Four Things You May Not Know about Ecologist E.O. Wilson

By Erin Weeks

Edward O Wilson Red Hills, Aalabama  2010 by Beth Maynor Young 6x9_0

(Photo: Beth Maynor Young)

Edward O. Wilson is one of the most renowned living biologists, the world’s foremost authority on ants, and for a little while at least, a member of the Duke faculty.

Wilson is on campus teaching the first of an annual course, part of a recent partnership between the E.O. Wilson Biodiversity Foundation and Duke’s Nicholas School of the Environment. Feb. 11, he spoke to a sold-out auditorium about “The Diversity of Life,” a lecture that was equal parts awe-inspiring facts, humorous anecdotes from a life in science and call to arms for future generations.

Here are four things the audience learned last night about E.O. Wilson.

1. He’s dabbled in dreams of Jurassic Park. When asked what he thought of de-extinction, the plan to resurrect vanished species using their DNA, Wilson enumerated all the reasons why the efforts may be futile: we have only genetic shreds; the appropriate habitat may be gone; we can’t produce breeding populations from limited DNA.

But then he paused. “I’ll tell you frankly,” he said, “I’d like to see a mammoth.”

2. He made his first scientific discovery as an adolescent. An eye permanently damaged in a fishing accident led the young Wilson to his interest in ants, which he could view up close. One day in his native Alabama, he discovered a ferocious mound-building species he’d never seen before. He didn’t recognize it then, but those were among the first of the destructive red fire ants that would soon invade the entire Southeast, causing billions of dollars of economic and medical damage.

3. The man is 84 and still going strong. Professor Wilson closed his talk with a passage from his newest book, arriving in April, called “A Window on Eternity: A Biologist’s Walk Through Gorongosa National Park.” He’s written two dozen other books, including a foray into fiction at age 80 (the novel, called Anthill, won him the 2010 Heartland Prize for fiction).

4. The future is in nematodes. Or fungi. Or Archaea. Throughout the talk, Wilson reiterated his hopes for young scientists to become the cataloguers and guardians of Earth’s immense biological diversity. Only a fraction of the planet’s estimated species of nematodes, fungi and Archaea are known to science, and “these little things run the world,” he said.

The need for “-ologists” has never been greater, he said.

(Photo: Jared Lazarus)

(Photo: Jared Lazarus)

VIEW THE ENTIRE TALK (YouTube, 1:10 with introductions)

Turtle Sexes are Temperamental

Guest post by Lauren Burianek, doctoral candidate in cell biology

A pair of one-week-old red-eared sliders. The one on the right looks a little cranky. (Tadpole667 via Wikimedia Commons)

A pair of one-week-old red-eared sliders. (Tadpole667 via Wikimedia Commons)

When humans are developing, they snuggle in a warm environment and everything is provided by the mother. The sex of this developing fetus is determined by its individual genetic makeup, particularly the presence of the X and Y chromosomes.

But laid as an egg in a hole on a riverbank, the sex of a red-eared slider turtle is determined by the temperature at which the egg is developed.

At temperatures above 84.6°F, the hatchling will develop into a female, but at lower temperatures, the hatchling will develop into a male. However, at exactly this temperature (called the pivotal temperature), half of the hatchlings will be female and the other half will be male.

Scientists have no idea how temperature affects the sex of the turtle hatchlings, but researchers in Blanche Capel’s lab at Duke are trying to find out.

Red-eared sliders breed in late spring near riverbanks in Louisiana. Researchers carefully collect the eggs from common nesting spots and send the eggs to Duke University. In the Capel lab, graduate student Mike Czerwinski then buries the eggs in sand and places them into incubators at different temperatures. From here, he will analyze the gonads, or sexual organs, of the turtle embryos incubated at the different temperatures.

Grad student Mike Czerwinski in the Capel lab.

Grad student Mike Czerwinski in the Capel lab.

Czerwinski and his colleague Lindsey Mork discovered that when the turtle embryos were incubated at the pivotal temperature, both gonads developed into either testes or ovaries, but rarely did the two gonads develop into one of each.

