Difference between revisions of "Colin Carlson"

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[[Category:EEB People]]
 
[[Category:EEB People]]
  
I am a first semester Honors junior in EEB, and I work with [[Tobias Landberg]] on a research project studying the behavior and morphology of the common snapping turtle (''Chelydra serpentina''), based on footage from a Crittercam project. The footage, collected over the summer, was from three turtles: Jawless and Lafayette from Wethersfield Cove, and Snippy from Shenipsit Lake.  
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[[Image:Anysberg.jpg|365px|left]]
(see the [[snapping turtle research team]] page for the full story on the turtles). Also, for more information on Crittercam itself, visit [http://www.nationalgeographic.com/crittercam/ National Geographic's Crittercam Homepage].  
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I am Master's student in EEB. In 2012, I graduated from UConn with a B.S. in EEB and a B.A. in Environmental Studies. I'm currently studying plasticity in the genus ''Pelargonium'', for which I was awarded a '''[http://act.org/goldwater/sch-2011.html 2011 Goldwater Scholarship]'''. I was also named a '''[http://udall.gov/OurPrograms/MKUScholarship/MKUScholarship.aspx 2010 Udall Scholar]''' and a '''[http://truman.gov/meet-our-scholars/meet-our-scholars-detail?ScholarUserId=c0224ca5-ed75-4c1a-b66e-574db4b54d24 2011 Truman Scholar]''' for my environmental work on and off campus.  
 
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The purpose of this project is to analyze the behavior of the turtles based on the Crittercam data. This analysis encompasses the breath, dive, pausing, walking, and other aspects of locomotion of the three turtles.
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===Research Interests===
 
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Plant conservation and climate change; functional and evolutionary ecology; ecological modelling.
==Snapping Turtle Research==
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===Quantified Behaviors===
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==Current research: plasticity and climate change (2010-present)==
In all of the analyses, it was important to describe behaviors with a simple terminology. In my work on this project, I've decided upon a set of six different behaviors. The two most straightforward behaviors are breathing, in which the turtle comes up from the water and sticks out its head (either partially or fully) to breathe, and pausing, in which the turtle simply stays in place. The remaining four behaviors all occur during locomotion. Two of these are vertical swimming (swimming down from the surface of the water to the bottom, or swimming up from the bottom to the surface); moreover, horizontal swimming was also considered independently. Finally, "walking" along the rocky or sandy bottom of the body of water was considered a separate behavior from horizontal locomotion. The differences between these distinct behaviors are even clearer when considering the limb locomotion rates during these behaviors, discussed below.
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''"All is leaf, and through this simplicity the greatest multiplicity is possible." - Johann Wolfgang von Goethe''
  
In order to analyze these behaviors quantitatively, other related factors were brought into play: for instance, the amount of time the turtle spent during one "bout" of a particular behavior (which was often reduced to the amount of time visible on the camera, due to unclear or murky footage) was a useful measurement that helped determine each individual turtle's most common behavior. Another more quantifiable analysis was of limb cycle frequency, which was measured as (number of cycles)/(time), or in short, cycles/s. A cycle was defined as a movement of the front right limb, followed by a movement of the front left limb.
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My current research began as a simple project focusing on light-induced leaf shape dimorphism in South African ''Pelargonium'' L’Her (Geraniaceae). The focus of this research can be condensed into the following three questions:
  
===Breath-Dive Analysis===
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1. For what traits, in what species, is leaf shape plastic? (The "what?")
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2. Does selection appear to act on plasticity itself, and at what spatial/phylogenetic levels? (The "why?")
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3. Have leaf traits evolved independently in their plasticity, and is there any suggestion of evolutionary/environmental constraints on these traits and/or their plasticity? (The "how?")
  
[[Image:Breath Histograms.jpg|thumb|left|180px|Fig. 1: Breath duration histograms for the three turtles. From top to bottom, data collected from: Jawless, Lafayette, Snippy. Note that each graph is roughly centered at a different location.]]
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With the help of a CCB Summer Undergraduate Research Award, I traveled to South Africa during the summer of 2010 with the [http://hydrodictyon.eeb.uconn.edu/eebedia/index.php/South_Africa_-_IRES_2010 NSF IRES 2010 group] to measure leaf shape variation in a natural context. For the next year, I studied plasticity experimentally at UConn, examining plastic responses to water stress and shade cues, as well as the associated fitness costs and phylogenetic patterns of this phenotypic flexibility. In many ways, ''Pelargonium'' is an ideal model organism for testing theories of phenotypic plasticity's role in adaptive radiation, given its surprisingly high diversity and the impressive, widespread and diverse nature of plasticity in the genus.
[[Image:Dive Histograms.jpg|thumb|right|180px|Fig. 2: Dive duration histograms for the three turtles, in same order as Fig. 1.]]
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[[Image:red.jpg|285px|left]]
  
