This seems so dashed…plausible; many thanks for all the answers. Which were the humans, then, predators or prey? And what form did their evolution take in response to this arms race - purely cultural, such as learning better hunting or hiding techniques, or did being at the sharp end of nature affect brain evolution itself? Was skulking in the undergrowth or chasing things with pointy sticks selected for?
Geez John, the best ya got is that I said “millions” and you said “2 million”? Isn’t “2” a plural? Or are you betting the farm on “just under” 2 million. Darn, I mightly have slightly exageerated on a side note. Big whoop. Wiki sez "around 2.0 million years ".
:rolleyes:
*We don’t know. * There are several “major factors”, two are amoung the most important.
Note that I value your opinion and thoughts, and I really have no idea of why you are going off on me here. So tell ya what John, this is GQ, and not the PIT, thus your personal remarks aren’t appreciated, so let’s keep it to the fact, not opinions OK?
So again, here are my cites:
http://www.blackwell-synergy.com/doi/abs/10.1046/j.1466-822X.1998.00285.x?journalCode=geb
Do you think Drs. DAVID CHOQUENOT & D. M. J. S. BOWMAN are wrong, and what cites do you have to support your opinion?
http://www.pnas.org/cgi/content/abstract/99/23/14624
I]Do you think Drs. Barry W. Brook, and David M. J. S. Bowman are wrong, and what cites do you have to support your opinion?*
http://www.sciencemag.org/cgi/content/abstract/306/5693/70
Do you think Drs. Anthony D. Barnosky, Paul L. Koch, Robert S. Feranec, Scott L. Wing, & Alan B. Shabel are wrong, and what cites do you have to support your opinion?
Do you think Drs. Grayson & Meltzer are wrong, and what cites do you have to support your opinion?
Note that this last cite comes with 93 footnotes!
Have you even read those cites?
And while I am in awe of Colibri, somehow I doubt even he will say that "Drs. DAVID CHOQUENOT, D. M. J. S. BOWMAN, Barry W. Brook, Anthony D. Barnosky, Paul L. Koch, Robert S. Feranec, Scott L. Wing, Alan B. Shabel, Grayson & Meltzer " are all wrong and he is right. But he doesn’t say so, he more or less agrees with them. The difference is in degree, and there what we have is- from the experts- “Alternatively, climate change in the late Pleistocene may have played an important role in the extinction of Australian megafauna”, "Contrary to recent claims, the existing data do not prove the “blitzkrieg” model of overkill. " and "Firmer chronologies, more realistic ecological models, and regional paleoecological insights still are needed to understand details of the worldwide extinction pattern and the population dynamics of the species involved. "
I am not arguing opinions here in GD, Thems the facts, debate them, not me. OK?
You’re right! My bad, Dr. Deth.
DD: However, I still don’t think you’re reaching the same conclusion. Correct me if I’m wrong, but you seem to be saying that humans were not the major cause of any mass extinctions that were seen in the late Pleistocene:
That certainly cannot be said to characterized the conclusions reached in the thread I referenced. In fact, quite the contrary the contrary-- that in many instances the evidence points most strongly to human hunting as the major cause, with climate change playing only a minor role.
No John. Martin’s Overkill/Blitzkrieg hypothesis claims humans were **THE ** single cause. (and I read Princhester & robby posts as agreeing with this.) I said, humans were **a ** major cause.
My quote there was just paraphrasing what Drs. Grayson & Meltzer said: "The arguements that human hunters were responsible for the extintion of a wide variety of large Pleistocene mammals emerged in Western Europe during the 1860’s… Today the overkill position is rejected for wetsern Europe but lives on in Austrailia and North America. The survival of this hypothesis is due almost entirely to Paul Martin… In North America, archaeologists and paleotologist whose work focuses on the late Pleistocene routinely reject Martin’s postiion for two prime reasons: there is virtually no evidence that supports it, and there is a remarkably broad set of evidence that strongly suggests that it is wrong. In response, Martin asserts that the overkil model predicts a lack of supporting evidence, thus turning the absences of empirical support into support for his beliefs. We suggest that this feature of the overkill position removes the hypothesis from the realm of science and places it squarely in the realm of faith. One may or may not believe in the overkill position, but one should not confuse it with a scientific hypothesis about the nature of the North American past." Am I out of line by paraphrasing this as “In other words, you can believe in Overkill/Blitzkrieg just like you can believe in God or the Invisible Pink Unicorn. There is no scientific evidence for any of them.”?
