Mammoths lived on Wrangel Island, albeit in a pygmy form, right up to the late 3rd millennium BC – a surprising new discovery. William sent in the link to www.yahoo.com/news/study-reveals-last-woolly-mammoths-201105919.html … The majority of mammoths died out during the Younger Dryas event as a result of an abrupt switch in climate (and possibly other factors) but a few were left stranded on islands in the Arctic Ocean. It seems that in the Late Glacial Maximum these islands may have been part of the mainland (now submerged). Subsequently they became smaller in size, a fairly common occurrence in stranded island populations. Some mammoth died out earlier than others as the islands they survived on became less and less hospitable – and Wrangel Island appears to have been the last refuge. The late third millennium BC is regarded as a climate crisis period in which human societies were uprooted and migrated, sometimes over long distances. Mammoths on an island could not migrate. They were stuck where they were – and subsequently died out.
William also sent in a link to www.yahoo.com/finance/m/299980f9-150f-3b31-9d59-e001937434db/scientists-… … scientists now have evidence of a platinum rich meteor striking the Earth at the star of the Younger Dryas event. However, the authors emphasize 'platinum rich cosmic dust' which might not be the same thing as a meteor strike.
PS .. a couple of days later I came across this link – why Hobbits were so small (at www.livescience.com/why-hobbits-were-so-small.html ) … which puts it down to living on a small island with a lack of predators. In those instances mammoths and hippos (on Mediterranean islands for example) became small whilst small bodied species evolved to become larger (such as rats and insects). Biologists have proposed several mechanisms that could be responsible for this evolutionary trend – such as a lack of predators on islands. Elephants and Hippopotamus evolved to be large creatures in order to fend off predators – or present a bigger challenge to them. Also, islands may have a restricted food resource so evolving into smaller animals makes sense. In the Live Science link the author is looking for an explanation for the diminutive size of hobbits on Flores Island and he suggests a similar reason – noting that they are really a dwarf form of Homo erectus. One may assume similar factors were involved on islands in the Arctic Ocean. One thing is clear and that is that mammoths did survive deep into the Holocene – in a very cold environment. Some explanation on what food resources were available to them is required. Presumably they wer able to adapt to the new conditions they found themselves in – including changing their diets. In fact, their diet may have played a major role. Whilst we know that early to mid Holocene was somewhat warmer than the modern world – the treeline somewhat further to the north than it is nowadays, one would still have thought that animals living in the Arctic Circle would have had a migratory diet (like herds of reindeer and caribou). These dwarf mammoths were stuck on an island in the Arctic Ocean and it is remarkable that they survived for so long as elephants eat a lot of vegetation.
One other thing is that Wrangel Island did not attain its current size until around 6000BC (or later) – and researchers have assumed it was colder during the Late Glacial Maximum than it is on Wrangel Island in the present day. It is thought that humans migrating, or exploring, led to their demise – or a sudden icing event. The late 3rd millennium BC is associated with abrupt climate change in various parts of the world and therefore they may have died out as a result of the onset of cooler weather and therefore a lack of dietary fibre. The nearby St Pauls Island mammoths died out somewhat earlier (late 4th millennium BCF) also associated with a prolonged period of cooler weather across the northern hemisphere. No doubt the final word on this subject has not as yet been written.