ABSTRACT A central question in ecology and evolution is to understand why sexual
selection varies so much in strength across taxa; it has long been known that ecological …

Polyandry, by elevating sexual conflict and selecting for reduced male care relative to
monandry, may exacerbate the cost of sex and thereby seriously impact population fitness …

Insects display a staggering diversity of mating and social behaviours. Studying these
systems provides insights into a wide range of evolutionary and behavioural questions, such …

The rapidly evolving and often extraordinarily complex appearance of male genital
morphology of internally fertilizing animals has been recognized for centuries [1] …

Speciation has been a major focus of evolutionary biology research in recent years, with
many important advances. However, some of the traditional organising principles of the …

Despite the key functions of the genitalia in sexual interactions and fertilization, the role of
sexual selection and conflict in sha** genital traits remains poorly understood. Seed …

In the seed beetle Callosobruchus maculatus, the male intromittent organ is covered in
sharp spines that pierce the female copulatory tract wall during mating. Although the fitness …

Traits that increase a male's fertilization success during sperm competition can be harmful to
females and therefore represent a source of sexual conflict. In this review, we consider the …

Males can harm the females that they interact with, but populations and species widely vary
in the occurrence and extent of harm. We consider the merits and limitations of two common …

Competition between males and their sperm over access to females and their eggs [1–3]
has resulted in manifold ways by which males try to secure paternity, ranging from physically …