Conservation Biology, Extinctions, and Biodiversity

    Conservation Biology began as a recognized discipline in the 1980's, with the launching of the Journal of Conservation Biology and its associated society in 1987. Unfortunately, the discipline, as its related predecessors, has been working to save threatened and endangered species only, and primarily relies on Robert MacArthur's and E. O. Wilson's 1967 "Theory of Island Biogeography" (Princeton University Press). Larry Harris (1984) in "The Fragmented Forest: Island Biogeography and the Preservation of Biotic Diversity" (University of Chicago Press) points out that for many species, especially the large ones, there isn't a preserve large enough to prevent their dwindling in numbers and subsequent extinction. Preserves are routinely set up to retain large species for about 100 years. Jack Ward Thomas (1990. A Conservation Strategy for the Spotted Owl) recognized this when planning for the threatened Spotted Owl management in the Pacific Northwest Forests.

    Given the current extinction crisis (the sixth major extinction in the history of the world) and the huge numbers of humans exploiting every inch of it, there are too many species that will not get recognition or money to save. Many of those species will never even be known by humans before they go extinct. Conservation biologists do not have the resources, more or less the knowledge, to rescue all threatened and endangered species. Even if we did rescue all the species that are on the brink of extinction, is that enough? Preserves are modeled to retain species in the form we know them today. There is no theory in conservation biology that addresses how we conserve the processes that produce biodiversity.

    By keeping diversity stagnant, we are affecting ecosystems in ways we don't understand. And by keeping diversity stagnant, we are ignoring future diversification of extant species or populations. I have argued for more than two decades we need to develop efforts and strategies to enhance diversification. That's why I think John McDonald's articles are exciting. He has proposed a possible model of macroevolution, that if understood, might be applied to dwindling populations to enhance genetic and future biodiversification.

    McDonald's argument rests on founder-effect speciation, a mode of speciation thought not to have had much impact on biodiversity to this point. Given that threatened and endangered species are so because of small populations, it's important to study mechanisms of founder-effect speciation to apply to conserving species. Therefore, I propose that McDonald's model is an appropriate starting point.

    J.F.. McDonald. 1990. Bioscience
    Macroevolution and Retroviral Elements

    J.F. McDonald 1995 TREE 10:123-126
    Transposable elements: possible catalysts of organismic evolution

    J.F. McDonald. 1993. Curr. Opinion in Genetics and Development 3: 855-864.
    Evolution and consequences of transposable elements

    Mara McDonaldOct 30, 2009 11:56 AM

    Interview with David Quammen

    What do you think environmentalists have to learn from Darwinian evolution?

    If environmentalists are responsible for leading the fight to preserve species, to stave off the sixth great extinction, to prevent habitats from being chopped up into tiny pieces that can't support viable populations, then they need to understand how evolution functions -- the importance of variation within populations, the amount of time it takes to create biological diversity, the necessity of habitat diversity to create species. Anybody who's arguing with the general public and politicians about things going extinct needs to understand where biological diversity, complexity, and adaptation come from, and how slow the process is, and how many of the things we're doing on this planet prevent further evolution, further speciation, from ever happening.