ريتشارد دوكنز's Blog, page 563
February 12, 2016
Fossils Shed New Light on Human-Gorilla Split
Photo credit: Gen Suwa
By Charles Q. Choi
Fossils of what may be primitive relatives of gorillas suggest that the human and gorilla lineages split up to 10 million years ago, millions of years later than what has been recently suggested, researchers say. The finding could help resolve a controversy over the continent where the ape and human lineages first evolved, the scientists added.
Although the fossil record of human evolution is still patchy, it is better understood than that of great apes such as chimpanzees and gorillas. Since few great ape fossils have been found in Africa so far, “some scientists have forcefully suggested that the ancestors of African apes and humans must have emerged in Eurasia,” said study senior author Gen Suwa, a paleoanthropologist at the University of Tokyo.
To shed light on the evolution of the ape and human lineages, Suwa and his colleagues investigated the Afar rift of Ethiopia. Previous research at the Afar rift unearthed fossils of some of the earliest known hominins — that is, humans and related species dating back to the split from the ape lineages.
The research team focused on the Chorora Formation, the oldest known sediments from the Afar rift. (The formation gets its name from Chorora, a village in the area.)
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Can Dementia Be Prevented? Education May Bolster Brain Against Risk
Photo credit: Nanette Hoogslag/Getty Images/Ikon Images
By Nancy Shute
The odds of getting Alzheimer’s disease or other forms of dementia are declining for people who are more educated and avoiding heart disease, a study finds. The results suggest that people may have some control over their risk of dementia as they age.
This isn’t the first study to find that the incidence of dementia is waning, but it may be the best so far. Researchers looked at 30 years of records from more than 5,000 people in the famed Framingham Heart Study, which has closely tracked the health of volunteers in Framingham, Mass.
They found that the incidence of dementia declined about 20 percent per decade starting in the 1970s — but only in people who had at least a high school education. The decline in people diagnosed with Alzheimer’s wasn’t statistically significant, but there were fewer people with Alzheimer’s, which could have affected that result.
The study, which was published Wednesday in the New England Journal of Medicine, also looked at risk factors for heart disease and stroke, including smoking, obesity and high blood pressure. They found that the people who had better markers for cardiovascular health, such as normal blood pressure, were also less likely to develop dementia.
“That’s telling us that perhaps better management of cardiovascular disease could potentially help in the reduction of dementia,” says Claudia Satizabal, an author of the study and an instructor in neurology at the Boston University School of Medicine.
To figure out what this all means, we called Dr. Kenneth Langa, a professor at the University of Michigan who also studies trends in dementia. Here are highlights from the conversation edited for length and clarity.
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February 11, 2016
A Parasite, Leopards, and a Primate’s Fear and Survival
Photo credit: Francois Savigny/Minden Pictures
By Carl Zimmer
Many of our primate ancestors probably ended up in the bellies of big cats. How else to explain bite marks on the bones of ancient hominins, the apparent gnawing of leopards or other African felines?
Big cats still pose a threat to primates. In one study of chimpanzees in the Ivory Coast, for example, scientists estimated that each chimp ran a 30 percent risk of being attacked by a leopard every year.
A new study suggests that the big cats may be getting some tiny help on the hunt. A parasite infecting the brains of some primates, including perhaps our forebears, may make them less wary.
What does the parasite get out of it? A ride into its feline host.
The parasite is Toxoplasma gondii, a remarkably successful single-celled organism. An estimated 11 percent of Americans have dormant Toxoplasma cysts in their brains; in some countries, the rate is as high as 90 percent.
Infection with the parasite poses a serious threat to fetuses and to people with compromised immune systems. But the vast majority of those infected appear to suffer no serious symptoms. Their healthy immune systems keep the parasite in check.
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Science Teachers’ Grasp of Climate Change Is Found Lacking
Photo credit: Max Reed
By John Schwartz
Most science teachers in the United States spend some time on climate change in their courses, but their insufficient grasp of the science as well as political factors “may hinder effective teaching,” according to a nationwide survey of the profession.
The survey, described in the current issue of the journal Science, found that teachers spent little time on the topic — just one to two hours on average over an academic year.
“It’s clearly not enough time to really provide students with a good scientific understanding,” said Eric Plutzer, the lead author of the paper and a professor of political science at Pennsylvania State University.
Many teachers also provide misinformation about climate change, the survey found. The evidence that human activity is a major cause of recent climate change is overwhelming, but 30 percent of the 1,500 teachers surveyed said they emphasized that recent global warming “is likely due to natural causes,” while 12 percent said they did not emphasize human causes. Half of that 12 percent said they did not discuss any causes at all.
Close to a third of the teachers also reported conveying messages that are contradictory, emphasizing the scientific consensus on human causation and the idea that many scientists believe the changes have natural causes.
The authors of the paper suggested that those teachers “may wish to teach ‘both sides’ to accommodate values and perspectives that students bring to the classroom.” The survey also found, however, that only 4.4 percent of teachers said that they had faced overt pressure from parents, school administrators or the community to teach about climate change.
Professor Plutzer, who is the academic director of Pennsylvania State’s survey research center, said that he and his colleagues were surprised by the level of ignorance the teachers showed in the survey, especially in describing the current state of scientific consensus on the topic.
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Gravitational Waves Found: Kip Thorne Explains
Scientific American's Josh Fischman talks with renowned astrophysicist and general relativity expert Kip Thorne about the discovery of gravitational waves by the LIGO Project, co-founded by Thorne.
