Top ScienceNews stories: Frogs that fluoresce and brainless animals that sleep(?)
|December 30, 2017||Posted by News under Evolution, Intelligent Design|
Cassie Martin on ScienceNews’s most noteworthy 2017 animal stories, among which are
First fluorescent frogs might see each others’ glow (Susan Milius)
And it is true fluorescence. Compounds in the frogs’ skin and lymph absorb the energy of shorter UV wavelengths and release it in longer wavelengths, the researchers report online March 13 in Proceedings of the National Academy of Sciences. But why bother, without a black bulb? Based on what he knows about a related tree frog’s vision, Taboada suggests that faint nocturnal light is enough to make the frogs more visible to their own kind. When twilight or moonlight reflects from their skin, the fluorescence accounts for 18 to 30 percent of light emanating from the frog, the researchers calculate.More.
Apparently, their social life is more complex than one might expect. It would be interesting to know whether they are the only fluorescent frogs and whether, if so, they are among the last or the first of a type. Or a ramble down a byway in the history of life.
To test sleep, researchers don’t letsleeping jellyfish lie. (Mariah Quintanilla)
Some species of upside-down jellyfish (Cassiopea) meet all of the criteria for entering a “sleeplike state,” a group of Caltech researchers report September 21 in Current Biology. The jellyfish seem groggy after a sleepless night and quickly waken from their slumber when fed, experiments show.
It’s a surprising find: Sleep and sleeplike states have been documented in a wide range of animals — from microscopic wormlike nematodes to, of course, humans (SN: 10/24/09, p. 16). But until now, the behavior has been observed only in animals with a centralized nervous system and brain.
Jellyfish operate on a decentralized net of nerve cells. “It’s the first animal that doesn’t have a centralized nervous system that also sleeps, that we know of,” says biology graduate student and coauthor Ravi Nath. Adds coauthor Michael Abrams: “Sleep is not solely generated by animals with brains.”
The finding is raising new questions about when — and why — sleep evolved. More.
As Quintanilla goes on to say, jellyfish are about 600 million years old and most of the explanations for why humans sleep probably do not apply to them.
See also: Cosmos Magazine’s Top Ten includes: Universe’s underlying symmetry still baffling and human evolution timeline drastically stretched. Re human evolution, we hope no one’s career got wrecked in the past few decades, doubting whatever “ding dong Darwin” was the bumf of the day. It’s becoming increasingly clear that most of the certainty has been ideological, not scientific.
Millennial classic edition: Science writer Michael Shermer makes Scientific American’s Top Ten stories list In general, Scientific American is getting pretty self-absorbed when this is a top story. … Overwhelmed by 2017 events? Eh? Gawrylewski apparently isn’t old enough to remember the Cuban Missile Crisis, the moon walks, the fall of the Soviet Union, mapping the human genome… to throw out just a few. She sounds so, well, “millennial,” fronting perennial and often petty gripes as if they were historic changes. Of course, millennials could always grow up. The world out here is actually pretty interesting, provided they can stand it.
A top anthropology finding of year show humans cognitively closer to dogs than chimps
American Council for Science and Health’s 10 biggest junk stories for 2017 include… Stephen Hawking