I’m a little late on announcing this since I have been in the field in Puerto Rico for the past week, but I’m extremely excited to announce that our manuscript on urban adaptation in Anolis cristatellus is now online as accepted in the journal Evolution!
This paper is the culmination of the first 3 years of my dissertation work on the Puerto Rican crested anole (Anolis cristatellus). In 2012 I analyzed populations of wild urban and forest lizards and found phenotypic shifts in traits related to performance (limb length, lamellae number) and thermal ecology. These trait shifts were in the directions we predicted based on the differences in urban habitats – that is: warmer temperatures because of the urban heat island effect, more open areas with fewer trees, broader perches such as walls, and smooth manmade substrates such as metal, glass, and painted concrete.
After establishing that phenotypes differ between urban and natural populations we knew the next step was to determine if these were genetic shifts or merely plastic responses. I say “merely plastic responses,” but really, plastic responses can be just as important in altering the trajectory of evolution in urban areas. For example, perhaps a plastic response in one trait allows the animals to persist in urban areas while selection slowly acts on other traits to optimize them for their new (and distinctly different) environment. Of course, plastic traits are not inherited and so do not constitute adaptive evolution alone, and so we set out in 2013 to conduct a common-garden experiment. We reared offspring from an urban and a natural population in identical conditions after collecting eggs from wild caught pairs. At a year of maturity, we measured the same traits and found that the shifts in limb lengths and lamellae numbers were in fact preserved in the second generation, indicating that the traits have a genetic component.
So what’s next? I’ve been busy at work since we finished this project in measuring natural selection in the wild via mark-recapture and am currently (as in today!) quantifying differences in performance on various manmade and natural substrates. All this in addition to processing the large amount of data generated from scanning and x-raying over 1500 lizards over the past 5 years! I’ve got more manuscripts in the works, so keep checking back for updates :). I will also be attending the following conferences this year (so be sure to find me and say hi!) – Evolution, JMIH, and ESA (I will be part of the symposium on urban ecology in Latin America).