Dorsoventral comparison of intraspecific variation in the butterfly wing pattern using a convolutional neural network.

Butterfly wing patterns exhibit notable differences between the dorsal and ventral surfaces, and morphological analyses of them have provided insights into the ecological and behavioural characteristics of wing patterns. Conventional methods for dorsoventral comparisons are constrained by the need for homologous patches or shared features between two surfaces, limiting their applicability across species. We used a convolutional neural network (CNN)-based analysis, which can compare images of the two surfaces without focusing on homologous patches or features, to detect dorsoventral bias in two types of intraspecific variation: sexual dimorphism and mimetic polymorphism.

Reproductive advantage of the winners of male-male competition in Drosophila prolongata.

In the resource-defence mating system, where males compete for limited resources to acquire females, male traits associated with fighting ability are selected, leading to the evolution of sexual dimorphism. However, the evolution of sexual dimorphism is also driven by other mechanisms, such as female selection. Therefore, to elucidate the evolutionary mechanisms of male traits, it is necessary to clarify their contribution to fitness through male-male competition.

A courtship behavior that makes monandrous females polyandrous.

Females of many animal species mate several times with different males (polyandry), whereas females of some species mate with a single male (monandry) only once. Little is known about the mechanisms by which these different mating systems evolve. Females of Drosophila prolongata mate serially, unlike Drosophila melanogaster females that refuse to remate for several days after their first mating (remating suppression [RS]).

Intra- Versus Inter-Sexual Selection on Sexually Dimorphic Traits in .

Sexual dimorphism, such as sexual size dimorphism (SSD) and sexually dimorphic exaggerated traits, often evolves via sexual selection. In many species, evolution of sexual dimorphism is thought to be driven by either of the two forms of sexual selection: intra- and inter-sexual selection. In some species, however, intra- and inter-sexual selection act simultaneously on the same sexually dimorphic trait.