Wednesday, February 24, 2010

Evolution revealed by resurrecting historical resting eggs

Recently published in the January issue of Evolutionary Ecology!

Derry, A.M., S.E. Arnott, and P.T. Boag. 2010. Evolutionary shifts in copepod acid tolerance in an acid-recovering lake indicated by resurrected resting eggs. Evolutionary Ecology 24: 133-145.
http://www.springerlink.com/content/668651t1247q3v18/fulltext.pdf

Long-lived resting eggs of zooplankton are an ecological and evolutionary reservoir that can impact population and community responses to environmental change in lake ecosystems.
I investigated if adaptive shifts in copepod acid tolerance had arisen over a century of environmental change in an acid-recovering lake by resurrecting resting eggs dating from the late 1800s to present. My results suggest that copepods underwent shifts in acid tolerance following both anthropogenic acidification and pH recovery. Further, I found evidence to suggest that maternal effects (the effects of female body condition on the fitness of their offspring) can have an important role for the fitness of older zooplankton genotypes, irrespective of egg age, when historic resting eggs are given an opportunity to hatch into contemporary communities. Adaptive responses through time are important to consider because of their potential to influence community-level interactions in ecosystems recovering from anthropogenic disturbance.

Ben and I are planning to do some individual-based modelling to learn further about the effects of stochastic hatching from historical resting egg banks on contemporary evolution to environmental change.