Individual variation and selection for phenotypic plasticity of laying date and clutch size across different environmental conditions in Tree swallow (Tachycineta bicolor).

Several studies have emphasized that phenotypic plasticity should be a key mechanism to cope with current rapid environmental changes by allowing individuals to quickly express new adaptive phenotypes. Yet, few studies have investigated the evolutionary potential of plasticity for multiple traits simultaneously and using several different environmental variables. Here, we assess the extent of variation in, and the selection acting on phenotypic plasticity of key ecological traits, laying date and clutch size, using five environmental variables, in a Tree swallow (Tachycineta bicolor) population monitored since 2004.

Sporadic Events Have a Greater Influence on the Dynamics of Small, Isolated Populations Than Density Dependence and Environmental Conditions.

AbstractDensity dependence is often assumed in population dynamics, but its importance in small, isolated populations has been questioned. We evaluated the relative influence of density dependence, environmental conditions, and sporadic events (disease outbreaks and specialist predators) on annual population growth rate, annual female reproduction, and annual survival of juveniles and adult females in three populations of mountain ungulates. We analyzed long-term (30-47 years) individual-based data on two bighorn sheep populations and one mountain goat population in Alberta, Canada.

Early and adult life environmental effects on reproductive performance in preindustrial women.

Early life environments can have long-lasting effects on adult reproductive performance, but disentangling the influence of early and adult life environments on fitness is challenging, especially for long-lived species. Using a detailed dataset spanning over two centuries, we studied how both early and adult life environments impacted reproductive performance in preindustrial women. Due to a wide geographic range, agricultural production was lower in northern compared to southern parishes, and health conditions were worse in urban than rural parishes.