Tests of phenotypic and genetic concordance and their application to the conservation of Panamanian golden frogs (Anura, Bufonidae)

Evolutionarily significant units (ESUs) differ in the extent to which they capture, or even consider, adaptive variation, and most such designations are based solely on neutral genetic differences that may not capture variation relevant to species’ adaptabilities to changing environmental conditions. While concordant patterns of divergence among data sets (i.e. neutral and potentially non‐neutral characters) can strengthen ESU designations, determining whether such criteria are met for highly variable taxa is especially challenging. This study tests whether previously defined ESUs for endangered Panamanian golden frogs ( Atelopus varius and Atelopus zeteki ) exhibit concordant variation among multiple phenotypic traits and mitochondrial DNA sequences, and the extent to which such divergence corresponds to environmental differences. Multivariate analyses identify phenotypic and genetic differentiation consistent with proposed ESUs and support the status of A. varius and A. zeteki as separate species. Moreover, the significant association detected between ESU co‐membership and genetic similarity, which remained strong after removing the effect of geographic distance, also indicates that genetic differences are not simply due to isolation by distance. Two phenotypic characters (body size and the extent of dorsal black patterning) that differ among ESUs also co‐vary with environmental differences, suggesting that to the extent that these phenotypic differences are heritable, variation may be associated with adaptive divergence. Lastly, discriminant function analyses show that the frogs can be correctly assigned to ESUs based on simultaneous analysis of multiple characters. The study confirms the merit of conserving the previously proposed golden frog ESUs as well as demonstrates the utility and feasibility of combined analyses of ecological, morphological and genetic variation in evaluating ESUs, especially for highly variable taxa.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102716/1/j.1365-294X.2007.03369.x.pd

Importance of genetic drift during Pleistocene divergence as revealed by analyses of genomic variation

Determining what factors affect the structuring of genetic variation is key to deciphering the relative roles of different evolutionary processes in species differentiation. Such information is especially critical to understanding how the frequent shifts and fragmentation of species distributions during the Pleistocene translates into species differences, and why the effect of such rapid climate change on patterns of species diversity varies among taxa. Studies of mitochondrial DNA (mtDNA) have detected significant population structure in many species, including those directly impacted by the glacial cycles. Yet, understanding the ultimate consequence of such structure, as it relates to how species divergence occurs, requires demonstration that such patterns are also shared with genomic patterns of differentiation. Here we present analyses of amplified fragment length polymorphisms (AFLPs) in the montane grasshopper Melanoplus oregonensis to assess the evolutionary significance of past demographic events and associated drift-induced divergence as inferred from mtDNA. As an inhabitant of the sky islands of the northern Rocky Mountains, this species was subject to repeated and frequent shifts in species distribution in response to the many glacial cycles. Nevertheless, significant genetic structuring of M . oregonensis is evident at two different geographic and temporal scales: recent divergence associated with the recolonization of the montane meadows in individual sky islands, as well as older divergence associated with displacements into regional glacial refugia. The genomic analyses indicate that drift-induced divergence, despite the lack of long-standing geographic barriers, has significantly contributed to species divergence during the Pleistocene. Moreover, the finding that divergence associated with past demographic events involves the repartitioning of ancestral variation without significant reductions of genomic diversity has intriguing implications — namely, the further amplification of drift-induced divergence by selection.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75590/1/j.1365-294X.2005.02711.x.pd

INTEGRATING COALESCENT AND ECOLOGICAL NICHE MODELING IN COMPARATIVE PHYLOGEOGRAPHY

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73659/1/Appendix+S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/73659/2/j.1558-5646.2007.00117.x.pd

Temperature-Dependent Effects of Cutaneous Bacteria on a Frog’s Tolerance of Fungal Infection

