pz

Uh-oh. Now you've done it: that's another of Deloria's bug-a-boos from Red Earth, White Lies. He claims that this story about the concurrency of the megafauna extinctions with the arrival of Native Americans is another lie spread by European colonialists to denigrate native peoples.

I fear this will inspire poor Men_In_Black529 into greater volumes of outrage.

[ August 19, 2002: Message edited by: pz ]</p>

The Lone Ranger

Oh dear, what have I done?

lpetrich

There was a similar mass extinction in Europe at this time, the end of the last Ice Age; one wonders why the timing of both mass extinctions, especially given these circumstances:

Ends of previous ice ages had not caused mass extinctions.

Europe's human population had coexisted with Europe's megafauna during the last Ice Age, even making cave paintings of some now-extinct beasts.

So could a combination of end-of-ice-age climate change and human hunting pushed several species over the edge?

[ August 19, 2002: Message edited by: lpetrich ]</p>

The Lone Ranger

Indeed. A great many of the large animal species native to Australia, Madagascar, New Zealand, Cuba, and virtually every other large landmass on Earth just happened to go extinct shortly after humans arrived. An interesting coincidence, no?

As E. O. Wilson has pointed out, the only large landmass where these mass extinctions didn't occur (excepting Antarctica) in near coincidence with the arrival of humans is Africa, where the megafauna had coevolved with humans, and so were apparently better-adapted to dealing with them.

Cheers,

Michael

[ August 19, 2002: Message edited by: The Lone Ranger ]</p>

Richiyaado

Mibby:

ps418:

Just to clarify, I think mitochondrial DNA data strongly suggests that modern humans are neither descended from or related to Neanderthals except by common ancestry. IIRC, Neanderthal populations had already penetrated into the Middle East and Europe before modern humans emerged from Africa less than 200,000 years ago.

Vorkosigan

I don't buy this explanation at all. Let me propose an alternate: killing megafauna is easier and takes less time than learning the intricacies of the local gathering environment. In other words, hunting was a second-best strategy pursued because the invading H saps did not know the ways of the local flora....whereas in Africa humans knew the local flora, which was a more reliable food source.

mibby529

But there's no evidence. However, even you have to admit that it's more likely they just evolved to their modern, smaller equivalents. (For example, saber-toothed tigers becoming mountain lions.)

Anohter meta-argument with no evidence presented.

Anyway, Lone Ranger, I never said we did. I just said we knew what hunting to extinction would do.

So where are these African megafauna, anyway? By that logic, they should still exist. <img src="graemlins/banghead.gif" border="0" alt="[Bang Head]" />

And what about linguistic evidence? The current timeline, with ppl entering Europe 30,000 years ago and America 12,000 years ago, doesn't mesh with linguistic evidence. There are more languages indigenous to the United States alone than indigenous to Europe. And American Indian langauges generally don't have the same similarity to each other as European languages.

Coragyps

African megafauna, Hmm, let's see....elephant, hippo, rhinoceros, .....
Yep. They still exist, all right.

scombrid

Nothing fails like prayer and superstition.

If Asians originated in North America, where did the North Americans come from? I know of no scientific origin theory that supports human origins anywhere other than Africa. How did the Africans get to N.A. before they emigrated to Asia?

You won’t believe assumptions, fine. However, you have failed to address genetic markers that indicate human origins in Africa and eventually native American origins in Asia. You failed to refute the existence of a land passage. The land bridge is a plausible way for those people to have arrived here. An alternative hypothesis for migration would be appreciated; either that or your story explaining human origins in either north or south America. My understanding is that we aren’t genetically close to new world primates. How did humans arise if not from primates in Africa?

Mageth

Discovery Channel aired a good program on the mass extinction of megafauna just the other night.

There are three competing theories for the mass extinction of megafauna (which happened in several locations anywhere from 50k (Australia) to 700 (New Zealand) years ago. These theories may be referred to as chill, kill and ill. One thing these various extinctions have in common is that they all seem to coincide with the arrival of H. sapiens in the affected environments.

"Chill" proposed drastic changes in climate stressed megafauna (which reproduce much more slowly, and in smaller numbers than smaller species) to the point of extinction.

"Kill" proposes that the arriving humans hunted the large animals to extinction. Another factor here is that arriving humans may have burned off large amounts of habitat to clear land, etc. (There is direct evidence of this in Madagascar).

"Ill" is a relatively new, but very interesting, theory, and proposes that the humans (and their domesticated animals, e.g. dogs) carried pathogens that the formerly isolated animals had little or no resistance to. Disease killed the beast.

Some scientists interviewed on the program think that there may be no one cause. It very well may have been a combination of two or more of these factors, and perhaps other factors we don't yet understand. Populations stressed by the climate change, with their prime habitat reduced or gone, and with their numbers decreased, may have been more susceptible to hunting and/or disease.

This sounds like a solid theory to me. Hunting and habitat destruction by arriving humans may have contributed to the extinctions, but I don't think they are the only factors in the extinctions. Nevertheless, if the humans wouldn't have arrived, more of the megafauna may have survived.

And BTW, I don't think mountain lions are direct descendants of saber-toothed cats, that went extinct only 10-20k years ago, IIRC.

[ August 20, 2002: Message edited by: Mageth ]</p>