Saturday, February 18, 2012

Nowhere to hide- the megafauna refuge in Tibet

Where did wooly mammoths and wooly rhinoceri hang out in between ice ages?

Earth was host to a magnificent ecosystem thousands of year ago- movingly drawn on the walls of Chauvet and other caves by our artistic ancestors. Wooly mammoths, wooly rhinoceri, aurochs, giant rhinoceri, and cave lions, among others. The ice ages ebbed and flowed, and these animals with them, until humans gave them nowhere to hide and upended the ages-old ecological order. Where did these animals stay during the warm periods? Where would they be now?

Wooly mammoths and rinoceri seem to have evolved in step with this era of ice ages, which began about 2.6 million years ago and rolled in 100,000 year cycles through the last million years. 100,000 years isn't enough time to evolve a wooly rhinocerous, but 3 million years is. A recent paper in Science tells of a new fossil found in Tibet of a proto-wooly rhinocerous from 3.7 million years ago, indicating that Tibet was the birthplace of at least some of the cold-adapted megafauna that was so successful during the ice ages. It notes also that the outer margins of Tibet where part of the known range of wooly rhinos, indicating that this area served as its refuge during warmer interglacial periods as well.

Elasmotherium, the giant rhinocerous.
It is worth noting that the Himalayas are thought to have begun exhibiting alpine conditions due to plate tectonics only from about 3 million years ago, contrary to earlier estimates, and closely consistent with the current paper's estimates. At any rate, once cold-adapted megafauna developed in Tibet, they found huge areas of the northern hemisphere hospitable during the ice ages, and were even able to meander over to North America. For instance, our bison diverged from the Tibeten yak only 2 million years ago.

How wonderful it would be to come upon these animals today. But of course Tibet has also been colonized by humans- the people of Tibet, who themselves became somwhat biologically adapted to the cold and altitude, and doubtless extirpated the rhinos, who with their formidable horns were so well-defended against all other predators.

Of the not-so-mega fauna that remain, do they have a chance? If we are not killing them directly, are we giving them wide landscapes to flourish in? Are we giving them millions of years to adapt to the climate change we are bringing on; even thousands?

  • Jobs and redistribution are required.
  • On why the unemployed must be made miserable, whoever may be at fault.
  • Printing money is indicated.
  • Iran, still in ferment.
  • Occupy, taking it to the citadels of ... regulation.
  • The climate change denial industry- corrupt, corrupting, and paid for by you-know-who.

1 comment:

  1. Megafauna! My new favorite word.

    I also love that there used to be giant beavers. So Dam cool.