Adaptive introgression of a visual preference gene.

Visual preferences are important drivers of mate choice and sexual selection, but little is known of how they evolve at the genetic level. In this study, we took advantage of the diversity of bright warning patterns displayed by butterflies, which are also used during mate choice. Combining behavioral, population genomic, and expression analyses, we show that two species have evolved the same preferences for red patterns by exchanging genetic material through hybridization.

Adult neurogenesis does not explain the extensive post-eclosion growth of mushroom bodies.

Among butterflies, have a unique behavioural profile, being the sole genus to actively feed on pollen. learn the location of pollen resources, and have enhanced visual memories and expanded mushroom bodies, an insect learning and memory centre, relative to related genera. These structures also show extensive post-eclosion growth and developmental sensitivity to environmental conditions.

Rapid expansion and visual specialisation of learning and memory centres in the brains of Heliconiini butterflies.

Changes in the abundance and diversity of neural cell types, and their connectivity, shape brain composition and provide the substrate for behavioral evolution. Although investment in sensory brain regions is understood to be largely driven by the relative ecological importance of particular sensory modalities, how selective pressures impact the elaboration of integrative brain centers has been more difficult to pinpoint. Here, we provide evidence of extensive, mosaic expansion of an integration brain center among closely related species, which is not explained by changes in sites of primary sensory input.

Parallel evolution of behavior, physiology, and life history associated with altitudinal shifts in forest type in Heliconius butterflies.

Parallel evolution of morphological traits is widely reported, providing evidence for the role of local conditions in driving adaptive divergence. Comparatively, fewer studies have tested for parallelism in behavior, and it is less clear to what extent heritable behavioral shifts contribute to adaptive divergence. We exploit repeated incipient speciation across altitudinal gradients to explore behavior and physiology in Heliconius butterflies adapted to high-elevation.

The evolution of adult pollen feeding did not alter postembryonic growth in butterflies.

For many animals, the availability and provision of dietary resources can vary markedly between juvenile and adult stages, often leading to a temporal separation of nutrient acquisition and use. Juvenile developmental programs are likely limited by the energetic demands of many adult tissues and processes with early developmental origins. Enhanced dietary quality in the adult stage may, therefore, alter selection on life history and growth patterns in juvenile stages.