On a Physicist Who Understood the Human Side of Science

I dug into the MIT archives to learn more about late physics professor Victor Weisskopf. His apprenticeship with Niels Bohr taught him not just about quantum electrodynamics but also about the value of living in a frequently silly community that could approach problems from multiple angles. Read the story on Scope.

On NOVA Next: Stereotype Threat and Biased Testing

The good folks at NOVA Next were good enough to publish my article on a new social psychology experiment. Stereotype threat is when someone fears they are at risk of confirming a negative stereotype about their group. It helps explain why women and ethnic minority students underperform on standardized exams that begin by asking for your sex and ethnicity. The researchers I spoke to found that stereotype threat's effect can be reversed under certain conditions, though.

Reporting on Brain Implants for Depression

from WIkimedia Commons, user Andreashorn.

Right now my classmates and I are focusing on how to write a science news article. My first go at this can be found on Scopeweb, which is our program's online publication. It involved diving into research on using deep brain stimulation, a treatment involving a small electrode implanted in the brain, to treat depression. It was fascinating to learn about an area of medical research in which doctors do not agree on where to take the research next, and I'll be interested to follow the story as it evolves. 

You Can't Build a Better Tuna

RoboTuna

Here's the first short essay I wrote for the Science Writing program at MIT. As a warm-up exercise, we were tasked with observing an object at a local museum and writing 500-800 words on it.

Though over twenty years old, RoboTuna looks like a freshly caught fish partway through filleting.

Its fabric skin is pulled back to reveal slender plastic ribs and motor-guts near its head, but the layer of synthetic scales between ribs and skin still clings to its back half. A wire threads through each belt of long, thin scales, creating a series of overlapping scale-belts down its body. Six joints down its spine give it the potential to ripple like a tuna hurtling after prey. RoboTuna is ready to swim as smoothly as a real fish.

Drones for Watching Beavers and Whales?

Are drones capable of non-evil purposes? Actually, are they even capable of a use that doesn’t make them look creepy and intrusive? (I feel that drone engineers need to do more to make drones that don’t instantly remind me of the Viper probe droid that the Imperial Fleet sent to spy on the Rebel base on planet Hoth.)

There is a surprising application for robotic aircraft that gives me a teaspoonful of hope. In a paper in the Journal of Unmanned Vehicle Systems (a journal whose title will always sound creepy to me) four researchers describe how they used a drone to survey the impacts of a pair of reintroduced beavers on ecosystem structure.

Photo by Per Harald Olsen

Conservationists in the United Kingdom are engaged in a major project of reintroducing the beaver to their country. Overhunting forced the species to local extinction as early as the 16th century. By damming streams and creating ponds and wetlands, beavers make a huge contribution to local diversity. Amphibians, fish, arthropods, plants and more all depend on the habitat created by beavers.

This study observed a pair of beavers brought to a first-order stream in southwestern England. The drone, a hexacopter equipped with a camera, was able to provide good images of beaver activity such as gnawed trees and dams under construction. And with software, the researchers converted these photos to computer models capable of telling us about hydrology, topography, vegetation structure, and other interesting landscape variables.

Unfortunately, the researchers only studied this site after the beavers had done their work, so they weren’t able to make comparisons to how the site was before the beaver engineers got to work.

Nonetheless, what the study suggests will be possible soon is very promising. The drone method is not just trendy. It’s cheaper than piloted aircraft, and, since it is low-altitude, it provides higher resolution data. It’s less labor intensive and faster than doing surveys on foot. You also avoid disturbing sensitive wetlands, which can be harmed by trace amounts of chemicals or pathogens found on researchers. The wildlife themselves are less bothered by a quiet hexacopter than a human or a piloted helicopter. And though the study didn’t mention it, a programmable aircraft is more rigorous than a human observer. Human estimations of vegetation parameters is notoriously prone to error.

Lastly, the drones don’t have a social schedule or a preference for warm or cold weather, and can be kept to inhumane and demanding survey schedules that even a seasoned field biologist would reject.

Another study in the same issue showed perhaps even more exciting benefits to drone surveys of whales. The surveyors launched the hexacopter from small craft at sea, where piloted aircraft would have been expensive and unfeasible. Since the whale pod showed no behavioral changes, the paper concluded that the drone did not bother them. From a height of 35 meters, the drone’s images showed enough detail for the biologists to identify each whale by its markings. And, because the drones can be kept to a constant altitude, biologists can use their photos of whales to calculate precise sizes and track growth rates for each whale.

I would be sad if the advent of drone ecology would mean the disappearance of human-led field surveys. We probably don’t have to worry about that any time soon. The main thing is to celebrate that we have found a socially and environmentally beneficial use for at least a few of those freaky airborne robots.

Of Swallow Wings and SUV Windshields

I often think of high-rise buildings, subways, and dams when I think about characteristic human changes to the landscape. But in terms of acreage, high-input agricultural zones have been a more widespread and comprehensive land use change in the past two centuries. This land use type includes not just the actual cornfields but also the houses, grain elevators, country highways, and small towns that support the farming. The cumulative effect has been to almost wipe out grasslands worldwide, replacing them with an ecosystem with many different pressures and opportunities than the previous one.

