The energetic costs of sexually selected traits. Design by Anita Weissflog.
Elephant tusks, giraffe weevil heads, and the ornamented plumage of many birds are all examples of sexually selected traits. Competition for reproductive opportunities drives the evolution of many of these extreme structures. These animal weapons and ornaments are sometimes large and conspicuous; they draw our attention and capture our curiosity. However, the fact that sexually selected traits get so big and are so diverse also provides unique opportunities to examine key questions about how animal traits develop, persist, and change. Insects exhibit among the most extreme examples of elaborate or exaggerated traits and provide tractable avenues to uncover the processes that shape these structures.
Sexually selected traits are often tied to energetics and metabolism in fundamental ways - and new findings from the field of metabolic ecology and sub-cellular energetics may provide insight into the shared processes that shape trait exaggeration and diversification. My research integrates research from mitochondrial respiration, natural history, and evolutionary biology to shed new light on long-standing questions in biology:
1) How do these structures grow and develop during ontogeny?
2) What are the selective mechanisms that lead to, and sustain trait exaggeration?
3) What are the physiological processes that allow animals to pay the energetic costs of bearing and maintaining these extreme structures?
4) How are these extreme structures shaped by their evolutionary history across a phylogeny?
My research program focuses on non-model insect systems that often bear exaggerated morphology to provide new perspectives on the factors that may be important in shaping the evolution of these structures. I examine allocation trade-offs during trait growth and development, measure selection in wild populations, measure the muscle, oxygen transport, and mitochondrial properties of animals bearing this extreme morphology, and try to understand the mechanisms by which different species develop shared or unique pathways to grow, use and maintain weapons and ornaments.