• Molecular evolution of martens (genus Martes)

      Stone, Karen Denise (2000-08)
      Molecular studies provide the opportunity to re-evaluate and further investigate hypotheses such as those related to phylogenetic relationships, inter- and intra-continental colonizations, population differentiation, and the dynamics of hybrid zones. Three sets of molecular markers, nuclear and mitochondrial, were used to examine phylogenetic relationships among species within a holarctically distributed genus (Martes), and intraspecific diversification and population differentiation within American marten (Martes americana). In American marten, two morphological groups ('americana' and 'caurina') have been recognized, though the level of distinctiveness between them has been debated. My data supported the fossil record's indication that early radiations gave rise to two subgenera of the genus Martes (Pekania and Charronia) and that a more recent, possibly rapid, radiation gave rise to species of the third subgenus (Martes). Two colonizations of North America are evident, one by members of the subgenus Pekania, and another by the subgenus Martes. However, contrary to hypotheses based on morphological evidence, the 'americana' and 'caurina' subspecies groups of Martes americana represent only one colonization. Cytochrome b data were consistent with the recognition of these as monophyletic clades; however, aldolase C sequences and microsatellite data indicated that these generaly parapatric groups interbreed in at least one region of limited geographic overlap. These clades probably were isolated during the late Pleistocene in eastern and western refugia, but geographic separation apparently has not led to reproductive isolation. My data also indicated two colonization events for the Pacific Northwest by American martens (one by each clade). Due to patterns of genetic variation, I hypothesize that the 'caurina' clade spread along the North Pacific Coast, including southeastern Alaska, earlier than the 'americana' clade, and that these clades have now formed a zone of secondary contact on Kuiu Island in southeastern Alaska. Microsatellite data revealed population differentiation among many island populations in the Pacific Northwest, but possible gene flow among several near-shore island and mainland populations was suggested. Analyses of genetic and geographic distances suggested that colonization history had a strong effect on present day population structure and that oceanic straits and possibly other physiographic features posed significant barriers to gene flow.
    • Molecular Identification And Analysis Of Treponematosis (Syphilis, Bejel, Yaws, Or Pinta) In Ancient Mummified Remains From Northern Chile And Southern Peru

      Kaye, Michelle; Irish, Joel (2008)
      The sequencing of Treponema pallidum subsp. pallidum, the bacterium that causes syphilis, and the identification of a family of 12 genes with sequence similarity that allows scientists to distinguish between treponemal subtypes has opened up a new line of inquiry for biological anthropologists. This research contributes genetic evidence of pre-contact treponematosis in the Americas; by combining osteological and molecular evidence with data on environment and cultural practices, it also furthers our knowledge of human-pathogen interaction. This research assessed the presence of treponematosis, a bacterial spirochete, in the DNA of skeletal and mummified human remains from northern Chilean cemeteries dating from 5000 BC to AD 1100. The objectives were to: (1) determine whether treponemal DNA could be successfully recovered, amplified, and identified by subspecies from ancient bone and tissue, (2) compare any ancient sequences generated to the modern strains present in the National Center for Biotechnology Information (NCBI) GenBank database, (3) test the null hypothesis that treponematosis was not present in the New World before European contact, and (4) explore which cultural factors may have contributed to the spread of treponematosis in these groups. This research established a foundation for future treponemal studies through the development of primers and protocols for the analysis of ancient treponemes. The results of this study suggest that the inhabitants of this region suffered from a systemic bacterial infection, likely a chronic form of non-venereal treponematosis: yaws or bejel. Potential treponemal DNA was recovered from bone in an individual dated 202 cal BC--cal AD 3 from the Azapa valley. An investigation of Chinchorro artificial mummification suggests that their mortuary practice likely did not result in a higher frequency of treponematosis, as compared to later and inland groups. Rather, status and socioeconomic factors may have played a role in differential infection rates between those mummified in complex styles and those in natural or less complex styles. Further analysis of human remains with suspected treponemal lesions is necessary to reconstruct the history of treponematosis, improve our understanding of their pathogenesis, and guide scientists in developing preventative measures.
    • Molecular Mechanisms Of Metabolic Control In The Arctic Ground Squirrel

