No, it doesn’t preclude it. What it does do is keep humans from living in areas where the flies are prevalent - unless they are prepared to die young, and miserably. Yes, I know that in some parts of Africa, people take that as a rational choice, but not that many. Most hunting is done by men who go into the areas, and leave as soon as they’ve made their kills. Some of them still get nailed by the flies.
Incidentally, I believe there’s some evidence that the scrubby “native” African cattle have some resistance to the trypanosomes, developed over centuries. Of course, they’re not economic to herd, but they do provide marginal competition with the indigenous species.
Are we not, however, dealing with a rather incomplete record of human settlement in the Americas? IIRC, recent discoveries have pushed the dates for human settlement back by several hundred years. If that’s the case, then we might have been mucking things up for the mammoths and the like a bit longer than is commonly thought.
And in this thread, tisiphone makes the claim that legends exist of folks in the Americas hunting mammoths (post 44). She makes other discussions about it in that thread. Now, maybe the local tribes were pulling a fast one on the pale faces, I don’t know.
The new Panama Bridge of Life Museum of Biodiversity, scheduled to open in Panama City in 2008.
The gallery on the Great American Biotic Interchange will feature 97 life-size sculptures of the animals that moved between North and South America after the isthmus of Panama closed about 3 million years ago, up to the size of mastodonts and giant ground sloths.
No different definition. A small number of large species survived the extinction. However, in North America as elsewhere except Africa a very large percentage of the largest species went extinct. Buffalo, moose, and brown/grizzly bears are among the very few survivors of a North American fauna that once included several species of mastodonts and mammoths, giant sloths, giant short-faced bears, camels, horses, and so on.
As I have already pointed out, the survivors are only a small proportion of what once existed. And hunting no more has to explain why all large mammals didn’t go extinct any more than any other hypothesis does.
You bring this point up in every one of this threads, and it has consistently been refuted. Of course no species is “successful and widespread” at the time it goes extinct. (E.g. Steller’s Sea Cow, which had a very restricted range when it was driven to extinction by hunting, but almost certainly became so due to aboriginal hunting before discovery). Humans have caused the virtual extinction of a number of species of large mammals in historical times (all species of rhinos, American bison, wisent, wild horses, wild camels, aurochs) that only have survived due to substantial conservation efforts of as domesticated populations. And since humans can survive on small game while still hunting rare large animals whenever they come across them, hunting pressure never really drops off. There’s really no question that hunting by humans has the potential to cause extinctions of large mammals.
Your conclusion here seems to be based mainly on a lack of reading comprehension. It’s not exactly a “new article,” having been published in 2004, and we have discussed it here before. You still have apparently only read the abstract. As I have pointed out before, and as you seem to have forgotten, the article itself indicates that human impacts were probably the most important factor in North America, with climate change having mainly local effects.
As I have said, Martin’s specific overkill hypothesis for North America - which hinges on Clovis hunters - has not been supported. This does not refute the importance of human impacts, including hunting, as being the driver of most megafaunal extinctions either in North America or elsewhere.
While it is possible to find articles disputing specific aspects of the megafaunal extinction, as I have mentioned, the general consensus of scientists at present, as described in the Barnosky et al (2004) article, the first one I commented on above, is that human impacts and human hunting were in general more significant than climate change in causing megafaunal extinctions in most regions.
Thanks for citing this, because it actually refutes many of the points you have tried to make. As tim314 says, it lists objections to the hunting hypothesis, and presents evidence against those objections.
Specifically it notes:
DrDeth, it would better if you would actually read and try to understand your cites, and post a synopsis, rather than Googling a bunch of articles and posting great gobs of undigested information, much of which is irrelevant and some of which actually is directly opposed to the points you seem to be trying to make. This is not terribly helpful.
Note that this article is on the Plio-Pleistocene extinctions during the Great American Biotic Interchange, long before modern humans existed, not the late Pleistocene and Recent extinctions almost three million years later. It doesn’t have much direct bearing on the question of human impacts or hunting.
I don’t find the tale persuasive, in light of the amount of exploration that has been done for various reasons in the far north. Also, there are many anthropologists who find studying the Arctic peoples irresistible, given that they have - or, at least, had, up to about 50 years ago - the most nearly unaltered cultures of any of the native peoples of North America. Such stories would have been collected and investigated.
I find the still unconfirmed survival of the ivory-billed woodpecker far more plausible than the survival into historic times of any sort of extinct megafauna. It’s not as though they had any place to hide, the way that mammals have managed to do in SE Asia and Papua-New Guinea. The larger the individual members of a species are, the harder it is for them to remain unnoticed. There are other issues regarding the survival (which necessarily includes an adequate replacement reproduction rate) of group members. Large species have low reproductive rates and longer lifespans. For a technical explanation, see selection theory. That should help you understand why I’m not ready to accept any such tales. They’d require a certain minimum size population, which simply could not persist without becoming known, in that ecology.
I think that the comet explosion provides - among other things - a very plausible explanation for why modern bison are dwarfed, compared with their Clovis era ancestors. I suggest that anyone who has a serious interest in this issue will find it worthwhile to follow progress of the investigation of evidence both for and against the comet burst. As I said in my first post, it seems to me at least as persuasive as the K-T extinction event - barring someone’s finding a better explanation for the physical evidence.
This is a very interesting point; lions can’t survive on squirrels and songbirds when zebra aren’t available. Are humans unique in being able to effectively hunt such a large range of potential prey?
Pretty much. While many large predators do take small game sometimes, we are essentially the only top predator that is so omnivorous, with the exception of bears. And bears, even the giant short-faced bear which was probably more carnivorous than contemporary bears, probably rarely if ever took adult mastodonts or mammoths.
Humans will take anything from insects to elephants, and use a lot of plant foods on top of it. Because we are not dependent on large game, we can probably maintain higher population densities than the average specialized top predator.
Exactly. As the OP, I have to say, DrDeth, that you haven’t posted a single thing that was either relevant to what I was asking or intelligently summarized/presented.
You seem not to understand what an ad hominem attack is either. I specifically addressed what was factually wrong with your cites. I have not attacked the cites simply because you were the one providing them. You haven’t actually mounted any coherent argument - in fact, I’m not exactly sure what the point of most of your posts has been. Your cites are in fact mostly from credible sources - and I have cited Barnosky et al myself before. The problem is, they often don’t really say what you claim they say, contradict your own statements, or else are quite beside the point with regard to the OP.