Then, they incubated the turtle embryos at the pivotal temperature, dissected the two gonads and incubated each of them at different temperatures, either male-developing or female-developing temperatures. Surprisingly, the separated pairs of gonads still attempted to develop into the same sex regardless of the incubation temperature.

Tyrannosaurus Rex may have had temperature-sensitive eggs too. (tlcoles via Wikimedia Commons)

Tyrannosaurus Rex may have had temperature-sensitive eggs too. (tlcoles via Wikimedia Commons)

For example, if one of the gonads incubated in the male-developing temperature readily turned into a testis, the other gonad of the embryo, even though it was incubated in female-developing temperatures, is slower to develop into an ovary than expected, suggesting that it was genetically predisposed to be a testis.

“The results are exciting because it shows that there is a global mechanism beyond temperature dependence that allows for sex determination,” said Czerwinski. “All we’ve known up until now is that temperature is important for these turtles, but now we know that there also has to be a genetic component. Sex determination is so varied between different species, but this might give us insight into how we’re all connected.”

Climate change could definitely be a factor in the survival of these turtles and other temperature-dependent species. After all, the dinosaurs are thought to have exhibited temperature-dependent sex determination.

With increasing temperatures, a higher proportion of hatchlings will be females. Snapping turtles, however, have found a way to combat this – by moving north. The same species of snapping turtles exhibit different pivotal temperatures at different latitudes.

Evolution truly is an amazing process.

Pretty pictures show lemurs responding to changing climate

Guest Post by Sheena Faherty, Biology Graduate Student 

Madagascar’s much-adored and fuzzy lemurs might be “sweated out” of habitats by warming environments under global climate change. Or will they?

A team of researchers at the Duke Lemur Center is employing high-tech heat cameras used in  fire fighting, sports medicine and cancer diagnostics to take “glowing” rainbow pictures of lemurs and their forest surroundings. The results look similar to a child’s coloring project gone rogue.

A mother and baby Coquerel's Sifaka at the Lemur Center in thermograph and visible light. (Leslie Digby)

A mother and baby Coquerel’s Sifaka at the Lemur Center in thermograph and visible light. (Leslie Digby)

This technology, known as infrared thermography, is a camera that allows researchers to detect surface temperatures of lemurs and their hang-outs in the forest—at different depths and heights—and on varying surfaces such as the ground, leaves, and tree trunks.

Combining these data with records of where an animal prefers to spend time, the researchers can begin to determine what temperatures make lemurs most happy.

Leslie Digby, an associate professor in the Department of Evolutionary Anthropology, and her students want to see  how the lemurs are changing their behavior to warm-up on cool days, and cool-down on warm days without having to shiver or sweat.

This sounds rather like a lizard basking on a rock during a sunny day to warm his cold-blooded body up, but lemurs aren’t cold-blooded. They shouldn’t have to do this.

It turns out that even though lemurs are warm-blooded, they can conserve precious energy by channeling their inner Buddha — using sunning behaviors, just like lizards, to fine-tune core body temperatures.

Digby’s team is trying to understand why some species have seemingly restricted territories, even without obvious geographical barriers like mountain ranges or rivers. They suspect temperature plays a part.

“We know that primate species ranges have been very different in the past, so understanding how flexible these animals are, or [are] not, to temperatures can help us understand these larger scale impacts [of changing climate]”, says Digby.

Figuring out how animals respond to alterations in their environment, like rising temperatures, can help scientists anticipate species’ survival in the face of globally changing climates. And knowing which areas of the forest are preferred by lemurs, could help direct conservation efforts, like reforesting parts that have been cut down, or preserving those areas that have not.

Changing temperatures will undoubtedly have major impacts on lemur home ranges in the future, potentially altering them until the animals  are forced into an area outside their thermal limits. By gearing her research toward understanding the thermal tolerances of lemurs, Digby is doing her part to protect the vulnerable lemurs.

