Biology

Biology

Spotlight on Student Research

 

Dani Amoroso

Dudleya is a genus of succulent plants. Many species are restricted to narrow geographic ranges, and many closely related forms live in differing climates. Previously, the Wilson lab found an intriguing set of correlations among nine Dudleya: rare species tended to be smaller and to rush to reproduction, whereas more widespread species tended to delay reproduction and grow larger vegetatively. Dani Amoroso set out to study whether such correlations might represent evolutionary trends across the genus more broadly. She studied 21 species, growing them at a coastal garden and an inland garden and measuring survival though the summer without water. She was able to solidly reject the characterization of Dudleya evolution as following trends. Climate-of-origin was unrelated to survival though the summer, seed size, and mature plant size. Also, seed size did not predict germination rate. Amoroso found that the niches of the species have diverged as evidenced by differences in survival between close relatives, but divergence has been quite idiosyncratic for the various pairs of close relatives. Quite possibly the previous results were caused by divergence between two or a very few lineages in combination with phylogenetic conservatism. Advisor: Paul Wilson.