a cul-de-sac in the cliff face of the Roche du Solutré. There they were ambushed and dispatched with spears. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [April 24, 2006, 10:46pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/36 "2006-04-24T22:46:47Z")
> [@BrainGlutton](#): > > Between 13,000 and 9,000 years ago, a great many “megafauna” – large mammals – went extinct all over the world. That simply isn’t true. The first of the great megafaunal extinctions occurred in Australia and New Guinea and was complete by 30, 000 ybp. All terrestrial animals weighing over 200kg became extinct and something in the order of 90% of species weighing over 50kg became extinct. The list of animals eliminated included giant kangaroos, giant tortoises, giant snakes, flightless birds and gigantic wombat type grazers. The last of the great megafaunal extinctions occurred in New Zealand and was completed within the last 500 years, probably as recently as 250 ybp. All animals weighing over 50kg became extinct. The list of species eliminated included giant flightless birds, amphibians and reptiles. In between those two dates we have a series of other extinction events in New Caledonia, Madagascar, the Americas and so forth. It is the extreme length of the extinction period that is most compelling for implicating humans. Had all the events occurred over just 4000 years as you claim then the debate would be firmly settled in favour of climate change, with the human involvement being minimal to non existent. After all humans had been living in Australia for over 20, 000 years by the dates you suggest, and people hadn’t even arrived in Madagascar or New Zealand. In the former case we would have to conclude that if humans practices hadn’t eliminated those species previously then they couldn’t be blamed for an event that coincided with similar extinctions elsewhere. In the latter then of course humans couldn’t be blamed because humans didn’t exist. But the truth is that the extinction events were spread over a period of 30, 000 years, not 4000 years as you suggest. That makes climate change much harder to justify. Now we not only have to justify why the last warming event had such a dramatic effect, we have to justify why a whole series of events had such a dramatic effect. The extinctions in the Americas coincided with a period of warming and increasing precipitation associated with the end of the ice age. In Australia and New Guinea with a period of cooling and drying associated with the onset of the last ice age. In Madagascar with a period of increasing climate variability. In New Zealand with a period of minor cooling associated with the Little Ice Age. And so on and so forth for various landmasses. Those facts are highly problematic for any climatic explanation. Not only weren’t the recent glaciation and de-glaciation events in any way unusual but any climate change hypothesis has to also explain why these events occurred in such a diversity of climate transitions. Hotter, cooler, wetter, dryer, more variable generally and so forth. New Zealand and Madagascar being particular difficult to explain via climate change because in both locations the events occurred in periods of relative climatic stability and acted on suites of species that had just managed to survive the ice age. It’s kind of hard to argue that a dozen moa species weathered the real ice age of 10, 000 ybp but succumbed to the little ice age 500 ybp. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [April 24, 2006, 11:15pm UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/37 "2006-04-24T23:15:50Z")
> [@Barnosky courtsesy of Colibri](#): > > The recent information now points toward humans precipitating the extinction, but also to an instrumental role for late Pleistocene climatic change in controlling its timing, geographic details, and perhaps magnitude. While the process is doubtless complex I fail to see any practical distinction between “humans precipitated the extinctions with the timing and extent dictated by climate” and “humans caused the extinction”. I’ve really never understood those who try to adopt such a position position as though somehow mitigating the role of humans. Basically what it comes down to is that these suites of species had weathered worse climate changes before and survived. Then humans come along and apply so much pressure to them that the next climate change exterminated them. That may well be the case, but the practical upshot is that the extinctions are 100% attributable to humans. If humans hadn’t altered the environment and applied so much hunting pressure that these species couldn’t migrate or otherwise tolerate the losses that climate change wrought then they would still be with us. The humans may not have literally speared the last individual but it was human action that eliminated them. > [@Ale](#): > > It would be a compelling case to the (mostly) human caused extintion if it can be stablished that a sizable proportion of the extinct animals fit within the group of animals humans hunted; mammoths, some species of large deer and moas fit the bill in that aspect. That is indeed the case. Giant tortoises, moas, pygmy hippos, bison and so forth would all be considered prime game animals. > [@](#): > > My take on this is that humans and animals at the end of the glaciar period were put on a fragile situation, humans had the edge (more than often the silex edge of a spear) to survive under uncertain conditions by preying on the large mammals at hand. The ecologically strained stocks of megafauna just needed a little poke to spiral into extinction. The problem is that the extinctions didn’t occur at the end of the last glacial. That is only true of the Americas, and really only true of North America. In the rest of the world the extinctions occurred at the beginning of the last glacial or well after the last glacial had ended. > [@ralph124c](#): > > Excuse me, but are horses easily hunted? I can understand slow lumbering animals like the mammoths becoming prey for humans (likewise the giant sloths). But horses are fast, and naturally wary animals. I don’t see how a few bands of humans, equipped with stoneheaded spears, could actually hunt and kill enough horses to wipe them out. One point is often overlooked in these arguments is that animals do not have any natural