A ringtailed lemur striking the classic belly-warming Buddha pose in one of the natural enclosures at Duke Lemur Center. (David Haring)

A ringtailed lemur striking the classic belly-warming Buddha pose in one of the natural enclosures at Duke Lemur Center. (David Haring)

Humans, Whales and Taylor Swift

by Ashley Mooney

The similarities between chromium workers and whales are greater than one might think.

Environmental toxicology researcher John Wise has been studying the connection between exposure to pollutants and the onset of cancer in humans. To understand the link, he said one must take into account all species, especially whales. Wise spoke at Duke Oct. 25 at the Inaugural Duke Distinguished Lecture in Cancer and the Environment.

800px-Chromium_crystals_and_1cm3_cube

Chromium crystals. Courtesy of Wikimedia Commons.

“For environmental health for me, [the Earth] is the big picture,” Wise said. “This is home and we only have one, so we have to think pretty hard about environmental health.”

Wise studies the effect of pollutants—specifically forms of chromium—on genetic material in humans, marine mammals, and birds and other marine species.  While the standard approach to environmental toxicology research is to conduct epidemiology studies on highly exposed populations and then expose animals to high doses of the toxin, Wise has adopted a new method of study.

“We don’t really know what high-dose exposures mean on a day-to-day basis,” he said.

To understand the relationship between chromium exposure and the onset of cancer, Wise looks at the personal factors that affect one’s health, such as an individual’s body and genome, lifestyle, daily exposures and what kind of environment one lives in.

“We need to know mechanism: how does a normal cell become a tumor cell?” he said. “For a long time that is where the field has been hung up, trying to identify the ultimate carcinogen.”

Most forms of naturally occurring chromium are not toxic. Man-made hexavalent chromium, however, has been shown to cause lung cancer in those who are regularly or heavily exposed to it. Prolonged exposure induces an altered chromosome number and structure, as well as DNA double strand breaks.

Chronic exposure to chromium also causes a shift from more a protective form of DNA repair called homologous recombination to a less stable and error-prone pathway called non-homologous end joining. This means that cells will have permanently deficient repair mechanisms.

Wise applies his research in the context of ocean health, namely how chromium exposure might harm whale DNA.

Most ocean pollutants, including the toxic form of chromium, are in the ocean sediment. As the ocean becomes increasingly more acidic, the sediment breaks off and poses a growing threat to marine species.

Wise measured chromium levels in baleen whale skin, and found that Atlantic seaboard species—the northern right whale, fin whale and humpback whale—have 16- to 41-fold higher levels than other baleen whales.  Toothed whales living in the Gulf of Mexico exhibited levels that resembled those found in chromium workers who died of lung cancer.

A humpback whale surfacing for air. Courtesy of: Protected Resouces Division, Southwest Fisheries Science Center, La Jolla, California. swfsc.nmfs.noaa.gov/PRD/.

A humpback whale surfacing for air. Courtesy of: Protected Resouces Division, Southwest Fisheries Science Center, La Jolla, California. swfsc.nmfs.noaa.gov/PRD/.

In whales, chromium can lead to DNA damage and reproductive suppression.

“There’s only 400 [northern right whales] left in existence,” Wise said. “If you only have 400 animals, you need every single one of them [to be able to reproduce].”

Wise said he hopes his research will encourage people to think more about habitat degradation and climate change, and how they affect all species.

taylor-conor-sailing-team, courtesy of popdust.com

Wise (back right) photographed with his lab and Conor Kennedy (back left). Courtesy of popdust.com.

His lab, however, has recently gained publicity not for its research, but for the public figures that have worked with it. Conor Kennedy, a member of the influential Kennedy family, worked with Wise’s team and Ocean Alliance last year. At the time he was dating pop-star Taylor Swift.

“[He was], like any other high school student, constantly texting on his phone and I would do what I did with my kids and the other students, and say ‘put the girl down, we have to go to work,’ not knowing the girl was Taylor Swift,” Wise said. “It really hit home that we were traveling in very different circles.”

Students Create Multimedia Ocean Conservation Text

By Ashley Yeager

This screenshot shows one of the opening page of of Johnston's new iBook. Image courtesy of Dave Johnston, Duke.