Overkill/Blitzkrieg (being a single source reason for the extinctions) is wrong, according to my sources, and according to Colibri, if I read his posts correctly.
I concur and have stated three times that humans were **a ** major cause. None of my cites goes so far as to be certain who or what was **THE ** major cause. I am not certain either. I suppose it could have been humans, but there doesn’t seem to be any good way of finding out for sure. All I am saying is that humans were not the only cause.
Oh, and one more thing. There is a very large gap between humans being a cause of the extinctions, and human hunting being a cause. Humans have two weapons in their “arsenal of extinction” that are far more potent than a flint spear- introduced species (and the attendant diseases) and habitat change/destruction. In fact, IMHO our “little freind” 
Rattus sp has caused more actual extinctions that us humans with puny spears clutched in our opposable thumbed hands. Of course, when H.Sapiens introduces Rattus, the forthcoming extinctions can be laid at our feet. My only “excuse” is the rather feeble “um, err, Rattus has been known to travel on it’s own, and err, umm, we didn’t mean to”. In fact, I personaly doubt if human *hunting * was a major cause (and that’s just an opinion, not back by much at all). But I have no doubt that humans certainly were.
*Even stone-age humans have been known to cause significant changes/destruction in habitats/the environment.
That was the only one in this thread. And the timeframe is not the only issue with that statement, because these extinctions have nothing to do with H.erectus, and H. sapiens did not enter Asia until 50k years ago (disregarding the small excursion made into the Levant about 100k years ago).
Well, of course there is no factual answer to that question, and so there is going to be a debate. I’m referencing the reader to the GD thread we did have the debate, and I’ve already quoted the conclusion, which are not the same as the ones you’ve been stating in this thread. Perhaps you’ve stated them poorly, or I’m reading them incorrectly. I’ll just leave the GD thread reference and let the reader judge for himself/herself.
Well, earlier posters claimed that there were lots of large mammal species in Africa "Princhester: When two species (predator and potential prey) evolve together, they fight an evolutionary arms race that tends to balance. You evolve a slightly better offensive mechanism, I evolve a slightly better defensive mechanism and so on.
Humans and big mammals “grew up together” in Africa.
However, where one predator which has evolved really good offensive mechanism moves to an entirely new area, it may come across prey that are a total mismatch.
Hence the big mammals in areas where humans moved late got hammered."
I assumed Princhester wasn’t limiting “humans” to H.Sapiens, as some 200K years isn’t a lot of time for species to get used to each other like he claimed. I was assuming humans meant all Homo sp, which have been around for some 10X longer, and their ancestors even longer.
John- do you have any refutations to my cites? Or do you concede them as valid?
The Aurochs? We came damned close with the North American Bison… Barbary Lion? The thylacine?
How about:
Alaska Muskox (last one shot 1865) Admittedly, some of these (but not all) appear to be subspecies. For example, musk oxen still exist.
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/AKMuskox.htm
Dawson Caribou (hunted to extinction with firearms in early 1900’s ).
