From Two Bulls, Nine Million Dairy Cows
There are more than 9 million dairy cows in the United States, and the vast majority of them are Holsteins, large bovines with distinctive black-and-white (sometimes red-and-white) markings. The amount of milk they produce is astonishing. So is their lineage. When researchers at the Pennsylvania State University looked closely at the male lines a few years ago, they discovered more than 99 percent of them can be traced back to one of two bulls, both born in the 1960s. That means among all the male Holsteins in the country, there are just two Y chromosomes.
“What we’ve done is really narrowed down the genetic pool,” says Chad Dechow, one of the researchers.
The females haven’t fared much better. In fact, Dechow—an associate professor of dairy cattle genetics—and others say there is so much genetic similarity among them, the effective population size is less than 50. If Holsteins were wild animals, that would put them in the category of critically endangered species. “It’s pretty much one big inbred family,” says Leslie B. Hansen, a Holstein expert and professor at the University of Minnesota.
Adapting to Climate Change in Alaska
[…] In the off-grid homes of Alaskan hunters, naturalists and Native weavers—and in the offices of land managers working in America’s largest national forest—I asked this question over and over again. We were talking about climate change. […]
Places close to our poles are getting hotter quicker. Temperature increases in the north have doubled the global average since the mid-20th century. As a young scientist pursuing my PhD, I thought that understanding the ways in which the old-growth forests of southeast Alaska were changing, and how people were coping with those changes, could provide insight into how people might respond to climate change in other parts of the world.
No End in Sight for Record Midwest Flood Crisis
The 2019 Mississippi River flood fight is going to slog deep into the summer — and maybe much longer.
While communities north of St. Louis are beginning the expensive path to recovery after record-breaking winter and spring precipitation and runoff, people below the Missouri River are shoveling mud from their houses and praying for a dry spell.
The Lower Mississippi Valley remains in a flood crisis as high water continues to swamp streets, homes, businesses, sewage and water treatment plants, and farm fields, including across some of the poorest counties in the United States.
What made humans 'the fat primate'?
Blame junk food or a lack of exercise. But long before the modern obesity epidemic, evolution made us fat too.
"We're the fat primates," said Devi Swain-Lenz, a postdoctoral associate in biology at Duke University. The fact that humans are chubbier than chimpanzees isn't news to scientists. But new evidence could help explain how we got that way.
Despite having nearly identical DNA sequences, chimps and early humans underwent critical shifts in how DNA is packaged inside their fat cells, Swain-Lenz and her Duke colleagues have found. As a result, the researchers say, this decreased the human body's ability to turn "bad" calorie-storing fat into the "good" calorie-burning kind.
The results were published June 24 in the journal Genome Biology and Evolution.
Some extinct crocs were vegetarians
Based on careful study of fossilized teeth, scientists Keegan ] and Randall Irmis at the Natural History Museum of Utah at the University of Utah have found that multiple ancient groups of crocodyliforms -- the group including living and extinct relatives of crocodiles and alligators -- were not the carnivores we know today, as reported in the journal Current Biology on June 27. In fact, the evidence suggests that a veggie diet arose in the distant cousins of modern crocodylians at least three times.
"The most interesting thing we discovered was how frequently it seems extinct crocodyliforms ate plants," said Keegan Melstrom, a doctoral student at the University of Utah. "Our study indicates that complexly-shaped teeth, which we infer to indicate herbivory, appear in the extinct relatives of crocodiles at least three times and maybe as many as six."
Optimal quantum computation linked to gravity
Information and gravity may seem like completely different things, but one thing they have in common is that they can both be described in the framework of geometry. Building on this connection, a new paper suggests that the rules for optimal quantum computation are set by gravity.
Physicists Paweł Caputa at Kyoto University and Javier Magan at the Instituto Balseiro, Centro Atómico de Bariloche in Argentina have published their paper on the link between quantum computing and gravity in a recent issue of Physical Review Letters.
In the field of computational complexity, one of the main ideas is minimizing the cost (in terms of computational resources) to solve a problem. In 2006, Michael Nielsen demonstrated that, when viewed in the context of differential geometry, computational costs can be estimated by distances. This means that minimizing computational costs is equivalent to finding minimal "geodesics," which are the shortest possible distances between two points on a curved surface.
