Recent insect declines have raised global concern, but assessing insect population trends remains challenging due to limited long‐term monitoring data. Understanding the timing of population changes is essential for discerning the relative impacts of drivers like land use modification and climate change. Importantly for conservation, species that have undergone recent declines should ideally also be distinguished from species...

The intensification of land use over past millennia has accelerated habitat loss and fragmentation. This is hypothesized to lead to reductions in population sizes and restrictions in gene flow, processes that amplify genetic drift with profound negative impacts on species and populations. However, empirical data on the population genetic impacts of habitat fragmentation remain limited, particularly for presumed abundant specie...

Understanding the role of genetic and nongenetic variants in modulating phenotypes is central to our knowledge of adaptive responses to local conditions and environmental change, particularly in species with such low population genetic diversity that it is likely to limit their evolutionary potential. A first step towards uncovering the molecular mechanisms underlying population‐specific responses to the environment is to carr...

Sperm competition drives traits that enhance fertilization success. The amount of sperm transferred relative to competitors is key for attaining paternity. Female reproductive morphology and male mating order may also influence fertilization, however the outcome for sperm precedence under intense sperm competition remains poorly understood. In the polyandrous spider Pisaura mirabilis , males offer nuptial gifts which prolong c...

The effective population size ( N e ) is a central factor in determining maintenance of genetic variation. The neutral theory predicts that loss of variation depends on N e , with less genetic drift in larger populations. We monitored genetic drift in 42 Drosophila melanogaster populations of different adult census population sizes (10, 50 or 500) using pooled RAD sequencing. In small populations, variation was lost at a subst...