Inbreeding is common in plant populations and can affect plant fitness and resistance against herbivores. These effects are likely to depend on population history. In a greenhouse experiment with plants from 17 populations of Lychnis flos-cuculi, we studied the effects of experimental inbreeding on resistance and plant fitness. Depending on the levels of past herbivory and abiotic factors at th...

Inbreeding coefficients of 30,794 registered Ayrshire cows were calculated from relationships between sire and maternal male ancestors. Average inbreeding coefficient of all cows was less than 1% and of the 5,202 inbred cows was 5.4%. Fewer than 2% of inbred cows had coefficients greater than 15%. Percent of inbred cows increased from 23% of cows born in 1972 to 43% in 1980. Over the same perio...

The objective of this study was to analyze the development of inbreeding and estimate inbreeding depression in the Danish populations of 3 major meat type sheep breeds. The pedigrees contained 29,336 Texel, 22,838 Shropshire, and 11,487 Oxford Down. The rate of inbreeding was approximately 1% per generation for all breeds, but the rate of increase in co-ancestry was somewhat lower (0.45 to 0.71...

Inbreeding results from matings between relatives and can cause a reduction in offspring fitness, known as inbreeding depression. Previous work has shown that a wide range of environmental stresses, such as extreme temperatures, starvation and parasitism, can exacerbate inbreeding depression. It has recently been argued that stresses due to intraspecific competition should have a stronger effec...

While extensive population genetic theory predicts conditions favoring evolution of self-fertilization versus outcrossing, there is no analogous theory that predicts conditions favoring evolution of inbreeding avoidance or inbreeding preference enacted through mate choice given obligate biparental reproduction. Multiple interacting processes complicate the dynamics of alleles underlying such in...

Inbreeding depression (reduced fitness of individuals with related parents) has long been a major focus of ecology, evolution, and conservation biology. Despite decades of research, we still have a limited understanding of the strength, underlying genetic mechanisms, and demographic consequences of inbreeding depression in the wild. Studying inbreeding depression in natural populations has been...

In wild populations, inbreeding tolerance is expected to evolve where the cost of avoidance exceeds that of tolerance. We show that in a wild population of bottlenose dolphins found in East Shark Bay, Western Australia, levels of inbreeding are higher than expected by chance alone, and demonstrate that inbreeding is deleterious to female fitness in two independent ways. We found that inbred fem...

We present a transcriptomic analysis aimed at investigating whether the changes in gene expression that occur under inbreeding generally reduce or enhance inbreeding depression. Discerning between these two alternatives can be addressed only when both changes in expression due to inbreeding and to inbreeding depression are estimated simultaneously. We used Affymetrix 2.0 arrays to study the cha...

dairy cattle breeding. Inbreeding decreases heterozygosity and increases the frequency of deleterious recessive genes, thereby reducing phenotypic performance and viability. This phenomenon, known as inbreeding depression, ultimately causes a decrease in dairy farm profitability. Inbreeding can be of particular concern for numerically small breeds that are making rapid genetic progress, such as...