      Barger, Jamie Louis; Boyer, Bert (2002)
      The annual cycle of the arctic ground squirrel (Spermophilus parryii) is characterized by periods of intense energy deposition and utilization, and therefore this species an attractive model for investigating the molecular mechanisms of metabolic control in mammals. In late summer, animals become hyperphagic and undergo intense fattening prior to hibernation. Leptin, a hormone produced by white adipose tissue, reverses obesity in rodent genetic models, but the effects of leptin on outbred rodent strains and wild species is modest. Similarly, administration of mouse recombinant leptin did not affect food intake or adiposity during prehibernation fattening in arctic ground squirrels. These results suggest that either prehibernation fattening is insensitive to negative feedback from leptin or that animals in general lack a negative feedback system controlling adiposity. At the terminus of prehibernation fattening, arctic ground squirrels commence hibernation, during which time nonshivering thermogenesis is invoked to maintain a high body temperature relative to sub-freezing ambient conditions. Thermogenesis occurs primarily by uncoupling oxidative phosphorylation and is catalyzed by mitochondrial membrane transport proteins. I compared the expression patterns of an established and a putative uncoupling protein gene (Ucp1 and Ucp3, respectively) in arctic ground squirrels as a function of temperature, hibernation, or fasting. As expected, levels of brown adipose tissue Ucp1 mRNA and protein were increased by cold exposure and hibernation and decreased by fasting. In contrast, levels of Ucp3 mRNA in skeletal muscle were not increased by cold or hibernation, but were paradoxically increased by fasting. Furthermore, I describe two independent studies that show that increases in the amount of UCP3 do not uncouple oxidative phosphorylation in vitro, suggesting that UCP3 does not mediate thermogenesis in skeletal muscle. Finally, I measured several parameters of mitochondrial bioenergetics in active and hibernating arctic ground squirrels to investigate if the reduced metabolic rate during hibernation is attributable to active suppression of metabolic rate or is instead a secondary consequence of the effects of low body temperature on enzyme kinetics. I show that mitochondrial substrate oxidation is depressed during hibernation, supporting the hypothesis that the reduced metabolic rate during hibernation is a partial consequence of active metabolic depression.
    • Molecular phylogenetics of arvicoline rodents

      Conroy, Christopher John; Cook, Joseph A. (1998)
      The impetus for this dissertation was an interest in geographic variation in Microtus longicaudus with a particular focus on populations in the Alexander Archipelago of southeastern Alaska. To establish a framework for interpreting intraspecific variation in M. longicaudus, I examined the phylogenetics of 28 species of the genus Microtus, including all North American species (Chapters 2 and 4). That study, which corroborates a rapid pulse of diversification noted in the fossil record, necessitated a deeper phylogenetic perspective. Thus, a third objective of the dissertation was to investigate relationships among genera of arvicolines within the framework of other murid rodents. I examined variation in the mitochondrial cytochrome b and ND4 genes using maximum parsimony, distance, and maximum likelihood phylogenetic analyses. Relationships at several taxonomic levels appear intractable due to rapid accumulation and survival of genetic lineages. These rapid radiations were found among species, genera, and possibly subfamilies; however, strong support at these levels for other taxa (e.g., the monophyly of Microtus) suggests these genes have strong phylogenetic signal. Many of the well-supported sister species pairs within Microtus (Chapters 2 and 4) had been previously identified based on morphologic or allozyme work (e.g., M. pennsylvanicus and M. montanus, M. pinetorum and M. quasiater). The sequence data supported a clade of taiga dwelling species in North America and a clade of eastern and central Asian species. The southernmost arvicoline species of Mexico and Guatemala, though previously suggested to be derived from a single ancient invasion, did not appear to be either ancient or monophyletic. Within M. longicaudus, a large east-west phylogeographic break was detected that is equivalent in genetic distance to other sister species pairs in the genus. This break may indicate mid to late-Pleistocene differentiation (Chapter 3) within the genus. At higher latitudes, populations of M. longicaudus exhibited evidence of recent range expansion including absence of correlation between geographic and genetic structure; and pairwise mismatches among DNA sequences with a single peak and few differences.
    • Molecular phylogenetics of the Bombycillidae and Limosa (Scolopacidae)

