Duke Research Blog

Following the people and events that make up the research community at Duke.

Category: Science Communication & Education Page 1 of 16

Building a Mangrove Map

“Gap maps” are the latest technology when it comes to organizing data. Although they aren’t like traditional maps, they can help people navigate through dense resources of information and show scientists the unexplored areas of research.

A ‘gap map’ comparing conservation interventions and outcomes in tropical mangrove habitats around the world turns out to be a beautiful thing.

At Duke’s 2019 Master’s Projects Spring Symposium, Willa Brooks, Amy Manz, and Colyer Woolston presented the results of their year-long Masters Project to create this map.

You’d never know by looking at the simple, polished grid of information that it took 29 Ph.D. students, master’s students and undergraduates nearly a full year to create it. As a member of the Bass Connections team that has been helping to support this research, I can testify that gap maps take a lot of time and effort — but they’re worth it.

Amy Manz, Willa Brooks, and Colyer Woolston present their evidence map (or gap map) at the 2019 Master’s Projects Spring Symposium

When designing a research question, it’s important to recognize what is already known, so that you can clearly visualize and target the gaps in the knowledge.

But sifting through thousands of papers on tropical mangroves to find the one study you are looking for can be incredible overwhelming and time-intensive. This is purpose of a gap map: to neatly organize existing research into a comprehensive grid, effectively shining a light on the areas where research is lacking, and highlighting patterns in areas where the research exists.

In partnership with World Wildlife Fund, Willa, Amy, and Colyer’s team has been working under the direction of Nicholas School of the Environment professors Lisa Campbell and Brian Silliman to screen the abstracts of over 10,000 articles, 779 of which ended up being singled out for a second round of full-text screening. In the first round, we were looking for very specific inclusion criteria, and in the second, we were extracting data from each study to identify the outcomes of conservation interventions in tropical mangrove, seagrass, and coral reef habitats around the world.

Coastal Mangroves (Photo from WikiCommons: US National Oceanic and Atmospheric Administration)

While the overall project looked at all three habitats, Willa, Amy, and Colyer’s Master’s Project focused specifically on mangroves, which are salt-tolerant shrubs that grow along the coast in tropical and subtropical regions. These shrubs provide a rich nursery habitat to a diverse group of birds and aquatic species, and promote the stability of coastlines by trapping sediment runoff in their roots. However, mangrove forests are in dramatic decline.

According to World Wildlife Fund, 35 percent of mangrove ecosystems in the world are already gone. Those that remain are facing intense pressure from threats like forest clearing, overharvesting, overfishing, pollution, climate change, and human destruction of coral reefs. Now more than ever, it is so important to study the conservation of these habitats, and implement solutions that will save these coastal forests and all the life they support. The hope is that our gap map will help point future researchers towards these solutions, and aid in the fight to save the mangroves.

This year’s team built a gap map that successfully mapped linkages between interventions and outcomes, indicating which areas are lacking in research. However, the gap map is limited because it does not show the strength or nature of these relationships. Next year, another Bass Connections team will tackle this challenge of analyzing the results, and further explore the realm of tropical conservation research.

Post by Anne Littlewood, Trinity ’21

Science Gets By With a Little Help From Its Friends

There are many things in life that are a little easier if one recruits the help of friends. As it turns out, this is also the case with scientific research.

Lilly Chiou, a senior majoring in biology, and Daniele Armaleo, a professor in the Biology Department had a problem. Lilly needed more funding before graduation to initiate a new direction for her project, but traditional funding can sometimes take a year or more.

So they turned to their friends and sought crowdfunding.

Chiou and Armaleo are interested in lichens, low-profile organisms that you may have seen but not really noticed. Often looking like crusty leaves stuck to rocks or to the bark of trees, they — like most other living beings — need water to grow. But, while a rock and its resident lichens might get wet after it rains, it’s bound to dry up.

If you’re likin’ these lichens, perhaps you’d like to support some research…

This is where the power of lichens comes in: they are able to dry to a crisp but still remain in a suspended state of living, so that when water becomes available again, they resume life as usual. Few organisms are able to accomplish such a feat, termed desiccation tolerance.

