The thermohaline expressway: the Southern Ocean as a centre of origin for deep-sea octopuses

This project is funded by the Natural Environment Research Council, UK under their Antarctic Funding Initiative and was awarded to Louise Allcock (Principal Investigator), Jan Strugnell (Postdoctoral researcher and co-investigator) and Alex Rogers, Martin Collins and Paulo Prodohl (all co-investigators).

The proposal uses octopuses as model organisms to test the hypothesis that the Antarctic has acted as a centre for evolutionary innovation and radiation and as a source of taxa that have invaded the deep sea. It is likely that the deep-sea fauna was depauperate following extinction events associated with past global climate change causing, for example, deep ocean oxygen minima. Such events have been recorded from the late Cretaceous and Palaeocene / early Eocene, prior to the opening of the Drake passage. The subsequent development of deep-water connections between the Southern Ocean and the major oceans which surround it would have facilitated the expansion of biogeographic boundaries. The present study aims to characterise the micro- and macro- evolutionary processes of endemic Antarctic octopod fauna and the macro-evolutionary processes of the deep-sea octopod fauna using molecular techniques. Bayesian methodologies incorporating fossil constraints will then be used to estimate the divergence times of these taxa, thereby providing a means of testing the hypothesis that, in evolutionary history, Antarctic taxa invaded the deep sea.

The first major findings of the project have been published in the journal Cladistics. Strugnell et al., 2008. The thermohaline expressway: the Southern Ocean as a centre of origin for deep-sea octopuses. Cladistics 24:1-8. PDF available from [e-mail]. The research has received wide press attention as a result of being selected as a Census of Marine Life highlight in their fourth progress report. See for example http://news.bbc.co.uk/1/hi/sci/tech/7715741.stm