The results of this analysis, which are summarized in Fig. 1 and 2, were different for all three of the turtles, yet there are shared trends in their breathing and diving behavior, and these trends indicate a relationship between these two behaviors.  
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After completing these projects, I entered a new phase in my research, focused on turning our new understanding of the limits and costs of plasticity into valuable information on species vulnerability to climate change. The project focused in particular on evaluating the vulnerability of ''P. elongatum'', a species that is currently classified as Least Concern in South Africa, and that has displayed tremendous plasticity in both natural and experimental settings. ''P. elongatum'' has served as a "testing ground" for a novel set of spatially-discrete models that include the costs of plasticity into otherwise entirely climate-driven ecological niche models, with the goal of understanding the consequences of potentially-costly plasticity for population survival.
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Thus far, these models have suggested that the future of ''P. elongatum'' is strongly dependent on demographic conditions, and while the species may indeed be low priority for conservation, a very small range of variation in seed and adult survivorship could even have the ability to drive the species to extinction in the next ten years. (More about these findings will be presented this April at Frontiers in Undergraduate Research and the results of the models are also currently being prepared for publication.) Ultimately, it is my hope that this project will take a crucial first step towards applying theoretical models of plasticity and extinction risk to actual high-diversity, high-plasticity, high-risk clades.  
  
Statistical analyses indicate a strong relationship between breath and dive duration, especially for Snippy. These factors of breath and dive duration ultimately go hand in hand. I have also statistically tested this fit, and found a strong positive correlation. The order of breaths relative to dives is not significant: the fits with dive length are equally significant for a breath and the preceding dive, and the breath and following dive. The lack of a difference is nevertheless an important result, as it indicates the turtles are neither "preparing for" or "recuperating from" dives. This is not to say these are not possible explanations for some of this behavior, but instead, the data is inconclusive as to whether these are in fact components of the turtle's breathing behavior.
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==Other research projects==
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====Snapping Turtle Research (2008-2010)====
  
Another important conclusion that could potentially be drawn from this data pertains to the influence of landscape on these turtles' behavior. For breath duration, which is summarized in Fig. 1, the three turtles were each slightly different, yet Jawless and Lafayette were more similar to eachother than to Snippy. This is also true of the distribution of dive durations for the three turtles, summarized in Fig. 2. A potential explanation of this difference is based on the depth of the water the turtles were inhabiting during the filming: whereas Jawless and Lafayette are in shallow water and so do not have to swim vertically as much as Snippy (who is in much deeper water), which may reduce the turtles' need to breathe longer breaths. Nevertheless, there are differences between Jawless and Lafayette, as turtles are like fingerprints: no two are exactly the same.
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This project analyzed the behavior of three Snapping Turtles (''Chelydra serpentina'') along the Connecticut river. The footage, collected over the summer, was from the turtles Jawless and Lafayette from Wethersfield Cove, and Snippy from Shenipsit Lake. (see the [[snapping turtle research team]] page for the full story on the turtles). Also, for more information on Crittercam itself, visit [http://www.nationalgeographic.com/crittercam/ National Geographic's Crittercam Homepage]. This analysis encompassed the breath, dive, pausing, walking, and other aspects of locomotion of the three turtles. If you would like to read more about the actual data analysis, check out [[Snapping Turtle Research: Analyses and Conclusions]].
  
===Pausing Behavior & Limb Frequency Cycles===
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My research on this project was divided into two main stages. First came an analysis of the duration and frequency of breathing and diving behaviors, which revealed a strong positive relationship between breath and dive duration. Second, I described behavioral patterns in the turtles through an analysis of locomotion that was divided into five sub-categories, and I found strong differences between average limb frequency cycles.
  