Researchers explore use of new materials to create more efficient solar cells
A team of Florida State University researchers is pioneering innovative ways for solar cells to absorb and use infrared light, a portion of the solar spectrum that is typically unavailable for solar cell technology.
Their work is published in two new studies published in the journal Matter and the Journal of Physical Chemistry Letters.
"We're working on a process to optimize the efficiency of solar cells," said Assistant Professor of Chemistry and Biochemistry Lea Nienhaus. "The main drive is to optimize this process for solar applications."
Trauma of Australia’s Indigenous ‘Stolen Generations’ is still affecting children today
Indigenous children in Australia who live in families that experienced forced separations in much of the twentieth century are more likely than other Indigenous children to have poor health and negative school experiences, according to a landmark government report released this month.
As many as one in three Aboriginal and Torres Strait Islander children were taken from their families and communities between 1910 and the 1970s, under racist government policies that tried to force Aboriginal people to assimilate with white Australians. The children were brought up in institutions or foster homes, or were adopted by white families. The Australian government formally apologized to members of these ‘Stolen Generations’ in 2008.
In the latest report, the Australian Institute of Health and Welfare, a government-funded statistics agency, used existing data from surveys of Aboriginal and Torres Strait Islander people to conduct the first national study of how the forced separations have affected children in subsequent generations. Previous reports looked at the impacts of these policies on the Stolen Generations themselves, and on their adult descendants.
NASA drone will soar over Saturn's largest moon
NASA will send a dual-quadcopter drone to hop across the surface of Titan, Saturn’s largest moon, the agency announced on 27 June. Named Dragonfly, the mission will launch in 2026 and arrive at Titan in 2034.
“Dragonfly is really a Mars-rover-sized drone that we’ll be able to fly from place to place on Titan,” says Elizabeth Turtle, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, who leads the mission.
The nuclear-powered Dragonfly can fly tens of kilometres in less than an hour, allowing it to cover ground much faster than a wheeled rover could. Over the course of a two-year mission, the drone could traverse hundreds of kilometres.
MIT Created a Better Rain-Deflecting Material That's Like a Force Field For Liquids
We’ve already figured out how to treat surfaces so that liquids, like spilled food or raindrops, quickly bead up and roll away. Every time you wax your car you’re helping it shrug off a downpour. But for vehicles like planes, it only takes a split second for a raindrop to turn to ice when it hits a freezing fuselage, creating safety risks on the aircraft. To combat this, researchers at MIT have found a way to make water-repellant surfaces better shed a soaking.
The new method builds on research from about six years ago when it was discovered that small macroscopic features added to a surface, like a series of nearly imperceptible ridges, helped break up a water drop’s shape and symmetry as it recoiled from an impact, increasing the speed at which it bounced away from that surface. The amount of time a drop was in contact with a surface was reduced by about 40 percent, which also reduced the amount of time there was for thermal exchange. In other words, it reduced the risk of raindrops having enough time to turn to ice.
The Gateway Protecting the Arctic's Oldest Sea Ice Has Collapsed Months Ahead of Schedule
Every summer as the Arctic warms up, seasonal highways open on the ocean, allowing sea ice to migrate southward and melt. Now, satellite data is revealing that the gateway to one critical highway—the Nares Strait dividing northwest Greenland and Canada’s Ellesmere Island—has broken up months ahead of schedule. And that could spell even more trouble for the Arctic’s oldest and most critically-endangered sea ice.
Normally, Baffin Bay just south of the Nares Strait remains closed off to marauding sea ice from the north until June, July or even August, thanks to the presence of an ice jam that forms at the strait’s northern mouth between November and January, taking on a spectacular, arch-like shape. This year, however, the Nares Strait arch began to disintegrate in March. Kent Moore, a sea ice researcher at the University of Toronto described its collapse as “pretty rapid,” with the arch gone in the span of just a few days.
