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Lessons from a lizard, making connections in the world of biology

September 28, 2013

Guest post by Adam Emerick

Nature is truly the best teacher. You can learn about biology from worms or learn physics from raindrops. These concepts are taught in school, but come from pretty pictures in books and packed classroom lectures. There is definitely a disconnect between concepts on paper and the reality of the natural world, but for those who know where to look, there are connections all around us. Seeing something in nature can either push someone to try to understand it, or it can just continue to reinforce a known concept. Because of this, some of the best teachers I have ever had are animals, and I recently saw the whole concept of evolution represented in a tiny lizard.

My masters project involves a little known and even more rarely seen organism called the Florida Sand Skink, a unique lizard that lives a subterranean existence in the sands of the central Florida ridges. Capturing these elusive reptiles requires a great deal of work, but when I first encountered them it brought with it with it an enlightenment that any amount of physical effort would have been worth. They are a textbook example of how adaptation can shape an organism into a form suited for its particular environmental niche. Isolation in the high sand hills and scrub of Florida by glacial melting hundreds of thousands of years ago transformed a population of surface dwelling lizards into sleek, shovel nosed burrowers with an elongated bodies and comically reduced limbs. I quickly became obsessed with finding out more about other sand-dwelling lizards. Research led me to at least a dozen other species of sand swimming skinks distributed all over the planet, from the dry forests of Madagascar to the sand dunes of the Australian outback. Most intriguing was their similarity; despite thousands of miles and millions of years of separation, they all looked like my sand skinks, some nearly identical except for external coloration or markings. Natural selection in an environment with similar demands for survival pushed these animals to take nearly identical forms.

Eastern Legless Skink South Africa-Photo by Tyrone Ping

Eastern Legless Skink
South Africa-Photo by Tyrone Ping

Southern Sandslider Skink Australia-Photo courtesy of ugmedia.com

Southern Sandslider Skink
Australia-Photo courtesy of ugmedia.com

Florida Sand Skink United States  Photo by Adam Emerick

Florida Sand Skink
United States
Photo by Adam Emerick

These are not exceptional occurrences by any stretch of the imagination, and this is only one example of what the natural world can teach us, or the concepts it can reinforce. I knew that evolution and natural selection were real, but actually seeing and holding an animal that was the result of the process in my hand was extremely satisfying. There are wonderful lessons of biology everywhere: in the shapes of leaves, the distance birds sit on a telephone line, even the number of times a frog croaks on a rainy night. Understand the concepts, but open your eyes and consider the world around you. You would be amazed what you can learn from a frog.

Florida Scrub-Jay research at Archbold Biological Station

September 17, 2013

A guest post by Erin Feichtinger

The sun rises, revealing the dense fog enveloping the scrubby landscape. Even in April, it’s warm and humid at dawn, a harbinger of the heat to come. The scrub is a relict ecosystem, one once common in the southeast but now trapped in peninsular Florida. We are searching for Florida Scrub-Jays, birds that are found only in the Florida scrub in fire-maintained habitats featuring short, scrubby oaks. Florida Scrub-Jays are cooperative breeders, meaning that the young stay with their parents for at least a year to aid in raising their siblings and territory defense. The population of scrub-jays here at Archbold Biological Station has been the subject of a long-term study that began in 1969. Scrub-jay breeding pairs establish territories that they occupy until death. Each spring, the territories are mapped. Once a month, the researchers visit every jay territory and conduct a census. This is our task today.

I hop into the truck with binoculars and a jar of peanuts. The jays that live here are trained to respond to a “pshh” sound and retrieve peanuts thrown by the biologists.

“Pshh!” we say.

Florida_Scrub_Jay

I turn and hear the flap of wings descending near the truck. The peanuts bring the jays close so we can read the bands around their legs. Each jay has a unique color combination of three bands that serves as an ID. Because all territories are visited once a month and each jay has a unique ID, we can determine which jays are still in the population and when they have died. During the breeding season, the researchers follow the fates of all nests and nestlings. This allows them to determine how many young each breeding pair produces. From the information on survival and reproduction on every jay that has lived and died at Archbold in the past 44 years, we can analyze how the population as a whole has changed over time.

