Here is an interesting paper by Dale Guthrie (see below for the reference and actual access to a PDF copy of the article) on the "persistence" of Mammuthus primigenius during the Holocene on remnants of the Bering Land Bridge. Without being as young as the recent Wrangel Island discoveries (see below for the reference), it does add to our understanding of the "passing", as it were, of an ever changing Mammoth Steppe Biome which, had, over many millennia, a profound impact on the nature and timing of human dispersals across northern Eurasia and into the New World.
EurekAlert – 6 June, 2004
Mammoths stranded on Bering Sea island delayed extinction
Fossil is first record in the Americas of a mammoth population to have survived the Pleistocene
Woolly mammoths stranded on Pribilofs delayed extinction Fossil is first record in the Americas of a mammoth population to have survived the Pleistocene
St. Paul, one of the five islands in the Bering Sea Pribilofs, was home to mammoths that survived the extinctions that wiped out mainland and other Bering Sea island mammoth populations.
In an article in the June 17, 2004 edition of the journal Nature, R. Dale Guthrie, professor emeritus at the Institute of Arctic Biology at the University of Alaska Fairbanks, says that when mammoths on the mainland of Alaska and other Bering Sea islands died out during the extinctions at the end of the Pleistocene era (about 11,000 years ago) those on the Pribilofs survived and new radiocarbon dates show how.
It was a matter of being in the right place at the right time and the mammoth tooth fossil that demonstrates Guthrie's point is the first record in the Americas of a mammoth population surviving the Pleistocene.
"During the last glacial maximum, when the sea level was about 120 meters below its current level, what are now the Pribilofs were simply uplands connected to the mainland by a large, flat plain, " Guthrie said.
Using accelerator mass spectrometer (AMS) radiocarbon dating, bathymetric (water depth) plots, and sea transgression rates from the Bering Sea, Guthrie found that the mammoths became stranded on the Pribilofs about 13,000 years ago during the Holocene sea level rise after the last glacial maximum.
"Woolly mammoths became extinct on the mainland about 11,500 radiocarbon years ago, " Guthrie said. At that time St. Lawrence Island was part of the Alaska mainland and presumably subject to the same extinction pressures as the mainland, but St. Paul had been an island for about 1,500 years.
"Radiocarbon-dated samples from St. Lawrence Island show similar dates of extinction to the mainland, " Guthrie said, "but a sample from St. Paul dates to only 7,908 radiocarbon years old, into the mid-Holocene, which is much later. "
The mammoths were able to survive on St. Paul so long as the island provided enough grazing forage and there were sufficient numbers of animals to prevent inbreeding pressures, Guthrie said, and at its present size of 36 square miles is too small to sustain a permanent mammoth population. St. Paul became that size about 5,000 years ago, so mammoths likely became extinct prior to that time.
St. Paul lies about 300 miles west of the Alaska mainland, and 750 air miles west of Anchorage.
R. Dale Guthrie, professor emeritus Institute of Arctic Biology, University of Alaska Fairbanks, 907-479-6034, firstname.lastname@example.org
Marie Gilbert, publications and information coordinator, Institute of Arctic Biology, University of Alaska Fairbanks, 907-474-7412, email@example.com
PDF of Guthrie's Nature article, "Radiocarbon evidence of mid-Holocene mammoths stranded on an Alaskan Bering Sea island" and an image of Dale Guthrie holding a mammoth molar are available by contacting Marie Gilbert, 907-474-7412, firstname.lastname@example.org
Vartanyan, S. L., Garutt, V. E. & Sher, A. V. 1993. Holocene dwarf mammoths from Wrangel Island in the
Siberian Arctic. Nature 362, 336–339.
The actual paper also contains a rather brief allusion to the implications of such a find relative to early adaptations on the part of human groups "en route" for the hearth of North America. Here are the last paragraphs:
Closely linked to this matter of Pleistocene island extinction is the controversy over the timing and routes by which humans first entered North America. A 'coastal route' camp argues for an early colonization (around 13,000 yr BP), whereas the 'overland' camp points to a route between the Cordilleran–Laurentide glaciers, and highlights evidence in the range of 12,000–11,000 yr BP. The St Paul Island mammoth brings a new piece to this puzzle. If there were coastal watercraft colonists, and they became the continent’s 'super-hunters' as per the overkill theory, we might ask why did they not find and kill off mammoths on St Paul? Mammoths on that earlier island complex at 13,000 yr BP would have been easily visible in a treeless landscape when St Paul was separated from the mainland by a narrow channel, in the most likely path of coastal watercraft colonists (Fig. 1b). This becomes part of a broader issue because dwarf mammoths of the California near-shore Channel Islands pose a similar situation. There is no evidence that the Channel Island dwarf mammoths were hunted at around 13,000 yr BP, and they did not become extinct at that time. Rather, these island mammoths became extinct at the time Clovis-aged people invaded the islands at around 11,000 yr BP21. Clearly, some island mammoth extinctions were the result of human colonization; however, on St Paul that does not seem to have been the case.
It appears, from the somewhat cryptic last sentences, that Guthrie is still holding on dearly to his views, re: a short "Peopling of the New World" chronology.