The Ptarmigan's Dilemma: An Exploration into How Life Organizes and Supports Itself
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Winner of the 2010 Lane Anderson Award
Drawing on breakthrough research in evolution, genetics, and on their extensive work in the field and lab, wildlife biologists John and Mary Theberge explain for non-scientists the real facts of life.
Birds that suddenly grow gall bladders, when their species has none. Moose with antlers so big they encumber their movement through the forest. Butterflies that risk extinction by overwintering en masse. These are just a few stories the Theberges tell in their examination of what the mechanisms of evolution are and how they work. With examples from the very latest discoveries in genetics and ones they have made in their own field work, The Ptarmigan's Dilemma is a ground-breaking explanation of evolution for non-scientists.
By marrying the separate sciences of ecology and genetics, the Theberges paint a picture far richer than either discipline can alone of how, for almost 4 billion years, life on Earth has evolved into the rich diversity that's under threat today. Along the way, they explain just what "the survival of the fittest" really means, how dramatic evolutionary changes can take place in just one generation, and how our too-little knowledge of or interest in how life on Earth organizes and supports itself is rapidly making us a danger to ourselves.
2003). 33. S. Weidensaul, Living on the wind, across the hemisphere with migratory birds (New York: North Point Press, 1999), 369–70. 34. J. Muir, in Linnie Marsh Wolfe, ed., John of the mountains: the unpublished journals of John Muir (Madison: University of Wisconsin Press, 1938). CHAPTER 4: THE PERFECT MOOSE 1. P.S. Martin and H.E. Wright, Jr. “Pleistocene extinctions,” Proceedings of the VIIth Congress of the International Association for Quaternary Research, vol. 6 (New Haven: Yale
their way back to the same reserve, and even the same natal trees used by their great-great-great-grandparents. At dawn we entered the monarch reserve. Beams of sunlight penetrating from breaches in the canopy outlined the ghostlike oyamel firs swathed with butterflies – a perfect ecological integration between species and their environment. The limbs of the firs, heavy with the dense assemblages of monarchs, quivered slowly as the sun’s rays touched each cluster. Butterfly after butterfly
classic example is the demise of the mule deer population that once lived on the Kaibab plateau north of Arizona’s Grand Canyon. There, in that magnificent forest of native blue spruce, wildlife managers committed a costly mistake. Between 1906 and 1924 the predators – wolves and cougars – were culled. The result was an explosion of mule deer at an enormous rate of up to 20 percent per year. The deer herd increased from 4,000 to about 100,000 animals; then, in 1924, it collapsed. A forest
typical of a larger area, and go at it. Communities of species, in contrast, are much more difficult to study. And then to draw broad conclusions about what ecosystems do? That is a challenge. For a long time, the question of what ecosystems do haunted our field work as we hiked or paddled along or sat by the campfire. A little devil seemed to be sitting on our shoulders, asking, “Can’t you figure it out? Can’t you figure it out?” Is the ecosystem out there beyond the firelight just getting
more to it. If ours is a complete explanation, then science is at an end. Instead, in every field, science progresses. One discovery leads to another, the questions becoming more fundamental all the time. That is what makes science exciting. We eventually sold our home in southern Ontario and moved to British Columbia, so we can no longer walk to the silver maple swamp and ponder the secrets of wood ducks. We still visit our cabin near Algonquin Park, however, nestled beside a beaver pond