Humans arrived to the Americas earlier than thought

Adam Khor

Smilodon populator probably ate ppl too.

http://www.newscientist.com/article/dn23441-humans-may-have-reached-the-americas-22000-years-ago.html

Wibbs

Oh the Clovis adherents will freak about that one.

Capt'n Midnight

in Brazil

So we were responsible for the mega fauna extinctions all along.

Wibbs

Yea it's almost a rule when us modern humans show up mega fauna extinctions follow close on our heels*. In Europe, Australia and most recently in New Zealand. So if a place has one and other scientists stick to a claim that we didn't show up for thousands of years afterwards I tend to think "Oh really?".




*except in Africa. The local fauna knew us well to avoid or get stampy with us from the start.

Adam Khor

Wibbs wrote: »

*except in Africa. The local fauna knew us well to avoid or get stampy with us from the start.

But then what happened to Pelorovis, Megalotragus, Homotherium and the like?

JuliusCaesar

Are they still saying they arrived via the Bering Straits and made their way southward? Only earlier than previously thought?

And do tell more about the mega-fauna extinctions and the arrival of humans. Links would be good! Thanks!

Capt'n Midnight

JuliusCaesar wrote: »

mega-fauna extinctions and the arrival of humans

http://bit.ly/12cbznj :pac:


They've shown the Falkland Islands wolf got there when sea levels were lower so travel can be done over even longer distances - though see Wallace Line for the exact opposite where even a short gap kept species apart

Wibbs

Adam Khor wrote: »

But then what happened to Pelorovis, Megalotragus, Homotherium and the like?

Oh true, but we seemed to have had less of an impact in Africa compared to other environments.

JuliusCaesar wrote: »

Are they still saying they arrived via the Bering Straits and made their way southward? Only earlier than previously thought?

Earlier than previously thought, but by the same route. Though I personally would favour some influx from Europe. We might have made it to the new world along the edge of the Atlantic pack ice. The Clovis culture which is the cast in stone(no pun) start date for most academics for peopling of the Americas looks incredibly like similar stone tool cultures in France around the same time. I suppose it possible that we got to the Americas by island hopping in the Pacific, but I doubt it myself.

And do tell more about the mega-fauna extinctions and the arrival of humans. Links would be good! Thanks!

Here's one. It seems to be still up in the air whether it was us or climate change responsible, I'd sit somewhere in the middle, but more looking at us. The climate change was a major stressor, but we were the coup de grace. For me it's too much of a coincidence that the timing of the extinctions follows our arrival in a new environment. Plus more recent extinction events that had little or no climate variable. EG New Zealand. If you had a secret stash of moas and released them into the wild of New zealand any time since they died out, they'd live happily. The biggest factor was us showing up.

Capt'n Midnight

Short version, Intelligent and mobile species from Neanderthals to relatives of elephants were wiped out. Island dwarfism shows that it's extremely unlikely that they died out due to a gradual loss of food. The survival of African species shows it wasn't any global catastrophe.

Wibbs wrote: »

Oh true, but we seemed to have had less of an impact in Africa compared to other environments.

mostly because those animals co-evolved with us and had plenty of time to realise that anything standing upright is something to run away from really fast

For me it's too much of a coincidence that the timing of the extinctions follows our arrival in a new environment. Plus more recent extinction events that had little or no climate variable. EG New Zealand. If you had a secret stash of moas and released them into the wild of New zealand any time since they died out, they'd live happily. The biggest factor was us showing up.

And all the large species trapped on islands.

The Irish Elk survived in Siberia until 7,000 years ago
lots of species survived in remote niches until a few thousand years ago

we're probably responsible for the dwarf elephants of malta and cyprus

look at how many of these guys are now extinct
https://en.wikipedia.org/wiki/Insular_dwarfism
https://en.wikipedia.org/wiki/Island_gigantism


https://en.wikipedia.org/wiki/Megafauna

Outside the mainland of Afro-Eurasia, these megafaunal extinctions followed a distinctive landmass-by-landmass pattern that closely parallels the spread of humans into previously uninhabited regions of the world, and which shows no correlation with climatic history (which can be visualized with plots over recent geological time periods of climate markers such as marine oxygen isotopes or atmospheric carbon dioxide levels).[19][20] Australia was struck first around 45,000 years ago,[21] followed by Tasmania about 41,000 years ago (after formation of a land bridge to Australia about 43,000 years ago),[22][23][24] Japan apparently about 30,000 years ago,[25] North America 13,000 years ago, South America about 500 years later,[26][27] Cyprus 10,000 years ago,[28][29] the Antilles 6000 years ago,[30] New Caledonia[31] and nearby islands[32] 3000 years ago, Madagascar 2000 years ago,[33] New Zealand 700 years ago,[34] the Mascarenes 400 years ago,[35] and the Commander Islands 250 years ago.[36] Nearly all of the world's isolated islands could furnish similar examples of extinctions occurring shortly after the arrival of Homo sapiens, though most of these islands, such as the Hawaiian Islands, never had terrestrial megafauna, so their extinct fauna were smaller

large enough list of species here
https://en.wikipedia.org/wiki/Pleistocene_extinctions

The Late Pleistocene extinction event saw the extinction of many mammals weighing more than 40 kg.

In North America around 33 of 45 genera of large mammals became extinct.
In South America 46 of 58
In Australia 15 of 16
In Europe 7 of 23
In Subsaharan Africa only 2 of 44

The extinctions in the Americas entailed the elimination of all the larger (over 100 kg) mammalian species of South American origin