8. Jan, 2017

Melting permafrost exposes ivory treasures

The permafrost is  the layer of the  soil that remained frozen  over  thousands of years. It covers the high mountains and glaciers at lower latitudes, as well as the Arctics, Alaska and Siberia at the higher latitudes of our globe.  Worldwide, it contains 1700 billion tons of organic material equaling almost half of all organic material in all soils*. Permafrost temperatures have increased since the early 1980s,  resulting in melting ice and  thawing of organic material embedded in the ice layers. While the deeper layers still remain frozen year-round, the soil extending several feet below the surface thaws each summer.

In  northern Siberia the shrinking permafrost  has caused  contorsion and damage of  almost 60% of all residential buildings. Another effect of the melting permafrost is the thawing of frozen peat bogs in the landmass of Siberia, wich releases billions of tonnes of methane.  Over thousands of years  siberian bogs have been absorbing these hydrocarbon gasses from the atmosphere and storing it at peat deposits. But now the protecting layers of ice are melting, the organics trapped in permafrost start decomposing at a fast rate. Obviously, a lot of greenhouse gases, such as carbon dioxide and methane are now released into the atmosphere. The result is a positive feedback loop: methane is supposed to cause climate warming, which causes more permafrost to thaw, which causes more gas to be produced, which causes more warming.

The fate of the mammoths.  Woolly mammoths are the shaggy giants that roamed northern Siberia in the latest glacial period  of the Pleistocene epoch.They became extinct about 10,000 years ago, with the last species probably dying out only  some 4000 years ago. The abrupt warming at the end of the glacial period that melted large ice masses and drowned their grassland habitats, is one possible reason of their disappearance. Ancient hunters that killed the mammoths for their meat could have been another factor. When the ice age ended and temperatures became more moderate, large tundras became more accessible for humans who advanced northwards exploring new territories. As they spread out they came into contact with the mammoths, which they  hunted for their meat, bones and skin

Sci fi talk says that it could be possible to reconstruct the genome sequence of the extinct mammoth by using tissue of the frozen carcasses. In one recently  recovered 30.000 year old mammoth the  blood vessels and intestines with faeces were still intact. The next step would then to create a viable embryo and clone the mammoth back. Its called the science of de-extinction: bringing extinct species back to modern time. Is it indeed possible to clone the mammoth back? Some scientists, like  Beth Shapiro, evolutionary biologist and pioneer in ancient DNA research say yes. Elephants with genes modified to express mammoth traits could expand into the Arctic, re-establishing lost productivity to the tundra ecosystem. 

The hunt for mammoth tusk Another side effect  of the  more recent melt down of the permafrost is that the icy layers that covered mammoth graveyards in the Nordic tundra’s became gradually thinner. In Yakoetia, an area in East Siberia, mammoth skeletons with their enormous curved  ivory tusks even became  exposed to the air. Hundreds of Yakutiyan men have now become tusk hunters, following their ancestors’ routes, and chasing the same Paleolithic beasts**. But the modern hunters are not after mammoth meat to survive in their harsh environment but their valuable tusks, and  cross the tundra on snowmobiles, hydrofoil boats, even all-terrain vehicles with tank treads. The collaps of the Soviet Union,  the search for big  money  and the Chinese ivory trade have fueled the Siberian mammoth yusk trade. Chinese demand now seem to have doubled the price of top-grade mammoth tusks to around $400 a pound in Yakutsk. Almost 90 percent of all mammoth tusks hauled out of Siberia—estimated at more than 60 tons a year, end up in China. Sadly, the mammoth ivory has not put an end to the slaughtering of African elephants,  and illegal elephant ivory and legal mammoth ivory are reported to end up in the same carving workshops in China.

Source and links

J. Severinghaus; E. Brook (1999). "Abrupt Climate Change at the End of the Last Glacial Period Inferred from Trapped Air in Polar Ice"Science286 (5441): 930–4.

Beth Shapiro (2016). Princeton University Press. ''How to Clone a Mammoth: The Science of De-Extinction''.