Holey hypervolumes! The multivariate geometry of adaptive radiation.

We seek a maths, physics or engineering graduate with an interest in biology, or a biologist with good mathematical skills, for an exciting, international, interdisciplinary, collaborative PhD to investigate multidimensional variation in the shape (phenotype) of fish, and the ecological characteristics of the environments they inhabit. The successful candidate will use large existing datasets to develop cutting-edge analyses of multivariate phenotype distributions, ecological variables and the relationships between them, within a phylogenetic context. The student will receive training in advanced mathematical and statistical methods, and in evolutionary biology, including fieldwork in Scotland, and practical training in quantification of morphological phenotypes. The successful candidate will be based in Nottingham, but will visit Arizona State University, USA.

Many individual properties of environments and organisms (‘phenotypes’), such as pH, temperature, colour or size have continuous distributions, which makes it tempting to assume that all possible combinations of environmental and phenotypic variables can occur in the natural world. However variables are commonly intercorrelated: as one changes, so do others, and this can mean that certain combinations are rare or missing when plotted in multidimensional spaces (‘hypervolumes’). The existence of discontinuities (‘holes’) in environmental or phenotypic hypervolumes are relevant to thinking about e.g. niche structure, the evolution of biodiversity and transitions between environmental states. They could be important for our understanding of the consequences of environmental change and organisms’ abilities to respond to it.

Until very recently the detection of holes in multivariate space has not been possible, but Ben Blonder, an assistant professor at Arizona State University, and a project collaborator, has recently developed a method to do so (2016, American Naturalist). This project will use his method, and others, to develop novel mathematical analyses of existing data describing multivariate variation in three spined stickleback fish and their environments, as they adapt to those environments during adaptive radiations (the differentiation of an ancestral species into divergent new populations or species). We aim to address three simple, but novel questions, and to then develop further analyses:
(a) Are there holes in multivariate phenotypic distributions? Their existence would suggest contraints on the filling of phenotypic space.
(b) What constraints might be responsible for phenotypic holes? They might coincide with environmental or genetic discontinuities.
(c) Do holes represent phylogenetic constraints or opportunities? Holes could represent ‘the road not taken’ in a taxon’s evolutionary history, but could also represent evolutionary opportunity in the taxon’s future.

The project will be based in the MacColl lab, http://ecology.nottingham.ac.uk/AndrewMacColl/index.php, a friendly, dynamic and well-funded group, embedded in a wider cohesive group of ecologists and evolutionary biologists http://ecology.nottingham.ac.uk/index.html.

Applicants should have an interest in evolutionary biology and/or ecology and a STRONG NUMERICAL/MATHEMATICAL background. Applicants should hold a minimum of a UK Honours degree at 2.1 or equivalent in a STEM subject (science, technology, engineerings, maths). Candidates with additional (e.g. Masters) qualifications will be looked on favourably.

The University of Nottingham is one of the world’s most respected research-intensive universities, ranked 8th in the UK for research power (REF 2014). Students studying in the School of Life Sciences will have the opportunity to thrive in a vibrant, multidisciplinary environment, with expert supervision from leaders in their field, state-of-the-art facilities and strong links with industry. Students are closely monitored in terms of their personal and professional progression throughout their study period and are assigned academic mentors in addition to their supervisory team. The School provides structured training as a fundamental part of postgraduate personal development and our training programme enables students to develop skills across the four domains of the Vitae Researcher Development Framework (RDF). During their studies, students will also have the opportunity to attend and present at conferences around the world. The School puts strong emphasis on the promotion of postgraduate research with a 2-day annual PhD research symposium attended by all students, plus academic staff and invited speakers.