Variable Development

At the organismal level, embryos and larvae are also subject to environmental variation in the water column and are capable of receiving environmental cues and of responding with adaptive modulation of developmental timing, morphogenesis, and/or behavior. Plasticity of developmental timing, morphology, and behavior in embryos/larvae has been documented across multiple phyla in response to different environmental parameters, but the molecular mechanisms and the functional ecological and evolutionary consequences are just now being illuminated. Behavior is often considered as a primary mode of adaptive response since it is so flexible on rapid timescales.  However, early in development, organisms may be more developmentally plastic than their adult counterparts; and thus, they may be able to respond to environmental challenges on ecological timescales via changes in developmental timing or form, providing another important mechanism for adaptation to an increasingly variable environment.

I integrate different areas of biology including marine ecology, developmental biology, and neuroscience to elucidate the molecular mechanisms of developmental plasticity in larvae and embryos. I am interested in how the larvae receive environmental cues and translate those cues into developmental changes in timing or form. Defining the molecular mechanism, allows me to experimentally manipulate the response to address the adaptive value, costs, and buffering capacity (limits) of the plastic phenotypic responses.

My recent work has focused on one such developmental response: the growth of sea urchin larval feeding structures relative to food availability.  Altered temperatures have the downstream affect of potentiating trophic mismatches such that food may not be available while the larvae are in the water column.  This may be especially problematic for sea urchins; in the North Sea, the seasonal peak of echinoderm larvae in the plankton has shown a larger shift forward than many of their potential prey (Edwards & Richardson, Nature 2004).  Alteration of feeding structures or feeding behaviors to increase food acquisition could thus be essential to mediating temporal variation in trophic match/mismatches. Pre-feeding sea urchin larvae can detect the availability of algae and adjust the size of their feeding apparatus accordingly - large if low food, small if high food.  But how do they detect the algae and subsequently alter their morphological development?  Is this response adaptive?  Can it buffer against potential trophic mismatches?

updated 12/08/2010