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/DawCarib.htm
Newfoundland Wolf (last one shot 1911)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/NewfWolf.htm
Oregon Bison (1840’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/OreBison.htm
Arizona Wapiti (last one shot 1907)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/AZWapiti.htm
Eastern Woodland Bison (early 1800’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/EstBison.htm
Badlands Bighorn Sheep (1905)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/BadBHShe.htm
Caribbean Monk Seal (1930’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/CMnkSeal.htm
Steller’s Sea Cow (1768)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/StSeaCow.htm
Schomburgk’s Deer (last shot 1932)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/SchoDeer.htm
Japanese Wolf (early 1900’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/JapaWolf.htm
Giant Aye Aye (1930)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/GiAyeAye.htm
Cape Red Hartebeest (1930’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/CRedHart.htm
Burchell’s Zebra (early 1900’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/BurZebra.htm
Blaaubok (early 1800’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/Blaaubok.htm
Cape Lion (1865)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/CapeLion.htm
Quagga (1865)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/Quagga.htm
Atlas Bear (1840)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/AtlaBear.htm
Rufous Gazelle (1894)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/RufGazel.htm
Pyrenean Ibex (last one shot 1907)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/PyreIbex.htm
Syrian Bear (1930’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/SyriBear.htm
Caucasus Bison (early 1900’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/CauBison.htm
European Wild Horse (1700’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/EurWHors.htm
Tasman Tiger (1930’s)
http://www.uwsp.edu/geO/faculty/heywood/geog358/extinctm/TasTiger.htm.
And I fail to understand your concept of “near extinction” by hunting as somehow not being relevant. Do you mean that if people shoot 99% of a population, but 1% die from other causes, that’s not an extinction caused by hunting? If so, your argument is silly. The hunting is the cause of the extinction. But for the hunting, the population would have been likely to survive.
Or are you referring to populations that were almost wiped out, but last minute conservation laws (or other human conservation activity) prevented the extinction? In other words, the gorilla, or Great Plains Bison scenario? If that’s the case, you win the semantic point (the population isn’t extinct) but lose the overall point (Organized human conservation efforts are 150 years old, at best – the World Wildlife Federation has very few stone age hunters among its members.)
I happen to be traveling in Mexico at the moment, and posting from an internet cafe in a small town in Oaxaca, so I don´t have time to really address the issues raised here in detail. However, since I am being cited here I should perhaps clarify my own position on the matter. I think that the arrival of modern humans in an area was the key factor involved in most of the megafaunal extinctions. Climate had some influence on the specific timing of extinctions, and perhaps on some individual species; but the vast majority of the megafauna would still be extant today without the influence of human activity.
I’ll try to have a look at this thread again when I get back home next week.
PS. There’s some damn nice birds here. 
Sure. Rub it in.
Good list. None of the links work for me. But I’ll search them out tomorrow. Nearly all appear to be sub-species.
Steller’s Sea Cow was a distinct species. But there was maybe around 1000 of them alive when Steller found them (and ate them 
). It wasn’t “successful” (at that point in time anyway) and likely Steller just hastened the extinction by a few decades. Sad story though.
Well, read those cites. They seem to say climate was as important as human intervention. I’d like to get your take on them. However, when you say “without the influence of human activity” do you mean the full range of human activity- hunting, habitat destruction, and introduction of new species & diseases? Or, are you thinking more like Martin? 
Have fun, get some good birding in, 
don’t drink too much!
Sorry about the links. Try deleting the final semicolon.
I was just stating a theory I’d heard, as I said. I don’t have any expertise.
And yes I meant Homo generally, not H. Sapiens in particular.
- “Not Extinct”
- “”“”
- Subspecies, and "The standard explanation has long been that the Newfoundland Wolf was hunted or trapped out of existence; partly because of its fearsome reputation as a livestock killer, partly because of the bounty on its head, and partly just for sport. Indeed, wolf numbers did appear to decline, somewhat, towards the end of the last century. But, recent evidence indicates that the real cause of the wolf’s demise may, actually, have been a fluke combination of SEVERAL factors. The main factor seems to have been the drastic decline of the Newfoundland caribou population, from perhaps 120,000 animals in 1915, to as few as 5000-6000 animals in 1925. "
- Subspecies
- Not extinct The return of the Wapiti to Arizona. A salute to Robert N. LOONEY, pioneer Arizona physician - PubMed
6 Subspecies - Not extinct http://www2.nature.nps.gov/YearinReview/05_G.html
- Still looking, but doubtful. Good example!
9.Already discussed. Not “successful” - Schomburgk’s Deer: a bit obscure, but it qualifies. There’s still hope, however.
- Island Subspecies.
