Sex, death and extinction: testing the role of harvesting and sexual selection in determining adaptation

Queen Mary University of London is announcing an exciting opportunity for an allocated four-year PhD position in the Evolution and Development group in the School of Biological and Chemical Sciences. The successful candidate will start their project in September 2019 and will participate in training and cohort activities of the London NERC DTP.

The London NERC Doctoral Training Partnership brings together eight of the world’s leading research centres in environmental science. Our partnership provides innovative doctoral training in a multidisciplinary research environment and fosters links between centres of research excellence, spanning NERC’s environmental science remit.

About the Project
Sexual selection is important in determining the outcome of population-level processes such as speciation, adaptation and extinction. Of particular importance is the role of sexual selection in driving adaptation to changing environments. Strong sexual selection leads to reproductive skew in favour of a few “high quality” males, or, in sex role reversed species, females. When the environment is changing this leads to faster adaptation because those males which are well adapted to the new environment obtain a disproportionate number of matings, leading to faster spread of their genes and a reduced risk of extinction (Martínez-Ruiz and Knell 2017 and references therein). Research at QMUL indicates that human activity can disrupt these processes because human harvesters such as trophy hunters specifically target male animals with exceptionally large antlers, horns, or other secondary sexual traits. A new model (Knell and Martínez-Ruiz 2017) shows that the removal of small numbers of the best ornamented males can reverse the adaptive benefits of sexual selection and cause extinction. This important result arises because rather than those individuals with the ‘best’ genes acquiring the majority of the matings, ensuring rapid spread of adaptation through the population, these high-quality individuals are instead removed, substantially lowering the adaptive capacity of the population.

This is clearly an important result with the potential to influence wildlife management worldwide. Thus far, however, we only have data from one simulation model to help us understand the effect of selective harvest on populations experiencing environmental change. For this studentship I propose a combination of laboratory experiments and further modelling to allow us to test these ideas empirically and to explore the relationship between selective harvest and population responses to changing environments in more realistic settings.

Testing the effect of selective harvest on responses to changing environments
We propose to empirically test the effect of removing large, well ornamented males using a well-established model laboratory system, namely the stalk-eyed fly, Teleopsis dalmanni. Stalk-eyed flies are strongly sexually selected, and the length of the eyestalks is known to be strongly condition dependent. We will expose replicated laboratory populations of T. dalmanni to directional environmental change in two forms: firstly increasing temperature and secondly increasing concentrations of copper in their food, and impose harvesting regimes of varying selectivity, ranging from random removal of individuals of both sexes to highly selective removal of the males with the longest eyestalks only. Comparing the adaptive responses of these populations using measures including size, longevity, fecundity and egg to adult survivorship will allow us experimentally to quantify the effect of selective harvest of males with large sexual ornaments when a population is exposed to continuous environmental stress.

For further information please contact the relevant supervisor. Candidates are strongly advised to make contact with the potential supervisor to prior to applying.

How to Apply
Applicants should include a supporting statement, CV, transcripts and certificates, details of two referees, and indicate the relevant supervisor and project title in the application form. Shortlisted candidates will be invited to interview in March 2019.

Please click here to apply: https://mysis.qmul.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RFQM-C1ZF-09&code2=0010