Chiou and Armaleo are trying to understand how lichens manage to survive getting dried and come out the other end with minimal scars. Knowing this could have important implications for our food crops, which cannot survive becoming completely parched. This knowledge is ever more important as climate becomes warmer and more unpredictable in the future. Some farmers may no longer be able to rely on regular seasonal rainfall.

They are using genetic tools to figure out the mechanisms behind the lichen’s desiccation tolerance[. Their first breakthrough came when they discovered that extra DNA sequences present in lichen ribosomal DNA may allow cells to survive extreme desiccation. Now they want to know how this works. They hope that by comparing RNA expression between desiccation tolerant and non-tolerant cells they can identify genes that protect against desiccation damage.  

As with most things, you need money to carry out your plans. Traditionally, scientists obtain money from federal agencies such as the National Science Foundation or the National Institutes of Health, or sometimes from large organizations such as the National Geographic Society, to fund their work. But applying for money involves a heavy layer of bureaucracy and long wait times while the grant is being reviewed (often, grants are only reviewed once a year). But Chiou is in her last semester, so they resorted to crowdfunding their experiment.

This is not the first instance of crowdfunded science in the Biology Department at Duke. In 2014, Fay-Wei Li and Kathleen Pryer crowdfunded the sequencing of the first fern genome, that of tiny Azolla. In fact, it was Pryer who suggested crowdfunding to Armaleo.

Chiou (left) and Armaleo in a video.

Chiou was skeptical that this approach would work. Why would somebody spend their hard-earned money on research entirely unrelated to them? To make their sales pitch, Chiou and Armaleo had to consider the wider impact of the project, rather than the approach taken in traditional grants where the focus is on the ways in which a narrow field is being advanced.

What they were not expecting was that fostering relationships would be important too; they were surprised to find that the biggest source of funding was their friends. Armaleo commented on how “having a long life of relationships with people” really shone through in this time of need — contributions to the fund, however small, “highlight people’s connection with you.” That network of connections paid off: with 18 days left in the allotted time, they had reached their goal.

After their experience, they would recommend crowdfunding as an option for other scientists. Having to create widely understood, engaging explanations of their work, and earning the support and encouragement of friends was a very positive experience.

“It beats writing a grant!” Armaleo said.

Guest Post by Karla Sosa, Biology graduate student


Meet New Blogger Anna Gotskind: Science and Gilmore Girls

Hello! My name is Anna Gotskind. I’m a first year originally from Chicago. I plan to double major in biochemistry and environmental science and policy with a certificate in innovation and entrepreneurship (I know it’s a mouthful).

I fell in love with science in seventh grade, inspired by a great teacher named Mark A. Klein. He wore a different tie every day of the year, had tarantulas as pets and frequently refused to say anything but “9” until 9:00 am. He also taught me to appreciate research and discovery, guiding me as I conducted my first independent experiment on the caffeine content in tea which helped me win my middle school science fair.

One of my other role models is Rory Gilmore from the T.V. show Gilmore Girls (yes, I am aware that she is a fictional character). Inspired by watching her write for the Yale Daily News I decided to join the Duke Chronicle when I got to campus. I quickly learned that I loved writing for a publication but more specifically that I loved writing about science. It was incredibly exciting for me to read a study, interview the researchers who conducted it and then translate the information into a story that was understandable to the public. Beyond this, it was also incredible to be exposed to groundbreaking research that had real-world impacts. Essentially, it made me feel like a “Big Girl” and when you’re only 5’0” tall, sometimes that’s necessary.

Rory Gilmore

My love for science does not end in the classroom. My greatest passion is travel and I’ve been fortunate enough to travel around the world with my family exploring some of nature’s greatest wonders. We’ve hiked Bryce Canyon in Utah, Ali San in Taiwan and Masada in Israel. In December 2018 we ventured to the Galapagos, which as an aspiring environmentalist was an incredible experience. We go to see tortoises, iguanas, penguins, sharks and sea lions mere feet away. Right now I’m working with Duke Professor Stuart Pimm on a Big Cats Conservation Initiative sponsored by SavingSpecies, analyzing camera trap data of species in Sumatra, Brazil, and Ecuador. So who knows, I may be off there next. For more pictures check out my Instagram page @annagotskind (shameless plug).

