Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Marina de la Cámara (1), Sigurður S. Snorrason (1), Kalina H. Kapralova (2)
Starfsvettvangur / Affiliations: 1. Háskóli Íslands; 2. Keldur
Kynnir / Presenter: Kalina H. Kapralova
Ecological specialisation often occurs along predictable and well-established axes. These specialisations may generate convergent phenotypes across populations and species, for example in body size (large vs small individuals). Such convergence in body size is a common phenotypic output in populations with high rates of diversification. Evolutionarily young systems with high rate of ecological specialisation represent a unique opportunity to study the origins of convergent phenotypic specialisations. The Arctic charr in Thingvallavatn (Iceland) is one such system: since the last glaciation (12K years ago) this species has diverged along the benthic-limnetic ecological axis and has evolved discrete large and small phenotypes: a small benthic (SB) and a large benthic (LB) charr within the benthic morphotype and a small planktivorous (PL) and large piscivorous (PI) within the limnetic morphotype. We assessed the historical and genetic nature of this phenotypic convergence in body size in Thingvallavatn. We found that, while the LB charr evolved rapidly and early in the population history, the PI evolved more recently as a result of complex patterns of introgression between the PL and the LB. In addition, we found shared islands of differentiation between large and small pairs. One such island of differentiation encompasses the glypican-6, a protein coding gene which is involved in growth control and cell division.