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Triops (Branchiopoda: Notostraca) and Streptocephalus (Branchiopoda: Anostraca) are two crustaceans which cohabitate in ephemeral freshwater pools. They both lay desiccation resistant eggs that disperse passively to new hydrologically isolated environments. The extent of genetic distance among regions and populations is of perennial interest in animals that live in such isolated habitats. Populations in six natural ephemeral pool habitats located in two different regions of the Sonoran Desert and a transition area between the Sonoran and Chihuahuan Deserts were sampled. Sequences from Genbank were used for reference points in the determination of species as well as to further identify regional genetic distance within species. This study estimated the amount of within and between genetic distance of individuals from each region and population through the use of a neutral marker, cytochrome oxidase I (COI). We concluded that, although the method of passive dispersal may differ between the two genera, the differences do not results in different patterns of genetic distances between regions and populations. Furthermore, we only found the putative species, Triops longicaudatus "short", with enough distinct speciation. Although Triops longicaudatus "long" and Triops newberryi may be in the early stages of speciation, this study does not find enough support to conclude that they have separated.
ContributorsMurphy Jr., Patrick Joseph (Author) / Rutowski, Ronald (Thesis director) / Cartwright, Reed (Committee member) / Lessios, Nikos (Committee member) / School of Life Sciences (Contributor) / School of Human Evolution and Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The giant green sea anemone, Anthopleura xanthogrammica, hosts two different endosymbiotic algae. One is a unicellular chlorophyte, Elliptochloris marina; the other is Symbiodinium muscatinei, a dinoflagellate. Hosting these different symbionts influences the life history strategy of A. xanthogrammica's congener A. elegantissima, directly impacting its reproductive strategy (asexual vs. sexual). My study sought to examine whether the type and density of symbiont also affects the reproductive condition of A. xanthogrammica, which reproduces only sexually. Gonad development was measured in anemones from Slip Point, Clallam Bay, WA and Tongue Point, WA along with symbiont type and density per mg of anemone protein. The results indicate a trend towards brown anemones having more developed gonads, especially in males. This may mean that A. xanthogrammica anemones that host zooxanthellae are more reproductively fit than zoochlorellate anemones. Thus, it may be favorable for anemones to host zooxanthellae. This is especially true in summer months when the high temperatures and mid-day low tides coincide with the period of most rapid gonad development.
ContributorsGasbarro, Ryan Patrick (Author) / Neuer, Susanne (Thesis director) / Rutowski, Ronald (Committee member) / Bingham, Brian (Committee member) / Barrett, The Honors College (Contributor) / School of Earth and Space Exploration (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Two primary contexts for the adaptive evolution of bright coloration are competition for mates (i.e. mate choice) and avoiding predator attacks (i.e. warning coloration). Bright animal coloration can be iridescent, in which the surface appears to change color with changing viewing or illumination angle. Bright animal coloration can also be produced by pigments, which do not appear to change color with changing viewing or illumination angle. The Pipevine Swallowtail, Battus philenor, is unique in having both sexual signals and warning coloration that include iridescent and pigment components, both of which are variable in color. The aim of our study was to examine the role genes play in producing this variation, providing us a sense of potential indirect benefits of female choice. We tested the hypothesis that color variation has a genetic component. We predicted that in a full-sib analysis there should be greater variation in the coloration of the sexual and warning signal among families than within families. We reared B. philenor under standard laboratory conditions and analyzed heritability using a full-sib analysis. We collected reflectance measurements for components of the sexual and warning signal iridescence using a spectrophotometer and used CLR (color analysis software) to extract brightness, hue, and chroma values. We used a multivariate ANOVA (IBM SPSS, v. 21) to analyze the warning signal variation, and a generalized linear mixed model (IBM SPSS, v. 21) to analyze the sexual versus warning signal variation in males. A significance value of 0.05 was used for both analyses. Our results indicated a genetic component to coloration, implicating indirect benefits in B. philenor female mate bias. Further research on bright coloration in B. philenor indicates that there may also be direct benefits of female mate choice.
ContributorsOlzer, Rachel Maureen (Co-author) / Raymundo, Andrew (Co-author) / Pegram, Kimberly (Co-author) / Rutowski, Ronald (Co-author, Thesis director) / Pratt, Stephen (Committee member) / Papaj, Daniel (Committee member) / Barrett, The Honors College (Contributor) / School of Social Transformation (Contributor) / School of Social Sciences (Contributor)
Created2014-12
Description
Rock Doves (Columba livia), also known as pigeons, are a common sight to city dwellers around the world. Often overlooked as urban pests, these birds have intriguing iridescent coloration on their necks that has been the subject of few studies. Previous studies have documented the multimodal reflectance spectra of the iridescence and the keratin cortex microstructures responsible for those properties, but do not address questions about the biological context of this coloration. In this study, I explore the factors that affect how this directional signal might appear to intended receivers (assumed to be females). Pigeon neck feathers were obtained from captive-raised birds and measured for reflectance values at numerous angles in the hemisphere above the feather to obtain a directional reflectance distribution. Each feather was mounted individually, and measurements were taken at a consistent location on the feather using a spectrophotometer; the collector was positioned directly above the feather, while we moved the light source in both azimuth and elevation on a Carden arm to simulate changes in pigeon movements during courtship. Depending on the elevation and azimuth of the light source, pigeon neck feathers shift in appearance from green to purple, with an accompanying shift in the location and intensity of reflectance peaks. Additionally, this unique coloration is due to multiple reflectance peaks in the avian vision field between 300 and 700nm. These data coupled with qualitative behavioral observations of Rock Dove courtship inform our understanding of how the color signal is displayed and how it appears to a potential mate; as a female observes the movements in a male courtship display, properties of the iridescence utilize multiple viewing angles to create a dynamic color array.
