When relatives mate, their inbred offspring often suffer a reduction in fitness-related traits known as "inbreeding depression." There is mounting evidence that inbreeding depression can be exacerbated by environmental stresses such as starvation, predation, parasitism, and competition. Parental care may play an important role as a buffer against inbreeding depression in the offspring by allevi...

Polyandry is often hypothesized to evolve to allow females to adjust the degree to which they inbreed. Multiple factors might affect such evolution, including inbreeding depression, direct costs, constraints on male availability, and the nature of polyandry as a threshold trait. Complex models are required to evaluate when evolution of polyandry to adjust inbreeding is predicted to arise. We us...

The inbreeding depression of fitness traits can be a major threat for the survival of populations experiencing inbreeding. However, its accurate prediction requires taking into account the genetic purging induced by inbreeding, which can be achieved using a "purged inbreeding coefficient." We have developed a method to compute purged inbreeding at the individual level in pedigreed populations w...

While much attention has been paid to the effects of inbreeding on fitness, this has mostly come from a genetic perspective. Consequently, the interaction between inbreeding and the environment is less well understood. To understand the effects of inbreeding in natural populations where environmental conditions are variable, we need to examine not only how the effects of inbreeding change among...

Many species expanded their geographic ranges from core "refugium" populations when the global climate warmed after the Pleistocene. The bottlenecks that occur during such range expansions diminish genetic variation in marginal populations, rendering them less responsive to selection. Here, we show that range expansion also strongly depletes inbreeding depression. We compared inbreeding depress...

Title of Dissertation: GENETIC MANAGEMENT, INBREEDING DEPRESSION AND OUTBREEDING DEPRESSION IN CAPTIVE POPULATIONS Jonathan D. Ballou, Doctor of Philosophy, 1995 Dissertation directed by: Dr. Gerald S. Wilkinson Associate Professor Department of Zoology The patterns and severity of inbreeding and outbreeding depression in organisms have been used to address fundamental questions relat­ ing to b...

The evolutionary history of widespread and specialized species is likely to cause a different genetic architecture of key ecological traits in the two species groups. This may affect how these two groups respond to inbreeding. Here we investigate inbreeding effects in traits related to performance in 5 widespread and 5 tropical restricted species of Drosophila with the aim of testing whether th...

Many plants are perennials, but studies of self-fertilization do not usually include features of perennial life histories. We therefore develop models that include selfing, a simple form of perenniality, adult inbreeding depression, and an adult survivorship cost to seed production. Our analysis shows that inbreeding depression in adults diminishes the genetic transmission advantage associated ...

Accurate inference of relatedness between individuals in breeding population contributes to the precision of genetic parameter estimates, effectiveness of inbreeding management and the amount of genetic progress delivered from breeding programs. Pedigree reconstruction has been proven to be an efficient tool to correct pedigree errors and recover hidden relatedness in open pollinated progeny te...