ريتشارد دوكنز's Blog, page 700
August 31, 2015
In the Classroom: The Ocean’s Got Chemistry
Nikita Daryanani is a summer intern at NCSE. She recently graduated from UC Davis with a degree in Environmental Policy Analysis and Planning, and is interested in global climate change and environmental justice.
If you’ve ever been snorkeling or diving (or watched Finding Nemo), you know that the ocean is a wonderful, colorful place that’s full of all kinds of creatures. But what you may not know is that even the ocean is vulnerable to the effects of climate change. This is because when we think of climate change and pollution, we think of giant smokestacks emitting thick, grey smoke into the clear blue sky, not into the ocean below.
But carbon dioxide in the atmosphere can affect the ocean, too. As it is absorbed by the ocean, the water becomes more acidic. As carbon dioxide emissions increase, the acidity of the ocean increases as well. This is called “ocean acidification.”
We’ve talked about the chemistry aspect of ocean acidification before on our blog, but if you’re looking for a resource that explains how this change in ocean chemistry is harming marine organisms, take a look at EarthVision Institute’s video on ocean acidification and coral reefs.
Marine ecologist Joanie Kleypas uses a very helpful analogy to explain the process of ocean acidification in a way that’s easy to understand. In this video, Kleypas compares it to the carbonization of water to make soda. When you put water in a closed bottle and add carbon dioxide to it, the water absorbs it and becomes bubbly, but also, more acidic. As it turns out, the same thing happens with the ocean, just without the bubbles. But unlike the water bottle, there are millions of species of plants and animals that live in the ocean and they need the ocean’s pH to stay pretty stable.
One of the most important of these are coral reefs. According to Kleypas, “a third of the world’s fish species use a coral reef at some time or another.” They use it for nurturing their young, hiding from predators, as a food source, and more. No wonder scientists are so worried about this. She also points out that many organisms found in coral reefs have medicinal properties that are used in modern medicine. So it’s not just fish that benefit from having coral reefs around—humans do, too!
EarthVision has various other videos on subjects such as the scientific process and the polar vortex, as well as time-lapse videos of melting glaciers, so it is definitely worth checking out the website. We realize that videos only get you so far in a classroom, so you might couple the ocean acidification video with some of their other materials or a classroom activity that could really bring the point home.
Ocean acidification has been called “climate change’s evil twin” for good reason. It is a problem that is just as relevant and just as worrisome as climate change. Teaching kids about this issue not only allows them to learn about some interesting chemistry and biology concepts, but helps them better understand the scope of the challenges we are facing in the future.
Are you teaching about ocean acidification in your classroom this coming year? What resources are you using?
Image from usfwspacific from Flickr
Answer Monday!
Last week, I unleashed my inner Ansel Adams and gave you a dramatically lit fossil with distinct ridges. What was it?
Museum of Comparative Zoology, Harvard University
A trilobite, of course! Trilobites are arthropods, making them close cousins (evolutionarily speaking) to living groups such as insects, crustaceans, and spiders. They first appeared, complex eyes and all, around the Cambrian “explosion” about 521 million years ago. Paleontologists are confident, however, that their true origin was in the Precambrian. The American Museum of Natural History has a lovely corner of their webpage devoted to trilobites. The Introduction page was clearly written by a paleontologist who moonlights as a poet:
Though their true origins remain shrouded in Precambrian mystery, there can be little doubt that the root stock of the trilobite lineage stretches well back into that poorly understood period of our planet's early history. Yet as soon as their remains started filling the fossil record at the dawn of the hallowed Cambrian Explosion, trilobites were already the unquestioned kings of the Earth's primordial seas. These strangely beautiful creatures—named not for their distinctive cephalon, thorax and pygidium (head, body, tail), but rather for the three lobes that divide their lateral symmetry—would eventually evolve into more than 20,000 scientifically recognized species and dominate the world's oceans for the next quarter of a billion years.