Space station mold survives 200 times the radiation dose that would kill a human
As anyone who’s ever had a mold infestation knows, the fungi can be very hard to kill. It turns out mold may also be highly resistant to the harsh conditions of outer space. Its spores can survive doses of radiation 200 times higher than those that would kill a human, researchers reported here today at the Astrobiology Science Conference. Such hardiness could make it difficult to eliminate mold's health risks to astronauts. Mold might also one day threaten other parts of the solar system—with hitchhiking mold spores from Earth.
Astronauts on the International Space Station (ISS) already constantly battle with mold, which grows on the station’s walls and equipment. That mold, of course, is in a protected structure in low-Earth orbit, where radiation doses are low. Outside of the station, doses are higher—and they would be higher still on the hull of a spacecraft going to Mars or beyond.
Cockroaches may soon be unstoppable—thanks to fast-evolving insecticide resistance
The day that squeamish humans—and exterminators—have long feared may have come at last: Cockroaches are becoming invincible. Or at least German cockroaches (Blattella germanica) are, according to a new study. Researchers have found that these creatures, which have long been a prevalent urban pest, are becoming increasingly resistant to almost every kind of chemical insecticide.
Not all insecticides are created equal. Some degrade the nervous system, whereas others attack the exoskeleton; they also have to be left out for varying amounts of time. But many insects, including cockroaches, have evolved resistance to at least one of the most commonly-used insecticides. And because cockroaches live only for about 100 days, that resistance can evolve quickly, with genes from the most resistant cockroaches being passed to the next generation.
Air pollution 'may affect number of eggs ovaries can produce'
Air pollution has been linked to a drop in activity of a woman’s ovaries, researchers have revealed.
Experts say the findings suggest the female reproductive system is affected by environmental factors, although the study does not look specifically at the impact of air pollution on fertility.
However, they added that if such an effect were permanent, it might mean that women might have a shorter period of their life in which to reproduce and an earlier menopause.
'Giant wombat' fossil discovered by council workers in Australia
A “giant wombat” fossil has been discovered by local council workers in the Monaro region of southern New South Wales.
Two Snowy Monaro regional council employees found the fossilised jaw of a baby diprotodon last Friday at an undisclosed location that is known for such paleontological findings. […]
Diprotodons were a type of megafauna that were widespread across Australia and co-existed with the Indigenous population for thousands of years. The exact time of extinction is contested and estimates vary between 7,000 and 40,000 years ago.
Apollo 11 tapes bought for $218 may sell for millions after nearly being lost
When Gary George bought a truckload of videotapes for $218 from a US government surplus auction more than 40 years ago, he planned to sell them to television stations – to record over.
Fortunately, he decided to hold on to the three tapes labelled “Apollo 11 EVA”, which have since been identified as the only surviving original recording of the first moon landing, in 1969.
Now the tapes – which include Neil Armstrong’s famous words “That’s one small step for man, one giant leap for mankind” – are to go on sale in July at Sotheby’s in New York, where they are expected to fetch as much as $2m.
The collection also includes footage of Buzz Aldrin walking in minimal lunar gravity, planting the US flag on the moon, collecting samples.
Scientists think some supermassive black holes didn’t start as stars
In the most simple terms, the model suggests that supermassive black holes formed "very, very quickly over very, very short periods of time" and then stopped suddenly. "Supermassive black holes only had a short time period where they were able to grow fast and then at some point, because of all the radiation in the universe created by other black holes and stars, their production came to a halt," Basu said. Until now, the current understanding was that stellar-mass black holes form when the center of a massive star collapses in on itself. In contrast, Basu and Das suggest that some black holes originate from direct-collapses, not stellar remnants.
Paleontologists Uncover New Insights into Non-Iridescent Feather Colors in Prehistoric Birds
A pigment called melanin gives black, reddish brown and gray colors to birds and is involved in creating bright iridescent sheens in bird feathers.
This can be observed by studying the melanin packages called melanosomes, which are shaped like little cylindrical objects less than one-thousandth of a millimeter and vary in shape from sausage shapes to little meatballs.
However, besides iridescent colors, which is structural, birds also make non-iridescent structural colors. Those are, for example, blue color tones in parrots and kingfishers.
Until now, it was not known if such colors could be discovered in fossils.
