Thursday, June 26, 2008

Immigrating to America

A couple of days ago I finished reading The Eternal Frontier: An Ecological History of North America And Its Peoples by Tim Flannery, the Australian mammal expert and ecologist. I really enjoyed the book. It is written on an epic scale covering the natural history of the continent over last 65 millions years. The earth went through a rapid period of reorganization of its terrestrial and marine ecosystems following a mass extinction and Flannery chooses that event to begin his exploration. Covering 65 million years in 300 odd pages means that the book moves along at a fairly brisk pace but I thought Flannery has done an exceptionally skillful job of identifying the higher level geological and climatic controls on the transformation of North America over this period. This gives the book a well defined framework within which to think through the ecologic, bio geographic and evolutionary patterns exhibited by the continents fauna and flora. Cultural patterns too as Flannery devotes the last segment to the arrival of humans and their considerable impact on the terrestrial and marine biosphere.

North America at various times over the past 65 million years has been attached to Asia and Europe through land "bridges". That has enabled it to be the land of immigrants as mammalian groups of Asian and European stock made their way into the continent and evolved a unique north American characteristic over time. This has mostly been a one way traffic, of all the modern placental mammals, only camels, horses and dogs are north American exports of ancient pedegree. Apparently, no one wants to leave once inside the continent and Flannery sees a continuity in the immigration patterns of another mammal - Homo sapiens. Since I am not a vertebrate paleontologist or a mammal expert, I liked the part of the book that dealt with human arrival and impact more than some of the early pre-human history. The modern north American ecosystems have been rendered depauperate of mammalian megafauna and other animal and plant groups and Flannery gives ample evidence in the form of timings of extinctions and some ingenious research on mammoth tusks that it has been mostly human influence and not climatic changes that is to blame. The book deals with big themes, extinction, migration and evolutionary adaptation of groups of organisms over large periods of time, but I found enough small details and asides that weave through the narrative and makes reading a pleasure in the first place. Details that you can ruminate over, those that suddenly crystallize some nebulous ideas and thoughts you have. You also now possess some fodder to impress friends over coffee. Why is cactus common in the Sonaran desert of Arizona and not in the Australian desert? Answer: Even if scant, the plant does needs predictable rainfall and nutritious soil. The Australian desert is bereft of either. Why did the field of vertebrate paleontology develop to the extent it did in the U.S and not in Canada? Answer: The ice age glaciers covering large expanses of Canada but not the U.S. ground up literally to dust the sediment cover and entombed fossils. The Canadians had little to work with. And this gem: The key to the bison's role in the prairie ecosystem lay in the fact that the great grassland were piss-driven. Buffalo urine fertilized the grasslands!

Flannery is pretty severe on the human propensity and ability to devastate the environment and treat fellow human beings with astonishing intolerance. He has a lot to say about the relationship of native Indians and the Europeans. The conflicts and wars were known to me, but I learnt something new in his explanation on the different approaches taken by the Spanish, French and English settlers. The Spanish came as a state and having defeated the incumbent Indian state, simply took over possession of state property. They never worked the land themselves, but collected taxes and used labor just as the native Indian chiefs had done. This though limited their influence over only the captured property and not much beyond. The French came as fur traders and developed a sort of a business relationship with the Indians. This meant they had to maintain good relations with the Indians. Grabbing land was self-defeating as they had to rely on the Indians for sources of fur and other goods. The English though came either as Puritan rebels with a belief that this was the chosen land, or as commerical expansionists, who saw Indians are competitors for the rich soil and resources they craved for. Winning land became an all consuming goal and the eventual victory handed them the biggest share of the continent.

Flannery identifies three phases of human occupation in North America. A pioneer phase, a period of ecologic release and finally adaptation. According to him much of North America is still stuck in the second phase, one in which people are living as if on the frontier, appropriating resources with scant regard to the consequences. Adaptation, where one learns to live within the constraints imposed by the environment is slow in coming. It's hard to disagree with the general tone of this argument, but humans do have an ability to reinvent themselves, none more so than North Americans and change is slowly coming. Two recent news items caught my eye that gives me some hope. Plans are afoot to restore part of the great plains prairie, the vast sea of grasslands that was home to the great buffalo herds of the past. And yesterday came the news that Florida is planning to acquire several thousand hectares of land from sugar companies and revert in back into a marshland, connecting Lake Okeechobee to the southern everglades national park. This won't transform the landscape to a pre-human form, for the prairie and the everglades have themselves been forged by early human activity. There is a radical remedy proposed in the book to correct that too, namely the re-introduction of fauna which disappeared from North America 13,000 to 10,000 years ago. Let lions, camels and peccaries roam again on reserve lands. This may make ecologic sense, but just take notice of the vociferous objections by ranchers to the re-introduction of one carnivore species, the wolf, in Yellowstone and I have doubts about anything more ambitious being put into action in the foreeable future. As managers of the biosphere we need to find a compromise between development and bringing reserve areas back to an acceptable state of "pristineness", and these two experiments on the prairie and the everglades look promising.

This is a cracking good book. Go get it.

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