Hormones mediate major physiological and behavioural components of the reproductive phenotype of individuals. To understand basic evolutionary processes in the hormonal regulation of reproductive traits, we need to know whether, and during which reproductive phases, individual variation in hormone concentrations relates to fitness in natural populations. We related circulating concentrations of...

Many populations are composed of a mixture of individuals that reproduce at different times, and these times are often heritable. Under these conditions, gene flow should be limited between early and late reproducers, even within populations having a unimodal temporal distribution of reproductive activity. This temporal restriction on gene flow might be called "isolation by time" (IBT) to ackno...

The objective of this study was to describe the genetic and phenotypic relationship between milk urea nitrogen (MUN) and reproductive traits in Iranian Holstein dairy cows. Test-day MUN data obtained from 57 301 dairy cows on 20 large dairy herds in Iran between January 2005 and June 2009. Genetic parameters for MUN and reproductive traits were estimated with a five-trait model using ASREML pro...

The objective of the study was to analyze the reproductive longevity of 2 selected lines of rabbits. The first one was the Prat line, a line selected in Spain on litter size at weaning, and raised in overlapping generations. The second one was a French line, the A1077 line, selected on litter size at birth and individual weight at 63 d of age, managed in batches, and artificially inseminated wi...

Differing biomass allocation strategy could be a necessary plant-trait associated with invasive weeds in an alien environment. The present study focused on exploring differential biomass allocation pattern as an invasive plant-trait in the two pantropical invasive malvaceous weeds Sida acuta Burm f. and Sida cordifolia L. in an anthropic peri-urban vegetation in Indian dry tropics. Eighty plant...

The reproductive biology of non-avian theropods, primarily maniraptorans, is revisited using recent fossil discoveries in the framework of the extant phylogenetic bracket. It is apparent that non-avian theropods shared some reproductive characters with crocodilians, some with birds, but also possessed their own unique features. Whereas the non-avian theropod reproductive system retained primiti...

The genetic basis of fitness traits has been studied widely in animals, yet the contribution of genetic variation to these traits in humans is controversial. In particular, it is difficult to disentangle genetic versus environmental effects on fertility, because of within-family correlations of sociocultural, economic, and other nongenetic factors that influence family sizes. In this study, we ...

to provide reliable information concerning reproductive potential of hippodamia variegata goeze and its prey (aphis fabae), their related life tables were studied under controlled laboratory conditions (at 23?c). the unprocessed data of life tables were analyzed taking the euler-lotka as the basis model. standard error of population growth parameters was calculated using the jackknife re-sampli...

Most evolutionary research on biological invasions has focused on changes seen between the native and invaded range for a particular species. However, it is likely that species that live in human-modified habitats in their native range might have evolved specific adaptations to those environments, which increase the likelihood of establishment and spread in similar human-altered environments. F...

Secondary sexual traits in females are a relatively rare phenomenon. Empirical studies have focused on the role of male mate choice in their evolution; however, recently it has been suggested that secondary sexual traits in females are more likely to be under selection via reproductive competition. We investigated female competition and the influence of female phenotype on fitness in Onthophagu...