Elephants or lions? There was once a European lion that was purportedly driven to extinction to satisfy the Roman craving for games, but I have not heard of an elephant population driven to extinction in historic times.
Are you trying a whoosh? Or taking a slap at Middlecase? Jaynes’ book isn’t taken seriously by anyone these days except possibly those in the tinfoil brigade. It could be a fine background concept for an sf novel, but it isn’t science.
Yes Voodoochile you are being too pedantic. Lighten up. This is a message board not an issue of “English language quarterly”. If you genuinely can’t comprehend what I posted let me know, but I suspect you understood my meaning perfectly.
Elephants as a group aren’t. As I posted in that other thread that has been linked to, there’s some reasonable evidence that the north African elephant is extinct and became so in historical times. 5000 years ago there were 5 species of elephant on Earth, today there are only three.
Not at all. Considering for example that stoneage Indians deforested vast amounts of North America by the use of fire and changed the ecology of the rest also by the use of fire. If 90% of what are now the great plains are naturally savanna and forest it’s hard to imagine how those stoneage people could not have caused mass extinctions. The same is true for Australia where burning converted thousands of millions of hectares of vine thicket and rainforest into savanna and grassland, with the predictable result.
While the theory that stone age humans caused extinctions exclusively by hunting may be doubtful for the reasons you give, those reasons can’t be validly used to cast doubt on stone-age humans causing such mass extinctions at all as you have done. Many people like yourself fail to appreciate that stone age humans were just as prone of causing massive environmental changes and habitat destruction as modern humans. As you have pointed out massive environmental changes and habitat destruction do indeed cause mass extinctions.
Well I’m not sure what the rolleyes smiley was meant to insinuate. But you apparently don’t realise that bison are perfectly capable of surviving on grasslands and savannas as well as forests. Indeed they survive better in those conditions. When the closed forests were removed the ground sloths, mastodon etc lost there food supply while the cheetahs and other predators lost the shelter they needed to survive. You seem to be labouring under the impression that the only way that stone age people can cause extinctions is by hunting. The reality is that few, if any, scientists subscribe to such a theory. Massive environmental change wrought by these stone age people, primarily through the use of fire, coupled with hunting is what caused the demise of these species.
I think your theory needs a lot of work then.
There were no dingos in Australia at the time that the last large flightless bird went the way of the dodo. Dingoes are a very recent introduction, less than 5000 years. The last of the flightless birds vanished about 30,000 years ago. The only rats on the continent at the time had been happily living side by side with those birds and there ancestors for over half a million years when the birds vanished.
The “Great Plains” were not Forests during any recent (post-man) epoch. They could have been so during earlier & different climates, but Man didn’t casue the Great Plains. Although the Amerinds certainly had an effect on the environment, and thus that could have caused marginal species to go extinct, I am not so sure about thriving species. If Man did some of them in- I’d guess it is because they were on their way out anyway, as the climate was changing during that time. We both agree that simple hunting certainly wasn’t the cause.
Like I said - “direct” action by man was unlikely to be the cause of extinction of any thriving species. I have no problems with “indirect changes”. It is a fact that if the “niche” is still there, it is very very hard to eliminate a sucessful species by predation. Remove the niche… and it is very easy.
AFAIK- the Dingo came over with some of the first Bushmen. But that isn’t my field, so I’ll defer to others. Anyway- for every species Man has killed by direct action- there have been a hundred killed by his introduced pests and another hundred or more by his effect on the environment. It is very hard to eliminate a species by “Hunting” alone.
The European Lion might be a such a case, but certainly man had hit heavily into it’s territory and it’s prey before they killed the last one.
Not as far as I’m aware…more information?
DrDeth I have no idea where you are getting your information form but I’m getting the impression you’re just making it up. First your claim that dingoes and feral rats could possibly have been responsible fir the extinction of large flightless birds when none existed at the time and now this.
Can we have any reference at all to support your above claim.
In contradiction of it I suggest you read “Americans and their forests” By M. Williams. It gives an excellent overview of the structure and extent of pre-Columbian forests based on a variety of methods and concludes that at least 40% and as much as 90% of the prairie ecosystem of North America is naturally treed.
And I don’t have any objection to that idea.
What I do object to is your claim that because direct action is unlikely to be the cause it is therefore “extremely doubtful” that “stone-age humans” could have caused mass extinctions at all.