A Parrot my little brother Avi photographed in the Amazon Rainforest in Ecuador

I’m very excited to continue exploring and writing about the research being done on Duke’s campus!

By Anna Gotskind

Overcoming Judgment Biases in STEM

Beginning in childhood we all develop unconscious stereotypes that influence how we see ourselves and others – including what careers we choose, and who we choose to recruit, hire or promote in the workplace.

Researchers discussed the origins and effects of these judgement biases during a virtual conference titled Mitigating Implicit Bias: Tools for the Neuroscientist, which was put on by the Society for Neuroscience and screened by DIBS at Duke on Jan. 23 and 24.

Associate professor of neuroscience Anne Churchland of Cold Spring Harbor Laboratory proposed several ideas for overcoming gender bias in the workplace, especially for women in STEM or other male-dominated domains. Asking questions, speaking with authority (particularly about one’s own work), finding a way to communicate with senior colleagues, trying risky experiments, making one’s achievements known, sending one’s work to high-level journals, and applying to awards and grants are her main suggestions. Above all these strategies, she recommends finding good friends and colleagues to help. As research shows, when women are successful in arenas that are viewed as distinctly male, both women and men like them less. These negative reactions can be discouraging and even career-affecting, and any support system will help to overcome that struggle.

The ‘Brilliance Barrier ‘ is a judgement bias explored by Andrei Cimpian’s research at New York University. One study shows that for every ten parents who searched on Google, “Is my daughter talented?”, twenty-five parents looked up “Is my son talented?”

Another study describes the gendered reviews on ratemyprofessor.com. Men are two to three times more likely to be called genius than women. Women though are more likely to be portrayed as warm or caring.

Cimpian uses these studies to develop the Field-specific Ability Beliefs hypothesis (FAB). FAB attributes women’s underrepresentation to a combination of the idolized brilliance/genius and the “brilliance” equals men stereotype. The higher the FAB in a field, the greater the emphasis on brilliance in it. When graphing the percentage of women with PhDs and the FAB for a specific field such as philosophy or physics, higher FABs are associated with a lower number of PhDs. African American representation also decreases as the FAB increases. Cimpian classifies one potential mechanism of this trend as minorities having less interest in fields with high FABs. In addition, increased bias, discrimination, and imposter syndrome could explain why minorities appear to avoid getting PhDs in high FAB fields.

Cimpian also demonstrates how susceptible children are to judgement biases. At age five, the percentage of girls who pick their own gender as “really, really smart” and the percentage of boys who do the same are similar. When children reach seven though, the percentage of boys choosing men exceeds the girls picking women. He suggests de-emphasizing brilliance, genius, and gifted in favor of work ethic because minorities are more likely to be recommended when the job description asks for commitment than when it asks for intelligence. Language has the potential to change the amount of representation in high FAB fields, such as STEM.

Image result for jackie fleming cartoons
Never Give Up – Cartoon by Jackie Fleming

Lastly, psychology professor Ione Fine at the University of Washington talked about the hiring process in her lab and how she reduces bias by laying out and weighting criteria beforehand. Instead of focusing on objective criteria like GPA and GRE scores, she advocates for more interviews with set lists of questions and a paper discussion. She also recommends calling the recommendation letter writers. After selecting a diverse group of research assistants, Fine then makes sure they have the proper support and mentoring. Reinforcing that they were chosen for their potential and that she is their advocate helps them feel empowered to succeed in her lab. Through mentoring and supporting diversity, anyone can help minorities overcome the judgement biases surrounding them.   

Finding Success in Science and the Economic Brain

How can we understand how humans make decisions? How do we measure the root of motivation?

Gregory Samanez-Larkin, an assistant professor in Psychology & Neuroscience at Duke, uses neuroeconomic and neuromarketing approaches to seek answers to these questions. He combines experimental psychology and economics with neuroimaging and statistical analysis as an interdisciplinary approach to understanding human behavior.

