Understanding the evolution of kin recognition and altruistic behaviour

Organisms often make self-sacrifices that benefit the group. But why make costly sacrifices when you could simply freeload on the sacrifices made by others? Kin recognition provides a (selfish) genetic solution whereby individuals direct fitness benefits toward relatives that carry common genes. The ‘greenbeard’ locus, named after a Richard Dawkins thought experiment, provides a mechanism for this. In this, a single gene produces a signal (a green beard), identifies that signal in others, and modifies behaviour to direct help towards other green bearded individuals. However, their selective advantage should cause them to sweep to fixation, causing them to lose any information content (Crozier’s paradox). Despite this, we recently discovered a greenbeard system in a social microbial model, Dictyostelium discoideum (Gruenheit et al. 2017). In this system some individuals sacrifice themselves and die to help the remaining cells disperse as spores. The project aims to test the idea that greenbeard sequence variation allows individuals to measure their relatedness and adjust how much of a sacrifice they are willing to make (e.g. less self-sacrifice when they are not with relatives) (Madgwick et al. 2018). You will be able to employ modelling, genomic data and cutting edge molecular tools. The project provides an unprecedented opportunity to understand the evolution of kin recognition, how it controls recognition and how it elicits behavioural responses.