Variation in temperature but not diet determines the stability of latitudinal clines in tolerance traits and their plasticity.

Latitudinal clines are routinely used as evidence of adaptation across broad climatic gradients. However, if environmental variation influences the strength of latitudinal clines, then clinal patterns will be unstable, and using patterns of adaptation to predict population responses to global change will be difficult. To test whether environmental variation influences latitudinal clines, we sampled five populations of spanning 3000 km of east coast Australia, and measured stress tolerance (heat, cold and desiccation) and body size on flies that developed in six combinations of temperature (13°C, 25°C and 29°C) and diet (standard and low-calorie) treatments.

Untangling plastic responses to combined thermal and dietary stress in insects.

Animals are exposed to changes in their environmental conditions daily. Such changes will become increasingly more erratic and unpredictable with ongoing climate change. Responses to changing environments are influenced by the genetic architecture of the traits under selection and modified by a range of physiological, developmental, and behavioural changes resulting from phenotypic plasticity.

Digest: Evaluating sexual conflict in the genome.

Audet et al. (2024) investigate the genomic basis of sexual conflict in response to sexually discordant size selection in Drosophila melanogaster. They report interesting morphological changes in sexual dimorphism and multivariate allometry.

Within-population variation in body size plasticity in response to combined nutritional and thermal stress is partially independent from variation in development time.

Ongoing climate change has forced animals to face changing thermal and nutritional environments. Animals can adjust to such combinations of stressors via plasticity. Body size is a key trait influencing organismal fitness, and plasticity in this trait in response to nutritional and thermal conditions varies among genetically diverse, locally adapted populations.

The proximate sources of genetic variation in body size plasticity: The relative contributions of feeding behaviour and development in Drosophila melanogaster.

Body size is a key life-history trait that influences many aspects of an animal's biology and is shaped by a variety of factors, both genetic and environmental. While we know that locally-adapted populations differ in the extent to which body size responds plastically to environmental conditions like diet, we have a limited understanding of what causes these differences. We hypothesized that populations could differ in the way body size responds to nutrition either by modulating growth rate, development time, feeding rate, or a combination of the above.

Does local adaptation along a latitudinal cline shape plastic responses to combined thermal and nutritional stress?

Thermal and nutritional stress are commonly experienced by animals. This will become increasingly so with climate change. Whether populations can plastically respond to such changes will determine their survival.