I have read (most recently in a GQ thread today) that large land mammals in the Americas disappeared around the time that Homo Sapiens invaded the Americas. Coincidence? Probably not. But if not, how is it that large land mammals like the elephant and the giraffe survived in africa, which is where humans originally evolved?
The easy, and likely to be incomplete answer, is that they knew us from the start and therefore never trusted us as far as they could spit.
Same reason the native population mostly died off when Europeans came over, while the Europeans didn’t? The Europeans had time to get used to bugs (i.e. by repeatedly having a good chunk of their population die off), while the Americans didn’t.
So I think the large land mammals in Africa grew up with the increasing sophistication of humans and over the span of hundreds of thousands were able to cope with it.
Of course, there are plenty of other theories about animals in the Americas. They include the possibility of an asteroid impact while ice sheets were covering the ground.
The coincidence of the animals dying as humans arrive might be more than just a coincidence, but it could be that humans just pushed already stressed populations over the edge. That’s a different idea scenario than hunting healthy otherwise healthy populations into extinction, especially when a sizable number of large native mammals (bison, elk, etc.) did survive.
This is one of the biggest questions in the extinction of megafauna throughout much of the world over the past few ten thousands of years. Elsewhere extinction of the megafauna - in Australia, in the Americas, in New Zealand, in Madagascar - followed the arrival of humans, rather than being correlated with any similar environmental change. Only in Africa did much of the megafauna survive. The best guess so far is that because these animals had evolved together with humans and human ancestors for millions of years, they were better adapted to be able to survive in contact with us.
However, given the nearly global extent of the extinctions, it is necessary to look for causes that apply to all areas. The extinction in Australia took place about 20,000 years before that in the Americas, that in Madagascar and New Zealand took place about 10,000 years later. There was no common climatic or other change to link these areas; the only commonality is that the extinction followed the arrival of modern humans.
Rhinos and Tigers survived in Asia long after humans dropped by. In North America, Buffalo, Grizzly Bears, Alligator Snapping Turtles, Alligators, Crocodiles, and Condors survived long after humans arrived. It seems to be Europeans in particular who are associated with the extinction of large animals around the world.
Absolute racist nonsense.
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Outside Europe, Europeans have been responsible for the extinction of just a handful of large animals. At least 95% of the large mammal species were exterminated by the original human settlers.
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Bison, aurochs, lions, bears and golden eagles all survived in Europe long after humans arrived too. What significance do you think that has? Nobody ever asked why humans killed off all the megafauna (although they did in New Zealand and Madagascar and came within a hair’s breadth in Australia and New Guinea). The question was why so much of the megafauna survived in Africa.
question - did that surviving megafauna survive north of the equatorial jungle or only south of it? Because, AFAIK, people got across the Congo region relatively recently. So, maybe they just didn’t have enough time for the hunting?
Also, do deer, elks, wolves and bears in medieval and modern Europe qualify as megafauna? And why should possible extinction of tigers be considered a bigger deal than the survival of European bears?
Both, but primarily south.
But according to this we would expect there to be fewer megafaunal species in southern Africa, and we actually find more.
There’s no strict definition, but megafauna is commonly defined as those species larger than human sized.
I don’t know, why should it?
In addition to the possibility of human-driven extinction, there’s the fact that Eurasia and North America were hit by the ice ages much more severely than Africa and India. Having to cope with a rapidly changing (on a geologic/evolutionary timescale) environment couldn’t have made things any easier for megafauna species. For example, in addition to human hunting the Wooly Mammoth might have been finished off by the end of the ice age climate they were adapted to.
why should there be fewer species there if humans came there only recently? The migration is believed to have been north to south.
In addition, the population density in many areas of Southern Africa has been and still is low even in recent times. Is there lots of megafauna running around the densely populated Nigeria or the Great Lakes region?
Not really. The genus Homo arose in southern Africa and migrated North. I assumed that was what you were talking about.
We have no idea where H. sapiens sapiens evolved, if that’s what you mean, just “somewhere in Africa”. The evidence is far to scanty and we travel way too fast to say precisely where. Even if a North African origin is posited, it would be NE Africa, so there’s no reason to cross the Congo to get to southern Africa from NE Africa. We were certainly in South Africa by 90, 000 year ago at the very latest, so it’s hard to argue that this was “relatively recent” compared to an species origin of just 140, 000 years ago. IOW we’ve spent at least 2/3 of our existence in southern Africa.