A trilobite display at the American Museum of Natural History in New York (Futureman1199 via Wikimedia Commons)
Trilobites are just cool. They vary in size from tiny to holy-moly enormous, some rolled up like modern-day pill bugs, and some had crazy horn-like things. But more than just cool, trilobites are extra important to paleontology because they have a specific trifecta of characteristics: they are found globally, they are numerous, and they are diverse. These characteristics make trilobites ideal index fossils. Index fossils are distinctive fossils used to compare and establish the relative ages of rocks around the world. Overall, trilobites are present in over 270 million years of Earth’s history (from about 521–250 million years ago), but each of the 20,000+ species of trilobite are present for just a sliver of that time. So if you find Trilobite A in a layer of shale in Italy but not in the layers above or below, then when you find Trilobite A in a layer of shale in Pennsylvania, you know that those rocks are the same age as their Italian counterparts. Cool, right? And as you learned in a previous post, you can’t date fossils directly, but with some directly dateable igneous rocks thrown into the mix, we can put together a nice timeline using this kind of correlation. Helping the cause is the fact that trilobites, like most living arthropods, molted. Every shed exoskeleton was another opportunity for fossilization.
This particular trilobite is a Chotecops ferdinandi (formerly Phacops ferdinandi) from the Hunsrück slate in Germany, famous for its exceptional preservation of Devonian fauna. And if you’re in the Hunsrück slate, you’re going to see a lot of these guys: they’re said to be the most common macrofossil there. Fossils from Hunsrück are [image error]Pyritized fossil echinoderm (Homalozoa) from the Hunsrück-Museum (via Wikimedia Commons)
extra cool because they have been pyritized—which, sadly, doesn’t mean they got hooks and eye patches, but it does mean that the organic material was replaced with the mineral pyrite. Pyritization is rare in the fossil record, and occurs when sulfur and iron are present in an anoxic (no-oxygen) environment. Unfortunately, the fool’s golden color of pyrite isn’t as obvious in this specimen as it is in some others, such as this echinoderm from the same locality.
Congratulations to John Harshman, who got the genus AND locality! I am most impressed, sir! My hat off to you.
Are you a teacher and want to tell us about an amazing free resource ? Do you have an idea for a Misconception Monday or other type of post? See some good or bad examples of science communication lately? Drop me an email or shoot me a tweet @keeps3.
A Tribute to Oliver Sacks from Colleague and Friend Christof Koch
Oliver Sacks has left the world. The British-born neurologist-cum-writer who called New York City his home for the past half century died yesterday at his Greenwich Village apartment at the age of 82.
Sacks practiced and revived an almost extinct form of medicine that consisted of literary case studies focusing on the singular neurological patient hidden underneath the dry diagnostic labels of autism, ocular cancer, amnesia, Tourette’s syndrome, Parkinson’s disease, achromatism, blindness and so on. Sacks excelled at bringing the individual to life, describing with a riot of coruscated imagery and an exuberance of words what it was to be so afflicted and how it affected the patient’s life.
Through his many books, and the movies and documentaries they inspired, Sacks brought the mind–brain connection to the reading public. He educating those who would never think of opening a neuroscience treatise describing how the aftermath of a stroke, virus infection or other physical pathology leaves telltale signs and causes specific symptoms and deficits in the mental life of the brain. In his writings Sacks documented the inability to perceive a familiar face (such as the signature case of face blindness in The Man Who Mistook His Wife for a Hat, the loss of color vision despite the eyes being physically intact or that strange malady known as the “sleepy sickness,” encephalitis lethargica, that struck the world during World War I and was the theme of his landmark work, Awakenings. These books brought him fame, a dedicated readership and helped to displace Freudian narratives that dominate public discourse in favor of neuroscientific ones.
