Molecular phylogenetics of geographically restricted Acropora species: Implications for threatened species conservation
MetadataShow full item record
To better understand the underlying causes of rarity and extinction risk in Acropora (staghorn coral), we contrast the minimum divergence ages and nucleotide diversity of an array of species with different range sizes and levels of threat. Time-calibrated Bayesian analyses based upon concatenated nuclear and mitochondrial sequence data implied contemporary range size and vulnerability are linked to species age. However, contrary to previous hypotheses that suggest geographically restricted Acropora species evolved in the Plio-Pleistocene, the molecular phylogeny depicts some Indo-Australian species have greater antiquity, diverging in the Miocene. Species age is not related to range size as a simple positive linear function and interpreting the precise tempo of evolution in this genus is greatly complicated by morphological homoplasy and a sparse fossil record. Our phylogenetic reconstructions provide new examples of how morphology conceals cryptic evolutionary relationships in this keystone genus, and offers limited support for the species groupings currently used in Acropora systematics. We hypothesize that in addition to age, other mechanisms (such as a reticulate ancestry) delimit the contemporary range of some Acropora species, as evidenced by the complex patterns of allele sharing and paraphyly we uncover. Overall, both new and ancient evolutionary information may be lost if geographically restricted and threatened Acropora species are forced to extinction. In order to protect coral biodiversity and resolve the evolutionary history of staghorn coral, further analyses based on comprehensive and heterogeneous morphological and molecular data utilizing reticulate models of evolution are needed.
Showing items related by title, author, creator and subject.
Abundance, distribution and new records of scleractinian corals at Barrow Island and Southern Montebello Island, Pilbara (Offshore) BioregionRichards, Zoe; Rosser, N. (2012)The local abundance and distribution of scleractinian corals were documented near Barrow Island in the Pilbara (Offshore) Bioregion, Western Australia. Using a standard rapid ecological assessment method we recorded 204 ...
Exploring Symbiodinium diversity and host specificity in Acropora corals from geographical extremes of Western Australia with 454 amplicon pyrosequencingThomas, L.; Kendrick, G.; Kennington, W.; Richards, Z.; Stat, Michael (2014)Scleractinian corals have demonstrated the ability to shuffle their endosymbiotic dinoflagellate communities (genus Symbiodinium) during periods of acute environmental stress. This has been proposed as a mechanism of ...
Phylogenomics provides new insight into evolutionary relationships and genealogical discordance in the reef-building coral genus AcroporaRosser, N.; Thomas, L.; Stankowski, S.; Richards, Zoe; Kennington, J.; Johnson, M. (2016)Understanding the genetic basis of reproductive isolation is a long-standing goal of speciation research. In recently diverged populations, genealogical discordance may reveal genes and genomic regions that contribute to ...