Emperor penguins: not so dedicated parents
When it comes to heroic parents, it is difficult to overcome the emperor penguin. But a new study suggests that reality may not be up to the legend.
Male emperor penguins are famous for not eating for 115 days as they mate and then protect a lone egg from the brutal winter winds. The dramatic images of the semi-annual ritual, which begins with a 100-kilometer Antarctic walk to a breeding ground in the interior, helped make the "March of the Penguins" of 2005 one of the most taquilleros documentaries of all time.
But researchers who visited a different colony say that they witnessed the animals take breaks from their breeding tasks to go fishing in the winter darkness, challenging the popular notion that they are the most dedicated parents in nature.
The behavior was observed at Cape Washington in Antarctica at the end of May 1998 – after the breeding season began and the sun remained fixed for winter – by a team led by Gerald Kooyman, a marine biologist at the Institute Scripps of Oceanography from UCLA, San Diego.
At the end of their visit to the cape, they had witnessed more than 100 emperor penguins swimming or returning from the sea.
Before leaving, the researchers labeled four birds with satellite tags and "water switches" that allowed them to track how far the animals traveled and how often they entered the sea. The data confirmed that the penguins continued to take moonlight baths throughout the breeding season. The researchers believe that the males ceased their hunting activity once the females laid their eggs.
The findings, published in the Journal of Experimental Biology, suggest that previous research on emperor penguins focused on a population too small to be considered representative of the entire species, Kooyman said.
"Almost all the studies on winter breeding have been carried out from the Dumont D & # 39; Urville research station, which is about 100 meters away from a colony," he said. That colony is also 100 kilometers from the edge of the ice, which makes it impossible for the penguins that breed there to rest to fish.
Find the oldest fossils of moths and butterflies
Any curious child who has caught a butterfly by hand, only to find his fingers covered in messy dust, has unwittingly removed the scales of the insect. These microscopic plates cover almost every part of a butterfly, and are the ones that help paint their wings in a variety of colors, from bright cobalt blue to orange and black patterns.
Although most people go to a garden if they want to see the scales of a butterfly in action, the search for wing scale Timo van Eldijk required drilling more than 1,000 feet into the ground. Then, he extracted pieces of fossilized insect from the black mud using a probe with a human hair tip.
In a study published last week in the journal Science Advances, van Eldijk and his colleagues discovered wing scales of approximately 200 million years old belonging to ancient members of the order of the insects Lepidoptera, (named after the Greek words for "scale" "and" wings ") that include butterflies and moths.
" These scales are the oldest evidence of moths and butterflies, "said van Eldijk, a student at the University of Utrecht in the Netherlands during the investigation. "It extends the range to which we know that the butterflies existed in about 10 million years."
The scales can also provide information on the early evolution of the tubular tongue of the insect or proboscis, which the authors suggest evolved tens of millions of years before there were flowers rich in nectar.
Van Eldijk made the discovery while working with Bas van de Schootbrugge, a geoscientist from the University of Utrecht, in a project to investigate ancient pollen in the fossil record. For that project, the team drilled in the depths of northern Germany to collect sediments from the time of the extinction event. Then they dissolved the rock into chemicals that consumed any material that was not organic, leaving pollen samples in a black glue.
But when analyzing the dark solution they came across a new mystery: several unknown scales were left behind in the dirt. The team soon discovered that the scales belonged to extinct relatives of modern butterflies and moths.
He and his team discovered about 70 flakes or fragments of scales, with which they dated about 200 million years ago.
If we ever get to Mars, beer would be fine
Here is an interplanetary botanical discovery that led university and non-NASA scientists to find: Hops – the flowers used to add a pleasant bitterness to the beer – grow well in Martian soil
"I do not know if it's a practical plant, but it's going pretty well," said Edward Guinan, professor of Astronomy and Astrophysics at Villanova University.
Last semester, 25 students took Guinan's astrobiology class, about the possibility of living in another place in the universe.
For the laboratory part of the course, the students became farmers, experimenting to see what crops could grow on the Martian soil and feeding future travelers there.
Of course, no one has brought anything from the red planet, but spacecraft like NASA's Phoenix Mars lander have analyzed the Martian soil in great detail. Based on these measurements, scientists have found a reasonably good reproduction on earth: crushed basalt from an ancient volcano in the Mojave Desert. It is available to buy and Guinan bought 100 pounds.
The Martian soil is very dense and dries quickly, perhaps better to make bricks than to grow plants, which have trouble driving their roots.
For the most part, students chose practical and nutritious plants such as soybeans and kale as well as potatoes.
And a group chose the hops.