The emphasis of modern medicine on molecular mechanisms, pharmacological interventions, magnetic scanners and other complex instruments is a great and powerful machine; yet it is also an impersonal one, both in its practice once the patient passes through the maw of the hospital and in its view of patients as statistical entities, with a precise numerical code for his or her medical condition and a “metadata” field to account for any peculiarities. Neuroscience’s take on the nervous system is an even more abstract one, treating members of the same species as statistical variants on a common theme, experiments that flatten individual subjects into averages.
Sacks begged to differ—he brought out the unique, the idiosyncratic in each one of his patients. He was dispassionate enough to apply the same artistic temperament to himself, as in his account of his ocular melanoma, a condition that would finally kill him. Surgical removal of the tumor with focused radiation saved most of his retina but left an empty region, void of visual processing, termed a scotoma, in his right eye. One chapter of The Mind’s Eye (2010) detailed his changed visual experience—how the nothingness that is the scotoma filled in when looking at a blue sky or at a patterned brick wall. Like a child playing with a new toy, Sacks experimented with his gaze to discover the limits of this fill-in phenomenon. When he closed his left eye Sacks “amputated” his leg by moving his gaze until it was contained within the scotoma. Yet when he wiggled his leg the sensory-motor feedback from what he couldn’t see rendered it visible in a ghostly sort of way. Conversely, a flock of birds that entered his scotoma abruptly disappeared, only to emerge intact on the other side. He meditated on his loss of the sense of depth and other changes to his sight.
Although Sacks aspired to be a scientist early on in his career, he wisely followed a different calling—that of physician. He cared about particulars, leaving to others inductive inferences from the particular to the general. Yet he loved chemistry and biology and kept close company with many of its practitioners, through visits and hand-written correspondence—no e-mailing for Sacks.
It was through his friendship with Francis Crick that I first met Sacks. Subsequently, I would visit him in his warm and book-cluttered apartment in Manhattan’s Meatpacking District whenever I could. We would swap old and new scientific discoveries. I vividly remember debating with him on Charles Darwin’s view on the mental life of the lowly earthworm. We would trade gifts. He would leave me with his latest book or article or crampons he thought I was more likely to use or would bequeath me colorful knitted socks. He was an imp who retained a childlike wonder about the world and all of its inhabitants, whether ferns, squirrel monkeys or people. And he never lost the sense of the sheer miracle of existence. He reminded me of a big, lovable teddy bear, and I often felt the urge to simply hug him.
Sacks epitomized the ancient dictum, ars moriendi ars vivendi est—that is to say, the art of dying is the art of living. I did talk to him about his cancer and he was unafraid, calmly speaking about how much time was left to him. (He expressed the same sentiments in a widely circulated New York Times editorial.)
Let me end with a quote that epitomized the Oliver Sacks I knew and admired. It is from a wise man who lived a long time ago, the Roman emperor Marcus Aurelius: “Pass then through this little space of time conformably to nature and end thy journey in content, just as an olive falls off when it is ripe, blessing nature who produced it, and thanking the tree on which it grew.”
Oliver Sacks—I salute your memory. I am glad that we shared a few precious moments of eternity.
—
Christof Koch writes the “Consciousness Redux” column for Scientific American MIND and is president and chief scientific officer of the Allen Institute for Brain Science.
Public Health Hero Jimmy Carter; SciAm Turns 170
Jimmy Carter talks about his public health efforts to eradicate guinea worm and improve global mental health and women's health. Plus, magazine collector Steven Lomazow brings part of his collection to the Scientific American 170th birthday party.
Oliver Sacks, Who Depicted Brain-Disorder Sufferers’ Humanity, Dies
“I am a man of vehement disposition, with violent enthusiasms and extreme immoderation in all my passions,” wrote Oliver Sacks six months ago in a New York Times op–ed in which he told the world that he was dying of cancer. And although he admitted to feeling an incipient sense of detachment from the transient events of the day, the renowned neurologist and peerless chronicler of the quirks and intricacies of the human brain said he was doubling down on life: “I have to live in the richest, deepest, most productive way I can.”