The first stage of locomotion analysis in my snapping turtle research was a preliminary analysis of when the turtles paused, and when the turtles were locomoting. This analysis did ''not'' include when the turtle was breathing, and did not differentiate between different forms of locomotion. This analysis provided a framework for knowing when the turtles were pausing. The analysis was thus a preparatory step to simply get a sense for the overall behavior trends, before beginning the more specific and quantified analysis.
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====Sacred Groves and Community-based Conservation (2010-2012)====
[[Image:JawlessEscapes.jpg|thumb|left|200px|Fig. 3: Jawless Locomotion Data Over Time. Cycles per second are plotted over locomotion bout number. Note the negative trend.]]
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As sacred groves are one of the most ancient forms of community-based conservation, my Environmental Studies senior thesis seeks to understand a number of questions about their function and distribution, with a particular focus on tracing the origins of tree worship on a global scale. By using comparative linguistics, ethnographic records and archeobotany, I have attempted to trace these origins as far back as they go, to approximately 10,000-15,000 BP. Ultimately, my goal is to understand why groves are so stable - and how this stability can be achieved by secular conservation institutions. Moreover, as globalization eradicates local tradition and culture in many places, the socio-religious foundation that supports maintenance of sacred groves is becoming precarious. In order to ensure the ecological integrity and cultural heritage embodied in sacred groves, it is necessary to consider the social, political and environmental factors that influence the formation, preservation and potential destruction of sacred groves and the belief systems that maintain them.
[[Image:TherealSnippybreath&dive.jpg|thumb|right|210px|Fig. 4: Time Plot, Breath and Dive Duration Over Time for Snippy (Blue Line = Dive Duration; Black Line = Breath Duration)]]
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The major start to analyzing locomotion data came in recording limb frequency cycles for the three turtles. During continuous bouts of locomotion, the number of limb movements on one side (chosen to be the right side, which happens to be more visible in the footage) of the turtle (a logical proxy for the number of limb cycles) is recorded, as is the time duration of the bout. By dividing the movements into duration, a measure of cycles per second for limb cycle frequency is created. This is currently complete for Jawless and Snippy, and is underway for Lafayette.
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====Conservation Philosophy and Career Aspirations====
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<tt>''"I know the human being and fish can coexist peacefully." - George W. Bush''</tt>
  
Plotting the LCF variable over time (using locomotion bout number as a chronological proxy for time), there is clearly a negative trend in Jawless's limb cycle frequency (See Fig. 3). This suggests an escape response, with high initial locomotion rates that decline as the turtle "relaxes,"  or in more scientific (and accurate) terms, decreases its overall stress level in response to a lack of human intervention and adjustment to the context. The Snippy data does not suggest an escape response, as Snippy's behavior is relatively constant throughout the video. Lafayette, who ranks in inconsistency somewhere between Snippy and Jawless in this footage, may demonstrate an escape response, though the data analyzed so far is inconclusive.
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One of the major problems that faces conservation and environmental advocacy is that advocates don't always understand science, and environmental biologists aren't always skilled advocates (no offense, guys!). This gap between activism and science is one that I have found to be a major obstacle in my environmental work as director of the [http://webpages.charter.net/cool_coventry_club/home.htm Cool Coventry Club] and as a steering comittee member of the Connecticut Youth Activist Network, and it is one that has shaped my career goals profoundly. More about me: I'm part of the EcoHouse living community on campus (and will continue to be next year), a member of environmental organizations such as EcoHusky, and this October I was the chief organizer of the first-ever UConn Environmental Justice Forum, funded by the [http://humanrights.uconn.edu/ Human Rights Institute]. After I graduate from UConn, I plan to go to graduate school to receive my Ph.D., and ultimately hope to stay in academia, conducting research with conservation-relevant implications.
  
===Methods of Locomotion===
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==Publications==  
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[http://hydrodictyon.eeb.uconn.edu/eebedia/index.php/Tobias_Landberg Landberg, T.], Carlson, C. J., Abernathy, K., Luginbuhl, C., Gemme, P. and Mergins, C. (2010) Natural History Notes: CHELYDRA SERPENTINA SERPENTINA L. (Eastern Snapping Turtle). SURVIVAL AFTER INJURY. Herpetological Review 41(1):70-71. {{pdf|Landbergetal2010Jawless.pdf}}
  
[[Image:SnippybehaviorANOVA.jpg|thumb|right|Fig. 5: Bar Chart with Intervals for Snippy Locomotion. There is a significant difference between the LCF of horizontal swimming and all the other behaviors, but those other three behaviors are not significantly different.]]
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==Poster Presentations==
  
For these turtles, there are different methods of locomotion that can be differentiated into four behaviors: moving horizontally, swimming up, swimming down, and walking. To monitor limb frequency cycles differing between these behaviors, every bout of locomotion was recorded with the kind of behavior as well as limb cycle frequency.  
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Carlson, C.J., C.D. Schlichting, and A.M. Wilson. (2012) Phenotypic plasticity and extinction risk in South African plants: a reaction norm approach to ecological modeling. UConn Frontiers in Undergraduate Research Poster Exhibition. April 13-14, 2012. {{pdf|http://hydrodictyon.eeb.uconn.edu/eebedia/images/1/12/Frontiers2012.pdf}}
  