fear of humans. Anywhere in the world where animals have never seen a human predator they show absolutely no fear of humans. People can simply walk up to them and hit them on the head. There is no reason to assume this wasn’t equally true of horses in the Americas. This point really doesn’t get stressed enough in these debates. Humans in naïve ecosystems are formidable predators because we simply don’t look or move like predators. Animals have never learned to fear us Under those circumstances humans can wreak havok and worse still they become extremely wasteful. Buffalo or moa are slaughtered and only the prime cuts taken, with the rest of the carcasse left to rot. Under those conditions human populations soar and the hunting pressure on the animals is massive. How much damage would a tribe of 20 people do to a herd of horses if every morning you could simply walk up to the herd and spear one for breakfast? It’s not inconceivable that even a small band of humans would exterminate naïve horses as readily as they exterminated other naïve animal populations. Speed is only an advantage of the animal knows to run away. ---
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [April 25, 2006, 12:22am UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/38 "2006-04-25T00:22:20Z")
I saw a skeleton of one at the Harvard Museum of NH-weird! Those things were like tanks…were they wiped out by humans? And, how come humans never wiped out the African elephant? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [April 25, 2006, 12:27am UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/39 "2006-04-25T00:27:43Z")
> [@Blake](#): > > While the process is doubtless complex I fail to see any practical distinction between “humans precipitated the extinctions with the timing and extent dictated by climate” and “humans caused the extinction”. I’ve really never understood those who try to adopt such a position position as though somehow mitigating the role of humans. I agree with you on that. I should perhaps have been more explicit in my first few posts that the key factor was humans, with climate being involved mainly in determining some of the regional details. One scenario, however, that has not been confirmed is Paul Martin’s extreme “blitzkrieg” hypothesis for the extinction event in the Americas due to the rapid expansion of Clovis hunters. It’s now pretty well established that the human presence in the Americas predates Clovis, and that humans co-existed with the megafauna for longer than had initially been supposed. The process may have been “sitzkrieg” (attrition) rather than blitzkrieg. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [April 25, 2006, 1:09am UTC](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398/40 "2006-04-25T01:09:16Z")
> [@ralph124c](#): > > What Wiped Out the Glyptodons? I saw a skeleton of one at the Harvard Museum of NH-weird! Those things were like tanks…were they wiped out by humans? It’s impossible to say, but humans doubtless hunted them. It’s interesting how closely the glyptodonts parallel the horned turtles of Australasia in size, diet and form, all the way down to the spiked tail. Both groups seem to have filled the same ecological niche and in both cases they vanished very shortly after human contact which suggests human involvement. The thing is that being built like a tank is a great defence against lions or wolves, but for humans it simply makes the species a type of canned food. Even assuming the defensive form is largely impregnable if the species refuses to move they will simply be boiled in their own shells. If the do move they will have their eyes or joints attacked. Either way they are going to die. > [@](#): > > And, how come humans never wiped out the African elephant? Humans did wipe out at least one species of African elephant and almost certainly exterminated several species of Asian and European elephants. Only three species of elephants remain. Once again the point to realise is that African and Asian species had evolved along with our species. African species had been defending against hominids from inception and as a result relatively few African species fell, and the extinction rate was necessarily slow as the species were locked in an evolutionary arms race with humans and only vanished after they lost the race. Meanwhile Asian species were confronted with _Homo erectus_ which had limited intelligence and an even more limited tool kit. Erectus does seem to have caused the loss or serious population decline in some Asian species, including several elephant species. Nonetheless Asian species came to know that hominids were predators and a personal threat before hominids could cause widespread extinctions. In contrast when _H. sapiens_ swept into parts of island Asia and later to Australia, Madagascar and the Americas they were fully evolved with modern intelligence and adaptability and a largely modern toolkit and were themselves largely free of the diseases and predators they had evolved with in Africa. As a result humans hit those places hard and reproduced fast and to large extent the species simply couldn’t cope. African elephants meanwhile simply continued to evolve side by side with humans as they always had done. There was no shock of initial contact, no need to cope with human numbers swollen from an abundance of new resources or lack of disease and predators. One interesting side note is that in other parts of the world animal tend to dwarf after human contact. Moose, kangaroos and kiwis to name just a few all shrank dramatically after humans arrived. This is presumably because human hunters favoured the largest individuals when making a kill. In contrast African elephants and buffalo and perhaps a few other species all seem to have increased in size in response to hunting. That once again suggests that having evolved alongside the humans as humans were inventing hunting skills the larger more aggressive animals were favoured because they could see off a less efficient hunter. In contrast naïve species simply couldn’t hope to deal with fully evolved humans in that manner. [Previous page](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398.md?page=1) [Next page](https://boards.straightdope.com/t/what-caused-the-pleistocene-holocene-extinction-human-hunters-or-climate-change/353398.md?page=3)