The extent of migration among populations drives population structure. With enough migration, populations become homogeneous and behave as a single larger population. As migration rates decrease, populations drift apart and become differentiated. By measuring the amount of differentiation, we can determine the extent of migration between them. But what happens when there are unsampled populations also exchanging migrants?
This is a little different from my usual Crowdsourcing ConGen posts. I recently completed my qualifying exams for PhD candidacy, so have a very large reading list compiled for population and conservation genetics. So, if you’re interested in the field, you should check out some of these papers, and if you know of any others that should be included, please let me know in the comments. Read More
When presented with a threatened population in need of conservation, the simplest and most basic question a manager can ask is “how big is it?” Unfortunately, this is one of the most challenging questions to answer. Determining the number of individuals in a population is fundamental to effective management. Small, concentrated populations can be destroyed in a single sweep, while large, broadly distributed populations require more resources and complex management involving many stakeholders.
A population that is easy to sample is rare. Animals move – sometimes over enormous distances. Habitats are difficult or impossible to access. Entire popualtions may be adept at avoiding capture. For most populations, it is impossible to count every individual. In marine ecosystems populations can span the entire globe, and the cost of mounting an expedition to systematically sample all members is huge. In order to get accurate estimates of the number of individuals, ecologists have had to devise statistical techniques to estimate the size of a population.
This is the first entry in Crowdsourcing ConGen. This entry is meant to be half of an Introduction which lays out the framework for what conservation genetics is, its philosophical basis in population genetics, and why it’s a meaningful method of inquiry for conservation. This first section is meant to outline foundational concepts in population genetics. It is not meant to be a detailed summery of population genetics, but needs to be accurate and clear.
Conservation genetics provides essential information for the management and protection of species and ecosystems. Despite it wide applicability and concrete, quantifiable output, very few people in management and policy making positions, as well as in the general public, understand what conservation genetics is and how it can be used. Concepts like F-statistics, effective harmonic population size, the coalescent, along with a host of complex and convoluted equations tend to make the literature impenetrable. Add to that an ever changing host of molecular markers – allozymes, AFLPs,RFLPs, SNPs, microsatellites, mtDNA, 28s, and others – each with their own methods, assumptions, and caveats, and the field becomes almost unapproachable, even to other geneticists.