Interactions between environmental stress and genetic diversity in reef building corals

Open Access
Author:
Polato, Nicholas Renzo
Graduate Program:
Ecology
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
March 01, 2012
Committee Members:
  • Iliana Brigitta Baums, Dissertation Advisor
  • James Harold Marden, Committee Member
  • Stephen Wade Schaeffer, Committee Member
  • Francesca Chiaromonte, Special Member
Keywords:
  • Coral
  • population structure
  • microsatellite
  • thremal stress
  • microarray
  • GxE interactions
  • climate change
  • gene expression
Abstract:
In corals, dispersal is accomplished during a brief larval phase during which rapidly developing embryos are transported by the currents to potential settlement sites. Demographic viability and genetic structure of adult populations are defined in large part by variation in larval survival and duration of the larval phase. Changing climate patterns in the world's oceans are driving extreme temperatures during the summer months when many corals reproduce, and even minor temperature increases during this important life history phase have profound effects on both larval survival and duration. In this context, an assortment of molecular tools, targeting both neutral and functional variation, have been applied to coral populations to understand post dispersal patterns of genetic structure in adult populations, and the physiological response of developing larvae to thermal stress. Results suggest that important variation in both environmentally plastic and genotypically defined traits exists within populations and may contribute to the ability of corals to adapt to warming seas. The conclusions of this research show that coral species possess important variation within and among populations. This variation affect traits that are expected to directly influence the development and performance of larvae under thermal stress. These observations raise the hopes that coral populations do possess sufficient variation in adaptively relevant traits to deal with rising sea surface temperatures.