News and notes about science
PROTECTION SOUGHT FOR ONE-OF-A-KIND WOLVES
Conservation groups submitted an emergency petition last month requesting that the U.S. Fish and Wildlife Service increase protection for the only wild population of red wolves left in the world.
Red wolves, which are bigger than coyotes but smaller than gray wolves, are the only wolf species found completely within the United States.
Trapping, shooting, poisoning and destruction of habitat in the 1960s eliminated all but 17 of them from their native range, primarily in the Southeast. The last animals were gathered and 14 were bred, then reintroduced in North Carolina in 1987. They were the first federally listed species to be returned to its native habitat.
The population has declined by more than 50 percent in just two years. There are only 45 to 60 red wolves living in the wild, and they are threatened, mostly by hunters mistaking them for coyotes and shooting them, said Tara Zuardo, a lawyer at the Animal Welfare Institute.
The petition calls for the Fish and Wildlife Service to establish two additional populations of red wolves in swampy areas in Alabama, Kentucky and other Southern states. It also seeks an upgrading of the status of red wolves, which are endangered, from “nonessential” to “essential.”
The change in status would grant reserved habitat to the species and require consultations with biologists over how changes to land use would affect the wolves. Joanna Klein THE MUTATION BEHIND THE MOTH
The story of the black peppered moth, whose colors changed from Oreo milkshake to dark chocolate during the Industrial Revolution in Britain, is an iconic tale of adaptive evolution. Now the plot thickens: In a study published in Nature, researchers have pinpointed the genetic mutation that led to the darker moth.
The black peppered moth became commonplace in Britain during the mid-18th century, after its original light, speckled wings became a clear target for predators against tree trunks darkened by coal soot. By blending with the trees, the moth avoided becoming lunch for birds.
After searching through a large area of the moth’s genome, Ilik Saccheri, an evolutionary ecologist, found that a single mutation on a gene called cortex was responsible for the wings’ black coloring. The gene is also at play in some butterflies, such as the one separated from moths by more than 100 million years of evolution.
Cortex probably controls the development of scales that form patterns on butterfly wings like tiles, said Nicola Nadeau, an evolutionary geneticist at the University of Sheffield.
Joanna Klein
ELECTRIC EELS TAKE A FLYING LEAP
This summer’s science horror blockbuster is a remake: Return of the Leaping Electric Eel!
The original dates to 1800 when the explorer Alexander von Humboldt was in South America and enlisted fishermen to catch eels for the then-new study of electricity. He wrote that the men herded horses and mules into a pond and the eels attacked, pressing themselves to the horses.
Or so Humboldt said; no other report of the phenomenon surfaced for more than 200 years.
But Kenneth Catania, a neuroscientist at Vanderbilt University, has a passion for Electrophorus electricus, the electric eel, and has now shown the eels will act in just this way. In 2014, he found that the eels used rapid pulses of more than 600 volts to cause the muscles of their prey to freeze.
Catania noticed another kind of behavior. He was using a metal handled net — wearing rubber gloves — while working with eels in an aquarium, and the eels would fling themselves into the metal and generate rapid electric shocks. The eels repeated the behavior in subsequent experiments, a report on which appears in Proceedings of the National Academy of Sciences.
“I hope this doesn’t make people more fearful,” Catania said, because the eels “are wonderful creatures and only shock people in self-defense.”
James Gorman
BUILT BY MICROBES, NOT ANCIENT GREEKS
So much for the Lost City of Zakynthos.
When snorkelers discovered what appeared to be pieces of ancient stonework, including columns and doughnut-shaped disks that might have been column bases, in a bay off the Greek island of Zakynthos several years ago, government archaeologists were sent to investigate. The debris might have been the ruins of a city, the scientists reported. But they found nothing else — no shards of pottery or other flotsam and jetsam of everyday existence — that would suggest that people had lived there.
Scientists have learned why: The columns and other objects, they say, are not stonework at all, but a natural byproduct of the breakdown of methane gas, perhaps several million years ago.
Julian Andrews, a geochemist at the University of East Anglia in England, said that the area was a “cold seep” where methane in deep formations moved up through faults and then through sediments in the seabed. Those sediments contain bacteria that consume methane for energy.
That consumption of methane, Andrews said, changed the chemistry of the seawater that saturated the sediments, causing dissolved minerals to precipitate out of the water as a rock called dolomite. And the dolomite cemented the sediment particles in place, forming concretions.
Henry Fountain