Athina Giannakara

Bielefeld University · Research Field of Brain and Behaviour

Self-fertilization (selfing) is thought to evolve as a way of guaranteeing reproduction when mate availability is low. Nevertheless, because it often leads to inbreeding depression (ID), many hermaphrodites postpone reproduction via selfing when mates are scarce to wait for potential outcrossing opportunities. Owing to varying demographic histories...

As a class, seminal fluid proteins are expected to exert strong effects on mating partners due to the selection pressures of sperm competition and sexual conflict. But because of the complexity of this secretion, linking specific proteins to downstream effects on own fitness—via manipulating the reproductive behavior, physiology, and ultimately the...

Phenotypic plasticity can enable organisms to produce optimal phenotypes in multiple environments. A crucial life history trait that is often highly plastic is sex allocation, which in simultaneous hermaphrodites describes the relative investment into the male versus female sex functions. Theory predicts – and morphological evidence supports – that...

Seminal fluid proteins (SFPs) are components of the ejaculate that often induce drastic changes in female physiology, such as reducing remating rate or shortening longevity. There is compelling evidence that these functions make SFPs a determinant of male reproductive success, and some evidence that males can strategically invest in their different...

The free-living flatworm genus Macrostomum is an emerging model system for studying the links between sex allocation, sexual selection and mating system evolution, as well as the underlying developmental and physiological mechanisms responsible for wide intra- and inter-specific variability in reproductive phenotypes. Despite compelling comparative...

Background Sperm competition between rival ejaculates over the fertilization of ova typically selects for the production of large numbers of sperm. An obvious way to increase sperm production is to increase testis size, and most empirical work has focussed on this parameter. Adaptive plasticity in sperm production rate could also arise due to varia...

Chemical communication underpins virtually all aspects of vertebrate social life, yet remains poorly understood because of its highly complex mechanistic basis. We therefore used chemical fingerprinting of skin swabs and genetic analysis to explore the chemical cues that may underlie mother–offspring recognition in colonially breeding Antarctic fur...