Who among us has not pondered the answer to this question? Well, I certainly have, and I am trying to answer it by studying marmots. I’m combining behavioral data with a marmot family tree to determine the heritability of various traits in this rodent population. Heritability is a fancy way of quantifying the extent to which your particular, individual genetic makeup influences who you are, what you look like, and how act. I’ve studied the heritability of running speed, wariness, foraging behavior, social behavior, and mass gain rate in marmots. Some traits are highly influenced by environmental variation, like changes in weather and food supply, while other traits are largely attributed to genetic differences among individuals. Furthermore, some traits are linked to each and occur within individuals in predictable patterns.
These patterns and heritability estimates are important to those of us that think about evolution, because a trait’s potential to change and respond to selection (i.e. evolve!) is influenced by its heritability as well as its relationship with other traits. By quantifying selection and heritability in natural populations, I seek to understand past, present, and potential future modes of evolution. Furthermore, the analysis methods I use allow me to identify other non-genetic factors that, combined with heritability, explain marmot behavior.