Gregory Samanez-Larkin 

From studying the risk tendencies in different age groups to measuring the effectiveness of informative messages in health decision-making,Samanez-Larkin’s diverse array of research reflects the many applications of neuroeconomics.

He finds that neuroeconomic and neurofinance tools can help spot vulnerabilities and characteristics within groups of people.

Though his Motivated Cognition & Aging Brain Lab at Duke, he would like to extend his work to finding interventions that would encourage healthier or optimal decision-making. Many financial organizations and firms are interested in these questions.

While Samanez-Larkin has produced some very influential research in the field, the path to his career was not a straightforward one.Raised in Flint, Michigan, he found that the majority of people around him were not very career-oriented. He found a passion for wakeboarding, visual art, and graphic design.

As an undergraduate at the University of Michigan-Flint, he was originally on a pre-business track. But after taking various psychology courses and assisting in research, Samanez-Larkin was captivated by the excitement and the advances in brain imaging at the time.

However, misconceptions about the field caused him to question whether or not going into research was the right fit, leading him to seek jobs in marketing and advertising instead. But in job interviews, he ended up questioning the methods and the ways companies explained the appeal of different ways of advertising. Realizing that he really enjoyed asking questions and evaluating how things work, he reconsidered pursuing science.

After a series of positive experiences in a research position in San Francisco, Samanez-Larkin began his graduate studies at Stanford University. The growing field of neuroeconomics — which combined his diverse set of interests in neuroscience, psychology, and economics — continued the “decade-long evolution” of Samanez-Larkin’s career.

Samanez-Larkin’s experiences in his career journey are reflected strongly in his approach to teaching.

“I feel like my primary responsibility is to help people become successful,” he says, as we sit comfortably on the sofas in his office.“Everything I do is for that.”

In his courses, Samanez-Larkin emphasizes the need to think critically and evaluate information, consistently asking questions like, “How do we know something works or not? How do I know how to evaluate if it works or not? How can I become a good consumer of scientific information?”

In his teaching, Samanez-Larkin hopes to set students up with usable, translatable skills that are applicable to any field.

Samanez-Larkin also hopes to support his students in the same way he received support from his previous mentors. “It’s cool to learn about how the brain works, but ultimately, I’m just trying to help people do something.”

Guest Post by Ariba Huda, NCSSM 2019

Gene-Editing Human Embryos: What, How, Why?

Every seat full. Students perched on the aisle stairs and lining the back walls.

What topic could possibly pull so many away from their final exams? Not “How to Stop Procrastinating” nor “How to Pass Life After Failing Your Exams” but rather “Gene-Editing Human Embryos: Unpacking the Current Controversy” on the Duke campus.

Since Chinese researcher He Jiankui announced at the Second International Summit on Human Genome Editing in Hong Kong that he made the world’s first genetically engineered babies, a debate on the ethical implications has raged on social media.

On December 6, the University Program in Genetics and Genomics and the Molecular Genetics and Microbiology department co-hosted a panel responding to He’s claims. Charles A. Gersbach from the Biomedical Engineering department lead the discussion of what exactly happened and then joined the panel which also contained Misha Angrist, a senior fellow in the Science & Society initiative;  Heidi Cope, a genetic counselor; Giny Fouda, an assistant professor in pediatrics; and Vandana Shashi, a genetic counselor.

Dr. He Jiankui announced he had used CRISPR to edit genes in twin embryos that were then born at full term.

But what exactly has He potentially done to these twin girls? Can they fly? Breathe underwater? Photosynthesize? Not exactly. He said he deleted a gene called CCR5 to increase their HIV resistance. Two percent of Northern Europeans naturally have a mutation that removes the CCR5 gene from their DNA and as a result do not display any traits other than increased HIV resistance.

Many researchers have explored blocking CCR5 activity as a potential HIV treatment. Using CRISPR-Cas9, a genetic engineering technology that can cut and paste specific sequences in the DNA, He targeted CCR5 during in vitro fertilization. According to his tests, he successfully removed both copies of the CCR5 gene in one of the girls. However, in the other girl, the CCR5 remained normal on one chromosome and on the other, CRISPR had deleted more than intended.  The effects of that additional deletion are unknown. 
Both the girls are mosaics, meaning the genetic change occurred in some of their cells and not in others, leading to still more uncertainties.