As carbon dioxide levels pass a new milestone, misconceptions about climate change persist

September 10, 2013

Guest post by Jeremy Cohen

Something happened on Earth this past month that hadn’t occurred in over three million years. Average carbon dioxide (CO2) levels in our atmosphere surpassed 400 parts per million (ppm), after hovering around 200-275 ppm between the dawn of human history and 1900. Since then, the sharp increase in CO2 concentrations is a consequence of the burning of carbon-based fossil fuels, such as coal, gas, and oil. Why is this important? CO2 does one thing very efficiently: it traps heat that arrives from the sun, keeping it on Earth and turning up the temperature of the planet (Figure 1).

co2

(Fig.1) Global temperature and CO2 levels have a close causal relationship, since CO2 traps heat. The spike in CO2 in the last 100 years suggests an increase in temperature to follow.

Unfortunately, warming is only one aspect of climate change. The planet is heating unevenly, causing widespread shifts in wind and weather patterns. Dry regions are becoming drier and wet areas are wetter, resulting in more droughts and floods and affecting the food supply. As the climate becomes more variable, extreme weather such as heat waves and storms are increasing in intensity. Rising sea levels threaten to displace billions and submerge coastal cities such as Miami and New Orleans. Ecosystems are shifting north and changing the timing of their seasons, threatening species that have adapted to specific environments. A recent USF study showed that parasites can adapt quicker than their hosts and benefit from rapid climatic shifts, suggesting that climate change can also bring an increase in disease.

Despite this, the same, tired misconceptions about climate change continue to float around the media. Although climbing CO2 levels and temperatures are finally starting to become well-accepted, the “controversy” has shifted to whether the ramifications of these increases are meaningful. A 2013 Gallup poll found that 40% of respondents thought the effects of climate change are “greatly exaggerated” in the media. Recently, an op-ed in the Wall Street Journal questioned whether CO2 is truly harmful, suggesting that it promotes plant growth. While technically correct, this point ignores a much greater problem: CO2-driven changes in global weather patterns that disrupt conditions to which plants have adapted. Similarly, the argument that CO2 levels have been higher in the distant past, also posed in the WSJ, ignores the fact that the Earth has never experienced such drastic rate of change in atmospheric content. Rates matter because species need time to adapt to changes in the environment, and sudden shifts can cause massive extinctions and a breakdown of ecosystem services we depend on. Although skepticism is healthy, in this case it is often used as a political tool by special interests that do not want CO2 emissions limited by policy. Among climate scientists, there is virtually no doubt that climate change is both human-caused and a severe threat to the well-being of humanity. A review of nearly 14,000 peer-reviewed articles published between 1991-2012 found that only 0.2% rejected climate change.

Sadly, I have little hope that policies to curb CO2 emissions will improve anytime soon, especially since the issue has become so politicized. For example, a recent study in PNAS suggested that people who identified as conservatives actively avoided products that are labeled as environmentally-friendly, even if they are efficient and cut personal energy costs. This is everyone’s planet and we must all act soon to slow the acceleration of this global catastrophe, regardless of ideology.

We’re back! (featuring Team Chordata)

September 4, 2013

After a bit of a hiatus, I have some exciting announcements. The first is that this little bugger has consumed my spare time, via nausea and compulsive internet shopping for car seats and cloth diapers:

Image

The second reason I’ve been busy is that I am teaching up a storm this semester. Aside from my official teaching assignment, I have developed a course at USF, “Sensibly Communicating Science.” Graduate students in the course will practice communicating to you, Dear Readers, in weekly installments. The topics will vary, but everyone will be discussing a topic about which they are passionate. Stay tuned and let us know what you think!

