The evolution of body shape in response to habitat: is reproductive output reduced in flat lizards?

Body size and shape are primary determinants of reproductive output in a variety of taxa, so selection favoring specific body sizes and shapes may, in turn, have a direct affect on reproductive output, and ultimately fitness. In reptiles, species that occupy rocky habitats are often flattened, a morphological character that aids locomotion and life on rocks, but which may constrain reproductive output by reducing the amount of abdominal space available to fill with eggs or offspring. Using 20 species of tropical skink from a wide range of habitats, we quantified habitat use, body height, body volume, and reproductive output, to determine whether the evolution of a flattened body was correlated with a reduction in abdominal volume, and, in turn, with reduced reproductive output.

Towards an integrated framework for assessing the vulnerability of species to climate change.

Climate change is a major threat to global biodiversity. A novel integrated framework to assess vulnerability and prioritize research and management action aims to improve our ability to respond to this emerging crisis.

Rarity of a top predator triggers continent-wide collapse of mammal prey: dingoes and marsupials in Australia.

Top predators in terrestrial ecosystems may limit populations of smaller predators that could otherwise become over abundant and cause declines and extinctions of some prey. It is therefore possible that top predators indirectly protect many species of prey from excessive predation. This effect has been demonstrated in some small-scale studies, but it is not known how general or important it is in maintaining prey biodiversity.

Terminal reproductive effort in a marsupial.

Life-history theory predicts that as organisms approach the end of their life, they should increase their reproductive effort (RE). However, studies on mammals often find that measures of RE do not vary with maternal age. This might be because offspring have some control over energy transfer which may constrain adaptive variation in RE by mothers, particularly in eutherian mammals where placental function is primarily controlled by offspring.