This week EEB welcomes Dr. Rute Clemente-Carvalho from the Department of Biology, Queen’s University:
What are the implications of miniaturization in amphibian body size – a remarkable example in the genus Brachycephalus
Body size matters in evolution because it contributes to ecological divergence and accompanies adaptive radiations in many clades. Drastic size changes, such as miniaturization, have been documented in all three amphibian Orders, and have evolved independently many times. Although diminutive size makes the amphibians more vulnerable to desiccation and predation, it also enables them to hide more easily, exploit alternate food sources, use physically smaller niches, and attain reproductive maturity at an earlier age. In addition, miniaturization is also followed by morphological novelties.
Toads of the genus Brachycephalus are endemic to the Atlantic rainforests of northeastern, southeastern, and southern Brazil, and are an outstanding example of miniaturization. In fact, one species, B. didactylus, is among the smallest frogs in the world, with a snout-vent length of just 10.2 mm. A remarkable phenotypic feature among Brachycephalus species is a gradient in the degree of mineralization of the skeleton, loss of cranial elements, fingers and toes, and morphological changes in structures such as the pectoral girdle. In my presentation, I will explore Brachycephalus morphological diversity, and its relationship with the phylogenetic hypothesis proposed, using a multilocus approach based on nuclear and mitochondrial genes.
The EEB Seminars run weekly, on Thursdays, in the EEB Lounge of the BioSciences Complex, Room 4338, from 12:30-1:30pm. Light refreshments are served starting at 12:15.