Defense against pathogens is one of many benefits that bacteria provide to animal hosts. A clearer understanding of how changes in the environment affect the interactions between animals and their microbial benefactors is needed in order to predict the impact and dynamics of emerging animal diseases. Due to its dramatic effects on the physiology of animals and their pathogens, temperature may be a key variable modulating the level of protection that beneficial bacteria provide to their animal hosts. Here we investigate how temperature and the makeup of the skin microbial community affect the susceptibility of amphibian hosts to infection by Batrachochytrium dendrobatidis (Bd), one of two fungal pathogens known to cause the disease chytridiomycosis. To do this, we manipulated the skin bacterial communities of susceptible hosts, northern cricket frogs (Acris crepitans), prior to exposing these animals to Bd under two different ecologically relevant temperatures. Our manipulations included one treatment where antibiotics were used to reduce the skin bacterial community, one where the bacterial community was augmented with the antifungal bacterium, Stenotrophomonas maltophilia, and one in which the frog’s skin bacterial community was left intact. We predicted that frogs with reduced skin bacterial communities would be more susceptible (i.e., less resistant to and/or tolerant of Bd infection), and frogs with skin bacterial communities augmented with the known antifungal bacterium would be less susceptible to Bd infection and chytridiomycosis. However, we also predicted that this interaction would be temperature dependent. We found a strong effect of temperature but not of skin microbial treatment on the probability and intensity of infection in Bd-exposed frogs. Whether temperature affected survival; however, it differed among our skin microbial treatment groups, with animals having more S. maltophilia on their skin surviving longer at 14 but not at 26°C. Our results suggest that temperature was the predominant factor influencing Bd’s ability to colonize the host (i.e., resistance) but that the composition of the cutaneous bacterial community was important in modulating the host’s ability to survive (i.e., tolerate) a heavy Bd infection

Integrated Vehicle-Based Safety System arbitration of heavy truck driver-vehicle interface (DVI) warnings

This report was prepared by Battelle, Center for Human Performance and Safety, for UMTRI under contract to the U.S. DOT.The Integrated Vehicle-Based Safety Systems (IVBSS) program is a four-year, two phase cooperative research program conducted by an industry team led by the University of Michigan Transportation Research Institute (UMTRI). The program goal is to integrate several collision warning systems into one vehicle in a way that alerts drivers to potential collision threats with an effective driver vehicle interface (DVI), while minimizing the number of excessive warnings presented to the driver. Basic program strategies for meeting this objective include systematically managing and prioritizing all information presented to the driver, minimizing the number of system false alarms, and restricting auditory alarms to higher urgency collision conditions. This report describes the methods and results associated with the integration and arbitration of DVI messages for the IVBSS heavy-truck program. The goals of message integration and arbitration were to 1) support a timely and appropriate response from the driver; 2) avoid contributing to driver errors, distraction, confusion, or information overload; and 3) support the development of an accurate and functional mental model of the IVBSS by the driver.National Highway Traffic Safety Administration, Washington DChttp://deepblue.lib.umich.edu/bitstream/2027.42/58359/1/101061.pd

ECOLOGICAL AND EVOLUTIONARY IMPLICATIONS FOR THE CONSERVATION OF PANAMANIAN GOLDEN FROGS.

The conservation of endangered species is best achieved by studies that consider both ecological and evolutionary aspects of population viability. Integrative research of this type is especially important for amphibian species as they have been plagued by rapid, global declines and extinctions in recent decades. The aims of this dissertation were to contribute to the conservation of two such declining amphibians, the Panamanian golden frogs, Atelopus varius and A. zeteki, as well as demonstrate the combined utilities of morphological, ecological, and genetic analyses in providing an integrative framework for informing wildlife conservation initiatives. The results of this research engender several important considerations for the conservation of these critically endangered and culturally important amphibians. In my first study, multivariate phenotypic and mitochondrial DNA analyses were used to verify that previously defined management units are supported by concordant patterns of variation among populations as well as to identify phenotypic traits that may be associated with adaptive divergence. The second study examined the contributions of alternative landscape factors to patterns of genetic variation among golden frog populations, highlighting the importance of maintaining the integrity of low slope areas, such as riparian habitat corridors and mountain ridges, for gene flow. The third and final study demonstrated the importance of genetic and phenotypic variability in allowing golden frog populations to adapt to environmental change by examining the relationship between thermoregulation behavior and susceptibility to a fungal epidemic. Here I demonstrated that the behavioral fever response mounted by one golden frog population is effective in reducing the odds of infection during a chytridiomycosis epidemic. I concluded by summarizing the implications of this work for the management of Panamanian golden frogs and considering the applicability of these findings to the conservation of other endangered species of Atelopus.Ph.D.Ecology and Evolutionary BiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/58388/1/clrichar_1.pd