Are you arguing that, pre-agriculture, Southern Africa was less densely populated than Australia or South America? I would need to see some evidence to believe such an extraordinary claim.
See above.
I don’t know about the “genus Homo”, but the Bantu and derived groups spread out from north-west of the Congo and eventually reached the Cape in the south Bantu expansion - Wikipedia. Meanwhile, while there was some pre-Bantu population in Southern Africa (ancestors of the Khoisan) maybe that population wasn’t very adept at hunting the megafauna. They certainly weren’t adept at dealing with the newcomers taking away their land and driving them into the desert…
Good question about continental comparisons. For that matter, I wonder if there was any pre-agriculture time in Southern Africa in the first place instead of the migration consisting of agriculturalists. And be that as it may, the ancestors of Zulu and Xhosa etc apparently were not so good at extinction hunting 
The Bantu were long established agriculturalists, and the expansion occurred many, many thousands of years after megafauna were exterminated
Some population? Hundreds of thousands.
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This was a clash between agriculturalists with more efficient crops and those without. Nothing to do with efficiency or intelligence.
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Are you arguing that the Khoi people suffered worse at the hands of invaders than the peoples of Australia or America, who did exterminate most of their megafauna?
Are you seriously arguing that the people of southern Africa may have invented agriculture 80, 000 years before anybody else, and kept it a secret and managed to hide any archaeological evidence of it?
That doesn’t seem very… likely.
Which is completely circular. We are attempting to explain why humans didn’t hunt animals to extinction in Africa. Pointing out that the groups living in Africa didn’t hunt animals to extinction is hardly explanatory.
Sorry, I wasn’t being serious with that comment.
I was serious in pointing out the arbitrary claim that fewer megafauna were killed by humans in Africa than other places. There were plenty of megafauna around the world that weren’t exterminated by humans before the invention of gunpowder. And there were megafauna that became extinct in Africa. Sivatherium was depicted in rock paintings 8000 years ago. The OP makes and assumption that doesn’t consider the number of species, species population, and the environmental capacity to support those populations, including the humans. Its not clear to me that the situation in Africa was any different that the rest of the world based on those factors.
It’s not arbitrary. It’s well established that a greater percentage of the megafauna survived in Africa than did in Australia or the Americas. (Some megafauna also survived in South Asia, but not as much as in Africa).
From Wiki:
The Americas once had several species of mammoths, several kinds of mastodonts, many species of giant ground sloths, glyptodonts, toxodonts, liptoterns, camels, llamas, various species of horses, sabretooth cats of several kinds, lions, cheetah-like cats, short faced bears, and an array of large hoofed mammals. Australia had diprotodonts, giant kangaroos, a marsupial “lion,” several other big types of marsupials, and giant lizards. Madagascar had an array of lemurs, some the size of a gorilla.
Very, very few actually, compared to what there once were. And very few species of megafauna that survived the earlier event were driven to extinction after the advent of guns (although many were reduced to low levels).
That just counts the number of species. The population sizes aren’t well established, and not all of the continents had the capacity to support the populations that existed in Africa. Humans may have killed megafauna at the same rate world-wide, and ended up with same situation. And without humans, the rate of extinctions for megafauna may have stayed the same as well. Where is the evidence that the number of species and population sizes was based on anything but the capacity of the environmental niche to support them, humans or not?
The number of species is so extremely disproportionate that it’s certain that there was a real difference.
Cite? There is no reason to believe that the capacity of the other continents to support megafauna was any less than it was in Africa (except perhaps in Australia, which had a lower diversity of climate and terrain, though Blake may be better able to address that issue.). There are a great number of fossil remains from North America at least; many species were widespread over the entire continent and apparently occurred in large numbers. There is every reason to believe that North America was very much like Africa in the number of big game species it supported, and that their populations were large.
Ridiculous. There is nothing in the ecology of Africa vs the rest of the world that would cause its populations of megafauna to be so wildly more numerous to account for the difference.
Without humans, there seems to have been comparatively little extinction of megafauna at all, anywhere.
Where is your evidence that carrying capacities were so extremely different? In North America, the huge numbers of bison on the Great Plains when Europeans arrived show that the area was capable of supporting megafauna in enormous numbers; it’s just that in the Pleistocene its diversity was much much higher (as it is in Africa today). In South America, the Pampas at one time had huge herds of feral cattle and horses that were introduced by the Spanish; these areas as well could support large numbers of megafauna.