Marine Evolutionary Ecology

From a certain perspective, the majority of animals in the sea are decidedly uncool. Mostly, they don't have cute little faces, can't go for help when the boat sinks and aren't particularly tasty. However, they
are some of the most abundant animals on the planet which means that they have evolved all sorts of amazing traits and are very easy to work on. That's why I'm interested in marine invertebrates such as bryozoans, ascidians and echinoderms. More specifically, I'm interested in using these animals to address fundamental ecological and evolutionary questions. For example, if you have only a limited amount of resources for reproduction, should you produce a lot of little offspring or just a few, big offspring? Which sex should be the most choosy and what determines an organism's choice of mate? These questions could be answered using elephants or rhinoceros but this would take longer, be very expensive and would inevitably involve some goring. Because of these and goring-unrelated reasons, I answer these questions using marine invertebrates. Fortunately, marine invertebrates turn out to an ideal group to examine some questions that ecologists have been interested in for quite some time.

My lab has two main questions of interest:

What are the causes and consequences of links between life-history stages in marine invertebrates?

&

Does sexual selection play a role in the reproductive strategies of marine free-spawners?

Students who wish to work in my lab should expect to work in the lab and the field in about equal proportions.

Selected Publications:

Marshall DJ, Cook CN & Emlet RB (). Offspring size effects mediate competitive interactions in a colonial marine invertebrate. Ecology in press

Evans JP, Marshall DJ, (2005). Male x female interactions influence fertilization success and mediate the benefits of polyandry in the sea-urchin Heliocidaris erythrogramma. Evolution 59: 106-112.

Marshall DJ, (2005). Geographical variation in offspring size effects across generations. Oikos 108: 602-608.

Marshall DJ, Steinberg PD, Evans JP (2004). The early sperm gets the good egg: mating order effects in free-spawners. Proceedings of the Royal Society of London: Series B 271: 1585-1589

Marshall DJ, Bolton TF, Keough MJ (2003). Offspring size affects the post-metamorphic performance of a colonial marine invertebrate in the field. Ecology 84: 3131-3137

Research Collaborators:

KEOUGH, Mick

Students:

ORTIZ Juan - PhD
CREAN Angela - PhD
BURGESS Scott - PhD
HART Simon - PhD
ALLEN Richard - PhD
BARR Lissa - PhD
ADAMS Matthew - BSc(Hons)
MC LEOD Laura - BSc(Hons)
AGUIRRE-DAVIES, Jorge - PhD
AGUIRRE-DAVIES Jorge - PhD