Glow-in-the-Dark Survival Skills.
Researchers investigating why a few species of millipedes glow in the dark set up a field experiment in California’s Giant Sequoia National Monument Park. They collected these strange millipedes, which are known to contain cyanide-like toxins, and combined them with a group of molded clay decoys that they constructed to resemble millipedes. Then, some of the real millipedes were painted to hide their bio-luminescence. The resulting three groups, real, painted and clay, were then left overnight. The result: far more non-glowing millipedes and clay decoys were attacked by rodent predators during the night than the naturally glowing ones. The experiment suggests that bio-luminescence in millipedes is an evolutionary adaptation that wards off predators by warning them that the millipedes contains toxins, such as cyanide.
Read the full story at Live Science.
Many Bird Species Met the Same Fate as the Dinosaurs.
When the Chicxulub meteorite slammed into the Gulf of Mexico some 65 million years ago, dinosaurs were not the only victims. New research has been undertaken to carefully identify numerous extinct North American bird species fossils. The Cretaceous bird fossils that were examined were from the collections of various museums. The results of the study indicate that these extinct bird species disappeared relatively suddenly, adding to the evidence that the extinction event was the same one that ended the dinosaurs’ reign. Modern birds are the descendants of the relatively few species that survived the calamity.
Read the full story at Science Daily.
A Plus in Arctic Ice Loss?
Although the increasing loss of arctic sea ice is rightfully decried by environmentalists, it would appear that the bowhead whale may be a beneficiary. The melting sea ice is opening up Canada’s northwest passage – a sea lane connecting the Pacific and Atlantic oceans that is normally blocked by ice. In Biology Letters, the authors describe how tracking with satellite telemetry found that a few bowheads are once again entering the northwest passage. The authors also suggest that in coming years, if the deterioration of sea ice continues, there will be additional cross-ocean intermingling of organisms through this route.
Honeyguide Birds: Parasitic Even at Birth
Honeyguide birds from Zambia are known to be parasitic to other bird species. Typically, they lay eggs in the nests of other birds and puncture the eggs of the host species to ensure the survival and care of their own offspring by the host birds. Now it appears that even the new hatchlings of honeyguides try not to leave their survival to chance. They are equipped to strike and kill the surviving hatchlings of their hosts. This invasive siblicide behavior recently was observed and documented for the first time in many years. The authors of the study report that although the young assassins will attack the host chicks and even the researcher’s finger, they do not bite the beaks that feed them – the host adults.
To Find Food, Just Click
Scientists studying fruit bats have identified the mechanism they use to find food in a crowded environment. Apparently, by changing the volume of clicks that they make with their tongues and by broadening or narrowing the range of their sonic signals, they can distinguish food from obstacles. Indeed, when the researchers deliberately created a crowded environment as part of the experiment, the bats covered far more area by simply increasing the volume and range of their clicks.
Read the story at The New York Times.
Dressing in Unsavory Wings.
Scientists in Europe have uncovered the genetics that enable a bizarre butterfly survival tactic. The Heliconius numata (commonly known as the passion-vine butterfly) uses extreme mimicry to avoid hungry predators. The species can alter their wing patterns to resemble other butterfly species that are notably foul-tasting to birds. The genetic trick involves “DNA flipping,” which causes multiple genes to be inherited as a “supergene.” The supergenes, in turn, influence wing pattern, color, and design – providing the tasty Heliconius numata access to some much-needed disguise.
Read the story at Science News.
Metal and Sugar Nano-architecture Can Fight Air Pollution?
What do you get when you lace sugar crystals with metal atoms? A carbon dioxide sponge, of course. Chemists at Northwestern University have discovered that this particular construct, a variant of one they discovered a year ago, has the capacity to absorb quantities of carbon dioxide gas. When using an indicator dye, the so-called “metal organic frameworks” (MOF) becomes saturated with carbon dioxide, turning a distinctly orange color. Their sponge-like nature, however, allows them to release the gas just as readily, returning the MOFs to their original yellow color. The authors cite the discovery’s low cost and simple manufacture as important factors for its future economic viability.
Read the story at Northwestern University News Center.
Aboriginal Ancestors Came Directly Out of Africa.
The New York Times reports that scientists have mapped the genome of Australian aborigines using a snippet of hair that was collected from the indigenous population a century ago. The genetic markers revealed by the sample confirm that the first settlers of Australia came directly from Africa and that they were not part of the splinter group that developed after the African diaspora into Asia and Europe some 50,000 years ago. If the finding holds up, it means that the Australian aborigines “have one of the oldest continuous population histories outside sub-Saharan Africa.”
Panda Poop May Contain Green Lessons.
How do pandas digest prodigious amounts of bamboo? The answer, apparently, might lead to new insights into bio-fuels of the future. Bacteria that help the panda breakdown cellulose in plants into nutrients may clue us in on how to successfully develop cellulosic biofuels – energy derived from non-food sources like grass, trees, and crop waste. Now, scientists are studying the poop of pandas with an eye (or nose) for identifying and cultivating the bacteria.
Read the story at Wired.
Animal Research Standards Found Lacking.
In this week’s edition of NatureNews, Scottish neurologist Malcolm Macleod discusses the perceived lack of rigid standards in animal medical research experiments. Among the deficiencies are the lack of adequate randomization, failure to insist on blind experimental parameters, and small sample size of the animals tested. Macleod also points out that external pressures on researchers put an unfair premium on positive results, at the expense of rigorous scientific impartiality. Macleod concludes that “we need to change the rules” to bring animal experimentation up to current scientific and ethical standards.