      Spellman, Garth Michael (2000-08)
      The Bombycillidae and their allies and Limosa and their allies represent ideal groups in which to use phylogenetic reconstruction to examine historic patterns of intercontinental colonization between North America and Eurasia and the role of intercontinental colonization in diversification. Molecular phylogenetic reconstruction suggests a Neotropical origin for the Bombycillidae and a subsequent colonization of Eurasia via Beringia, which is an exception to the normal pattern of a faunal exchange between these two continents. Molecular and morphological phylogenetic reconstructions suggest most relationships within Limosa are polytomous. Further analysis of the polytomous relationships indicates that the species of Limosa speciated relatively rapidly in relation to the average age of the lineages, and that intercontinental colonization probably played an important role in their diversification.
    • Molecular Population Genetics And Systematics Of Alaska Brown Bear (Ursus Arctos L.)

      Talbot, Sandra Looman; Follmann, Erich (2006)
      Complete nucleotide sequences of the mitochondrial cytochrome b, tRNAproline and tRNA threonine genes of the eight extant species of ursids, as well as 166 brown bears (Ursus arctos L.) from 10 geographic regions of Alaska and elsewhere, are used to generate hypotheses about phylogenetic relationships among ursids and phylogeographic relationships among brown bears. Additional data were obtained from mitochondrial DNA control region from over 200 brown bears among 14 populations in Alaska, to assess structuring among brown bears. Phylogenetic analyses indicate the giant panda (Ailuropoda melanoleuca) and spectacled bear (Tremarctos ornata) represent basal extant taxa. Ursines, including the sun bear (Helarctos malayanus), sloth bear (Melursus ursinus), Asiatic and American black bears (Ursus thibetanus and U. americanus), brown bear, and polar bear (U. maritimus) apparently experienced rapid radiation during the mid-Pliocene to early Pleistocene. The two black bears appear to be sister taxa; brown and polar bear are the most recently derived of the ursines. Polar bears apparently arose during the Pleistocene from within a clade of brown bears ancestral to populations currently inhabiting islands of the Alexander Archipelago of southeastern Alaska. Thus, brown bears are paraphyletic with respect to polar bears. Parsimony and distance analyses suggest two distinct clades of mtDNA: one (Clade I) composed only of Alexander Archipelago bears, and the other clade comprised of bears inhabiting all other regions of Alaska (Clade II). This latter clade represents bears inhabiting eastern (Clade IIa) and western (Clade IIb) Alaska. Mismatch analysis uncovered a pattern suggestive of recent expansion among some populations comprising Clade IIb. Over 90% of populations in Alaska were significantly differentiated as measured by variance in haplotype frequencies, suggesting limited contemporary female-mediated gene flow and/or shifts in gene frequency through genetic drift. The degree of population genetic differentiation revealed using mtDNA, as well as limited information from comparisons of multilocus microsatellite genotypes from bears representing four Alaska populations, suggests many Alaskan populations are evolving independently. Analyses of molecular variance gave little support for currently accepted subspecies hypotheses. This research has provided new perspectives on processes that drive population structure of brown bears of Alaska and worldwide.
    • Molecular systematics and biogeography of long-tailed shrews (Insectivora: Sorex) and northern flying squirrels (Rodentia: Glaucomys)

