By Charlie Whittaker
Mammoths have been in the news a lot lately, predominantly due to the recent discovery of a particularly well preserved specimen. There was talk of good condition blood being found, perhaps facilitating the extraction of DNA and the generation of new, 21st century edition woollies.
But how did they die out in the first place? Everything from climate change, to comet impact, through to human based overhunting have been bandied as reasons for the loss of the majestic mammoth from the face of the earth. But a new study suggests the answer may be a little more mundane than that.
I am, of course, talking about a grass invasion. Anti-climax I know, but consider this: the primary staple of mammoths and other “megafauna” found in that region of the world at the time were broad leafed, flowering plants called “forbs”. This is a diverse family, including tansies and yarrow, and would have represented a key source of protein for the animals.
This all changed about 10,000 years ago: the composition of the flora inhabiting the Arctic shifted substantially, becoming dominated by grasses.
Past studies have failed to pick up this shift, due to their reliance upon pollen analysis. An exceptionally useful marker of flora presence, fossilised pollen found in permafrost or frozen soil can paint a vivid picture of the diversity and makeup of the vegetation inhabiting a region at a given time. This picture can be skewed however, particularly in the case of grasses, which produce huge amounts of pollen and therefore bias the picture of the landscape painted.
This study looked at plant genetic material found in numerous permafrost samples, as well as analysing the DNA found in the guts of fossilised faeces of 8 animals (4 wooly mammoths, 2 wooly rhinoceroses, 1 bison and a horse) that lived in the Arctic during that period.
All of this showed the forbs to be a stable in the diet of these animals: rich in protein and other nutrients, their continued perseverance in the Arctic landscape is thought to have been essential to continued survival of the animals there.
When these disappeared, 10-15,000 years ago, being replaced with comparatively non-nutritious grasses, the animals there were deprived of a staple foodstuff. This is thought to have massively hastened their extinction.
So, if we do eventually resurrect any woolly mammoths, and you want to be kind, then get on their good side and buy them flowers!
Read the full study here.