Heritability of Traits from Parents to Young

The passing of morphological traits (heritability) from Magellanic penguin parents to offspring was studied by graduate student Laura Koehn. High heritability is important because without inheritance there is no potential for evolution. Laura estimated heritability for four structural traits (bill length, bill depth, flipper length, foot length) by comparing mid-parent size (the average of both parents’ sizes) and offspring size for each offspring gender. Bill size (depth and length) was significantly heritable from mothers and fathers to sons, and foot length from fathers to sons. No traits were significantly heritable from parents to daughters and flipper length was not significantly heritable for any gender. Bill sizes and feet are important for intrasexual competition among male penguins when fighting to obtain a mate or good quality nest. In contrast, females rarely fight and always get a mate. Morphological traits appear less important for females than males in acquiring a breeding site and a mate.  The results suggest intense sexual selection leads to higher heritability for these traits in male offspring.A manuscript of this research is currently under review at the journal The Auk.

Laura’s current research is with the Essington Research Group at the University of Washington’s School of Aquatic and Fishery Sciences and focuses on the relationships between small, pelagic forage fish (such as sardines, anchovies, etc.), their predators including seabirds, and fisheries for forage fish. Read more about this research at: http://faculty.washington.edu/essing/