- I am very doubtful of the 1930’s date here as all specimens seem to be in a semi-fossil state.http://cat.inist.fr/?aModele=afficheN&cpsidt=3305749
http://cat.inist.fr/?aModele=afficheN&cpsidt=3305749
13.Cape red Hartebeest - not extinct. http://www.bluewaterbiggame.com/game/african_cape_hartebeest.cfm
-
Not extinct. Burchell's zebra - Wikipedia
-
Blue Buck. Interesting case: "The German Peter Kolb was the first to write about the existence of a “blue buck” in 1719. *The bluebuck was clearly on its way to extinction, when European naturalists and hunters finally discovered it. * Its range was already small when Europeans who settled in the Cape Colony in the 17th and 18th century first saw this antelope. The Swedish naturalist Carl Peter Thunberg noted in 1774 that these animals were becoming rare. According to the German zoologist Martin Lichtenstein, the last bluebuck was killed in 1799, elsewhere he wrote 1800."http://home.conceptsfa.nl/~pmaas/rea/bluebuck.htm
-
Cape Lion. Subspecies. Possible not extinct- http://users.aristotle.net/~swarmack/nslions.html
National Geographic -
Subspecies "Because of the great variation in coat patterns (no two zebras are alike), taxonomists were left with a great number of described “species”, and no easy way to tell which of these were true species, which were subspecies, and which were simply natural variants…The quagga was the first extinct creature to have its DNA studied. Recent genetic research at the Smithsonian Institution has demonstrated that the quagga was in fact not a separate species at all, but diverged from the extremely variable plains zebra, Equus burchelli, between 120,000 and 290,000 years ago, and suggests that it should be named Equus burchelli quagga. " (It’s even been argued that the Quaaga was just a “variation”.)
-
Atlas bear. Interesting. Very little is known, may have been a subspecies aka “Ursus arctos crowtheri”, but certainly was already rare by 1600. Romans seems to have hunted it heavily for the arena. Oddly the Italian Wiki has the best info"http://64.233.179.104/translate_c?hl=en&sl=it&u=http://it.wikipedia.org/wiki/Ursus_arctos_crowtheri&prev=/search%3Fq%3DUrsus%2Bcrowtheri%26num%3D100%26hl%3Den%26lr%3D%26sa%3DG"
"The bear of the Atlas (Ursus crowtheri or, second crowtheri others, Ursus arctos) is one extinct subspecies of the tawny bear, diffused a time on the montuosa chain of the Atlas, from Túnez to Morocco. …Some consider the bear of the Atlas one species to himself being (Ursus crowtheri). However, the exemplary lack conserved for the sake of study renders impossible to verify this hypothesis.
Sources roman report as a time this animal was much diffusing on the Atlas, to the age covered for the greater part from forests of pines. Some rappresentazioni in mosaics roman of the zone are found again some and are probable that some exemplary were use you during the combats in the arenas. In XVIII the century, when the first scientific descriptions of the animal were had, the population of the bears of the Atlas was already considerably reduced because of the hunting and of the destruction of the habitat. " -
Rare, not “successful”, Possibly a subspecies, not enough specimins to determine. :
"*Little is known of this species other than sightings of small groups of gazelles in the mountainous forests above the Chelif valley of Algeria. The only people who were familiar with the Rufous Gazelle were furriers of Oran who saw it as a rare and costly pelt that they acquired every three or four years in the 1920s (Day 1981). These delicate, reddish gazelles disappeared during this period and, by the 1940s, were considered extinct. Three specimens were taken by museums (Day 1981). * " Possibly a subspecies, not enough specimins to determine.
20 Subspecies. Unknown cause. (wiki: . “Although her cause of death is known, the reason for the extinction of the species as a whole is a mystery. Some hypotheses include the inability to compete with other species for food, infections and diseases, and poaching.” ) -
Subspecies
-
Subspecies. It lives on, sorta, as the last bull was used to breed Wisents in captivity.
http://www.panda.org/faq/response.cfm?hdnQuestionId=20720050856402 -
Przewalski’s horse lives on, but in captivity only. The Tarpan is considered by some to not even be a Subspecies, but a race. They have bred Tarpans “back”:
http://home.conceptsfa.nl/~pmaas/rea/tarpan.htm "The first bred back Tarpan, a colt, was born May 22, 1933 at the Tierpark Hellabrunn in Munich, Germany.
