Genomics and the origin of marine species
Title
Genomics and the origin of marine species
General information
Our current understanding of the process of biological speciation, that mysteries of mysteries (Darwin 1859), comes largely from studies conducted on land or in freshwaters. Considering that a significant proportion of global biodiversity dwells in the oceans, surprisingly little is known about the origin of species in the sea, an environment characterized by few absolute barriers to dispersal, large populations sizes and high gene flow. Here, I propose to address this gap in our knowledge using the hamlets (Hypoplectrus spp, Serranidae), brightly coloured reef fishes from the tropical western Atlantic, as a model system. The hamlets have undergone a remarkable radiation in the Caribbean Sea and Gulf of Mexico, providing a marine equivalent to classic terrestrial and freshwater radiations such as Darwins finches, East African cichlids or Heliconius butterflies that promises to promote our understanding of speciation in the sea. In particular, the hamlets encapsulate the entire spectrum of genomic divergence, from genomic similarity to well-diverged species, providing a rare marine window into the evolutionary sequence between interbreeding populations and reproductively isolated species. I propose to leverage natural diversity in Hypoplectrus to characterize the patterns and processes underlying genomic divergence during speciation. Specifically, I will address the following questions: (i) What is the genomic architecture of speciation, and how does it evolve along the speciation continuum? (ii) What are the genomic elements underlying species differences, and do their evolutionary history differ from the rest of the genome? (iii) How repeatable are patterns of genomic divergence? (iv) Does speciation proceed in the presence of gene flow? These four questions will be addressed at three levels of genomic resolution, using a combination of (i) de novo RAD sequencing, (ii) mapped RAD sequencing, and (iii) whole-genome resequencing of a small subset of individuals. A total of 44 samples will be considered (n=444 individuals), including 15 species from 7 locations that cover the entire spectrum of population/species divergence, and for which two-thirds of the samples are already available. This project builds on eight years of previous work on the hamlets, involves six international and national collaborators, and is part of a larger research program aimed at integrating Hypoplectrus genomics with the ecological and behavioural aspects of reproductive isolation. It will provide unprecedented insights into the genomic bases of speciation and a better understanding of this extraordinary radiation and the general nature of speciation in the sea.
Start
September, 2015
End
August, 2018
Funding (total)
221000
Funding (GEOMAR)
221000
Funding body / Programme
-
DFG
/
Coordination
null
Contact