      Demboski, John Richard; Cook, Joseph A. (1999)
      Insight into phylogenetic and biogeographic relationships among several mammalian taxa in western North America was provided with DNA sequences of two mitochondrial genes (cytochrome b and ND4). Members of two species complexes of long-tailed shrews (genus Sorex ) and northern flying squirrels (genus Glaucomys) were examined, and a common theme of responses to past climate change and glacial cycles was evident. Diversification events indicated by the DNA sequences provide new perspectives regarding the deep and shallow history of these taxa. Analysis of seven species of the Sorex cinereus complex (and related species) revealed two major clades within the complex, Northern and Southern. These generally corroborate proposed morphological relationships and correspond to broadly defined habitat affiliations (xeric and mesic), respectively. Within the Northern clade, amphiberingian species represented a monophyletic group suggesting Beringia was a center of endemism. Next, five species of the S. vagrans complex and related species were assessed. Significant molecular variation was revealed that does not correspond to morphological differences within the complex. Two major clades within S. monticolus were observed, a widespread Continental clade (Arizona to Alaska, including S. neomexicanus) and a restricted Coastal clade (Oregon to southeast Alaska, including S. bairdi and S. pacificus). A regional examination of genetic variation in the northern flying squirrel in southeast Alaska was also performed. Results suggested that southern islands in the Alexander Archipelago were the result of recent colonization (founder event). Finally, a comparative phylogeographic analysis of a reduced data set (S. monticolus), a molecular data set for the American Pine Marten, Martes americana, and other published molecular studies were used to reexamine the role of glacial refugia in the biogeography of the north Pacific coast. Previous ideas regarding purported refugia may be overstated and may be the result of limited geographic sampling. This thesis provides new perspectives on processes (e.g., post-glacial colonization) driving mammalian phylogenetic and biogeographic structuring in western North America.
    • Molecules to marinescapes: the characterization of microbial life in the Arctic Ocean

      Hassett, Brandon T.; Gradinger, Rolf; Collins, R. Eric; Leigh, Mary Beth; McBeath, Jenifer; Lopez, J. Andres (2016-05)
      Microbes are the base of all marine food webs and comprise >90% of all living biomass in the world’s oceans. Microbial life and functioning in high-latitude seas is characterized by the predominance of unknown species that encode uncharacterized genes, replenish nutrients, and modulate ecosystem health by interfacing with disease processes. This research elucidates eukaryotic microbial diversity and functionality in Arctic and sub-Arctic marine environments by describing the culturable and genetic diversity of eukaryotic microbes and the life histories of marine fungi belonging to the Chytridiomycota. This work includes the description of two new mesomycetozoean species, the assembled and annotated genome of Sphaeroforma sirkka, the first description of a cryptic carbon cycle (the mycoloop) mediated by fungi from any marine environment, and the description of large-scale eukaryotic microbial diversity patterns driven by temperature and latitude in the eastern Bering Sea. These results help establish a valuable baseline of microbial diversity in high latitude seas.
    • Monitoring energy and nitrogen availability for Arctic caribou (Rangifer tarandus)

      VanSomeren, Lindsay L.; Barboza, Perry S.; Bret-Harte, M. Sydonia; Gustine, David D. (2014-12)
      Arctic caribou and reindeer (Rangifer tarandus) are an economically and ecologically important species. Rangifer populations are often affected by nutritional factors. Our ability to monitor nutrient supply to arctic ungulates is presently limited by a lack of techniques to consistently and easily measure availability of specific nutrients and which may disproportionately affect different segments of Rangifer populations. I refined and validated a method to measure availability of specific nutrients including nitrogen (N) and energy to caribou using purified fibrolytic enzymes and acid/pepsin to simulate digestion. I then used this method to measure how availability of nitrogen and energy was altered by anti-nutrients such as indigestible fiber and toxins. Digestible N contents in forages declined to almost zero by the end of the growing season, whereas digestible energy concentrations were still sufficient to meet basic maintenance requirements for caribou by the end of the growing season in shrub and forb forages. Shrubs contained the highest amounts of total N and energy, however this was reduced by fiber and toxins so that shrubs contained the lowest digestible N contents, especially for Betula nana. Graminoids were extremely low in digestible energy content, which may necessitate a high degree of selection among plant parts by herbivores. Dietary choice over long- and short-term periods may be assessed using non-invasive stable isotope techniques, nevertheless, the understanding of how isotopic signatures vary over spatial, temporal, and species-specific scales and how isotopic signatures are changed by digestive processes is limited. Monocot (graminoid) and dicot (browse and forb) forages both differed in values of 13C and 15N, however regional and seasonal shifts in 13C were larger than the differences among forage groups themselves. Forage isotopic signatures also changed after simulated digestive processes, yet this was only significant for species with very low (< 52.6 % N) or very high (> 36.6 % C) digestibilities. These studies suggest that nitrogen may be a limiting nutrient for caribou populations. Persistence of arctic caribou populations in a changing climate may depend, in part, upon continued access to calving grounds, the change in abundance of individual shrub species, and/or the ability of caribou to behaviorally and physiologically cope with increasing amounts of toxins in shrubs.
    • Monitoring small scale explosive activity as a precursor to periods of heightened volcanic unrest

