Staff Profiles

Santiago Castroviejo-Fisher

Research Associate

+1 (212) 769-5734
+1 (212) 769-5031
  • Research Interests

    Research Interests

      As an evolutionary biologist and zoologist, my main interests are to study, describe, name, and understand the diversity of life with an emphasis on organisms and species. To study current diversity I mainly use a historical approach based on disciplines such as phylogenetic systematics and biogeography. Inferring evolutionary history allows me to understand things such as phenotypic evolution, the origin and causes of the distribution of organisms, and species boundaries. I have focused my research on amphibians and reptiles of tropical America and, to a lesser extent, Africa.

      Current Research

      Amazon Biodiversity

      The Amazon Lowland rainforest, with more than 6 million Km2, harbors more than a quarter of Earth’s biodiversity. Nonetheless, its fauna and flora have been poorly studied even at the taxonomic level. Most studies in the region have been sporadic and based on few specimens from one or few localities. 

      In this project we aim to answer a series of questions related to the amazing levels of biodiversity in the Amazon. How did this diversity originate? How much of this diversity is still unknown to science? How much diversity are we loosing with habitat destruction? How much diversity are we protecting by creating a new national park?

      We are using amphibians as a study case to understand the diversity of the Amazon. We are applying a multidisciplinary approach that integrates classical disciplines such as taxonomy with recently developed techniques such as molecular phylogenetics, phylogeography and statistical bioacoustics. This multidisciplinary approach will allow us to identify areas of high species richness and endemism, evaluate the causes of the observed diversity and point out those linages that are evolutionarily unique. 

      I am coordinating this project together with José Manuel Padial, Andrew J. Crawford, and Ignacio De la Riva. This project is based on a network of collaborators including scientists from: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru and Venezuela

      Systematics and Evolution of Glassfrogs (Centrolenidae)

      During my PhD at Uppsala University, Sweden I studied glassfrog systematics, biogeography and evolution. I am still active in this research line and work in close collaboration with other scientists. Together with Juan Manuel Guayasamín we are studying the historical biogeography of centrolenids using sequences from 10 markers with roughly 60% species coverage. I also collaborate with Marco Rada in his Ph.D. thesis on the phylogenetic relationships of glassfrogs.

      Phenotypic Disparity and Concerted Evolution

      Why is phenotypic variability unevenly distributed among clades? This is a long-standing question in evolutionary biology and we are using glassfrogs as a model to study this pattern.

      Centrolenids are an excellent group to study the evolution of phenotypic disparity. The genus Hyalinobatrachium, 28 species, is one of the oldest clades of glassfrogs and is extremely monophormic showing little variation in its bauplan when compared to the remaining 11 genera. All Hyalinobatrachium species reproduce on the underside of leaves, i.e., males call from this side of leaves and females lay their egg clutches at or near calling sites. Thus, I hypothesize that once glassfrogs evolved the ability to reproduce on the underside of leaves, this new reproductive strategy imposed strong stabilizing selection on the morphology of these glassfrogs. Such stabilizing selection may constrain Hyalinobatrachium and other glassfrogs that have a similar reproduction strategy to be smaller, lighter, more transparent and with certain body proportions.

      I am doing this project in collaboration with Dayanna L. Sánchez Martínez, Andrew J. Crawford, Juan Manuel Guayasamín,Alejandro González Voyer and Marco Rada.


      Why do some groups of organisms have substantially more species than others? To try to answer this central question in biology we study diversification rates (speciation – extinction) and its relationships to intrinsic (e.g., phenotypic characters) and extrinsic (e.g., biogeographical events) variables. Currently, I am collaborating with José Manuel Padial and Alejandro González Voyer in this topic. In a first work, we are investigating the main causes behind the major amphibian radiation: Terrarana.

      Species Delimitation and Integrative Taxonomy

      Species is one of the most complex and debated concepts in biology. However, it is a fundamental unit of comparison in science and it is widely used by stakeholders (conservation, biomedicine, pest control, etc.). Thus I think it is very important to develop solid theoretical and practical basis to delimit species. Together with José Manuel Padial and Ignacio De la Riva, I have explored the use of multiple and independent lines of evidence under the evolutionary species concept to establish species boundaries.

  • Publications