These changes have measurable impacts on wildlife that are often surprising. Wild populations do not merely shuffle out of the way when humans come to settle. It is always a collision. Some are killed in droves like the American buffalo. Others slowly or steadily decline over many years, like grassland songbirds. And a few special species are able to adapt and thrive in the new ecosystem.

Photo by Don DeBold

Cliff Swallows are small, handsome flycatching birds with a blue back and wings, a white belly and a red throat. They create colonies of nests on vertical surfaces made from mud they carry in their beaks. In Nebraska, biologists have been studying the habits of Cliff Swallows for over 30 years. There, the birds are not nesting on natural cliffs but the constructed ones under highway overpasses and roadway culverts. Birds with shorter wings are better able to avoid passing cars, and short wings are now the norm in these cliff swallow populations, according to Charles Brown and Mary Bomberger Brown of U. Nebraska-Lincoln and U. Tulsa. They described their findings in a paper, “Where has all the road kill gone?” published in Current Biology in 2013.

Brown and Brown compared the roadkilled birds to a sample of birds which died accidentally while the researchers used mist-netting to capture individuals for study. They saw that the roadkilled birds almost all had longer wings than the rest of the population. Over the 30-year study, fewer and fewer birds ended up on the highway shoulder, and the general population’s wings got shorter.

To understand why short wings help you dodge a Hummer, we have to consider flight physics. Longer wings lead to efficient flight and shallow, graceful takeoffs by decreasing the amount of bird mass carried by each square inch of wing. But shorter, stubbier wings allow for greater maneuverability and more vertical takeoffs. These sharply angled takeoffs, the researchers believe, are what allowed the short-winged swallows to launch away from the road surface as a car approaches more successfully than their long-winged relatives.

While the outcome has a strange beauty, the process was plainly brutal. The selection pressure was millions of unforgiving windshields. Roadway traffic kills 80 million birds a year in the U.S. alone. If you look at Brown and Brown’s figures, you’ll see that even in a moderate year, they and their students collected tens of thousands of cliff swallow corpses. And these were the cliff swallow casualties only in their Nebraska study area. Not that the butcher’s bill here is so different from that resulting from other kinds of selective pressures. Evolution works through death—new forms arise because less successful individuals die.

Yet even though we can read the cliff swallow’s story as a success of natural selection, what stands out to me is how few species have been able to adapt this well. In the same region, birds such as Henslow’s Sparrow, the Upland Sandpiper, and the Greater Prairie Chicken have faced severe declines due to the loss and fragmentation of even marginally suitable habitat. For these birds, evolution would not be a matter of changing wing length but changing their entire lifestyle, something that is probably impossible within timescales meaningful to humans. Are the opportunities that one country highway creates for Cliff Swallows balanced by the splintering of the remaining lands for declining and endangered species?

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Citation

Brown, C.R., and M.B. Brown. 2013. Where has all the road kill gone? Current Biology 23:233-234.

How Small Jaws Got Bigger in Prairie Cornfields

Image from Doudna and Danielson (2015).

It can be hard to grasp how much humans have reshaped the landscape—particularly in agricultural regions like the Midwest. I struggle to picture prairie where corn and oak-lined subdivisions now stand. One window into these changes is to look at how our farms have widened some of the smallest of mammal mouths.

The arrival of massive corn and soybean fields forced prairie deer mice to shift their diets, according to a study by John Doudna and Brent Danielson of Iowa State published in the journal PLOS ONE this June. The researchers compared museum collections of deer mice skulls from before major agriculture to mice they trapped during 2012 and 2013 from the same regions. Instead of tiny wildflower seeds, deer mice started eating the many-times larger corn and soybean seeds left behind in Midwestern fields. The selective pressure of the new food sources led to populations with larger, more robust jaws able to handle cracking corn. I hope to give this topic a fuller treatment soon. For now, check out the original study!

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Citation
Doudna, J.W., and B.J. Danielson. 2015. Rapid morphological change in the masticatory structures of an important ecosystem service provider. PLOS ONE 10. doi:10.1371/journal.pone.0127218.

Fly in Your Burger?

"In a typical fast food meal of a hamburger, fries, and a milkshake, most of the components required an insect somewhere along the way; although the wheat in the bun is wind-pollinated, the other plants, from the cucumber for the pickle to the feed eaten by the cow, are insect-pollinated. Nicola Gallai from the University of Montpellier in France and her colleagues estimated the world economic value of pollination to be $153 billion, pointing out that this is nearly 10 percent of the value of agricultural production used for human food in 2005."

- Marlene Zuk,  Sex on Six Legs: On Life, Love, and Language from the Insect World

Just one more reason to think twice about that squeeze bottle of Bug-Blaster.

For me, science writers fall into two broad categories: those with scientific backgrounds and PhDs who have entered the realm of journalism, and those with hard-boiled reorting backgrounds who are exploring the realms of science. In practice, you hopefully won't be able to tell, from the text alone, what kind of writer wrote which successful popular science article or book. Dr. Zuk, an entomologist at the University of California-Riverside, falls into the first category. In preparation for my master's program, I'm trying to read a wide swath of authors and steal as many of their tricks as I can. Zuk spins off a new riff on the ever dependable method of putting economic value to overlooked wildlife: she shows us how many dollars worth of insects it took to produce your double cheeseburger with pickles and diced onions.