Molecular Biodiversity

Strugnell lab

Genetic signatures of historic climatic events in an Antarctic octopus

Repeated cycles of glaciation have had major impacts on the distribution of genetic diversity of the Antarctic marine fauna. We used microsatellites and partial sequences of the mitochondrial CO1 gene to examine genetic structure in the direct-developing, endemic Southern Ocean octopod Pareledone turqueti sampled from a broad range of areas that circumvent Antarctica. We find that the overriding pattern of spatial genetic structure can be explained by hydrographic and bathymetric features. The Antarctic Peninsula region displays a complex population structure, consistent with its varied topographic and oceanographic influences. Genetic similarities between the Ross and Weddell Seas, however, are interpreted as a persistent historic genetic signature of connectivity during the hypothesized Pleistocene West Antarctic Ice Sheet collapses.

Strugnell J, Watts P, Smith P, Allcock A (2012) Persistent genetic signatures of historic climatic events in an Antarctic octopus, Molecular Ecology, 21: 2775 – 2787.

Selected media

The Science Show with Robyn Williams (2013)

Southern ocean diversity

Southern ocean biodiversity reflects past climate, oceanographic, and tectonic changes. Molecular data from contemporary populations carry signatures of these processes. We review new molecular studies on southern ocean benthic fauna. Many of these studies focus on species with extensive geographic or bathymetric distributions, and resolve taxonomic questions. Reviewing all available data, we show that, in addition to reflecting life-history characteristics, the molecular signals found in these studies provide an insight into how species survived the last glacial maximum. We identify molecular signatures that are characteristic of surviving glacial cycles in small refuges on the continental shelf and distinguish them from molecular signatures that are indicative of surviving glacial cycles in the deep sea.

Allcock A, Strugnell J (2012) Southern ocean diversity: paradigms from molecular ecology, Trends in Ecology & Evolution, 27: 520 – 528.