In 1936, professor Vetulai of Poznan University also began attempts to breed the tarpan back to its original state. The Polish government commandeered all the Koniks, which displayed tarpan-like features. Two of the horses, a stallion called “Tref” and a mare called “Czajka”, even turned white in winter, but face, fetlocks, main and tail retained the dark colour, which the extinct tarpan also did. After 3 years there were 18 horses at Bialowieza, 8 having been born in the Bialowieza forest. Another reserve was established in the Popielno forest. The result of this selective breeding programme is that semi-wild herd of modern tarpans can be seen today. "
24. Thylacinus cynocephalus: Never common during historical times. A small hope there are still a few.
Of 24, then we have: 7 not extinct. 10 only subspecies, and some perhaps not extinct, at least one appears not hunted to extinction. One out of our period. 4 rare and not successful. Only two of 24 meet my criteria.8 Caribbean Monk Seal & 10 Schomburgk’s Deer. I listed “successful” as the list of known Pleistocene extinct mammals are known only from fossil specimens, and of course, normally we get mostly common species in the fossil record. With a species as rare as the Stellers’ Sea Cow, if that animal had disappeared during the Pleistocene, the chances of finding it in the fossil record is slim.
Hmm, that’s two species, after there are hundreds of times more humans, huge habitat destructions, and modern firearms. And dudes think that our Pleistocene ancestors managed to kill off some 40 major/successful species with just stone-tipped weapons? :dubious: :eek:
With all due respect, all but one of your cites are abstracts, and I don’t know how one goes about refuting an abstract. And I think you’re overstating the case when you insist on labeling the overkill hypothesis as stating that extinctions were caused solely by humans. The issue is whether or not humans were the sine qua non for those extinctions, and if you go back to the GD thread, I think **Blake **put it very well in this post:
Which also gives better context to what **Colibri **was saying.
Now, your finale cite is indeed a paper that claims that climate was the major cause, and the writers seem to have an almost personal animosity towards Martin. Whether or not that paper has become the new consensus, I would look to someone like **Colibri **to answer that question. This was, is and always will be a debate among scientists and scientists in certain fields are not always going to agree with scientists in other fields.
At any rate, you are now saying that you agree largely with what was said in the origional GD thread, so maybe I just misread your first few posts, but you sure seemed to saying that climate change is viewed as the major cause when you posted these:
Here’s a line from that last cite: “More than 40 years ago, Paul S Martin began to develop what has become the most visible explanation for these losses: the extinctions, he argues, were due entirely to the impacts of human hunting.” (cited and footnoted) To make things straight- the “Overkill” (aka
the “Blitzkrieg”) hypothesis does exactly claim that- the extinctions were due entirely to the impacts of human hunting. Note that **Colibri ** agrees that this is bunk "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."
Just in case you think my last cite was improperly citing Martin, here is another:
http://www.amnh.org/science/biodiversity/extinction/Day1/overkill/Bit1.html
And another:
"*Evolutionary biologist Jared Diamond embraced it in his popular books, 1992’s The Third Chimpanzee and again in Guns, Germs, and Steel: The Fates of Human Societies, which won the Pulitzer Prize in 1998. In a 2005 book, Twilight of the Mammoths: Ice Age Extinctions and the Rewilding of America, Martin extends his argument that “virtually all extinctions of wild animals in the past 50,000 years are anthropogenic.”
But not everyone is convinced.
Russ Graham, director of Penn State’s College of Earth and Mineral Sciences, cites a dearth of actual kill sites and other exceptions to the overkill chronology. “We’ve come a long way in the last 30 years as we’ve developed new techniques,” he says, referring to isotopic analysis of fossils, computer models and new archeological discoveries. “All they have is timing,” he says of overkill theorists.
Anthropologist Donald Grayson shares Graham’s suspicion that unwarranted enthusiasm for anthropogenesis is “playing a major role” in diverting attention from alternative explanations. In a chapter of a forthcoming book on the arrival of the first North Americans, Grayson attributes the bias to a political agenda: “One may applaud the intent, but it is hard to avoid the fact that overkill’s continued popularity in this context appears more closely related to the environmental movement than to any supporting evidence.”