Cheers,

Brittany and “Ziggy the Zygote”

The weirdest bird you’ve never heard of

April 30, 2013

In Tampa, we have some lovely community radio stations. In the car this morning, our local 89.7 WUSF was running a really nice piece on Alfred Russel Wallace (who, like Darwin, developed an evolution-by-natural-selection framework, but was beat to the publisher). Wallace worked throughout the Indo-Pacific islands and, among many other animals, studied megapodes. What’s a megapode? Literally it means “giant feet,” but in practicality, well, it’s one freaky bird.

Australian_Brush_turkey2

OK, so they’re dramatic-looking turkeys. NO. They also sound like a damn Dilophosaurus from Jurassic Park. Not impressed? They build giant nest mounds where heat from what is essentially a giant compost pile incubates their eggs for them. Some of them aren’t even afraid to harvest a little geothermal energy – these species seek out sources of volcanic heat and let the Earth’s core do the incubating. Also, the megapode chicks are completely badass. After spending two days digging out of their nest, they emerge victorious and fly away. Yes. Two-day-old chicks stand up and fly off.

Let’s all take a moment and be thankful for such weird, wonderful creatures. And also that they’re not any bigger, or we’d have baby megapodes a la Tremors 3.

Congressmen receive award for committment to biological research

April 16, 2013

Ah, it warms the cockles of my cranky, Tuesday afternoon heart to report that the Biological and Ecological Sciences Coalition have awarded Daniel Lipinski (D-Illinois) and Dave Reichert (R-Washington) the Congressional Leadership Award for the congressmen’s commitment to scientific research. How refreshing it is to see a Republican supporting scientific research! Although I maintain that reasonable people can disagree about politics, when one half of the two-party system casts itself as anti-science, we have a problem.

Representative Lipinksi is co-chair of the House Science, Technology, Engineering, Mathematics Education Caucus and sponsored the National Science Foundation Authorization Act of 2010, which authorized 8-10.7 billion dollars for the National Science Foundation in years 2011-2015.

Representative Reichert is noted for his efforts to support the conservation of Washington’s wilderness – as such, it’s not surprising to find him on the Wild Salmon Caucus in the House! He is also the co-chair of the National Parks Caucus and National Landscape Conservation Caucus, and a member of the Congressional Biomedical Research Caucus.

Read more about the award at the Ecological Society of America and the American Institute of Biological Sciences.

 

Another shady intelligent design website

April 8, 2013

While searching for the Twitter account of Cornelia Dean (of yesterday’s post), I came across this little gem, which is now included in the Coping with Creationism page: http://www.evolutionnews.org/. This website is run by the Discovery Institute, although you have to do a bit of digging to find out that this blog is not actually about evolution but about intelligent design from your friends at the Discovery Institute (arbiters of all things pseudoscience).

They wrote a scathing account of Dean’s chapter, “The Problem of Objectivity,” which emphasized the fact that journalists have wrongly been giving complete tow-heads equal time in debates over false controversies. The author instead focused on distorting quotes from the chapter. I wonder why? The non-existent controversies that Dean decried include the vaccine-autism debacle, global climate change, and — of course — evolution “versus” intelligent design.

Their website prominently features a link titled “intelligent design,” but cleverly links directly to an outside site… as if “the following link may or may not reflect the views of this alleged evolution website.” Right. That link contains lovely nuggets such as, “Intelligent design begins with the observation that intelligent agents produce complex and specified information (CSI).” Really? That’s a hell of a preliminary assumption. Of course, like many ID proponents, these folks have created a straw man argument. Although “intelligent agents” can produce complex information (do you watch Game of Thrones? So many subplots!), complexity can also arrive de novo – that is, on its own. This simply means that proteins formed in the Earth’s primitive days despite the presence or absence of any “intelligent agents.”

So, fellow profs and TAs, if you spot this bogie in your students’ references section, Just Say No. Although hopefully you already told them that websites are not peer-reviewed.