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Assorted Personal Notations, Essays, and Other Jottings

Posts Tagged ‘science

[LINK] “In a First, the FDA Clears Genetically Modified Salmon for Eating—It Just Took 20 Years”

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Nick Stockton of Wired notes the approval, after decades, by the FDA of a genetically-modified fish for human consumption. What did it take? A lot.

From their birth in freshwater lakes to getting caught in a fisherman’s net, it can take years for a wild salmon to wind up filleted and garnished with a lemon on your dinner plate. But for the Frankenfish that the FDA approved yesterday—the very first genetically modified organism declared safe to eat—the journey took more than 20 years.

It didn’t take that long because the science was hard. Researchers had already nailed down the genetic tweaks to bulk up the fish—technically called the AquAdvantage salmon—by the early 1990s. Starting with the genome of the Atlantic salmon, a heavily farmed species that’s nearly extinct in the wild, scientists made two changes. They took the gene for a growth hormone from the Chinook (or king) salmon, the largest of the Pacific salmon species, and kicked that hormone into overdrive with a promoter gene taken from ocean pout, an eel-like fish that can survive and grow in near-freezing waters. “Usually the salmon’s growth hormone gets turned off during colder months,” says Eric Hallerman, fish conservation scientist at Virginia Tech University. The pout’s promoter gene basically makes sure the Chinook growth gene never gets shut off. Voila: a mega-fish.

So why did AquAdvantage take so long getting to market? In part, because the government didn’t have a regulatory pathway for GM animals to become food at that time. Fish become food, which goes in your mouth, and the Reagan administration decided that modified animal foods fall under the FDA. That makes sense, because a modified animal could trigger some peoples’ allergies, and there have also been (mostly debunked) claims about GM organisms causing cancer. Those concerns have all been cleared up to the FDA’s satisfaction.

But the AquAdvantage also stoked environmental worries. For instance, what if this super fast-growing, fast-eating fish escapes and starts competing for resources with its wild cousins? Do you want extinction? Because that’s how you get extinction. You also don’t want GM fish and wild fish interbreeding, polluting the wild genomes with engineered sequences.

Written by Randy McDonald

November 20, 2015 at 2:29 pm

[LINK] “What Yeast Reveals About the Origins of Multicellular Life”

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Wired‘s Emily Singer describes how scientists have recreated a critical stage in the evolution of life.

Until one or two billion years ago, life on Earth was limited to a soup of single-celled creatures. Then one fateful day, a lonely cell surrendered solitude for communal living. It developed a chance mutation that made its progeny stick together, eventually giving rise to the first multicellular life.

With that simple innovation, a world of possibilities burst open. These new organisms were too big to be eaten, and their mammoth size allowed them to pull in more food from the environment. Most important, individual cells within the bunch could begin to specialize, taking on new functions, such as hunting, eating and defense. The transition to multicellularity was so successful that it happened over and over again in Earth’s evolutionary history—at least 25 times, and very likely more.

Multicellularity has clear advantages—just look at the menagerie of form and function among animals, plants and fungi. But scientists have long been puzzled as to how this transformation took place. A true multicellular organism acts as a unit, meaning that each cell must surrender its will to survive as an individual and act to ensure the survival of the larger group. “The problem with all the major evolutionary transitions is how Darwinian entities relinquish their individual fitness and become part of a higher-level unit,” said Richard Michod, an evolutionary biologist at the University of Arizona in Tucson.

Scientists are gaining insight into the process by re-creating the evolution of multicellularity in the lab. Using an approach known as experimental evolution, they prod single-celled microbes, such as yeast, algae or bacteria, to develop a multicell form.

“It’s easy to think of [these major transitions] as a giant leap in evolution, and in some sense that’s true,” said Ben Kerr, a biologist at the University of Washington in Seattle and one of the researchers studying major transitions in evolution. But each transition actually involved a series of small advances—the organisms had to evolve effective ways to stick together, to cooperate, to divide and to develop specialized jobs within the greater whole. “We’re trying to do the opposite of a giant leap. We’re trying to break one giant leap for evolution into an understandable series of small steps.”

William Ratcliff, a biologist at the Georgia Institute of Technology in Atlanta, and his collaborators have discovered a surprisingly simple route to multicellularity: a single mutation in yeast that adheres the mother cell to its daughter to create a snowflake-like shape. These snowflakes grow and divide in a way that provides a clever solution to one of the major pitfalls of multicellularity: the cheater problem, in which lazy cells take advantage of cooperative ones. And while the work hasn’t produced a true multicellular organism, the snowflake yeast has shown just how easy it can be for life to take the first step toward a major biological transformation.

Written by Randy McDonald

November 20, 2015 at 2:26 pm

Posted in Science

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[CAT] “Your Cat Doesn’t Really Want To Kill You”

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Barbara J. King’s NPR article tries to rephrase a recent research finding suggesting cats would behave no differently from lions, and not successfully. Yes, there’s variation within species, but the basic comparison seems to hold.

