Author Archives: dmdrown

Drown Lab > Articles by: dmdrown
02
Sep
Date September 2, 2015
Categories update

A journey north into the Arctic


September marks the beginning of the new academic year and with it brings a new cohort of graduate students to the Department of Biology and Wildlife. As a bonding experience each year, several researchers lead a trip up to Toolik Field Station in the Arctic. This field station is operated by the Institute of Arctic Biology here at the University of Alaska Fairbanks. The mission of the field station is
to support research and education that creates a greater understanding of the Arctic and its relationship to the global environment.

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Author dmdrown
16
May
Date May 16, 2015
Categories award

Human Microbiome curriculum development

This past month, the Alaska IDeA Network of Biomedical Research Excellence (INBRE) program put out a call for  curriculum proposals. INBRE is supported by a grant from the National Institutes of Health. An objective of the Alaska INBRE Research Training Core is to expand curricula in biomedical and health areas across the University of Alaska system. I worked with Dr. Mary Beth Leigh on a proposal that was just funded. This summer we will be developing a new course to be offered at UAF in the near future. Below is a short description.
Overview: It is now widely recognized that humans are host to a diverse assemblage of microbes (Blaser 2014b). This associated microbiota impacts the behavior, physiology and fitness of their host. The goal is to develop a new course that will broadly explore the biology of host-associated microbiomes. In the process, we will address humans as hosts and include model and non-model systems as tools for research in this complex field. This course will cover research questions on the ecology and evolution of host-associated microbiomes. Additionally, we will explore research methods and tools used to collect and analyze microbiome data.
Relevance to biomedical research: Understanding the role of the human microbiome is an important missing component of current investigations of the human health, so much so that the NIH started the Human Microbiome Project (HMP) in 2007. The HMP developed tools and initial datasets during the initial phase. Now that phase two is wrapping up, we have access to integrated datasets of both microbial communities and host properties. There is growing evidence that human health and disease are significantly impacted by host-associated microbes. The human microbiome is linked to a vast array of health concerns including: asthma and allergies (Reibman et al. 2008), cancer (Marchesi et al. 2011), malnutrition and obesity (Tilg and Kaser 2011), and autism and depression (Mulle et al. 2013). Some even argue that changes in health practices may have exacerbated these effects (e.g. increasing use of antibiotics) (Blaser 2014a).
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0 Comments Author dmdrown
08
May
Date May 8, 2015
Categories teaching

Evolution, Naturally Inspiring

This semester, some of my evolution students wrote blog posts over at Evolution, Naturally Inspiring on recent scientific research as an extra assignment. We know there is a need to communicate beyond our institutions. Making the science we do as public as we can is an important part of public outreach. What better way to help educate people about what we do then do show them the process too.
Assignment: Each student selected a paper from the primary literature. In addition to reading the primary source, I asked the students to delve into the broader context of the research. They drafted an initial post which I reviewed and made suggested. My suggested were to aid clarity, rather than provide editorial censoring. I really wanted each student's voice to shine through the blog post. Student then submitted a revised version of the post for two peer reviews. The final product was a post around 1000-1500 words including some properly cited images.
Goal: To think and writing critically about recently published scientific research on evolution and present that research to a broader audience.

Link to PDF of full assignment


This semester we had a total of seven posts covering many topics in evolutionary biology. Hope you enjoy.
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Author dmdrown
22
Aug
Date August 22, 2014
Categories meeting

Evolution 2014 social media wrap-up

Social media use among scientists has been growing. Nature just published the results of a broad survey of various social networks including Twitter. Given this, it seems timely to write up the quick analysis that I did this summer.
During the Evolution 2014 annual meetings I collected tweets using the hastag #evol2014. I did this based on  interest in network analysis  growing from my time at the Santa Fe Institute's Complex Systems Summer school. I don't have any particular agenda with this, mostly curiosity.

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Author dmdrown
08
Jul
Date July 8, 2014
Categories publication

NEW PUBLICATION: RUNAWAY COEVOLUTION

Mike Wade and I recently published a population genetics analysis of indirect genetic effects. We found that the coadaptive process between genes and heritable environments is much faster thangenetic adaptation to an abiotic environment. Most interestingly, the effects of increased inbreeding accelerate the adaptive process than equivalent amounts of linkage. We are currently extending this model to other kinds of genome interactions. Below is the abstract, be sure to check out the full paper online at Evolution. and you can find the data online at Dryad.
Drown_Wade_2014_Fig2_alt
Populations evolve in response to the external environment, whether abiotic (e.g., climate) or biotic (e.g., other conspecifics). We investigated how adaptation to biotic, heritable environments differs from adaptation to abiotic, non-heritable environments. We found that, for the same selection coefficients, the coadaptive process between genes and heritable environments is much faster than genetic adaptation to an abiotic non-heritable environment. The increased rate of adaptation results from of the positive association generated by reciprocal selection between the heritable environment and the genes responding to it. These associations result in a runaway process of adaptive coevolution, even when the genes creating the heritable environment and genes responding to the heritable environment are unlinked. Although tightening the degree of linkage accelerates the coadaptive process, the acceleration caused by a comparable amount of inbreeding is greater, because inbreeding has a cumulative effect on reducing functional recombination over generations. Our results suggest that that adaptation to local abiotic environmental variation may result in the rapid diversification of populations and subsequent reproductive isolation not directly but rather via its effects on heritable environments and the genes responding to them.
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Author dmdrown
19
Jun
Date June 19, 2014
Categories meeting

Evolution 2014 talk updates

The Evolution meetings start tomorrow. Final tweaks to the presentations are completed. I'm giving one talk and my coauthor is given a second talk the following morning.
Antagonistic Coevolution (302C)
Date: Saturday, June 21, 2014, 8:30 AM - 8:45 AM
Devin Drown and Michael Wade. How to train your symbionts: antagonistic coevolution and the evolution of transmission mode.
Sexual Selection (302C)
Date: Sunday, June 22, 2014, 8:45 AM - 9:00 AM
Michael Wade and Devin Drown. When mito-nuclear epistasis looks like genomic and sexual conflict.
As an aside, here is some the twitter activity leading up to the conference.
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Author dmdrown
12
May
Date May 12, 2014
Categories meeting

Evolution 2014

I'm heading to Raleigh, NC with many other members of the Wade lab for the annual Evolution meetings. Hope to see lots of you there or look for the #Evol2014 on Twitter. I'll be presenting some recent theoretical work that extends my research in transmission mode evolution (Drown et al 2013). My coauthor, Mike Wade, will present additional theory work on cyto-nuclear interactions.
Title: How to train your symbionts: antagonistic coevolution and the evolution of transmission mode
Abstract: Here we develop a general theory for the coevolution of transmission mode and virulence in host-symbiont interactions. The fidelity of an interaction, determined by transmission mode, has a direct effect on the efficiency of selection. This new theory will combine models to understand the mechanisms of virulence evolution in structured populations. We find that interaction of virulence and genetic structure determines the balance between hosts escaping virulent pathogens and host-symbiont coevolution reducing virulence.
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Author dmdrown
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