Researchers have conducted genetic engineering experiments on both somatic cells and human embryo cells that were never brought to term. (Somatic cells constitute all parts of the body other than the eggs and sperm.) But because He altered the twin girls as embryos and then they grew to full term, their children could inherit these changes. This alters their family line, not just a single individual, increasing the ethical implications.

According to Shashi, He’s experiment becomes difficult to justify. Additionally, embryos have not consented to these changes in their genetics, unlike a patient undergoing genetic therapy.

Many doctors, scientists, and journalists have also questioned He’s lack of transparency because he hid this work until his grand announcement, which caused China to arrest him. In addition, as Cope explained, “it is not typically the PI who does the informed consent process” as He did with these parents.

While He defends his work by saying that the girls’ father carries HIV and wished to increase the girls’ safety, the twins were not actually at great risk for HIV. Their father’s medical history does not increase their chances of contracting the virus, and the overall risk for HIV in China is low. As Fouda emphasized in the panel, “there was no justification for this experiment.” While He discussed the potential for genetic engineering to help society, for these two individuals, no medical need existed, and that increases the ethical dilemma.

A final concern of researchers is the current inability to ensure technical competency and accuracy. As seen by the additional deletion in one of the girls,  CRISPR-Cas9 still makes errors. Thus using it to alter not only a human being but all of that individual’s progeny would demand a much higher standard, something close to a life-or-death scenario.

But, the panelists also noted, if it hadn’t been He, it would have been somebody else. Perhaps somebody else may have done it more ethically with more transparency and a more traditional consent process, Angrist said.

While He’s claims have yet to be proven, the fact that they could reasonably be true has many concerned. The World Health Organization has announced that they will begin greater oversight of genetic engineering of the human germline.

On campus over the last weeks, I’ve heard mixed reviews on He’s work with some joking about future superhero babies while others have reacted with fear. The technology does live among us; however, the world is working on writing the guidebook and unrolling the yellow tape.

Post by Lydia Goff

New Blogger Jeremy Jacobs: What’s in a Name?

Surviving my first snow day at Duke

Let’s start with my name: Jeremy Abraham Jacobs. It’s a surprisingly Biblical one,
a name that draws more from the Judeo-Christian tradition than my
Indian roots. Jeremy, derived from the prophet Jeremiah and the depths of my mother’s imagination. Abraham, both the name of my father’s father and the patriarch of Judaism. And Jacobs, the latest Americanization of my family name Yakob, Chacko, then Jacob.

At the heart of my name is language, the offspring of a million-year synthesis of firing neurons, geography, and culture. I too grew up a child of intersection, living a blend of the Indian tradition my parents brought over with them and the rich culture of the Deep South that’s flavored ever moment of my life.

I’m a freshman here at Duke, with all the uncertainties—and possibilities—of an undeclared major. But my passion lies in the crossroads that has defined my life. I want to understand the inseparable intertwining of linguistics and neuroscience. And communication enthralls me, from the individual cells that make up the tongue to the Spanish pluperfect subjunctive.

Who knows if, after four years, organic chemistry will have knocked me off the pre-med track, or if English will still hold my interest as tightly as it does today? But for now, at least, mysteries like the power of a name still keep me invested in the intricate interplay of science and language.

Move-in day featuring an injured arm!

What cascading forces of nature and nurture brought my mother to a small hospital in Tupelo, Mississippi, where I came into the world kickin’ and screaming’ one hot July morning? Was there some memory burned into her hippocampus that caused her to choose the name “Jeremy” in a sea of Chad’s, Luke’s, or Matt’s? And how different would my life have been if my name were not Jeremy Abraham Jacobs but rather Aakash Bola, or Harley Covington Pike III?

It took generations of missteps, chance encounters, and biological improbabilities for this name to fall to me, for this name to be mine. Perhaps one day I’ll understand every aspect of my unlikely existence, every factor that led to the genetically unique organism currently typing up this article. More likely, though, is that I’ll spend my life exploring the unknown, learning more about my own place in the mechanisms of the world.

