The Philip M. Smith Graduate Research Grant for Cave and Karst Research

2016 Grants

Oana-Alexandra Dumitru ($2,800)
Ph.D. Candidate
School of Geosciences
University of South Florida

Five-million years of sea-level variability in the Western Mediterranean using cave deposits from Mallorca

Abstract - How quickly sea level rises ranks as a top priority in the Earth sciences. Because over one-third of the world’s population live along coastlines, even a slight rise of sea-level would have a substantial economic and societal impact. For this reason, there is a critical need to precisely predict how quick the sea-level will rise in the next decades and centuries. Past sea-level changes provide considerable insight into Earth’s tectonic and climatic history, and is of great importance to predict possible scenarios of rising seas. Of particular interest are the intervals of warmer-than-today climate, like the Last Interglacial and mid-Pliocene Warm Period (3.3 to 2.9 Ma). Over the past 5 million years repeated flooding events caused by sea-level rise in caves along Mallorca Island’s coasts left distinct carbonate encrustations called phreatic overgrowths on speleothems (POS). Preliminary data show that POS are suitable for absolute dating by using U-Th-Pb methods and they proved to be a valid and precise sea-level marker. All POS located 15 m or more above present sea-level returned preliminary U/Pb ages between 1 and 5 Myr, suggesting warmer-than-today climate, when sea-level rose due to significantly shrinking of northern and southern hemisphere ice sheets. Our aim is to precisely establish the timing, position, and duration of sea level high stands in western Mediterranean over the past 5 million years, using (POSs) from caves of Mallorca.


Jorge Luis Pérez-Moreno ($2,600)
Ph.D. Candidate
Department of Biological Sciences
Florida International University

Evolution in the underworld: Molecular insights from subterranean waters

Abstract- The unique characteristics of aquatic caves and of their predominantly crustacean biodiversity nominate them as particularly interesting study subjects for evolutionary biology. Cave animals usually undergo various distinct physiological, morphological, and behavioral changes, which together are commonly referred to as “troglomorphy.” Troglomorphic modifications can be classified in either progressive (enlarged sensory and ambulatory appendages, increased numbers of chemoreceptor setae, or enhancement of spatial orientation) or regressive (reduced pigmentation, reduction or loss of visual functions, or decreased metabolism) phenotypes, with cave fauna typically presenting a combination of both. The use of current and emerging molecular techniques, e.g. next-generation DNA sequencing, bestows an exceptional opportunity to answer a variety of long-standing questions pertaining to the realms of biogeography, population genetics, speciation, and evolution. I propose to use modern molecular methodologies to examine colonization patterns of caves, phylogeography, evolution, and functional adaptations within a variety of species within the sub-phylum Crustacea. For these purposes, phylogeographic and transcriptomic studies will be undertaken to investigate adaptations of troglomorphic cave life. With these, the present study will result in the discovery of evolutionarily significant patterns among cave fauna, and the underlying mechanisms that permit the survival and evolution of life in extreme environments such as caves.

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