      Worden, Anna K. (Anna Kristine); Dehn, Jonathan; Christensen, Douglas; Webley, Peter (2014-05)
      Volcanic activity can pose a threat to the public and infrastructure. This threat is mitigated by monitoring volcanoes and volcanic activity. In many places this can be hindered by remote location and high cost. Satellite remote sensing is a tool that can be used to safely monitor volcanic activity and aid in the mitigation of hazards and the implementation of hazard preparedness. Small scale explosive activity is often a precursor to periods of heightened volcanic activity. This activity is typified by distinct small explosions that eject hot material onto the flanks of a volcano and can be detected as thermal anomalies by satellite sensors. The aim of this study is to develop a monitoring tool to detect changes in the frequency of small explosions leading up to periods of activity with ash plumes and other volcanic activity. Development of this method was carried out on Stromboli Volcano in Italy, a very reliably eruptive volcano with a wide variety of other monitoring instrumentation collecting data. Once developed, the method was applied to three remote volcanoes in the North Pacific: (1) Chuginadak (Mt. Cleveland) and (2) Shishaldin in Alaska, USA; and (3) Karymsky Volcano in Kamchatka, Russia. The results produced at all four of these volcanoes showed distinct trends in activity, unique to each volcano, prior to periods of heightened eruptive activity. The method provides a baseline for the detection of precursory activity and these trends can be used on other volcanoes undergoing similar types and patterns of eruptive activity.
    • Monitoring stress hormones in rehabilitated and captive otariids

      Petrauskas, Lisa (2005-08)
      Cortisol and corticosterone are the primary mammalian stress hormones released in response to a perceived stressor. Cortisol is rapidly metabolized in the blood, while corticosterone is the dominant product in fecal material. Radioimmunoassay procedures to measure fecal corticosterone and serum cortisol in California sea lions were validated, and adrenal response to surgical and non-surgical procedures was assessed. Other objectives included seasonal and behavioral variability in fecal corticosterone concentrations in captive Steller sea lions, as well as adrenal response to various stressors of a rehabilitated Steller sea lion. There was a significant (P ... 0.05) adrenal response for rehabilitated California sea lions that underwent minor invasive surgical procedures. The small sample size in this study allowed the identification of a correlation of season and behavior in three captive Steller sea lions. This study found that peak fecal corticosterone values reflected responses to acute stressors during rehabilitation for a Steller sea lion pup. Overall, fecal corticosterone was an adequate tool for monitoring stress non-invasive1y in California and Steller sea lions. In turn, the results indicate that California sea lions may be a suitable surrogate species to study the adrenal response to more invasive procedures that may be used in Steller sea lions.
    • The moon was for witches