But I know, at least, that intersection follows me, even here at the Duke Research Blog. I’m thrilled to infuse my own mix of science, writing, and culture into each article I produce, so I can ignite the passions of others students of science who seek their own common ground.

Post by Jeremy Jacobs

The Importance of Evidence in Environmental Conservation

What counts as good evidence?

In medical research, a professional might answer this question as you would expect: evidence can be trusted if it is the result of a randomized, controlled, double-blind experiment, meaning the evidence is only as strong as the experiment design. And in medicine, it’s possible (and important) to procure this kind of strong evidence.

But when it comes to conservation, it’s a whole different story.

Dr. David Gill (photo from The Nicholas School)

The natural world is complicated, and far beyond our control. When studying the implications of conservation, it’s not so easy to design the kind of experiment that will produce “good” evidence.

David Gill, a professor in Duke’s Nicholas School for the Environment, recently led a study featured in the journal Nature that needed to  define what constitutes good evidence in the realm of marine conservation. Last Wednesday, he made a guest appearance in my Bass Connections meeting to share his work and a perspective on the importance of quality evidence.

Gill’s research has been centered around evaluating the effectiveness of Marine Protected Areas (or MPAs) as a way of protecting marine life. Seven percent of the world’s oceans are currently designated as MPAs, and by 2020, the goal is to increase this number to 10 percent. MPAs arguably have massive effects on ecosystem health and coastal community functioning, but where is the evidence for this claim?

Although past investigations have provided support for creating MPAs,  Gill and his team were concerned with the quality of this evidence, and the link between how MPAs are managed and how well they work. There have historically been acute gaps in study design when researching the effects of MPAs. Few experiments have included pre-MPA conditions or an attempt to control for other factors. Most of these studies have been done in hindsight, and have looked only at the ecological effects within the boundaries of MPAs, without any useful baseline data or control sites to compare them to.

As a result of these limitations, the evidence base is weak. Generating good evidence is a massive undertaking when you are attempting to validate a claim by counting several thousand moving fish.

Gill’s measure of ecosystem health includes counting fish. (Photo from Avoini)

So is there no way to understand the impacts of MPAs? Should conservation scientists just give up? The answer is no, absolutely not.

To produce better evidence, Gill and his team needed to design a study that would isolate the effects of MPAs. To do this, they needed to account for location biases and other confounding variables such as the biophysical conditions of the environment, the population density of nearby human communities, and the national regulations in each place.

The solution they came up with was to compare observations of current conditions within MPAs to “counterfactual” evidence, which is defined as what would have happened had the MPA not been there. Using statistical matching of MPAs to nearby non-MPA and pre-MPA sites, they were able to obtain high-quality results.

A happy sea turtle pictured in a marine protected area (photo from English Foreign and Commonwealth Office.)

The research showed that across 16,000 sampled sites, MPAs had positive ecological impacts on fish biomass in 71 percent of sites. They also discovered that MPAs with adequate staffing had far greater ecological impacts than those without, which is a pretty interesting piece of feedback when it comes to future development. It’s probably not worth it to create MPAs before there is sufficient funding in place to maintain them.

Gill doesn’t claim that his evidence is flawless; he fully admits to the shortcomings in this study, such as the fact that there is very little data on temperate, coldwater regions — mostly because there are few MPAs in these regions.

The field is ripe for improvement, and he suggests that future research look into the social impacts of MPAs and the implications of these interventions for different species. As the evidence continues to improve, it will be increasingly possible to maximize the win-wins when designing MPAs.

Conservation science isn’t perfect, but neither is medicine. We’ll get there.

Sean Carroll on the Evolution of Snake Venom

What’s in a snake bite?

According to University of Wisconsin-Madison evolutionary biologist Sean Carroll who visited Duke and Durham last week, a snake bite contains a full index of clues.

In his recent research, Carroll has been studying the adaptations of novelties in animal form, such as snake venom. Rattlesnakes, he explains, are the picture of novelty. With traits such as a limbless body, fangs, infrared pits, patterned skin, venom, and the iconic rattle, they represent an amazing incarnation of evolution at work.

