In a new paper in Trends in Ecology and Evolution, Dr Gabriel Jamie and Dr Joana Meier explore the phenomenon that the same polymorphisms often recur in many members of a species radiation (e.g. colour/pattern morphs, heterostyly, mating types, shell chirality). This phenomenon is puzzling because speciation often represents a barrier to the inheritance of the ancestral genetic variation underpinning polymorphisms. Generally, only a subset of the ancestral population go on to become founders of the new species. They outline the characteristics of polymorphisms that help their underlying genetic variation get inherited from ancestral standing variation, re-introduced through introgression or re-invented through mutation and also explore the factors influencing whether the requisite balancing selection operates widely across daughter species so that polymorphisms are maintained in many members of the radiation.
New paper on imperfect egg mimicry
Our paper “Combined measures of mimetic fidelity explain imperfect mimicry in a brood parasite-host system” has just been published in the journal Biology Letters. This study was led by Tanmay Dixit, and carried out together with Gary Choi, Salem al-Mosleh, Jess Lund, Jolyon Troscianko, Collins Moya, L Mahadevan, and Claire Spottiswoode, as part of a collaboration between our group and Prof. Mahadevan and his lab at Harvard University. Together we combined mathematical tools and field experiments in Zambia to quantify a key difference – “squiggle” markings – between the eggs of hosts (tawny-flanked prinias) and parasites (cuckoo finches). We showed that suboptimal behaviour on the part of prinias allows cuckoo finches to get by with an imperfect copy of prinia eggs.