will speak on
Testing for convergent evolution in semi-aquatic Anolis lizards
Oct. 15th at 12:30 – 1:30pm ET
Anolis lizards are a textbook example of convergent evolution. Independent anole lineages on each of the Greater Antillean islands have converged on the same six ‘ecomorphs’, categories encompassing morphology, ecology, performance, and behaviour. However, the majority of anole species, including those found on continental Central and South America, do not fit neatly into these categories. Of these ‘non-ecomorph’ anoles, there are twelve species which are always found within metres of neotropical streams, swim and dive to escape predators, and consume aquatic prey. Given the prevalence of convergence in anoles, we might expect these semi-aquatic species (that include 6 phylogenetically independent lineages) to exhibit broadscale convergence; yet previous work did not find evidence of morphological similarity between these lizards. To determine if semi-aquatic anoles should be considered a new ecomorph, I conducted a comprehensive study of their morphology, swimming performance, and underwater behaviours. In addition to finding multi-modal evidence of convergence, we also discovered a novel convergent respiratory behaviour that we have called ‘rebreathing’.