In a recent paper in the Journal of Archaeological Science titled “A requiem for North American overkill,” Grayson and fellow archeologist David Meltzer point out that Martin’s theory was published five years after the appearance of Rachel Carson’s exposé of the dangers of chemical pollution, Silent Spring, and the same year as the founding of the Environmental Defense Fund.
“We suggest that the overkill argument captured the popular imagination during a time of intense concern over our species’ destructive behavior toward life on Earth. It retains that grasp today,” they wrote. “It is easy to show that overkill’s continued popularity is closely related to the political uses to which it can be put.”*
John, you’re a great guy, and I am not going to class myself with Colibri, but you don’t seem to grasp this basic issue- the Overkill/Blitzkreig hypothesis is on a line with the Aquatic Ape hypothesis- it’s an extremist idea with few expert backers and less facts. It’s really not too unfair to compare it to the IPU, Martins idea is that far off. *Martin * is not saying “Humans are the major cause” (something which I can buy) he is saying “human hunting is the sole and only cause”- and over a very very short period. Bunk.
Now, it seems obvious that most of the real experts in this field now accept there are several factors- human intervention and climate change being the major causes. I agree. **Colibri ** seems to weigh in that Human intervention being more important that climate, but depending on the local and period, if I read him correctly. This is fine by me, but I take a more “we aren’t sure” position, that’s all.
“Sitzkrieg” is not incompatible with the overkill hypothesis which is: “the human destruction of native fauna either by gradual attrition over many thousands of years, or suddenly in as little as a few hundred years or less”. Are you perhaps focusing too much on the latter part of that definition? Note that **Colibri **mentioned the extreme part of that hypothesis. What you seem to be saying in this thread is that Martin got it sorta right, but he didn’t take into account any climatic factors. How that puts Martin’s ideas on par with the aquatic ape theory is confusing, to say the least, since that theory finds no support of any significance (either fully or partially) in the scientific community.
It’s true that when Martin first applied his hypothesis to the extinction event in North America, the consensus view was that the Clovis barrier was fact. We now know that pre-Clovis people did exist, and perhaps if he had known that at the time he would have been less eager to coin that snappy catch-phrase, “blitzkrieg”. Martin envisioned a literal invasion of paleo-Indians from the north wiping out the megafauna in their wake. That particular hypothesis seems highly unlikely now, but you can’t say the same about the more general hypothesis of the extinction being human cause (either fully or partially).
At any rate, I think you might be linking the human-caused part of the equation too closely to the particulars of Martin’s “blitzkrieg” hypothesis. It’s not the climate change hypthesis that “put the nail in the coffin”, but the discovery of pre-Clovis sites and a better understanding of exactly how the Clovis culture spread that forces us to revise that hypothesis to one that is spread out over a loner period of time, and that didn’t necessarily include a wave of north-to-south migration.
It’s been a long time since I read Martin’s book (the 1984 one), and I haven’t read his more recent book on the subject, so I don’t know how much he has conceded that climate was at at least a partial factor for the extinction event in the Americas.
And lest we forget, the OP is asking about Africa. It was propose, up thread, that because we (H. sapiens) evolved in Africa that the African megafauna evolved with us, and thus adapted to our hunitng skills. That’s a seductive argument, but I’m wondering if that is what biologists think. For one thing, our speices adopted newer hunting techniques quite rapidly, and much of that evolution was cultural/technological rather than biological. If you go back 100k years, you find anatomically modern humans in Africa (and a few in Israel), but they weren’t using tools that were appreciably more sophisticated than what the Neanderthals were using in Europe. It’s not until ~60k years ago that you start seeing an explosion of technical advances in the tool kit like the common use of bone and more finely crafted points as well as jewelry and other indications of artistic expression (indicating a cognitive development putting “them” on par with “us”). Recent findings of possible shell beads dating from ~ 75k years ago may push that date back further, but not by all that much.