From an ANOVA it appears swimming horizontally for Snippy was significantly slower than swimming vertically (in either direction) and walking (Fig. 5). However, because Jawless is in shallower water most of his behaviors can only be classified as horizontal swimming, as he has less of an "opportunity" to engage in vertical swimming. Moreover, Jawless and Snippy both demonstrate little *visible* walking, but whereas Jawless is likely not engaging at all in this behavior, Snippy is likely walking with his limbs not visible, making it mostly impossible to document this behavior. Consequently, this allows the analysis to be possible for Snippy, but as most of Jawless' behavior is horizontal locomotion, an ANOVA-like test would not be possible or particularly relevant.  
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Carlson, C.J. and C.D. Schlichting. (2011) Dimensionality and Diversification: “Shedding Light” on Natural Phenotypic Plasticity in Pelargonium (Geraniaceae). UConn Frontiers in Undergraduate Research Poster Exhibition. April 15, 2011.
  
This analysis will soon be complete for Lafayette as well; however, I expect to see results that are very similar overall to Jawless' behavior, though perhaps with more walking behavior than for the other two turtles. However, it should be noted that predictions such as these are not particularly reliable, as the three turtles all demonstrate individual differences.
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==Invited Talks/Other Presentations==
  
===Current Analyses===
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The origins and future of sacred forests: How the history of a dying institution can inform conservation in the twenty-first century. Sponsored by UConn Department of Anthropology. April 26, 2012.
  
Right now, I've finished analyzing breathing rates for all three turtles, a simple analysis of diving vs. pausing, and the data on limb locomotion rates for Jawless and Snippy. Although an analysis for Lafayette was attempted, unfortunately, Lafayette's footage does not show her limbs as much as would be necessary to complete an analysis, and so the locomotion data is restricted to the two turtles for which the limbs are visible.  
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Rethinking the scale of environmental tolerance: a new spatial modelling approach to plasticity and climate change. UConn Biology Undergraduate Research Colloquium. April 27, 2012.
  
[[Image:Labirintus3.jpg]]  
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[[Image:Labirintus3.jpg|left]]
Questions or comments can be sent to Colin.Carlson@UConn.edu
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Questions or comments about this page or its twin ([[Snapping Turtle Research: Analyses and Conclusions]]) can be sent to Colin.Carlson@UConn.edu

Latest revision as of 18:36, 18 August 2012

Anysberg.jpg

I am Master's student in EEB. In 2012, I graduated from UConn with a B.S. in EEB and a B.A. in Environmental Studies. I'm currently studying plasticity in the genus Pelargonium, for which I was awarded a 2011 Goldwater Scholarship. I was also named a 2010 Udall Scholar and a 2011 Truman Scholar for my environmental work on and off campus.

Research Interests

Plant conservation and climate change; functional and evolutionary ecology; ecological modelling.

Current research: plasticity and climate change (2010-present)

"All is leaf, and through this simplicity the greatest multiplicity is possible." - Johann Wolfgang von Goethe

My current research began as a simple project focusing on light-induced leaf shape dimorphism in South African Pelargonium L’Her (Geraniaceae). The focus of this research can be condensed into the following three questions:

1. For what traits, in what species, is leaf shape plastic? (The "what?")

2. Does selection appear to act on plasticity itself, and at what spatial/phylogenetic levels? (The "why?")

3. Have leaf traits evolved independently in their plasticity, and is there any suggestion of evolutionary/environmental constraints on these traits and/or their plasticity? (The "how?")

With the help of a CCB Summer Undergraduate Research Award, I traveled to South Africa during the summer of 2010 with the NSF IRES 2010 group to measure leaf shape variation in a natural context. For the next year, I studied plasticity experimentally at UConn, examining plastic responses to water stress and shade cues, as well as the associated fitness costs and phylogenetic patterns of this phenotypic flexibility. In many ways, Pelargonium is an ideal model organism for testing theories of phenotypic plasticity's role in adaptive radiation, given its surprisingly high diversity and the impressive, widespread and diverse nature of plasticity in the genus.

Red.jpg

After completing these projects, I entered a new phase in my research, focused on turning our new understanding of the limits and costs of plasticity into valuable information on species vulnerability to climate change. The project focused in particular on evaluating the vulnerability of P. elongatum, a species that is currently classified as Least Concern in South Africa, and that has displayed tremendous plasticity in both natural and experimental settings. P. elongatum has served as a "testing ground" for a novel set of spatially-discrete models that include the costs of plasticity into otherwise entirely climate-driven ecological niche models, with the goal of understanding the consequences of potentially-costly plasticity for population survival.