Beyond A Vision For The Future: Tangible Steps To Engage Diverse Participants In Inclusive Field Experiences

Synopsis Recent strides toward improving diversity, equity, and inclusion (DEI) in field biology present a unique opportunity for transdisciplinary exploration of the impacts and state of a topic that has remained hereto largely underexplored and under-discussed in the academic setting. Within current literature, themes of racial and gender inequity, power imbalances, unsafe environments, and underdeveloped infrastructure and resources are widespread. Thus, we organized a symposium that addressed these compelling issues in field biology DEI through a multitude of experiential and academic lenses. This article will orient the reader to the special issue and offer summative goals and outcomes of the symposium that can provide tangible steps toward creating meaningful improvements in the state of DEI and safety in field settings

Assay validation and interspecific comparison of salivary glucocorticoids in three amphibian species

Amphibians are one of the most threatened groups of species, facing stressors ranging from habitat degradation and pollution to disease and overexploitation. Stress hormones (glucocorticoids, GCs) provide one quantitative metric of stress,and developing non-invasive methods for measuring GCs in amphibians would clarify how diverse environmental stressors impact individual health in this taxonomic group. Saliva is an advantageous matrix for quantifying GCs, as it is sampled less invasively than plasma while still detecting both baseline and acute elevation of GCs within a short timeframe. Little work has employed this method in amphibian species, and it has never been pharmacologically and biologically validated. Here, we conduct analytical, pharmacological and biological validation experiments for measuring salivary corticosterone in three amphibian species: the American bullfrog (Rana catesbeiana), the green frog (Rana clamitans) and the northern leopard frog (Rana pipiens). These species are faced with a broad range of environmental challenges, and in part of its range R. pipiens populations are currently in decline. In addition to demonstrating that this method can be reliably used in multiple amphibian species, we present an examination of intrinsic biological factors (sex, body condition) that may contribute to GC secretion, and a demonstration that saliva can be collected from free-living animals in the field to quantify corticosterone. Our findings suggest that saliva may be useful for less invasively quantifying GCs in many amphibian species

Carotenoid Supplementation Enhances Reproductive Success in Captive Strawberry Poison Frogs (Oophaga Pumilio)

Amphibians are currently experiencing the most severe declines in biodiversity of any vertebrate, and their requirements for successful reproduction are poorly understood. Here, we show that supplementing the diet of prey items (fruit flies) with carotenoids has strong positive effects on the reproduction of captive strawberry poison frogs (Oophaga pumilio), substantially increasing the number of metamorphs produced by pairs. This improved reproduction most likely arose via increases in the quality of both the fertilized eggs from which tadpoles develop and trophic eggs that are fed to tadpoles by mothers. Frogs in this colony had previously been diagnosed with a Vitamin A deficiency, and this supplementation may have resolved this issue. These results support growing evidence of the importance of carotenoids in vertebrate reproduction and highlight the nuanced ways in which nutrition constrains captive populations. Zoo Biol. XX:XX-XX, 2013

Advanced EFL learners' beliefs about language learning and teaching: a comparison between grammar, pronunciation, and vocabulary

This paper reports on the results of a study exploring learners’ beliefs on the learning and teaching of English grammar, pronunciation and vocabulary at tertiary level. While the importance of learners’ beliefs on the acquisition process is generally recognized, few studies have focussed on and compared learners’ views on different components of the language system. A questionnaire containing semantic scale and Likert scale items probing learners’ views on grammar, pronunciation and vocabulary was designed and completed by 117 native speakers of Dutch in Flanders, who were studying English at university. The analysis of the responses revealed that (i) vocabulary was considered to be different from grammar and pronunciation, both in the extent to which an incorrect use could lead to communication breakdown and with respect to the learners’ language learning strategies, (ii) learners believed in the feasibility of achieving a native-like proficiency in all three components, and (iii) in-class grammar, pronunciation and vocabulary exercises were considered to be useful, even at tertiary level. The results are discussed in light of pedagogical approaches to language teaching