Study: Gray Seals Can Copy Human Speech and Songs
A team of researchers from the Scottish Oceans Institute at the University of St Andrews worked with three young gray seals and monitored them from birth to determine their natural repertoire.
These seals — Zola, Janice and Gandalf — were then trained to copy new sounds by changing their formants, the parts of human speech sounds that encode most of the information that we convey to each other.
Zola was particularly good at copying melodies that were played to her, copying up to ten notes of songs such as ‘Twinkle twinkle little star’ and other popular themes. Janice and Gandalf were taught combinations of human vowel sounds that they copied accurately.
'Destroyed' Trump golf course dunes to lose special status
The sand dunes at Donald Trump's Aberdeenshire golf resort are expected to lose their status as a nationally-important protected environment.
Government watchdog Scottish Natural Heritage has recommended that Menie links be removed from an existing site of special scientific interest (SSSI).
SNH concluded Mr Trump's golf course had "destroyed" the sand dune system, causing permanent habitat loss.
Greenland Ice Sheet: 'More than 50 hidden lakes' detected
Scientists have identified more than 50 new lakes of liquid water lying under the Greenland Ice Sheet. Only four had previously been detected.
Antarctica hides some 470 lakes beneath its ice but this latest UK/US study proves the northern polar region also has its share.
They are nothing like as big, however. The largest down south, Lake Vostok, is 250km long. The biggest subglacial lake in Greenland is just 6km long.
The Last of Its Kind
The biologist David Sischo has a tragic assignment: keeping vigil over a species’ sole survivor, then marking its extinction in real time.
Sometime on new year’s day, as the people of Hawaii recovered from a night of revelry, in a trailer on the outskirts of Kailua, Oahu, a 14-year-old snail named George died. David Sischo, who works in the trailer but was taking a rare day off, found out at 7 o’clock the next morning, when a colleague discovered George’s limp body and texted him. “I usually don’t hear from her that early, so before I even read the text, I felt that something bad had happened,” Sischo told me.
Few people would mourn a snail, but Sischo and his team had spent years caring for George. He was a daily constant, a familiar friend. He was also the last known snail of his kind, the final Achatinella apexfulva. It is said that everyone dies alone, but that was doubly true for George—alone at the end both in his cage and in the world.
When the last of a species disappears, it usually does so unnoticed, somewhere in the wild.
Sometime in the third century b.c., an earthquake struck the eastern Mediterranean. In Thonis-Heracleion, past its peak but still one of Egypt’s greatest ports, the ground began to shake, and the soil gave way. The city had been built upon low-lying islets, bits of silt and clay left behind from the Nile’s summer floods. Temples would have towered over the city, where each year, priests would form the earthly body of Osiris—the god of the afterlife and rebirth—from gold, barley grain, and river water.
In the smallest part of a second, the mud on which the city stood would have turned to liquid. The great temple to the supreme god Amun-Gereb fell into the sea.
The city did not vanish entirely that day, but without the temples, it lost its raison d’être. By the eighth century a.d., the last of its mud islets had slipped beneath the waves as the river shifted and the sea level rose. The city passed into the realm of rumor and myth. Herodotus, the Greek historian, wrote that Helen and Paris had visited before sailing to Troy. Stelae half-buried up the Nile mentioned it. A scroll found far to the south preserved a hint of its tax records. It was an antediluvian world barely more solid in history than Atlantis. No one knew where it was.
Renewable electricity beat out coal for the first time in April
A remarkable thing happened in the US in April. For the first time ever, renewable electricity generation beat out coal-fired electricity generation on a national level, according to the Energy Information Agency (EIA). While renewable energy—including hydro, wind, solar, geothermal, and biomass—constituted 23 percent of the nation's power supply, coal-fired electricity only contributed 20 percent of our power supply.
There are seasonal reasons for this happening in April. Wind power generation tends to be higher in spring and fall, hydroelectric generation usually peaks as winter snow melts, and lengthening days mean more solar power can be fed to the grid.
In addition, people use less electricity in spring, as it's not cold enough to need a lot of heating and not warm enough to require lots of air conditioner use. Coal-fired power plant owners, expecting this low demand, often use spring and fall to take their power plants offline for regularly scheduled maintenance.