MadSci Network: Evolution |
Mutation is a continuous process in all living organisms. As long as mutations are not inviable they result in variability (both latent and expressed) in populations of organisms. Evolution occurrs when the existing variability in a population allows that population to take advantage of changes in existing conditions. The effect of management practices on managed animal populations has been a great concern among zookeepers recently, especially as more reintroduction programs have been attempted. This has lead to efforts to recreate the mechanics of the animals true environmental interactions in the zoo. Two examples of this are the "teaching" of foraging behavior to golden lion tamarins prior to their release in Brazil and attempts to train black-footed ferrets to avoid badgers through the use of a radio-controlled badger mock up (Robo-badger, made famous my Dave Barry). These attempts to emphasize the coping skills learned in the wild are one facet of how zookeepers maintain healthy populations of wild animals. Another major effort is in the maintenance of genetic variability in captive populations through the management of breeding programs/studbooks. Though there has been some controversy on the true effect of inbreeding in captive populations it is generally believed that it adversely effects the long-term viability of the captive population. Good references to follow up on this include recent texts on conservation biology (Primack's Primer or Essentials and Meffe and Carroll's Principles of Conservation Biology) or for a more concise treatment see the chapter on conservation genetics in Avise's Molecular Markers, Natural History, and Evolution. As long as wild-type levels of genetic variability are maintained in captive or managed populations (though population bottlenecks and the concomitant reduction in genetic variability have been known to occur in nature and are believed to have been instrumental in hominid evolution) and biologically well-informed management practices are followed there is no reason to believe that the "evolution" of managed populations will be adversely affected.
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