WHAT IS CONSERVATION GENETICS?
Conservation genetics is a mixture of ecology, molecular biology, population genetics, mathematical modeling and evolutionary systematics (the construction of family relationships). It is both a basic and an applied science. Scientists must first understand the genetic relationships of the organisms under study. Once this basic science is understood by scientists, management techniques must then be applied by wildlife managers to preserve biological diversity in these species.
The organisms under investigation are usually endangered or threatened populations. To develop a management strategy, scientists ask: what has brought these populations to the brink of extinction, and what steps can be taken to reverse this trend? Information about the genetic diversity of the animals under study helps scientists and managers in forming strategies to preserve and protect the diversity of plants and animals worldwide.
What is genetic diversity?
Genetic diversity is a measure of the possible choices of information provided by a gene. For example, a particular gene may determine the flower color of a plant. Different choices (alleles) may exist for that gene (i.e. a pink allele, a purple allele, a white allele). In each case, the same gene determines flower color, but the exact DNA sequence of the alleles of that gene are different. When all or nearly all the members of a population have the same allele at a gene, that population is said to have low genetic diversity at that gene. If many varients exist for a gene sequence, that population has high genetic diversity at that gene.
Why is genetic diversity so important?
If genetic diversity becomes low at many genes of a species, that species becomes increasingly at risk. It has only one possible choice of information at all or nearly all of its genes -- in other words, all the individuals are nearly identical. If new pressures (such as environmental disasters) occur, a population with high genetic diversity has a greater chance of having at least some individuals with a genetic makeup that allows them to survive. If genetic diversity is very low, none of the individuals in a population may have the characteristics needed to cope with the new environmental conditions. Such a population could be suddenly wiped out.
The genetic diversity of a species is always open to change. No matter how many variants of a gene are present in a population today, only the variants that survive in the next generation can contribute to species diversity in the future. Once gene variants are lost, they cannot be recovered.