Thus far, these models have suggested that the future of P. elongatum is strongly dependent on demographic conditions, and while the species may indeed be low priority for conservation, a very small range of variation in seed and adult survivorship could even have the ability to drive the species to extinction in the next ten years. (More about these findings will be presented this April at Frontiers in Undergraduate Research and the results of the models are also currently being prepared for publication.) Ultimately, it is my hope that this project will take a crucial first step towards applying theoretical models of plasticity and extinction risk to actual high-diversity, high-plasticity, high-risk clades.

Other research projects

Snapping Turtle Research (2008-2010)

This project analyzed the behavior of three Snapping Turtles (Chelydra serpentina) along the Connecticut river. The footage, collected over the summer, was from the turtles Jawless and Lafayette from Wethersfield Cove, and Snippy from Shenipsit Lake. (see the snapping turtle research team page for the full story on the turtles). Also, for more information on Crittercam itself, visit National Geographic's Crittercam Homepage. This analysis encompassed the breath, dive, pausing, walking, and other aspects of locomotion of the three turtles. If you would like to read more about the actual data analysis, check out Snapping Turtle Research: Analyses and Conclusions.

My research on this project was divided into two main stages. First came an analysis of the duration and frequency of breathing and diving behaviors, which revealed a strong positive relationship between breath and dive duration. Second, I described behavioral patterns in the turtles through an analysis of locomotion that was divided into five sub-categories, and I found strong differences between average limb frequency cycles.

Sacred Groves and Community-based Conservation (2010-2012)

As sacred groves are one of the most ancient forms of community-based conservation, my Environmental Studies senior thesis seeks to understand a number of questions about their function and distribution, with a particular focus on tracing the origins of tree worship on a global scale. By using comparative linguistics, ethnographic records and archeobotany, I have attempted to trace these origins as far back as they go, to approximately 10,000-15,000 BP. Ultimately, my goal is to understand why groves are so stable - and how this stability can be achieved by secular conservation institutions. Moreover, as globalization eradicates local tradition and culture in many places, the socio-religious foundation that supports maintenance of sacred groves is becoming precarious. In order to ensure the ecological integrity and cultural heritage embodied in sacred groves, it is necessary to consider the social, political and environmental factors that influence the formation, preservation and potential destruction of sacred groves and the belief systems that maintain them.

Conservation Philosophy and Career Aspirations

"I know the human being and fish can coexist peacefully." - George W. Bush

One of the major problems that faces conservation and environmental advocacy is that advocates don't always understand science, and environmental biologists aren't always skilled advocates (no offense, guys!). This gap between activism and science is one that I have found to be a major obstacle in my environmental work as director of the Cool Coventry Club and as a steering comittee member of the Connecticut Youth Activist Network, and it is one that has shaped my career goals profoundly. More about me: I'm part of the EcoHouse living community on campus (and will continue to be next year), a member of environmental organizations such as EcoHusky, and this October I was the chief organizer of the first-ever UConn Environmental Justice Forum, funded by the Human Rights Institute. After I graduate from UConn, I plan to go to graduate school to receive my Ph.D., and ultimately hope to stay in academia, conducting research with conservation-relevant implications.

Publications

Landberg, T., Carlson, C. J., Abernathy, K., Luginbuhl, C., Gemme, P. and Mergins, C. (2010) Natural History Notes: CHELYDRA SERPENTINA SERPENTINA L. (Eastern Snapping Turtle). SURVIVAL AFTER INJURY. Herpetological Review 41(1):70-71. Pdficon small.gif

Poster Presentations

Carlson, C.J., C.D. Schlichting, and A.M. Wilson. (2012) Phenotypic plasticity and extinction risk in South African plants: a reaction norm approach to ecological modeling. UConn Frontiers in Undergraduate Research Poster Exhibition. April 13-14, 2012. Pdficon small.gif

Carlson, C.J. and C.D. Schlichting. (2011) Dimensionality and Diversification: “Shedding Light” on Natural Phenotypic Plasticity in Pelargonium (Geraniaceae). UConn Frontiers in Undergraduate Research Poster Exhibition. April 15, 2011.

Invited Talks/Other Presentations

The origins and future of sacred forests: How the history of a dying institution can inform conservation in the twenty-first century. Sponsored by UConn Department of Anthropology. April 26, 2012.

Rethinking the scale of environmental tolerance: a new spatial modelling approach to plasticity and climate change. UConn Biology Undergraduate Research Colloquium. April 27, 2012.

Labirintus3.jpg




Questions or comments about this page or its twin (Snapping Turtle Research: Analyses and Conclusions) can be sent to Colin.Carlson@UConn.edu