"Because they are students," Guinan said. "Martian beer."
For the experiments, the students had a small patch of a greenhouse, with a mesh screen that reduced sunlight to mimic the greater distance of Mars from the sun.
What he did "fabulous" in pure Martian soil was mezclum, a mix of small green salads, even without fertilizers, Guinan said.
When vermiculite, a mineral often mixed with heavy, sticky soils on Earth, added to Martian matter, almost all plants thrived. Because astronauts are not likely to transport vermiculite from Earth, but could have cardboard boxes, Guinan also tried to mix cardboard cut into Martian soil. That worked too.
The strange origin of the golden crown of a manakin
Three related species of manakins occupy adjacent plots of the Amazon rainforest: crowned with opal, crowned with snow and crowned with gold. All are fat as sparrows, small enough to cup one hand, and have radiant, greenish-yellow upper bodies with a golden underside.
Biologists are now discovering the mystery of how these neighboring birds became different species. Recently, a team of scientists confirmed in the Proceedings of the National Academy of Sciences that the Golden Crown manakin is a unique hybrid species that emerged from a cross between the acrobatic crowned with opal and snow capped about 180,000 years ago.
Although unique mating events between different species occur throughout the animal kingdom, it is believed that the establishment of a completely separate hybrid species is relatively rare.
For a new species to occur, it must isolate itself reproductively, or form a stable population that no longer mixes freely with its parent species, said Alfredo Barrera-Guzmán, who led the new research as a PhD student at the University. of Toronto Scarborough.
Manakins with an opal crown have an iridescent toupee, which evokes the mane of a unicorn. Snow-capped robbers are crowned with bright glacier patches. And the members of the hybrid species, the golden crown grip, show a yellow burst that matches their bellies. The chosen women prefer the particular color that the males of their own species possess, leading to reproductive isolation.
Hybrids are often seen as intermediate between progenitor species, which makes scientists skeptical about the possibility of obtaining a kind of golden crown by crossing plugs topped with opals and snowy crowns.
Scientists discovered that the warm crown of manakin comes from pigments called carotenoids, which birds obtain from their diet. When chemically shed these pigments, the feathers became grayish.
The team of Barrera-Guzmán suspects that the first masculine mixtures between snow-capped manakins and opal crowns had this opaque plume, an intermediate between the white and iridescent caps of their ancestors.
As the hybrids evolved in a segregated space, females may have preferred to mate with males that had a higher concentration of carotenoids in their corona, producing an attractive yellow glow, said Jason Weir, associate professor of evolutionary biology at the University of Toronto Scarborough and principal author of the new document.
Be jealous of these squirrels this winter
Most rodents are just rodents. And those who have exceptional skills are usually rats or cartoon mice.
But some forest rodents really have a superpower that helps them tolerate the cold and withstand harsh winters.
In the prairies from central Canada to Texas, members of a species known as ground squirrels with thirteen lines can adjust their body temperature to match the air that surrounds them. This is especially important during hibernation: you do not have to fatten up like bears or find warm shelters like mice and conventional rats. They sleep, surviving in bodies just above freezing. Another species, the Syrian hamster, does it too. "They combine cold-blooded and warm-blooded animals in one," said Elena Gracheva, a neurophysiologist at Yale University.
This mysterious ability to withstand prolonged cold (and even hypothermia) is due in part to an adaptation that these rodents developed into molecules they share with other mammals, including us, Gracheva and her colleagues found in a study published the month passed in the magazine Cell Reports The unique properties of TRPM8, a cold detection protein found in your peripheral nervous systems, protects these rodents from inclement weather. It is really important because if they are too cold, they can not hibernate.
New research brings scientists closer to understanding the enigmas of hibernation and solving a mystery about how this molecular sensor works. The work can also lead to therapies for allodynia, a nervous condition that causes some people to misperceive something normally not as cold as it is painful.
TRPM8 is an ion channel located in some neurons in the skin that covers the body and face. When exposed to cold air or certain chemicals, such as menthol, the pores open, allowing a flood of ions in the cell as fresh air through a window. This sends a signal to the central nervous system.
But something is different in the TRPM8 of thirteen Syrian ground squirrels and hamsters.
In a test involving surfaces of varying temperatures, the researchers discovered that squirrels and hamsters (to a lesser extent) did not seem to notice a temperature gradient that for us could be like the difference between jacket and jeans or tank. top-and-shorts weather. The mice were very aware of these temperature differences.
The team found a set of amino acids within the channel that were the source of apparent impermeability of the ground squirrel to cold to a certain temperature.
– New York Times News Service