Adam Kissai

2022 PhD Studentship
The evolution of same-sex sexual behaviour
Disentangling the ‘Darwinian paradox’ of homosexual behaviour in primates
Imperial College London

Same-sex sexual behaviour has been observed in a huge variety of species across the tree of life. As it does not result in offspring, previous theorising aiming to address why it occurs has focused on the seeming ‘Darwinian paradox’ that this behaviour may present – with an assumed negative fitness consequence of spending time engaging in same-sex sexual behaviour as opposed to mating that may result in offspring.

There is a lack of studies that systematically focus on same-sex sexual behaviour in animals.

Often research related to behaviour and genetics are separate, with two different scientific communities working in isolation, with a minority of research utilising both disciplines.

Together with colleagues from the research group led by Prof. Vincent Savolainen at Imperial College London, we aim to use an interdisciplinary approach to unravel the function and evolutionary foundations of same-sex sexual behaviour by integrating behavioural and genomic techniques.

Data is collected from a population of rhesus macaques on the island of Cayo Santiago. Photo: Unsplash/Nagara Oyodo
New scientific evidence

We investigate same-sex sexual behaviour by collecting high-quality and extensive data from a semi-free roaming population of rhesus macaques on a small island off the coast of Puerto Rico. We look at the social contexts in which same-sex sexual behaviour occurs, while using genetic and genomic analysis to begin to unravel its biological basis.

Our research is interdisciplinary at its core, we use both behavioural observation and genetic and genomic analysis. We hope for our investigation to bring further clarity to an aspect of behaviour whose causes and function are still unclear.

Tackling big evolutionary questions

Ever since learning about evolution in school I have been overwhelmed by the incredible power the theory has to explain the diversity of living things on this planet. I am constantly astounded that a single unifying theory can explain a vast diversity of phenomena across the millions of different species on this planet, making it one of the greatest scientific tools ever discovered.

After my PhD, I aim to continue doing research that integrates a diversity of techniques, including behavioural analysis, genomics and neuroscience, to address evolutionary questions at multiple levels of biological organisations.

I am specifically interested in primates and aim to identify the function and evolutionary origins of social behaviours related to communication and social organisation.

The EET scholarship, with its broad interest in evolution, gives me the freedom to explore these ideas using a diversity of experimental techniques.

I am passionate about open science and ensuring that scientific information is accessible to as many people as possible.