The extraordinary evolution of eyebrights (Euphrasia): parasitism, polyploidy & phenotypic plasticity

Thursday 14 February 2019, 1.00PM

Speaker(s): Alex Twyford, University of Edinburgh

Many biologists have questioned the existence of clear-cut plant species and have instead suggested that species are largely an arbitrary human construct. The question of the discreteness or objectivity of plant species has been driven by a handful of taxonomically complex groups where species discrimination is particularly challenging. Here we tackle the nature of species in one such ‘nightmare’ group, British eyebrights (Euphrasia), a genus characterised by recent postglacial divergence, parasitism, polyploidy, phenotypic plasticity and self-fertilisation. We use growth experiments with different hosts to understand species differences and to characterise life-history traits, and a diversity of genomic approaches (whole genome sequencing, transcriptome sequencing, population genomics, plastid sequencing) to understand how the transition to parasitism has shaped genomic diversity. We show that amongst the mess is a suite of definable genetic units that have evolved in response to the parasitic lifestyle. Our results highlight the need to study evolutionary processes in neglected taxonomically complex groups

Location: K018