How behaviour changes evolution: experiments with burying beetles

On Monday 15th January, a day often referred to as ‘Blue Monday’, our departmental blues were lifted by a superb talk by Professor Rebecca Kilner. A professor of evolutionary biology from the University of Cambridge, Prof Kilner treated us to an insight into her research on the influence of behaviour in evolution.

As Prof Kilner pointed out, just as evolution can shape behaviours, behaviours can also influence evolution through multiple mechanisms. Her research group have exploited the behaviours of their model system, the burying beetle, to aptly demonstrate this.

Prof Kilner began by explaining the marvellous but mildly morbid mechanisms of burying beetle life history. The parent beetles will find the carcass of a dead vertebrate and ingeniously prepare it with piercings and antimicrobial secretions before burying the remaining ball of flesh as food for their larvae. Supplementary to this comes varying degrees of parental care.

There are three principle ways by which Prof Kilner demonstrates that behaviour can influence evolution. The first of these is via eco-evo feedback imposing changes on ecological conditions. Through a neat series of experiments, Kilner’s group showed how the complex and arduous preparations that adult burying beetles make to carcasses significantly influences the carcass microbiota in ways that positively influence larval survival. Thus, parental behaviour influences the ecological conditions to which larvae are exposed.

Secondly, the team showed how behaviour can influence evolution by influencing social selection. Adult burying beetles provide varying degrees of parental care to their offspring, and Prof Kilner showed that this parental behaviour has a direct influence on the social interactions between kin: reduced parental care increases sibling cooperation whilst increased parental care increases sibling competition.

Finally, Prof Kilner explained how behaviours can influence the means by which traits are inherited via indirect genetic effects. Curiously, although adult body size shows large amounts of variation between species, it has very low heritability. However, the level of parental care has complex influences via indirect genetic effects on the body size of offspring.

It was delightful to learn about the fascinating lives of the burying beetle and see how Prof Kilner has so perfectly used this species to demonstrate the multiple ways in which behaviour influence evolution. The Zoology Department wish all the best to Prof Kilner in her future work and thank her for raising our spirits on this Blue Monday.

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