Abstract:

Parental investment is influenced by a range of ecological and life-history factors over evolutionary timescales, but their relative importance remains unclear. In this talk, I explore how environmental context, together with parental care strategies, has shaped reproductive effort across above- and below-ground clades, focusing on teleost fishes, passerines and earthworms. Using Bayesian phylogenetic comparative methods, I first evaluate potential drivers of variation in offspring size in a global sample of marine fish. I find that larger eggs are found in colder, oxygen-rich waters and environments with abundant but variable food regime, while hatch size also depends on the reproductive strategy exhibited by the species, with larger hatchlings in species with care. In passerines, where strategies with prolonged parental care dominate, I observe that the pattern of building larger nests in colder environments or habitats with reduced predation threat, first detected at population-level studies, does scale up globally and across a multitude of species. Finally, I turn to earthworms, a clade of around 6,000 species, with life histories that are less well studied than those of above-ground organisms. I outline the general landscape of research on earthworm life-history traits and highlight the potential for large-scale analyses of reproductive investment in this clade. 

About our speaker:

Dr Vanadzina’s work involves building, curating and analysing large trait datasets across a variety of taxonomic groups that can be used to answer questions about their global distribution and evolutionary history. She is currently a Postdoctoral Researcher at the University of Helsinki (Finland) working on variation in life-history traits in earthworms as part of the Ecological Data Sciences team with Helen Phillips. She did her PhD at the University of St Andrews, where she investigated the evolution of parental care, nest-building and associated life-history traits in passerines and teleosts.