Rattlesnakes: the picture of novelty (Photo from USGS)

Snake venoms contain a complex mixture of proteins. This mixture can differ in several ways, but the most interesting difference to Carroll is the presence or absence of neurotoxins. Neurotoxic venom has proven to be a very useful trait, because neurotoxins destroy the nervous tissue of prey, effectively paralyzing the animal’s respiratory system.

Some of today’s rattlesnake species have neurotoxic venom, but some don’t. So how did this happen? That’s what Carroll was wondering too.

Some genes within genomes, such as HOX genes, evolve very slowly from their original position among the chromosomes, and see very few changes in the sequence in millions of years.

But snake venom Pla2 genes are quite the opposite. In recent history, there has been a massive expansion of these genes in the snake genome, Carroll said. When animals evolve new functions or forms, the question always arises: are these changes the result of brand new genes or old genes taking on new functions?

Another important consideration is the concept of regulatory versus structural genes. Regulatory genes control the activity of other genes, such as structural genes, and because of this, duplicates of regulatory genes are generally not going to be a favorable adaptation. In contrast, structural gene activity doesn’t affect other genes, and duplicates are often a positive change. This means it is easier for a new structural gene to evolve than a regulatory one. Carroll explained.

Evolutionary Biologist Sean Carroll (Photo from seanbcarroll.com)

Carroll examined neurotoxic and non-neurotoxic snakes living in overlapping environments. His research showed that the most recent common ancestor of these species was a snake with neurotoxic venom. When comparing the genetic code of neurotoxic snakes to non-neurotoxic ones, he found that the two differed by the presence or absence of 16 genes in the metalloproteinase gene complex. He said this meant that non-neurotoxic venom could not evolve from neurotoxic venom.

So what is the mechanism behind this change? What could be the evolutionary explanation?

When Carroll’s lab compared another pair of neurotoxic and non-neurotoxic species in a different region of the US, they found that the two species differed in exactly the same way, with the same set of genes deleted as had been observed in the first discovery. With this new information, Carroll realized that the differences must have occurred through the mechanism of hybridization, or the interbreeding of neurotoxic and non-neurotoxic species.

Carroll’s lab is now doing the structural work to study if the genes that result in neurotoxic and  non-neurotoxic protein complexes are old genes carrying out new functions or entirely new genes. They are using venom gland organoids to look into the regulatory processes of these genes.

In addition to his research studying the evolution of novelties, Carroll teaches molecular biology and genetics at Madison and has devoted a large portion of his career to  storytelling and science education.

Meet New Blogger Anne Littlewood – Working on Biology and Puppies

My name is Anne Littlewood and I am a sophomore here at Duke. I grew up in San Francisco, spent a brief moment living on the island of Kauai, and finished high school in Pebble Beach, California. I am studying the intersection of biology and psychology here at Duke, in an effort to understand how biological mechanisms inform our interactions with the environment.

Snuggles in Puppy Kindergarten!

Outside the classroom, I can be found frequenting Duke’s beloved Puppy Kindergarten, where I work as a volunteer. Recently, I’ve become an Associate Editor for Duke’s literary magazine, The Archive. I love writing creatively, and it’s been so great to find a community of my literature- loving peers. I’m also participating in a Bass Connections project this year, and working on a team to evaluate the outcomes of different conservation interventions through the synthesis of an evidence gap map for World Wildlife fund.

Me and Cricket on Carmel Beach

Most of all I love to spend time outdoors, whether it’s exploring the mountains of North Carolina on a backpacking trip, lying in my hammock at Eno Quarry, or walking through the gardens each day on my way to class. I’m a huge animal lover, and I’m way too obsessed with my dog, a 12-pound cavalier King Charles spaniel named Cricket.

I’ve always been into science, but I think I really fell in love with Biology my freshman year of high school, when my all time favorite teacher, Mr. Cinti helped me extract my DNA one afternoon, just for fun. Writing is my passion, and I’m excited to explore my skills in a variety of genres this year. This blog is my first ever attempt at journalism/ science writing, and I’m excited to give it a try!

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