That’s totally invalid logic since it assumes that stone age humans were incapable of producing indirect actions that could lead to mass extinctions. On the contrary to this belief of yours there have been tomes produced to show that they were and are very much capable of inducting such changes. Since stone age humans could produce massive environmental changes your claim that their inability to cause extinctions directly makes it unlikely they couldn’t have cause exctinctions at all is proven to be logically flawed.
Well this is GQ, not IMHO so it might be best to stick to the facts rather what you ‘know’ in fields in which you have little knowledge.
The first fact is that there are no Bushmen in Australia. Bushmen live in southern Africa.
The second fact is that Bushmen don’t have dingoes and never have. Dingoes are an Australasian breed.
The third fact is that even the most cursory Google search would enable you to verify that dingoes arrive din Australia less than 6000 years ago. That’s 45, 000 years after the first humans arrived and 25,000 years after the last of the giant flightless birds vanished.
I appreciate that this isn’t your filed, but the least you could do is try a Google search before arguing with those of us whose field it is. When I say the dingo arrived around 6000 years bp I’m not just making shit up, I’m basing that on the best and latest scientific evidence. That particular fact isn’t that isn’t in the last controversial.
Your belief that dingoes and rats were somehow involved in the extinctions is no more based on fact and information than your belief that the great plains were not forested when human first arrived on them.
I don’t wish to sound to snappy DrDeth, but what precisely are you basing these beliefs of your on? The logic is obviously highly flawed and your knowledge of the facts seems to be very lacking. Is your belief purely personal opinion?
When did the giant flightless birds in Australia become extinct? Last I heard they still had emus and cassowaries. Unless you mean GIANT giant flightless birds.
Lemur we are specifically talking about those birds that are extinct. And there are several species of giant flightless birds that are no longer with us.
Like I said, I am not an expert on Australia. And don’t get snappy either- “bushmen” or “aboriginals”- you knew what I was talking about.
Nor did I disagree that early American man could cause some environmental changes- which could have led to extinctions. But there is no proof he did so either. What I object to is the idea of early man wiping out the whole MegaFauna with his clovis-pointed spears. Sure, with fire and such, they COULD had damaged the environment- but the population pressure was very low- it seems unlikely.
If Forests were the Climax growth expected on the Great Plains, you’d see sections return to that. Not so. Have any proof of your assertions? Unless by “Forest” you really mean “Savannah”- which is grassy plains with a few scattered trees. And, the GP did have a few such trees, so it isn’t hard to say that at one time the GP were more Savannah than Grasslands. But they don’t get enough rainfall to support a thick “forest”.
I concede anything related to Australasia & dingoes- don’t know much about it. But I do know a bit about North America. However- do note that the 'endemic" Australian genus of rat (Hydromyinae) was around before humans, but that our old freind Rattus could well have come over with the first Man. Rattus is a much different rat that the Hydromyinae sp, - smarter, more agressive- much more likely to prey upon eggs and such. So indeed- human introduced rats could be the cause. We KNOW how adept Rattus is at extintions.
Oh, and the Upland Moa (Megalapteryx didinus) - one of those Giant “Flightless birds” you claim were all extinct some “25,000” years ago- survived until at least 1500AD, perhaps even until 1642AD. True, that was a Moa that hid in remote areas of NZ, but the Giant Moas in NZ didn’t generally go extinct until 1200AD or so.
The thing is- climate changed in various times & places, and that allowed humans to arrive. Afterwards- species went extinct. Some say “See- humans arrive and whole fauna’s are wiped out”. But note that each significant migration of humans to a new continent was heralded aby a significant Climate change. It is MUCH more likely that the change in climate was guilty as opposed to humans. We know that such changes usually herald mass extinctions. New predators usually don’t wipe out successful species if their niche is still extant. Get rid of the niche however and GOOD-BYE! I just don’t see it. Most dudes that write books like that have a drum to beat and an axe to grind- and it is always “Blame the humans”. :rolleyes:
Cite, please? You surely must be including large numbers of insects in that number, since the vertebrate fauna of Australia could have numbered only a few thousand species. What evidence is there for widespread extinction other than among the megafauna? Or that such an enormous number of extinctions all took place within the first 1000 years after humans arrived?
