What drives dolphin evolution

The aim of the DOLPHIN ECOLOGY (Testing for ꞌꞌporousꞌꞌ genomic boundaries between habitat specialist populations of the spinner dolphin) project was to increase understanding of evolutionary mechanisms driving adaptation in the marine environment.

Research delved into the relationship between morphological, behavioural, ecological and genetic variation among populations of the spinner dolphin. The purpose was to identify those parts of the genome under different adaptive pressures between dolphins living in ecologically different habitats.

Next-generation sequencing technologies were employed to identify thousands of single nucleotide polymorphisms across the spinner dolphin genome. These were used to investigate six morphologically and ecologically distinct populations that had evolved to live in a particular habitat and to test for the presence of porous genomic boundaries between ecotypes.

Results showed that spinner dolphins living along the east coast of Australia experience different adaptive pressures than those at nearby locations. This may be due to the unique coral reef habitat of this region. The study also provided data on the levels of genetic isolation and diversity at different geographic locations for the spinner dolphin.

Data from the project is crucial to understanding the impact of human activities, as many spinner dolphin populations across the world are threatened by fisheries and the destruction of their habitat. Results from the project will help managers define and assess the species' vulnerability, thereby supporting its conservation.

DOLPHIN ECOLOGY results provide evidence that ecologically and morphologically divergent features have a genomic basis. In addition, the developed laboratory protocols and bioinformatics will benefit scientists working on population genomics and phylogenomics.