Monty A. Hawkins and Drs. Jack W. Sites Jr. and Brice P. Noonan, Biology

The lesser tree frog (Hyla minuta) is found in abundance throughout most of South America. Earlier studies have suggested that this taxon includes populations which differ significantly in ecological (Cardoso & Haddad, 1994) and morphological (Kaplan, 1994) characteristics (fig 1), and may include unrecognized species. Noticeable phenotypic variation occurs among populations (Figure 1). However to date little work has been done to determine the number of species that may be masquerading under the identity of H. minuta.

This research is the first of its kind to examine biological patterns across the Guiana Shield. Nor has a comprehensive study of the species Hyla minuta been done before. The results provide information that will aid in the identification of important areas within the Guiana Shield whose protection will serve to preserve and protect previously unidentified and endangered species. It will also assist the ongoing work to catalogue the biodiversity of the Guiana Shield.

As we better understand what climatic and geological events have driven speciation throughout the Guianan region, we will be able to determine where different biotic regions are found. As we identify the location of each biotic region we will highlight certain species that are not found within existing protected areas, and thereby contribute to ongoing planning of a regional reserve network to conserve the important biodiversity of this region.

The necessary DNA for this study was obtained from tissue samples collected from different areas of the Guiana Shield by Dr. Brice Noonan and collaborators from three other institutions. DNA was extracted from these tissues and then used to amplify a 750 base pair segment of the mitochondrial cytochrome oxidase-1 (CO1) and a 1000 base pair segment of the autosomal locus pinin (PNN). The amplified DNA segments were then submitted to the BYU DNA Sequencing Center. We have collected data from 90 individuals for these two different genes. The resulting sequences have been edited, aligned, and subjected to several methods of population, genetic and phylogeographic analyses to delimit species and reconstruct demographic histories. The results will help us be able to reconstruct some of the events that gave rise to the current biodiversity of the Guianan region.

In addition to the molecular work described above, I have also examined 29 different museum specimens and collected morphological data from these in an attempt to diagnose what appear to be different species within our Guianan H. minuta. The results of the morphological examination concur with Kaplan (1994) who suggests that what we currently recognize as H. minuta is actually a complex of species. These specimens I examined undoubtedly represent a complex of species that necessitate further work before species boundaries can be defined.

This research was supported by the ORCA Allen Y. V. Eng Signature Mentorship, the Department of Integrative Biology Travel Grant, the Department of Integrative Biology Undergraduate to Present, and the NSF Undergraduate Mentoring in Environmental Biology Grant. This support allowed me to present the results of this research at two international scientific meetings. I gave an oral presentation (March 2006) at the First International Congress on the Biodiversity of the Guiana Shield in Venezuela (presentation in Spanish) and a poster presentation in (June 2005) at the Evolution meetings in Fairbanks, Alaska. I am currently co-authoring a manuscript on this project to be published in the peer-reviewed journal Check List.

Sources

• Cardoso, AJ & CBF Haddad (1984) Variabilidade acústica em diferentes populaces aggressivas de Hyla minuta (Amphibia, Anura). Ciência e Cultura, 36, 1393-1399
• Kaplan M (1994) A new species of frog of the genus Hyla from the Cordillera Oriental in northern Colombia with comments on the taxonomy of Hyla minuta. Journal of Herpetology, 28, 79–87.