One of the major factors causing the extinction of the Passenger Pigeon was human disruption of their enormous breeding colonies. It is thought the species was adapted to breed in large concentrations, and when these were diminished the remaining birds were unable to breed successfully in smaller colonies. Although habitat destruction played a role, extinction of the Passenger Pigeon was largely due to direct human interference and hunting.
Other widespread, successful, and numerous species that have fallen victim to direct human hunting and interference include the Carolina Parakeet and Great Auk.
What you did say was that the inability of humans to hunt animals to extinction made it unlikely that stone age people were responsible for mass extinctions. As I have shown that logic is completely invalid and makes no sense.
Can we please start having some references for this string of assertions please Dr Deth? This is GQ, we are supposed to be dealing in facts. The fact that you keep posting erroneous assertion after erroneous assertion with absolutely no sign of providing references when asked isn’t helping anyone.
You clearly have no idea about this subject whatsoever. There is no reason why sections will return to forest in the near future simply because the system is stable in at least two forms: forest and grassland. That stability is modulated by the presence of fire. Once the trees are gone there is nothing to control the fires, which in turn destroy any establishing seedlings.
Yes, I just provided a reference to a book which has something like 3 chapters devoted to this. Are you reading my posts?
Once again this assertion is completely wrong, and once again I’m calling on you to back it up with a reference. A savanna is any forest or woodland with a continuous grassy understory.
I have no idea where you get the idea that a savanna has “a few scattered trees” but as usual in this thread you are totally incorrect. Here for example is a picture of a typical tropical savanna, as you can see the trees are neither few nor particularly scattered. ( http://www.wettropics.gov.au/images/dbimg/121_1.jpg). No it isn’t closed forest but by no stretch are tree densities in the hundreds of stems per hectare considered few and scattered.
And don’t get the idea that forest and savanna are mutually excusive terms because they are not.
Once again I’m calling you out. Reference please?
Once again, completely and utterly wrong, and once more DrDeth I imagine that you will be totally be unable to provide a reference for this erroneous comment.
There is no ‘the’ endemic Australian genus of rat. There are no less than 14 genera of endemic Australian rats and mice including no less than 7 species in the genus Rattus: R. colettii, R. fuscipes, R.leucopus, R.lutreolus, R.sordidus, R.vilossissimus and R. tunnei.
As you can see your belief that there is only one genus of endemic Australian rat is, like most of your other beliefs posted in this thread, completely and utterly wrong in every regard. That goes doubly for your belief that there are no endemic rats of the genus Rattus.
Your belief that Rattus could possibly have arrived with man is equally wrong. The oldest possible date attributed to humans in Australia is around 100, 000 years. The earliest member so the genus Rattus appear in the Australian fossil record at least 1 million years ago and based on dispersal are though to have arrived no later than 1.5 million ybp. There is no possible way that “Rattus could well have come over with the first Man” when the genus arrived on the continent over 1 million years before man.
DrDeth can I ask where you are getting these beliefs of yours from? Are you just making the information you post up as you go along? Can you provide a reference for anything you have posted here or is it all just baseless erroneous opinion?
No, in fact we know they couldn’t. We know that because no members of the genus Rattus had arrived for around half a million years before the extinctions. Can we please have a reference that human introduced rats could have been the cause?
Rubbish.
DrDeth moas have never lived in Australia. We were only ever discussing flightless birds of Australia. Moas were only ever found in New Zealand. That’s a separate country and quite along way over the water form Australia.
So, No! moas are not and never were one of those Giant “Flightless birds” I claimed claim were all extinct some “25,000” years ago because I only ever claimed the Australian flightless birds were extinct by that date. Unless of course you would like to find a reference that moas were an Australian bird.
At least most ‘dudes’ that write books actually have their facts straight. That’s more than can be said for you. Your facts are almost invariably wrong. Worse yet they can be readily proved wrong with a simple Google search. You are absolutely unable to provide any references of any sort to support your claims. Your logic is sloppy to the extreme. Your reasoning is flawed and it’s based on ignorant and incorrect beliefs.
In short there’s no reason I can see that your position is correct and given your misundertsnading of the facts and poor application of logic no possible way that it could be correct. But this is GQ. Can you please provide some factual answers to the questions, starting with references for the statements you made above that sure appear to be completely and utterly incorrect?
You don’t want me to get snappy, and yet you insist on posting incorrect statements and refuse to provide references or even admit that you don’t have any support for your claims. Instead in the very next post you repeat the same erroneous claim. That is going to make most people in GQ less than happy. We’re supposed to be providing facts here, not baseless opinion.