And that’s exactly what Sacks, 82, did before dying August 30 from melanoma that had spread to his liver. In a final flurry he completed a revelatory autobiography, On the Move: A Life, published to rhapsodic reviews in May; wrote a children’s book about the periodical table of elements (chemistry ranked among his immoderate passions); a philosophical ode to Sabbath as a day of rest; and other works, some of which will likely be revealed posthumously. His longtime assistant Kate Edgar told a New York Times reporter that Sacks, who always wrote with pen on paper, would likely die “with fountain pen in hand.”
In all his work—as a clinician and writer—Sacks applied acute powers of observation, far-ranging curiosity and compassion that reflected his personal familiarity with suffering and alienation. He said that he modeled his writing on the detailed, almost novelistic case studies that were popular in 19th-century medicine and was particularly inspired by the great, Russian neuropsychologist Alexander Luria.
Most scientists and clinicians interested in the brain tend to ponder the characteristic traits found across a population of patients with autism, Parkinson’s disease, schizophrenia and other conditions, but Sacks was fascinated by the uniqueness of individual patients and what light it shed on the human condition.
His works of nonfiction achieved the level of literary art in the way that only a handful of scientist–authors—Lewis Thomas, Stephen Jay Gould, for instance—have managed. (In fact The Rockefeller University recognized Sacks with a 2001 Lewis Thomas Prize.)
No wonder Sacks’s writing so often inspired other works of art. The title essay of his 1985 collection of case histories, The Man Who Mistook His Wife for a Hat—about a man with a brain disorder called visual agnosia that left him unable to understand what he was seeing—inspired a 1986 opera by the same name. His 1973 book, Awakenings—which documented Sacks’s remarkable experiment using the drug levodopa (aka L-dopa) to reactivate patients who had been frozen motionless for decades by encephalitis—was the basis for a 1990 movie with the same title, starring the late Robin Williams as a character based on Sacks.
Two films and a play were inspired by essays from An Anthropologist on Mars, a 1995 collection that also did much to reframe autism as a condition of abilities as well as disabilities. The title came from a profile of the autistic animal behaviorist Temple Grandin, who used the Martian metaphor to describe how it felt to be autistic person trying to understand ordinary human behavior.
Born in London, Sacks was the youngest of four sons of two doctors (his mother was one of the first female surgeons in the U.K.), both observant Jews. It is a remarkably distinguished family. Among Sacks’s relatives are Israeli statesman Abba Eban, Nobel Prize–winning mathematician Robert Aumann and American cartoonist Al Capp.
Sacks’s 2015 autobiography revealed for the first time that he was gay and spent decades in closeted loneliness and celibacy, finding love only late in life. A remarkable athlete, he set a weightlifting record (272 kilograms in the squat press) while living in southern California and continued to swim 1.6 kilometers a day in the waters near his home on City Island in New York City into his final years.
In his youth Sacks was a motorcycle enthusiast and a serious recreational drug taker who enjoyed experimenting with hallucinogens. In one drug-fueled fantasy described in his 2012 book Hallucinations, he engaged in a long philosophical discourse with a spider on the wall.
His almost reckless passion for exploring the fringe of experience and his outsider status as both a homosexual and expatriate almost certainly contributed to his ability to understand and sympathize with his patients. That, plus his personal psychological quirks: “I am very tenacious, for better or worse,” he wrote in the autobiographical essay A Leg to Stand On. “If my attention is engaged, I cannot disengage it. This may be a great strength—or weakness. It makes me an investigator. It makes me an obsessional.”
It is impossible to say how many careers in neurology, neuroscience and psychology were inspired by the work of Oliver Sacks or how many people with autism, Tourette’s syndrome and baffling post-stroke syndromes found themselves represented in his artful words and empathetic insights.
In his February op-ed about facing death Sacks once again conveyed his passionate appreciation for the uniqueness of individuals, expressing for fans the very sentiments so many would feel at his passing: “When people die, they cannot be replaced. They leave holes that cannot be filled, for it is the fate—the genetic and neural fate—of every human being to be a unique individual, to find his own path, to live his own life, to die his own death.”