This screenshot shows one of the opening pages of a chapter in Johnston’s new iBook. Image courtesy of Dave Johnston, Duke.

Duke marine biologist Dave Johnston and his students are back in business on iTunes.

They’ve just released The View From Below, a free iBook for middle school students and teachers that uses multimedia and classroom exercises to discuss overfishing, marine debris, climate change, invasive species and other issues related to marine conservation.

This is Johnston’s second digital textbook. His first was Cachalot, an iPad textbook covering the latest science of marine mammals like whales, dolphins and seals. Experts contributed the text, images and open-access papers.

The View From Below, however, is a bit different.

Undergraduate students in Johnston’s Marine Conservation Service Learning class wrote the book using Apple’s iBooks authoring tool. Johnston and Tom Schultz, Director of the Marine Conservation Molecular Facility at Duke’s Marine Lab, edited it.

“There are a lot of people exploring the use of the iBooks platform for student-generated content, among other development platforms,” Johnston says. “I don’t think we’ve seen many that focus on marine science yet though, and I’m pretty sure it’s the first marine conservation textbook written by students on the iTunes store.”

Johnston says the class chose to use the iBooks software because the technology is free, easy to use and provides “great templates to get things going quickly.” The software also works well because Duke’s Marine Lab has an iPad loaner program, making the tablet the platform of choice for developing and testing the textbook.

The middle school that the service learning class works with also has access to iPads for students and instructors, so the audience was there for the iPad format, Johnston adds.

His students chose to write the book as the class project to spur learning and discussion about some of the most serious problems facing Earth’s oceans.

“As the text indicates, all life on earth is ultimately supported by the ocean, so we need to take care of it,” he says.

Activist targets inner child not ‘target audience’

By Ashley Yeager

A baby albatross carcass full of plastic “food.” Credit: Chris Jordan.

When artist Chris Jordan works on a photograph or film, he doesn’t think about his audience. He said he thinks the phrase “target audience” is a disrespectful, manipulative business concept.

“I want to be as authentic as possible with my work,” Jordan said, explaining that each of his pieces instead taps into that “universality in us that we all carry, a deep appreciation for the abiding beauty of our world and the miracle of our own lives.”

An environmental activist as well as an artist, Jordan is challenging others to target that universality too as they convey messages about the issues that affect the planet.

Jordan spoke March 1 as part of a working group to discuss questions about how environmentalists, neuroscientists and artists can work together to better communicate about issues affecting the planet. The Nicholas School of the Environment and the Duke Institute for Brain Sciences sponsored the discussion.

Duke ecologist Nicole Heller moderated the discussion, opening it with the idea that scientists are frustrated with their inability to communicate with politicians and the public about the environment.

“In the ’70s, yucky or scary images might have worked, but now they don’t. That’s no longer appealing. We need different kinds of imagery to reach across people’s biases,” Heller said. She invited Jordan to speak because of his reputation for being able to move audiences from diverse backgrounds and education levels.

“Second graders are some of the most passionate and responsive to these issues,” Jordan said, adding that perhaps the best thing we can do is to appeal to an individual’s inner child – that curious spirit we have to understand how the world works.

One example of this approach is the film Jordan is working on to explore the mating dance of albatrosses on Midway Atoll in the Pacific Ocean. He’s photographed dead baby albatrosses, whose stomachs are full of plastic trash their parents fed to them because they mistake the plastic for food. The work was to make people aware of the plastic vortex, or Great Pacific Garbage Patch, swirling beyond the horizon and therefore beyond our conscious concern.

Jordan decided to capture the wonder of the albatrosses as they mate, rather than just their rotting carcasses, hoping to feed his audiences — no matter their background — with life, rather than depress them with death.

“Like the albatross, we first-world humans find ourselves lacking the ability to discern anymore what is nourishing from what is toxic to our lives and our spirits. Choked to death on our waste, the mythical albatross calls upon us to recognize that our greatest challenge lies not out there, but in here,” Jordan writes on his Web site.