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Gainesville, FL, United States

Kornilev Y.V.,University of Florida | Dodd Jr. C.K.,University of Florida | Johnston G.R.,Santa Fe College
Chelonian Conservation and Biology | Year: 2010

A decreased tannin load during 2006-2007 in a northern Florida blackwater river allowed us to make observations on the ecology of the Suwannee cooter (Pseudemys concinna suwanniensis), a species otherwise usually studied in clear, spring-fed rivers. We conducted a capture-mark-recapture study of this protected species and recorded the locations of marked individuals throughout a >7.4-km study site for >5 months. Large Suwannee cooters can be highly vagile and are capable of covering long distances rapidly (>1.5 km in a day), with few individuals found >5 km from previous capture locations. For large turtles, the propensity to move across different habitats and the size of the actively used linear home range varied extensively and were best explained by individual variation rather than by sexual differences. We observed an abundant population, including all size classes. Turtle distribution throughout the site was unequal among river sections and was positively correlated with the number of basking sites and water depth. We recommend basking counts to monitor population trends in blackwater rivers, especially under conditions of high tannin concentrations when hand capturing turtles is difficult. © 2010 Chelonian Research Foundation.

McGraw W.S.,Ohio State University | Vick A.E.,Santa Fe College | Daegling D.J.,University of Florida
American Journal of Physical Anthropology | Year: 2014

We present information on food hardness and monthly dietary changes in female sooty mangabeys (Cercocebus atys) in Tai Forest, Ivory Coast to reassess the hypothesis that thick molar enamel is parsimoniously interpreted as a response to consumption of hard foods during fallback periods. We demonstrate that the diet of sooty mangabeys varies seasonally, but that one food - Sacoglottis gabonensis - is the most frequently consumed food every month and year round. This food is the hardest item in the sooty diet. Given that this species has among the thickest enamel within the primate order, a plausible conclusion is that thick enamel in this taxon evolved not in response to seasonally critical function or fallback foods, but rather to the habitual, year round processing of a mechanically protected foodstuff. These data serve as a caution against de rigueur interpretations that reliance on fallback foods during lean periods primarily explains the evolution of thick enamel in primates. Am J Phys Anthropol 154:413-423, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Gulley J.D.,630 Dow Environmental science | Martin J.B.,University of Florida | Moore P.J.,University of Florida | Moore P.J.,ExxonMobil | Murphy J.,Santa Fe College
Earth Surface Processes and Landforms | Year: 2013

Formation of extensive phreatic caves in eogenetic karst aquifers is widely believed to require mixing of fresh and saltwater. Extensive phreatic caves also occur, however, in eogenetic karst aquifers where fresh and saltwater do not mix, for example in the upper Floridan aquifer. These caves are thought to have formed in their modern settings by dissolution from sinking streams or by convergence of groundwater flow paths on springs. Alternatively, these caves have been hypothesized to have formed at lower water tables during sea level low-stands. These hypotheses have not previously been tested against one another. Analyzing morphological data and water chemistry from caves in the Suwannee River Basin in north-central Florida and water chemistry from wells in the central Florida carbonate platform indicates that phreatic caves within the Suwannee River Basin most likely formed at lower water tables during lower sea levels. Consideration of the hydrological and geochemical constraints posed by the upper Floridan aquifer leads to the conclusion that cave formation was most likely driven by dissolution of vadose CO2 gas into the groundwater. Sea level rise and a wetter climate during the mid-Holocene lifted the water table above the elevation of the caves and placed the caves tens of meters below the modern water table. When rising water tables reached the land surface, surface streams formed. Incision of surface streams breached the pre-existing caves to form modern springs, which provide access to the phreatic caves. Phreatic caves in the Suwannee River Basin are thus relict and have no causal relationship with modern surficial drainage systems. Neither mixing dissolution nor sinking streams are necessary to form laterally extensive phreatic caves in eogenetic karst aquifers. Dissolution at water tables, potentially driven by vadose CO2 gas, offers an underappreciated mechanism to form cavernous porosity in eogenetic carbonate rocks. © 2012 John Wiley & Sons, Ltd.

Daegling D.J.,University of Florida | McGraw W.S.,Ohio State University | Ungar P.S.,University of Arkansas | Pampush J.D.,University of Florida | And 2 more authors.
PLoS ONE | Year: 2011

Morphology of the dentofacial complex of early hominins has figured prominently in the inference of their dietary adaptations. Recent theoretical analysis of craniofacial morphology of Australopithecus africanus proposes that skull form in this taxon represents adaptation to feeding on large, hard objects. A modern analog for this specific dietary specialization is provided by the West African sooty mangabey, Cercocebus atys. This species habitually feeds on the large, exceptionally hard nuts of Sacoglottis gabonensis, stereotypically crushing the seed casings using their premolars and molars. This type of behavior has been inferred for A. africanus based on mathematical stress analysis and aspects of dental wear and morphology. While postcanine megadontia, premolar enlargement and thick molar enamel characterize both A. africanus and C. atys, these features are not universally associated with durophagy among living anthropoids. Occlusal microwear analysis reveals complex microwear textures in C. atys unlike those observed in A. africanus, but more closely resembling textures observed in Paranthropus robustus. Since sooty mangabeys process hard objects in a manner similar to that proposed for A. africanus, yet do so without the craniofacial buttressing characteristic of this hominin, it follows that derived features of the australopith skull are sufficient but not necessary for the consumption of large, hard objects. The adaptive significance of australopith craniofacial morphology may instead be related to the toughness, rather than the hardness, of ingested foods. © 2011 Daegling et al.

Carrigan M.A.,Santa Fe College | Uryasev O.,Foundation for Applied Molecular Evolution | Frye C.B.,Foundation for Applied Molecular Evolution | Eckman B.L.,Foundation for Applied Molecular Evolution | And 3 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

Paleogenetics is an emerging field that resurrects ancestral proteins from now-extinct organisms to test, in the laboratory, models of protein function based on natural history and Darwinian evolution. Here, we resurrect digestive alcohol dehydrogenases (ADH4) from our primate ancestors to explore the history of primate-ethanol interactions. The evolving catalytic properties of these resurrected enzymes show that our ape ancestors gained a digestive dehydrogenase enzyme capable of metabolizing ethanol near the time that they began using the forest floor, about 10 million y ago. The ADH4 enzyme in our more ancient and arboreal ancestors did not efficiently oxidize ethanol. This change suggests that exposure to dietary sources of ethanol increased in hominids during the early stages of our adaptation to a terrestrial lifestyle. Because fruit collected from the forest floor is expected to contain higher concentrations of fermenting yeast and ethanol than similar fruits hanging on trees, this transition may also be the first time our ancestors were exposed to (and adapted to) substantial amounts of dietary ethanol.

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