Last week the European Union voted to ban neonicotinoid pesticides in an effort to fight colony collapse disorder among honeybees. Although research has clearly fingered these pesticides in bee behavioral problems, the ban is still rather speculative, as multiple environmental factors may be at play in CCD. Greg Laden writes “navigation over long distances, communicating with other bees about newly found hard to get and far away sources of food, mechanisms of controlling reproduction within the colony, thermoregulation of the hive, building and maintaining architecture,” and other bee necessities offer many points of vulnerability. Several EU member countries, including the UK, voted against the ban, resulting in a short-term imperative that Greg calls “more of a giant experiment than an actual ban.” Still, it’s a step toward understanding and alleviating the plight of one of humanity’s dearest friends.
Dr. Dolittle spent a few days at the Experimental Biology meeting of the American Physiological Society, learning incredible facts about animal adaptability. In the Sunday session, researchers showed that metabolic byproducts called ketones can protect against seizures caused by hyperbaric oxygen therapy, while seal pups, who fast for up to three months once weaned, increase their insulin resistance and become effectively diabetic. Monday taught us that insects lack lungs, instead exchanging gas through tiny valves called spiracles along their abdomen, while a Burmese python, after eating a meal up to 25% of its body weight, develops an enlarged heart to facilitate metabolism. From Tuesday Dr. Dolittle reports the pitfalls of doping elephants with LSD, and that specialized mitochondria supercharge hummingbird wings and rattlesnake tails. There are even more findings about low-oxygen, or hypoxic, adaptations, including turtle shells that prevent lactic acid buildup, and one researcher who raised geese so she could train them to fly in a wind tunnel while wearing gas masks.
A new strain of bird flu is circulating in China, and authorities are keeping a close eye on a potentially disastrous scenario. On Aetiology, Tara C. Smith writes that by now, “the microbe may have already become established in the population, adapting to humans stealthily before we were even aware of it.” Greg Laden writes, unlike H1N1 in 2009, the new H7N9 doesn’t sicken birds, making it more difficult to identify reservoirs of the virus. And according to the latest reports, it doesn’t make all people sick either. Documented infections are widespread in a populous region, and of more than 100 known cases, twenty people have died. So far there is no reason to panic—but the real threat lies in further mutation of the virus, and the emergence of a killer global flu.
Greg Laden reports that scientists have sequenced the genome of the Tammar Wallaby, which boasts “the longest period of embryonic diapause of any known mammal, highly synchronized seasonal breeding and an unusual system of lactation.” The new research “provides a hitherto lacking understanding of marsupial gene evolution and hopes to have identified marsupial-specific genetic elements.” Dr. Dolittle shares more amazing research on Life Lines, telling us seals can cool off their brains while diving to conserve oxygen. They do this by shunting blood “to large superficial veins allowing heat to escape to the environment” instead of “routing the blood through arterio-venous heat exchangers.” And on The Weizmann Wave, researchers conclude fruit bats use more than echolocation to navigate after gluing tiny GPS transmitters to their backs. Bats released 84 kilometers from home made straight for their old haunts—as soon as they had a line of sight. This suggests bats “watch for prominent visual landmarks” to “judge their distance and mentally triangulate their positions,” and could even “sense directional sea breezes or magnetic fields.”
- Kangaroo DNA has been sequenced for the first time on Greg Laden’s Blog
- Cool Brains on Life Lines
- Bat Maps on The Weizmann Wave
On Laelaps, Brian Switek considers the fate of Smilodon, a saber-toothed hypercarnivore that roamed through ancient Los Angeles. Although textbook descriptions of such animals are usually cut-and-dried, Brian writes that “genetic, anatomical, or behavioral variations are grist for natural selection’s mill,” and so individuals within a species can vary considerably over space and time. On Tetrapod Zoology, Darren Naish discusses the peculiar babirusa, a beast that looks like a pig, incorporates “deer-like slender legs and a multi-chambered stomach,” and has horn-like canine teeth growing from its snout. Babirusas display a wide range of morphology across their Indonesian habitat—and a male babirusa even begat hybridized offspring with a domestic pig in a zoo. Finally, on Gene Expression, Razib Khan reports new efforts to raise the Aurochs from the dead. Using preserved genes as a guide, breeders will “hunt for the variants in modern cattle strains” in an attempt to recreate the phenotype and genotype of this extinct piece of meat.
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Continue reading “Variations on a Theme”
On A Blog Around The Clock, Bora Zivkovic shares a newly published paper which he co-authored with researchers inspired by his blog. Their team recorded the egg-laying cycle of birds in the wild, where clutch sizes must answer to nature and not the hungry stewardship of a poultry farmer. They discovered that Eastern Bluebirds lay eggs along the same S-shaped interval curve observed in domesticated birds, which is “not dependent on external factors like food and energy, but [on] a fine-honed system of interactions between two circadian clocks.” On Not Exactly Rocket Science, Ed Yong enumerates the successful qualities of toads, which over a relatively short time “diversified into around 500 species and spread to every continent except Antarctica.” Although these pioneering amphibians may taste like chicken, some can lay clutches of 45,000 eggs at a time. On Neurophilosophy, Mo provides another example of circadian regulation, in the case of electric fish who must meter their power wisely. The discharge of some species, which can reach up to 500 volts, was found to be “weakest during the day, but its strength increased by approximately 40% at nighttime.” Fish use this electricity for perception as well as defense, and piscine social encounters also led to brief surges of power.
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Continue reading “Egg-laying and Circadian Clocks”