Project title: The evolution of sexual behaviours: developing and testing biological models of non-reproductive sex, including homosexuality
Supervisor: Professor Vincent Savolainen; Imperial College London, Life Sciences
Co-supervised by: Dr Richard Everitt (University of Reading; Mathematics and Statistics); Dr Jason Hodgson and Professor Emeritus Russ Lande FRS, Imperial College; in collaboration with Dr Emily Bethell (Liverpool John Moores University)
Project summary:
Sexual behaviour takes multiple forms across organisms, and although it has evolved for reproduction, it also serves other social purposes. Across species, males usually have sex with females (heterosexuality), however this is not always the case, and there are numerous possible variations. For example, homosexual behaviour is common throughout the animal world, and has often been considered an evolutionary paradox. The existence of the supposed paradox is likely a confluence of the assumption that those who engage in homosexuality fail to reproduce, coupled with cultural disapproval of homosexual behaviour. Some of this confusion may also stem from the fact that most researchers have considered sexuality to be a binary trait with either homosexual or heterosexual trait states. If sexual preference is a continuous trait influenced by many different genes of small effect, or some epigenetic marks canalizing a ‘mosaic’ development, then the persistence of homosexual behaviour is not particularly surprising. The seeming Darwinian paradox of homosexual behaviour has led to the development of several biological models to explain its prevalence. Most models fall into two broad categories: genetic and epigenetic models. Genetic models typically explain the persistence of a hypothetical homosexual gene variant (allele) through some indirect evolutionary advantage for that variant (e.g. see Savolainen & Lehmann, Nature 445:158, 2007). Epigenetic models explain homosexual behaviour as a result of heritable changes in gene expression patterns due to chemical modifications that occur to the DNA of developing organisms (Rice et al., Quarterly Review of Biology 87:343, 2012). These models each make clear predictions, however, there is only limited support for any of them. Also, these models may be too simplistic to account for the complexity of behaviours found in the wild. Furthermore, Savolainen & Hodgson (Encyclopaedia of Evolutionary Psychology, in press) have proposed an alternative model, the bisexual advantage model, whereby homosexuality is a quantitative trait controlled by many loci. This bisexual advantage model is perhaps the most conservative genetic explanation for the persistence of homosexual behaviour because sexuality would then follow the pattern of the vast majority of quantitative traits where intermediate phenotypes are favoured (Lande, Genetics Research 26:221, 1976). It may be the case that some degree of bisexuality is actually an evolutionary optimum phenotype in many species, including humans. The student will formalize mathematically models for the evolution of non-reproductive sexual behaviours depending on the ecology of species, and also including the bisexual advantage model proposed above. The student will make predictions using mathematical genetics, computer simulations and computing tools such as machine deep learning. S/he will also use and/or collect behavioural data in a well-established field system to test these predictions. This project will integrate approaches from evolutionary biology, animal behaviour, genetics and mathematical biology to disentangle the evolutionary ecology of sexual behaviours in natural environments, while addressing a problem with large social implications in human societies.
HOW TO APPLY:
You should send to [log in to unmask]:
(1) an extended CV;
(2) a covering letter explaining in details how you would fit and why you are interested in (3) the Centre for Doctoral Training in Quantitative and Modelling Skills in Ecology & Evolution (http://www.imperial.ac.uk/qmee-cdt/) and (4) that project;
(5) the names and e-mail addresses of two academic referees (at least one of them should have supervised you on a previous research project).
DEADLINE 19 JANUARY 2017
Note that you should meet the NERC eligibility criteria (i.e. be a resident in the UK)
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