Here’s What NASA Will Launch Aboard Its New Rocket In 2018
Photo credit: NASA
By Mary Beth Griggs
Great things come in very small packages. When the Space Launch System–NASA’s new heavy-duty rocket–lifts off in 2018, the primary mission will be to put the uncrewed Orion capsule in a safe orbit out past the moon. (Safe being a key word here.) But the secondary part of Exploration Mission-1 will be to launch several tiny satellites, sending them out to the moon, space, and even an asteroid.
Today, NASA announced which of these CubeSats will be on that first mission.
A few, including BioSentinel and LunaH-Map, already had a spot on Exploration Mission-1, but now it’s official, and five other projects have gotten the green light as well:
Near Earth Asteroid Scout (NEAScout) is a reconnaissance CubeSat that is set to visit an asteroid;
Skyfire will map the lunar surface;
Lunar IceCube will look for more water on the moon;
CuSP is a “space weather station” that will be on the lookout for solar particles;
Lunar Flashlight will look for locations where there is enough ice on the moon to be of use to future crewed missions.
Flip through the gallery above to learn more about each of the seven selected satellites. All of the CubeSats on Exploration Mission-1 are tiny–roughly the size of a shoebox–and light, with some clocking in at just 30 pounds. Fitting large numbers of scientific instruments in such a small space can be a challenge.
“It’s the most complicated game of Tetris you’ve ever played,” said Leslie McNutt, the project manager of NEAScout.
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“Einstein Would Be Beaming”: Scientists React to Gravitational Waves
The biggest news in physics in quite a while—the discovery of gravitational waves rippling through space-time—has scientists overjoyed around the world.
Researchers with the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced on Thursday that they had detected waves created when two black holes smashed into each other some 1.3 billion light-years away. The finding is the first direct confirmation of gravitational waves, as well as the strongest evidence to date that black holes exist, and the start of an age where scientists can use gravitational waves to study cosmic objects that otherwise cannot be seen.
“This is the first time the universe has spoken to us through gravitational waves,” LIGO executive director David Reitze told a packed house at a press conference held at the National Press Club in Washington, D.C. “Before now, we were deaf.”. The crowd erupted into applause when he confirmed the rumors that LIGO had found gravitational waves. “My reaction was, ‘Wow!’” he said of first seeing the data. “I couldn’t believe it.”
“This discovery has taken a long time,” LIGO spokesperson Gabriela González said.
“. There have been hundreds of people developing the technology, doing the analysis. We are very proud of this work taking a village, a worldwide village,” González added of the more than 1,000 researchers who work on the project.
LIGO collaborators with the European Virgo gravitational wave project held simultaneous announcements in Italy and Paris, while physics departments around the world hosted gatherings to watch the press conference webcasts. “It’s amazing to be here to finally see what we’ve been talking about for so long,” astrophysicist J. Richard Gott III said at the Princeton University gathering. His colleague, physicist Paul Steinhardt, echoed the sentiment: “I’m very excited about this. It’s the opening of a new era in astronomy in which we’re now going to begin to view the universe with a new set of waves: not light waves, but gravitational waves.”
At New York City’s Columbia University, a number of students and faculty could stake a claim to some of the fame. “I helped hand assemble 60 to 70 percent of the timing system,” graduate student Stefan Countryman said. “I’ve been working on it since I was an undergrad. [The discovery] is vindicating, and it’s just exciting scientifically.” Another LIGO collaborator at Columbia, Szabolcs Márka, added, “This will really let us listen to the music of the cosmos.”
“This has never been done before,” said Janna Levin, a theorist at Barnard College at Columbia. “It's like the first time a telescope was pointed at the sky.”
Scientists have essentially been waiting for this day for a century, since Albert Einstein predicted gravitational waves in 1916 on the basis of his general theory of relativity. “100 years feels like a lifetime but over the course of scientific exploration it’s not that long,” Neil deGrasse Tyson, director of the Hayden Planetarium at the American Museum of Natural History, said at the Columbia gathering. “I lay awake at night wondering what brilliant thoughts people have today that will take 100 years to reveal themselves.” At the D.C. press conference, Caltech physicist Kip Thorne imagined the visionary’s response to the news. “Einstein would be beaming. This is a very, very special moment.”
Scientists were near unanimous in agreeing that gravitational waves would revolutionize astronomy and allow for a whole new realm of study. Yet they did establish some limits to what they can do. “I don’t think it’s going to bring us any closer to being able to time travel,” Thorne said in response to a question at the announcement. “I wish it would.”
Should You Be My Valentine? Research Helps Identify Good And Bad Romantic Relationships
Photo credit:
Remove your rose-colored glasses and take a cold, hard look at your potential Valentine. Brittanie Loren Pendleton, CC BY-NC-ND
“Will you be my Valentine?”
People all across the country say those words in the run-up to February 14 and the Valentine’s Day holiday. Whether you’re asking a brand new paramour or a long-term partner, the question can evoke feelings both of romantic uncertainty and possibility.
But for the well-being of ourselves and our relationships, “Will you be my Valentine?” is the wrong question. Instead, the more important question to ask yourself is “Should you be my Valentine?”
February 10, 2016
If Meat Could Talk, Would You Still Eat It?
Photo credit:
shutterstock
Futurologist Ian Pearson recently predicted that by 2050 it will be possible to implant devices into our pets and other animals to give them the ability to speak to us.
This raises the interesting question of whether such a device would provide animals raised and slaughtered for food with a voice, and whether this voice would make us think twice about eating them.
When Eagles Scare: There Are Other Ways To Stop A Rogue Drone
Photo credit:
funkyfrogstock/Shutterstock
Reckless or criminal uses of drones are on the rise and police forces have reported “a spike” in the number of drone-related incidents in the UK, mirroring the growth in the technology’s popularity.
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