The research aimed to assess personality in four zoo-housed wildcats — two types of leopards, the lion and the wildcat of Scotland — and also in shelter-housed domestic cats. Based on ratings of the cats’ caretakers, three major personality dimensions were found per species.

The trouble came when the lion and the cat were both described with the same terms: dominance, impulsivity and neuroticism. Definitions in the article weren’t as clear as I’d hoped, but this last term seems to involve anxiety, suspicion and fearfulness of people.

(If you are interested in the results for the others, here they are: Wildcats’ personality dimensions were dominance, agreeableness and self-control; clouded leopards’ were dominance/impulsiveness, agreeableness/openness and neuroticism; and snow leopards’ were dominance, impulsiveness/openness and neuroticism.)

Here’s the thing: The researchers’ specific framing of the shared cat-lion terms must be grasped if the study itself is to be interpreted properly. Lead researcher Gartner notes that personality factors aren’t the same thing as individual traits. In other words, each lion and each cat can be assessed along a spectrum of the three factors, and each individual will differ in where it falls. It’s not inevitable that lions or cats will act any certain way.

Written by Randy McDonald

November 14, 2015 at 2:59 pm

Posted in Science

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[LINK] “Exxon Knew about Climate Change Almost 40 Years Ago”

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Scientific American‘s Shannon Hall reports on how Exxon, to its decided benefit, hid its knowledge of global warming.

Exxon was aware of climate change, as early as 1977, 11 years before it became a public issue, according to a recent investigation from InsideClimate News. This knowledge did not prevent the company (now ExxonMobil and the world’s largest oil and gas company) from spending decades refusing to publicly acknowledge climate change and even promoting climate misinformation—an approach many have likened to the lies spread by the tobacco industry regarding the health risks of smoking. Both industries were conscious that their products wouldn’t stay profitable once the world understood the risks, so much so that they used the same consultants to develop strategies on how to communicate with the public.

Experts, however, aren’t terribly surprised. “It’s never been remotely plausible that they did not understand the science,” says Naomi Oreskes, a history of science professor at Harvard University. But as it turns out, Exxon didn’t just understand the science, the company actively engaged with it. In the 1970s and 1980s it employed top scientists to look into the issue and launched its own ambitious research program that empirically sampled carbon dioxide and built rigorous climate models. Exxon even spent more than $1 million on a tanker project that would tackle how much CO2 is absorbed by the oceans. It was one of the biggest scientific questions of the time, meaning that Exxon was truly conducting unprecedented research.

In their eight-month-long investigation, reporters at InsideClimate News interviewed former Exxon employees, scientists and federal officials and analyzed hundreds of pages of internal documents. They found that the company’s knowledge of climate change dates back to July 1977, when its senior scientist James Black delivered a sobering message on the topic. “In the first place, there is general scientific agreement that the most likely manner in which mankind is influencing the global climate is through carbon dioxide release from the burning of fossil fuels,” Black told Exxon’s management committee. A year later he warned Exxon that doubling CO2 gases in the atmosphere would increase average global temperatures by two or three degrees—a number that is consistent with the scientific consensus today. He continued to warn that “present thinking holds that man has a time window of five to 10 years before the need for hard decisions regarding changes in energy strategies might become critical.” In other words, Exxon needed to act.

Written by Randy McDonald

November 2, 2015 at 8:33 pm

[CAT] “Are Cats Domesticated?”

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At least one person forwarded me links to Ferris Jabr’s New Yorker article examining the question of whether or not housecats are a domesticated species.

At first, the cat was yet another opportunistic creature that evolved to take advantage of civilization. It was essentially a larger version of the rodents it caught. Somewhere along the line, people shifted from tolerating cats to welcoming them, providing extra food and a warm place to sleep. Why? Perhaps because of the cat’s innate predisposition to tameness and its inherent faunal charm—what the Japanese would call kawaii. Look up photos of the thirty-eight or so wildcat species and you might be surprised at how easy it is to picture one curled up on the couch. Dogs likely initiated their own domestication, too, by prowling around campfires in search of food scraps. Whereas our ancestors quickly harnessed dogs to useful tasks, breeding them to guard, hunt, and herd, they never asked much of cats. We have also been slow to diversify cat breeds. Many dog, horse, and cattle breeds are more than five hundred years old, but the first documented cat fanciers’ show didn’t take place until 1871, at the Crystal Palace, in London, and the most modern cat breeds emerged only within the past fifty years.