      Malmberg, Chris (2012-05)
      'The Moon was for Witches' examines characters as they respond to their own impulse to turn memory into narrative. One character questions her ability to recount events accurately and wonders if she is more responsible for a tragedy than she has always believed; Another, in the midst of remembering, wonders at the disparity between his past and current feelings concerning a specific event, finding himself unable to decide which feelings are more real. Each of the characters in this collection wants, more than anything, to reconnect with some truth of an experience he or she recalls, but each finds such a connection impossible to make. They doubt even the fidelity of the stories of their cultures, the grand narratives that make self-consciousness possible. In 'The Moon was for Witches, ' memory is a threatening force which people draw upon for answers but receive only questions, from which any gift of understanding is probably an illusion, even as the nostalgia, pain, and revelations are real.
    • Moose (Alces alces) browse availability and use in response to post-fire succession on Kanuti National Wildlife Refuge, Alaska

      Julianus, Erin L.; McGuire, A. David; Nettleton Hollingsworth, Teresa; Kielland, Knut (2016-08)
      I examined post-fire moose habitat dynamics on Kanuti National Wildlife Refuge in interior Alaska with the objective of increasing understanding of local moose habitat characteristics. I estimated browse density, biomass, and summer browse use in a 2005 burn, 1990 burn, 1972 burn, and an unburned area. I revisited each site the following spring to estimate browse availability and removal during winter. In addition to evaluating browse production and use, I estimated proportional habitat use of varying-aged burns by 51 VHF-collared moose. I found that summer browse production and winter browse availability were highest in the 1990 and 2005 burns. I found that summer and winter browse use was highest in the 1990 burn. Collared moose generally avoided recently burned stands and demonstrated preference for >30 year old stands in both summer and winter. Moose demonstrated preference for unburned stands during calving. Although biomass production and availability were highest in 11 – 30 year old stands, disproportionate use of food resources in burns was evident. This disproportionate use of burns and food resources could be due to a variety of reasons including resource type, historic moose distribution patterns, and predation avoidance strategies.
    • Moose (Alces alces) browse enhancement and sustainable forestry as a rural development tool in the sub-Arctic boreal forest region of Alaska

      Cain, Bruce David (2014-05)
      This project studies indigenous and western moose browse management issues in the sub-arctic boreal forest and how this topic relates to rural development. Chapter one explains the methodology of the project. Chapter two describes how moose browse and biomass management support rural development and investigates productivity potential of combining moose browse management with sustainable forestry and biomass production. Chapter three investigates landscape and habitat management principles from a customary and traditional practice versus a scientific approach. It looks at management models in the following territories: Alaska, Canada, Continental US, Mongolia/Russia and Scandinavia. Chapter four investigates indigenous wildlife management systems and other indigenous wildlife policy issues. Chapter five is a selected annotated bibliography. The project has a focus on the Ahtna region of central Alaska and recognizes the implications of these issues for this region.
    • Moose abundance estimation using finite population block kriging on Togiak National Wildlife Refuge, Alaska

      Frye, Graham G. (2016-12)
      Monitoring the size and demographic characteristics of animal populations is fundamental to the fields of wildlife ecology and wildlife management. A diverse suite of population monitoring methods have been developed and employed during the past century, but challenges in obtaining rigorous population estimates remain. I used simulation to address survey design issues for monitoring a moose population at Togiak National Wildlife Refuge in southwestern Alaska using finite population block kriging. In the first chapter, I compared the bias in the Geospatial Population Estimator (GSPE; which uses finite population block kriging to estimate animal abundance) between two survey unit configurations. After finding that substantial bias was induced through the use of the historic survey unit configuration, I concluded that the ’’standard” unit configuration was preferable because it allowed unbiased estimation. In the second chapter, I examined the effect of sampling intensity on performance of the GSPE. I concluded that bias and confidence interval coverage were unaffected by sampling intensity, whereas the coefficient of variation (CV) and root mean squared error (RMSE) decreased with increasing sampling intensity. In the final chapter, I examined the effect of spatial clustering by moose on model performance. Highly clustered moose distributions induced a small amount of positive bias, confidence interval coverage lower than the nominal rate, higher CV, and higher RMSE. Some of these issues were ameliorated by increasing sampling intensity, but if highly clustered distributions of moose are expected, then substantially greater sampling intensities than those examined here may be required.
    • More than a shelter: a study of indigenous dwellings and contemporary, affordable housing in rural Alaska