Kentucky clerk seeks Supreme Court help to deny gay marriage licenses
Mike Wynn, The (Louisville, Ky.) Courier-Journal.
By Steve Bittenbender
A Kentucky county clerk petitioned the U.S. Supreme Court on Friday for an emergency order allowing her to continue to deny marriage licenses to same-sex couples, a move coming two days after a federal appeals court rejected her request.
In a related move, a federal judge refused to extend a stay of his own ruling requiring the clerk to furnish marriage licenses to gay and lesbian couples while she appealed on the grounds that her religious faith overrides her duties as a public servant.
U.S. District Judge David Bunning said earlier in August that Kim Davis had to live up to her responsibilities as the Rowland County clerk despite her religious convictions, and he issued a preliminary injunction requiring her to issue marriage licenses.
Bunning put his order on hold through Aug. 31 to give Davis an opportunity to ask the 6th U.S. Circuit Court of Appeals for a longer stay, which the appellate court denied on Wednesday. The circuit court found Davis had little chance of prevailing on the merits of her case.
Davis contends that to approve marriage licenses for same-sex applicants would violate her deeply held religious belief that matrimony is between one man and one woman.
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Ants have group-level personalities, study shows
JOHN TANN/FLICKR/CREATIVE COMMONS
By Claire Asher
If you stuck to Aesop’s fables, you might think of all ants as the ancient storyteller described them—industrious, hard-working, and always preparing for a rainy day. But not every ant has the same personality, according to a new study. Some colonies are full of adventurous risk-takers, whereas others are less aggressive about foraging for food and exploring the great outdoors. Researchers say that these group “personality types” are linked to food-collecting strategies, and they could alter our understanding of how social insects behave.
Personality—consistent patterns of individual behavior—was once considered a uniquely human trait. But studies since the 1990s have shown that animals from great tits to octopuses exhibit “personality.” Even insects have personalities. Groups of cockroaches have consistently shy and bold members, whereas damselflies have shown differences in risk tolerance that stay the same from grubhood to adulthood.
To determine how group behavior might vary between ant colonies, a team of researchers led by Raphaël Boulay, an entomologist at the University of Tours in France, tested the insects in a controlled laboratory environment. They collected 27 colonies of the funnel ant (Aphaenogaster senilis) and had queens rear new workers in the lab. This meant that all ants in the experiment were young and inexperienced—a clean slate to test for personality.
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Domestic Pigs Continued To Mate With Wild Boars
Photo credit:
Eduard Kyslynskyy/shutterstock
Pigs were domesticated from wild boars about 9,000 years ago. Researchers have long assumed that this process involved permanently isolating a few animals from the wild. But according to new findings published in Nature Genetics this week, pig domestication doesn’t follow this traditional model: Pigs continued to mate with wild boars even after they became domesticated.
August 30, 2015
New rules may end U.S. chimpanzee research
By David Grimm
No researchers have applied for required federal permits to conduct invasive research on chimpanzees living in the United States. That suggests that all U.S. biomedical research on chimps has stopped—or is about to stop—and it’s unclear whether the work will ever start again. Research on chimpanzees has been waning since 2013, when the National Institutes of Health (NIH) announced that it would phase out most government-funded chimp research and retire the majority of its research chimps to sanctuaries.
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Ancient Native Americans May Have Had Pet Bobcat
Shutterstock
By Tia Ghose
A 2,000-year-old burial mound discovered in the area that’s now Illinois contained the remains of a young bobcat, new research reveals.
The ancient bobcat was wearing a special collar and was found in a ritual burial mound normally reserved for humans.
“It really looked like it had been buried not because it was a feral accessory for a human, but because it was, in some way, kind of respected on its own,” said study co-author Angela Perri, a zooarchaeologist at the Max Planck Institute for Evolutionary Anthropology in Germany.
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