This relatively short and lenient period of selective breeding is manifest in the cat genome, Wesley Warren, a geneticist at Washington University in St. Louis*, said. In a study published last year, Warren and his colleagues analyzed DNA from several wildcats and breeds of domestic cat, including an Abyssinian named Cinnamon. They confirmed that, genetically, cats have diverged much less from their wildcat ancestors than dogs have from wolves, and that the cat genome has much more modest signatures of artificial selection. Because cats also retain sharper hunting skills than dogs, abandoned felines are more likely to survive without any human help. In some countries, feral cats routinely breed with their wildcat cousins. “There’s still a lot of genetic mixing,” Warren said. “You don’t have the true differentiation you see between wolf and dog. Using the dog as the best comparison, the modern cat is not what I would call fully domesticated.”

Not all researchers agree. “I don’t think it makes sense to talk about animals as semi- or fully domesticated,” Greger Larson, a paleogeneticist and archeologist at Oxford University and an expert on domestication, said. “Any threshold you try to define will necessarily be arbitrary.” Larson tends to agree with the views of Melinda Zeder, an archeologist at the Smithsonian Institution, who has written extensively on the domestication of both plants and animals. Zeder characterized domestication as an ongoing symbiosis between humans and another species—“a sort of pact that ends up being mutually beneficial,” she said. This relationship, she argued, can follow many paths and result in somewhat different outcomes, which she has catalogued. Sometimes people gradually domesticate a prey species—sheep, goats, cattle—or deliberately remove non-prey animals from the wild and breed them for a specific purpose, as we’ve done with horses. In other cases, hunger draws a wild animal—dogs, chickens, guinea pigs, cats—to human society, where it becomes increasingly tolerant of people. Even a single domestic lineage can contain varying degrees of dependency and a range of temperaments.

I’m inclined to say that they are whatever they want to be.

Written by Randy McDonald

October 31, 2015 at 8:27 pm

[CAT] “How A Photographer Captured The Beauty of Siberian Tigers”

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Simon Worrell of National Geographic interviewed Sooyong Park, a Korean photographer whose dedicated photography in adverse conditions has produced the book Great Soul Of Siberia: Passion, Obsession And One Man’s Quest For The World’s Most Elusive Tiger.

You studied literature for 17 years, and you write like a poet. How did you end up studying Siberian tigers? What is it about these tigers that draws the muse out of you?

For a long time I have been drawn to the beauty of living things and while literature is useful for explaining humanity, it is not enough for explaining nature. Science is more useful, but science is very dry. So I always wanted to fuse science and literature. To do that, I had to immerse myself in nature and observe living things with my own eyes and become one of nature’s species.

I focused on Siberian tigers, which are endangered and elusive. It was a challenge, and the difficulty in finding them led me deep into nature. After many years of study, I could identify individual tigers and recognize their family members. Understanding tiger families allowed me to peer more deeply into their lives: how they love, how they are born, how they live and die. They are not so different from human beings. Knowing that inspired compassion.

You spent six to seven months alone in a bunker during the long Siberian winters in hopes of filming Siberian tigers. Describe your bunker and how you survived the isolation and cold.

We called our bunkers ‘hotels’ to make them seem more comfortable. But in reality they were cramped, underground spaces measuring six feet by six feet by five. I had to stoop when standing up, but I spent most of my time sitting: waiting and watching for tigers with my camera. Outside it was -20F and snowy. I was unable to shower or turn a light on, and had to remain very quiet so as not to scare off the tigers, even though sometimes I wanted to shout. I felt as though I were in solitary confinement. I would read the labels of food containers for entertainment.

Written by Randy McDonald

October 31, 2015 at 8:25 pm

[CAT] “As Tiger Numbers Dwindle, Will Smugglers Target a Different Cat?”

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National Geographic‘s Rachael Bale tells a depressingly plausible story.

Among wild cats, clouded leopards are increasingly coveted—and bred in captivity—for commercial purposes, according to a new study from University of Oxford’s Wildlife Conservation Research Unit. They’re being sold into the pet trade, to tourist attractions offering cat encounters, and to other such profit-driven businesses.

Researchers Neil D’Cruze and David Macdonald reviewed import and export records filed with the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES), the body that regulates international wildlife trade, and found a 42 percent increase in the commercial trade of live clouded leopards from 1975 to 2013.

Clouded leopards are native to Southeast Asia and named for their distinctive spotted coats. They’re one of the smallest big cats, weighing up to 50 pounds and growing up to three feet long. They belong to an entirely separate taxonomic group from snow leopards and “regular” leopards, such as African and Indian leopards.

The reason for their new popularity has much to do with the decline of tigers, now estimated to number no more than 3,200, whose bones, feet and other body parts are highly prized in traditional medicine and for warding off evil.

Some 10,000 clouded leopards remain in the wild, with no single population larger than 1,000 individuals, spread from Indonesia to the foothills of the Himalayas and into China. They face a high risk of extinction, according to the International Union for Conservation of Nature Red List, a widely accepted international list of the conservation status of species.

Written by Randy McDonald

October 31, 2015 at 8:19 pm


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