In Chapter 4 "River of Bones," Stone writes of his trip to Siberia with Goto and Japanese businessman Kazutoshi Kobayashi. After a series of mishaps and unsuccessful mammoth hunting, they find a mammoth carcass. In Chapter 5 "The Rat Beneath the Ice," Stone introduces us to Bernard Buiges, a Frenchman born near Fez, Morocco, and Dutch amateur paleontologist Dirk Jan "Dick" Mol. Buiges hires Mol as a consultant on his mammoth hunting trips in Siberia.
I found Chapter 6 "A Deadly Chill," to be especially interesting. Stone discusses some of the hypotheses that have been proposed for the cause of the mammoth extinction. "As one expert put it, the end of the Pleistocene was not a mass extinction but rather an extinction of the massive," writes Stone. Cataclysmic floods (including the Noachian flood) to climatic changes have long been proposed as a cause, but climatic changes may be the true culprit. During the two million years that composed the Pleistocene Epoch (1.8 million to 10,000 years ago) global temperatures varied widely, swinging "from icehouse to hothouse at least twenty-three times." Almost all mammalian species survived these severe climatic changes, so why did the mammoths and other mammalian megafauna go extinct at the end of the last deep freeze, which began about 100,000 years ago? Be sure to read my article "Extinction IV: The Pleistocene Ice Age" for more information.
Proponents of the "overchill" hypothesis believe that the climate became too warm for mammoths, rather than too cold. Global temperatures rose 5 degrees Celsius in as little as twenty years, raising ocean levels at least 300 feet from glacial meltoff, flooding much of the mammoths' grazing land. The cold, dry grassland was transformed into boggy tundra that provided little nutrients. During the late Pleistocene Epoch, mammoths in Northern Siberia grew smaller, suggesting to some paleontologists that they were not getting enough to eat. (It has been estimated that an adult mammoth would need to eat 114,000 calories, about 500 pounds of forage, every day to survive.) In North America, however, mammoths were still doing well during the late Pleistocene Epoch. Did global warming really cause the mammoth extinction?
