From a genetic perspective, conservation biology requires the preservation of genetic diversity or variability. Over long periods of time, mutation provides the genetic variation upon which natural selection may act. However, in populations constrained in size over several generations, much of the genetic variation may be lost. Once lost, a very long time is required for mutation to reestablish pre.existing levels of genetic diversity. Moreover, many species are now subject to extreme and unnatural selection. It is therefore of practical importance to study the maintenance of genetic variation in small populations. Questions of gene survival in small populations have been well studied in recent years, and new statistical methodology has found application in the assessment of the genetic potential of small populations of endangered species, such as the Andean condor and Przewalski's horse. This statistical research will be extended in three projects by Dr. Elizabeth Thompson and her colleagues at the University of Washington. There are three aspects of the analysis of the pedigree structure of a small population, all of which are directly relevant to the genetic management, and thence to the conservation biology of species. From the central trio of pedigree, genetic model, and observational data, one can consider inferences of pedigree structure, inferences of the genetic basis of an observed trait, or computation of probabilities of gene survival or of specific phenotypic events. The currently proposed focus is the extension of previous methods and development of new approaches to these three areas, in the context of complex genetic data such as DNA.fingerprint data. An understanding of the genetic and genealogical structure of populations is fundamental to conservation, where endangered species exist in limited numbers or fragmented isolates. A study of the genetics alone cannot provide specific solutions. However, all species have genes, all populations have pedigrees, and all genetic isolates have a structure that will affect their maintenance and long.term survival.