      Combs, Esther Marcell (2003-05)
      The purpose of this study was to pursue an innovative idea to address the need for safe, affordable housing in the rural, subarctic area of the State of Alaska. A three pronged approach for data gathering included an extensive historical review of early indigenous cultures and dwelling design; a review of the roles of federal and state governments and their impact on the political economy and lifestyles of rural indigenous people; and interviews of homeowners to obtain their comments, preferences, and suggestions for design features in a home. The conclusions drawn from the findings indicated that the most important feature for a modern house in rural, subarctic Alaska is an enlarged Arctic entry way which was a feature of nearly all of the early indigenous dwellings albeit the simplistic, tunneled entry. Secondly, installation of a standby heat source or a backup, wood stove in homes; and, finally that planning, design and construction of a smaller, simplified house be pursued.
    • More than words: co-constructive dialogue as a strategy for technical, academic language acquisition (TALA) in an indigenous, middle school science classroom

      Ladwig, Joachim H.; Patterson, Leslie; Siekmann, Sabine; Martelle, Wendy (2019-05)
      This teacher action research study investigated how secondary science students respond to small group co-construction activities designed to help them produce collaborative summaries of scientific information. The principle research question guiding this study asks, "How do middle school students engage in content learning and in the use of technical academic language (TAL) during a science writer's workshop?" Building upon the work of previous investigators I studied how emerging bilingual Grade 8 students participated in a science writer's workshop as they co-constructed written summaries in small groups. After initial instruction about the science content, participants worked in table groups to begin their summaries and become comfortable with the process. Participants were regrouped for the final phases of the workshop as they revised their earlier work. Twelve classroom sessions were digitally recorded and from them 25 language-related episodes (LREs) from two small groups were identified for further investigation. LREs were transcribed and analyzed for patterns of student interaction and then correlated with students' written summaries. These deeper interaction patterns became the targeted categories of this investigation: teaming; going beyond the content; and disagreeing. Each of these patterns provide different opportunities for students to learn more about the science content and to use scientific language. The extra time for this collaboration allowed for more TAL usage and seemed to make a meaningful difference in these students' final writings. Further, analysis reveals that TALA is a complex sociocultural process and that the dialogic process inherent in the science writer's workshop is more important than the words alone. In this context, dialogue about science in the context of the science writer's workshop supported both content learning and the acquisition of TAL for these emergent bilingual middle school students.
    • A morphological and genetic investigation of the highest-latitude endemic passerine: McKay's bunting

      Maley, James Michael; Winker, Kevin; McCracken, Kevin; Powell, Abby; Olson, Link (2006-05)
      I used two different approaches to investigate different aspects of the highest latitude endemic passerine, McKay's Bunting (Plectrophenax hyperboreus). I tested whether or not the juvenal plumage of McKay' s Bunting is different from its closest relative, Snow Bunting (P. nivalis). Using light reflectance spectrophotometry to quantify visual differences, I found that McKay's and Snow buntings have significantly different juvenal plumages. This analysis supports their separation into two distinct species. Second, I investigated the genetic consequences of refugial isolation and the model of speciation that the genetic data fit. This species pair provides an excellent opportunity to investigate the genetic effects of speciation at high latitudes in a region known to be significantly impacted by Pleistocene climatic oscillations. Using a mitochondrial marker and anonymous nuclear markers, I found evidence for recent divergence and a very small founding population size of McKay's. After the founder event, there is evidence of a population expansion and a subsequent reduction of the McKay's population, probably as a result of rising sea levels and asymmetric hybridization into Snow Buntings postglacially colonizing Beringia. This recent, high latitude speciation event fits a model of founder effect peripatric speciation driven by a small founding population size and genetic drift.
    • A morphological and genetic review of the Pardosa groenlandica species complex (Araneae: Lycosidae)