Taken in order:
Cite: Flannery, T; 20 Million years of rangeland evolution Ion Australia.
6th Intnatl Rangelands Congress. 1999
“…we now know that until 100 000 years or so ago rainforests blanketed vast areas of eastern Australia and spread far inland.
…
[Regarding sediment cores from Lake George]
“Then at a point approximately 35, 000 years ago an abrupt change takes place in a period of less than 5000 years and probably less than 1000 years. Suddenly the number of microscopic charcoal fragments present in the sediment increases dramatically. At the same time almost all fire sensitive species … abruptly vanish and are replaced with fire promoting sclerophyll species. This abrupt change is unique in the 700 000 year history of the deposit and does not correlate to climate change.
…
the implications of these fire induced changes for life in Australia were far reaching and the impact on biodiversity must have been tremendous. [goes on to list known extinctions of megafauna and other large vertebrates] Working in concert their browsing appears to have maintained a complex vegetation mosaic allowing a diversity of plant and animal species to coexist. Estimating the level of diversity is hard to achieve due to the paucity of the fossil record… comparison with areas of rainforest and vine forest with comparable levels of floristic diversity suggests that that the entire area may have been home to as many as 7 million species of insect, 50 species of reptile… 200 species of fish…”
Yes, I’m including large numbers of invertebrates. The OP asked for animals, not just mammals.
What evidence is there? Largely what I presented above. A lot of it is deduced from the reduction in floristic diversity and a comparison to similar existing environments. Where you get a wide diversity of plants and wide variety vegetation communities there also tends to be a wide variety of invertebrates etc. Of course maybe Australia was the one exception to that rule but it seem reasonable to assume it wasn’t.
It’s basically the same way that people calculate the species loss from past deforestation in say, Brazil, We can’t know what actually lived in the deforested areas but we can reasonably assume it was in the same range as comparable areas that are still timbered.
How do we know they took place within 1000 years? We don’t ‘know’. Hence the reason I said probably. The change was certainly abrupt and 1000 years is a reasonable guestimate. It was also almost certainly human induced via fire. We can’t know that people didn’t live in the area for 10, 000 years and then one day discover how to use these fire in that manner, but once again it seems less probable than the alternative.
Soory Blake, I have enough of your insults and lack of references other that “you’re stupid and I’m right”. No more.
Oh, well- “Savanna: 1 A plain- characterized by coarse grasses and scattered tree growth”.
Bye. Argue with yourself.
That’ll do me Dr Deth. I’ve shown where you are plainly wrong on almost every point you made. You’ve admitted you can’t supply any references for your claims. You have agreed not to post such ignorant material in this thread any more.
That’s all I could have hoped for or expected really.
In my first post I said that moas were giant flightless birds akin to emus and cassowaries {ratites, if you want to be specific} Moas are extinct, emus and cassowaries aren’t.
To quote Stephen Jay Gould from Of Kiwi Eggs And The Liberty Bell in Bully For Brontosaurus {this thread probably needs some cites}: “We must cast aside the myths of noble non-Westerners living in eclogical harmony with their potential quarries: The ancestors of New Zealand’s Maori people based a culture on hunting moas, but soon made short work of them, both by direct removal and burning of habitat to clear areas for agriculture. Who could resist a 500 pound chicken?”
However, co-incidentally in today’s NZ Herald, there’s an interesting article about how the depletion of moa numbers may have been triggered before humans arrived, chiefly through volcanic activity - this though is hotly contested by others…{the Herald server seems to be down at the moment, but I’ll try and provide a link later}
Polynesian arrival in New Zealand was the last introduction of our species onto a considerable landmass for permanent habitation. The effect of man on the flora and fauna of this world had proceeded for thousands of years before the ancestors of the Maori came here. That’s even before you get to the argument as to which of our early ancestors first gets the mantle and title of “mankind”.
It’s a notion from out of Victorian times that the “noble savages” were in tune with the land and whatever dwelled upon it in NZ. The fallacy has been exploded since the 1980s.
BUT – seriously: due to the lateness of the effect of humans on NZ’s biological history, you can’t bring us into a debate on the earliest human-caused extinctions worldwide. If we are talking on a country-by-country or region-by-region basis, we’ll be at this forever.