Geographic Variation, Speciation and Clines explores the origins development of geographic variation, divergence, speciation. In particular it is concerned with genetic divergence as usually found on continents, among groups populations isolated only by distance. Although earlier writers this topic considered effects geography dispersal, intense differentiation speciation were thought to require complete isolation. Professor Endler shows how may develop in spite continuous gene flow....

Interpretation of genetic differentiation values is often problematic because their dependence on the level variation. For example, maximum GST less than average within population homozygosity so that for highly variable loci, even when no alleles are shared between subpopulations, may be low. To remedy this difficulty, a standardized measure introduced here, one which has same range, 0-1, all levels With measure, magnitude proportion possible subpopulation observed. This particularly...

Although highly variable loci, such as microsatellite are revolutionizing both evolutionary and conservation biology, data from these loci need to be carefully evaluated. First, because often have very high within-population heterozygosity, the magnitude of differentiation measures may quite small. For example, maximum GST values for populations with no common alleles at small less than average homozygosity. As a result, that variation independent recommended loci. Second, bottlenecks or...

▪ Abstract Inbreeding depression is of major concern in the management and conservation endangered species. appears universally to reduce fitness, but its magnitude specific effects are highly variable because they depend on genetic constitution species or populations how these genotypes interact with environment. Recent natural experiments consistent greater inbreeding more stressful environments. In small randomly mating individuals, such as characteristic many species, all individuals may...

ABSTRACT Five different measures of gametic disequilibrium in current use and a new one based on R. C. Lewontin's D′, are examined compared. All them, except the measure highly dependent upon allelic frequencies, including four that normalized some manner. In addition, suggested by A. H. D. Brown, M. F. Feldman E. Nevo, T. Ohta can have negative values when there is maximum rates decay infinite populations function initial array. The variances were large for all samples taken from at...

Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They used to gain ecological and evolutionary insights predict distributions across landscapes, ...Read More

Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They used to gain ecological and evolutionary insights predict distributions across landscapes, ...Read More

In the 1960s, when population geneticists first began to collect data on amount of genetic variation in natural populations, balancing selection was invoked as a possible explanation for how such high levels molecular are maintained. However, predictions neutral theory evolution have since become standard by which cases may be inferred. Here we review evidence acting major histocompatibility complex (MHC) vertebrates, system that defies many neutrality. We apply widely used tests neutrality...

The selective mechanisms for maintaining polymorphism in natural populations has been the subject of theory, experiments, and review over past half century. Advances molecular genetic techniques have provided new insight into many examples balancing selection. In addition, theoretical developments demonstrate how diversifying selection environments may maintain polymorphism. Tests current generation, recent past, distant provide a comprehensive approach evaluating impacts. particular,...

Balancing selection in the form of heterozygote advantage, frequency-dependent selection, or that varies time and/or space, has been proposed to explain high variation at major histocompatibility complex (MHC) genes. Here effect presence and absence pathogens over on genetic multiallelic loci is examined. In basic model, resistance each pathogen conferred by a given allele, this allele assumed be dominant. Given s selective disadvantage for homozygotes (and heterozygotes) without proportion...

Conservation genetics utilizes the tools and concepts of applies them to problems in conservation biology. For example, molecular genetic techniques, such as protein electrophoresis, analysis mitochondrial DNA highly variable nuclear genes (including fingerprinting), have been important documenting extent pattern variation endangered species. We review these techniques their advantages disadvantages, give examples application captive animal populations, pedigree has become basic approach...

The unprecedented rate of extinction calls for efficient use genetics to help conserve biodiversity. Several recent genomic and simulation-based studies have argued that the field conservation biology has placed too much focus on conserving genome-wide genetic variation, should instead managing subset functional variation is thought affect fitness. Here, we critically evaluate feasibility likely benefits this approach in conservation. We find population theory empirical results show...

ABSTRACT HLA data from the A and B loci for 22 populations were compared with neutrality expectations Ewens' sampling theory. In 25 of 44 cases, there was significantly less homozygosity than expected. Although a number factors can affect in this manner, upon close examination only symmetrical balancing selection appears to be consistent these data.