Patrick Martone

PhD Student

Patrick earned a BS in Biology and a BA in Mathematics from Duke University.

He joined the Denny lab to study evolutionary morphology and the interaction between biological structures and the physical environment. Patrick is a budding phycologist and, by all accounts, fills the "phyco-nerd" quota for the lab. He was immediately attracted to the morphological and phylogenetic diversity of marine macroalgae and has started investigating how seaweeds are mechanically designed to withstand intense wave forces.

For years biologists have stared out at the intertidal zone, watched waves break on the rocks, and wondered how organisms manage to live amidst the maelstrom. Of particular interest are seaweeds, which often grow quit large and cannot seek shelter when conditions worsen. Although the biomechanics of fleshy macroalgae has been an active area of research for decades, the mechanics of calcified macroalgae has gone almost completely unexplored -- yet coralline algae thrive in (and often dominate) wave-exposed habitats around the world.

Coralline algae fortify their cell walls with calcium carbonate, making them generally hard like corals. "Crustose" corallines grow primarily in two dimensions on hard substrata, avoiding hydrodynamic forces by keeping a low profile. Some crustose corallines grow calcified protuberances, but these stay relatively short to avoid breaking. "Articulated" corallines overcome the mechanical limitations of calcification by growing complex fronds composed of an alternating sequence of calcified segments (intergenicula) and uncalcified joints (genicula). These genicula lend flexibility to the otherwise rigid thalli and allow them to avoid breakage by reconfiguring in the flow.

Articulated corallines have evolved from crustose corallines three separate times in evolutionary history. Genicula in these groups are phylogenetically and developmentally distinct. This apparent example of convergent evolution suggests that flexible genicula are a common solution to producing upright fronds under the mechanical constraints of calcification. Patrick's thesis research examines the biomechanics and material properties of genicula: from the survival and ecology of calcified thalli, to the performance and strength of genicular tissue, to the characteristics of genicular cells and chemical composition of genicular cell walls.

Publications

Martone, P.T. (2006) Size, strength and allometry of joints in the articulated coralline Calliarthron. J. Exp. Biol. 209(9): 1678-1689