ContributorsFankhauser, Kaci Lynn (Author) / Rutowski, Ronald (Thesis director) / McGraw, Kevin (Committee member) / McBeath, Michael (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Historically, the study of cognition has focused on species-specific learning, memory, problem-solving and decision-making capabilities, and emphasis was placed on the few high-performing individuals who successfully completed cognitive tasks. Studies often deemed the success of a small fraction of individuals as suggestive of the cognitive capacity of the entire species. Recently though, interest in individual variation in cognitive ability within species has increased. This interest has emerged concomitantly with studies of variation in animal personalities (i.e. behavioral syndromes). Cognitive ability may be closely tied to personality because the mechanisms by which an individual perceives and uses environmental input (cognition) should influence how that individual consistently responds to various ecological demands (personality). However, empirical support for links between animal cognition and behavioral syndromes is currently lacking. I examined individual variation in cognition and personality in male veiled chameleons, Chamaeleo calyptratus. I considered three axes of personality (aggression, activity, and exploratory behavior) and cognition in a foraging context using visual cues − specifically, the ability to associate a color with a food reward. I found that aggression was positively correlated with the proportion of correct choices and number of consecutive correct choices. Also, one measure of exploration (the number of vines touched in a novel environment) was correlated negatively with the proportion of correct choices and positively with the number of consecutive incorrect decisions. My investigation suggests that more aggressive, less exploratory chameleons were more successful learners, and that there exists a shared pathway between these personality traits and cognitive ability.
ContributorsBruemmer, Sarah Adele (Author) / McGraw, Kevin (Thesis director) / Rutowski, Ronald (Committee member) / Ligon, Russell (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
Human perceptual dimensions of sound are not necessarily simple representations of the actual physical dimensions that make up sensory input. In particular, research on the perception of interactions between acoustic frequency and intensity has shown that people exhibit a bias to expect the perception of pitch and loudness to change together. Researchers have proposed that this perceptual bias occurs because sound sources tend to follow a natural regularity of a correlation between changes in intensity and frequency of sound. They postulate that the auditory system has adapted to expect this naturally occurring relationship to facilitate auditory scene analysis, the tracking and parsing sources of sound as listeners analyze their auditory environments. However, this correlation has only been tested with human speech and musical sounds. The current study explores if animal sounds also exhibit the same natural correlation between intensity and frequency and tests if people exhibit a perceptual bias to assume this correlation when listening to animal calls. Our principal hypotheses are that animal sounds will tend to exhibit a positive correlation between intensity and frequency and that, when hearing such sounds change in intensity, listeners will perceive them to also change in frequency and vice versa. Our tests with 21 animal calls and 8 control stimuli along with our experiment with participants responding to these stimuli supported these hypotheses. This research provides a further example of coupling of perceptual biases with natural regularities in the auditory domain, and provides a framework for understanding perceptual biases as functional adaptations that help perceivers more accurately anticipate and utilize reliable natural patterns to enhance scene analyses in real world environments.
ContributorsWilkinson, Zachary David (Author) / McBeath, Michael (Thesis director) / Glenberg, Arthur (Committee member) / Rutowski, Ronald (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2014-05
Description
This study examines pedestrian walking-side bias in America. We recorded the walking behavior of 430 pedestrian groups and analyzed the left-vs-right passing response around either a stationary obstacle or other oncoming pedestrians. Past research indicates about two-thirds of American pedestrian’s favor walking on the right side of a centrally located inanimate object. We test if this lateral bias is larger for interactions between bypassing people in larger group sizes. We tested two principal hypotheses: H1: Overall, pedestrians will exhibit a right-side passing bias, and H2: The magnitude of the right-side passing bias will increase as a function of group size. Our findings confirm H1: We found a reliable right-side pedestrian bias when pedestrians pass either an inanimate object or other people, a percentage that is similar to past findings. We also confirmed H2: when passing people but not obstacles. When individuals of groups pass other people, biases are additive, with the right-side lateral walking bias increasing by about 10% per additional pedestrian, reaching a ceiling of about 95% rightward paths for groups of five or more. In general, the right-side lateral walking-bias appears to be a prototypical example of a socially trained natural regularity that is readily modified by situational contexts. Findings from this study confirm that small individual biases accumulate into larger biases in groups, a principle that likely has wide ranging generalizability relevant to both the design of locomotive spaces as well as group dynamics in other more abstract socio-relational domains such as political views and prejudice.
ContributorsBills, Koop (Author) / McBeath, Michael (Thesis director) / Langley, Matthew (Committee member) / Rutowski, Ronald (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2022-05