      Slowik, Jozef; Sikes, Derek; Winker, Kevin; Cushing, Paula (2011-08)
      The Pardosa groenlandica species complex comprises seven recognized species, P. groenlandica (Thorell 1872), P. dromaea (Thorell 1877), P. tristis (Thorell 1877), P. prosaica Chamberlin and Ivie 1947, P. bucklei Kronestedt 1975, P. albomaculata Emerton 1885, and P. lowriei Kronestedt 1975. These species have overlapping distributions, creating sympatric occurrences with at least one other member of the complex. They can be found in Greenland, throughout Canada, and occur in the United States from the Rocky Mountains to the Pacific coast, through Alaska, and as far as eastern Siberia. These species' genitalia, which bear the primary diagnostic characters, are very similar and show large amounts of within-species and within-population variation. Because of this, they have seen various levels of taxonomic splitting and lumping from one species to the presently recognized seven. I evaluated the utility of the existing morphological diagnostic characters which, if geography is ignored, successfully diagnose only four species (P. albomaculata, P. lowriei, and P. bucklei, with the remaining species synonymized under P. groenlandica). Additionally, I sequenced five genes, two mitochondria) (COI & NDI), and three nuclear genes (ITS 1, 5.8S, and ITS2) of 144 specimens, to help clarify the taxonomy of the species complex. All seven species showed some level of polyphyly or paraphyly in their gene trees. A population genetics analysis of P. groenlandica and P. tristis from Colorado populations failed to find molecular divergence between the populations, raising questions about P. groenlandica occurring in Colorado, and/or the validity of P. tristis. These results question the value of using this genetic dataset to test species delineated using traditional taxonomic methods in the groenlandica species complex of the genus Pardosa. Reconciliation is likely only when genetic markers are studied that match the timing and rate of the observed phenotypic changes.
    • Morphological and phenological responses of butterflies to seasonal temperature increase in Alaska

      Daly, Kathryn Margaret; Breed, Greg A.; Sikes, Derek S.; Mann, Daniel H. (2018-12)
      Climate is changing rapidly at high latitudes, and the responses of insects provide early indications of the impacts these changes have on biota. Butterflies (Lepidoptera: Papilionoidea) are among the best-known Subarctic and Arctic insects, and research in Greenland has revealed significant declines in butterfly body sizes along with advances in the timing of their first flights in spring. These changes are ecologically significant because smaller body sizes can lead to reduced fecundity in butterflies, and earlier adult emergence can have detrimental effects across trophic levels because Lepidoptera are an important food resource for birds and mammals. The primary goal of this thesis is to expand the geographical scope of previous studies of butterfly responses to high-latitude warming by testing whether Alaskan butterflies have exhibited morphological (Chapter 1) and/or phenological (Chapter 2) changes in response to rising temperatures. The morphological parameter studied here is forewing length, and the phenological parameter the timing of the first-observed flight of the year. Results show that the wings of two out of three butterfly species studied from Alaska's North Slope and Seward Peninsula decreased as seasonal (spring and summer) temperatures rose between 1971 and 1995. For every 1° C increase in average seasonal temperatures, wingspans decreased by up to 1.4 millimeters in Alaska. This compares to decreases of up to 0.65 millimeters observed in Greenland. One Alaskan species, Colias hecla Lefebvre 1836, did not show significant change in its wing lengths, although it did exhibit significant decreases in Greenland. Differences in life-history traits among species appear to result in divergent responses in Alaskan butterflies, with Boloria freija (Thunberg, 1791), which overwinters as late-instar larvae, showing the greatest decrease in wing length compared to Boloria chariclea (Edwards, 1883) which overwinters as early-instar larvae. From the start of the collection record in 1966 onward, collection and observational records from Interior Alaska reveal an average phenological advancement of 1 to 5 days/decade in 13 spring-emerging butterfly species. The morphological and phenological changes found in some species of Alaskan butterflies correlate with recent climate change, though the effects differed among species. The eco-physiological responses to climate change observed here for butterflies are likely to be shared by other insect species living at high latitudes.