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Category: Biology

Primate memory

Primate memory

Tetsuro Matsuzawa writes: The most recent common ancestor of chimpanzees and humans lived between five and seven million years ago. This shared heritage became evident when sequencing revealed a 1.2% DNA difference between species. Chimpanzees have a living sister species, bonobos, that is equally closely related to humans. Both chimpanzees and bonobos are found only in Africa; this is also true of gorillas. Chimpanzees and humans shared a common ancestor with gorillas between eight and nine million years ago. Another…

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Flatworms can reproduce ripping themselves in half

Flatworms can reproduce ripping themselves in half

Ed Yong writes: When planarian flatworms want to reproduce, some have sex. Others, more straightforwardly, tear themselves in two. The latter option is fast and violent. The planarian begins as a small, flattened, sluglike creature with a spade-shaped head and two googly eyes. After a few minutes of stretching and ripping, it separates into two halves—a head and a tail. Within days, the head piece grows a tail. And even more miraculously, the tail regrows its head. “It’s just mind-blowing,”…

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The act of smelling

The act of smelling

Jude Stewart writes: If all our genius lies in our nostrils, as Nietzsche remarked, the nose is an untrained genius, brilliant but erratic. The human nose can detect a dizzying array of smells, with a theoretical upper limit of one trillion smells—yet many of us are incapable of describing these smells in words more precise than smelly and fragrant. Our auditory and visual receptors offer little mystery—they were mapped and explained by scientists many decades ago—but human olfactory receptors were…

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How memories persist where bodies and even brains do not

How memories persist where bodies and even brains do not

Thomas R Verny writes: I began exploring the concept of cellular memory – the idea that memory can be stored outside the brain, in all the body’s cells – after reading an article on Reuters headlined ‘Tiny Brain No Obstacle to French Civil Servant’ in 2007. It seems that a 44-year-old French man had gone to hospital complaining of a mild weakness in his left leg. Doctors learned that the patient ‘had a shunt inserted into his head to drain…

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DNA offers surprises on how Polynesia was settled

DNA offers surprises on how Polynesia was settled

Science reports: The peopling of Polynesia was a stunning achievement: Beginning around 800 C.E., audacious Polynesian navigators in double-hulled sailing canoes used the stars and their knowledge of the waves to discover specks of land separated by thousands of kilometers of open ocean. Within just a few centuries, they had populated most of the Pacific Ocean’s far-flung islands. Now, researchers have used modern DNA samples to trace the exploration in detail, working out what order the islands were settled in…

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The new science on how we burn calories

The new science on how we burn calories

Kim Tingley writes: It’s simple, we are often told: All you have to do to maintain a healthy weight is ensure that the number of calories you ingest stays the same as the number of calories you expend. If you take in more calories, or energy, than you use, you gain weight; if the output is greater than the input, you lose it. But while we’re often conscious of burning calories when we’re working out, 55 to 70 percent of…

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How synchronous firefly flashes illuminate the physics of complex systems

How synchronous firefly flashes illuminate the physics of complex systems

Orit Peleg writes: In the still of the Tennessee night, my colleagues and I are watching thousands of dim little orbs of light, moving peacefully in the forest around us. We try to guess where the next flash will appear, but the movements seem erratic, even ephemeral. This summer, as we set up our cameras and tents, I feel a crippling sense of dread. I had brought us all up here to the Great Smoky Mountains National Park, an unlikely…

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A quantitative theory unlocks the mysteries of why we sleep

A quantitative theory unlocks the mysteries of why we sleep

Van Savage and Geoffrey West write: Humans have long wondered why we sleep. A well-rested prehistoric mind probably pondered the question, long before Galileo thought to predict the period of the pendulum or to understand how fast objects fall. Why must we put ourselves into this potentially endangering state, one that consumes about a third of our adult lives and even more of our childhood? And we don’t do it grudgingly – why do we, along with dogs, lions and…

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Human gut bacteria could be accumulating our medications without our understanding the impact

Human gut bacteria could be accumulating our medications without our understanding the impact

Science Alert reports: When we take medicine, there are often unintended consequences. In the most common scenarios, these are known as side effects. But ‘side effects’ don’t begin to encompass the multitude of strange things that can happen when various compounds enter our system. Sometimes, these unintended consequences occur after drugs physically exit the body, with medicine finding a second life in animals accidentally exposed to the formulations downstream. Yet even before drugs have a chance to leave your body,…

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Having a concept of death is far from being a uniquely human attribute

Having a concept of death is far from being a uniquely human attribute

Susana Monsó writes: Humans have long thought of themselves as the only animal with a notion of mortality. Our concept of death is one of those characteristics, like culture, rationality, language or morality, that have traditionally been taken as definitional of the human species – setting us apart from the natural world and justifying our boundless use and exploitation of it. However, as I have argued elsewhere, the widespread notion that only humans can understand death stems from an overly…

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A new company with a wild mission: Bring back the woolly mammoth

A new company with a wild mission: Bring back the woolly mammoth

Carl Zimmer reports: A team of scientists and entrepreneurs announced on Monday that they have started a new company to genetically resurrect the woolly mammoth. The company, named Colossal, aims to place thousands of these magnificent beasts back on the Siberian tundra, thousands of years after they went extinct. “This is a major milestone for us,” said George Church, a biologist at Harvard Medical School, who for eight years has been leading a small team of moonlighting researchers developing the…

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On the evidence for fungal intelligence

On the evidence for fungal intelligence

Nicholas P Money writes: Mushrooms and other kinds of fungi are often associated with witchcraft and are the subjects of longstanding superstitions. Witches dance inside fairy rings of mushrooms according to German folklore, while a French fable warns that anyone foolish enough to step inside these ‘sorcerer’s rings’ will be cursed by enormous toads with bulging eyes. These impressions come from the poisonous and psychoactive peculiarities of some species, as well as the overnight appearance of toadstool ring-formations. Given the…

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Can progressives be persuaded that genetics matters?

Can progressives be persuaded that genetics matters?

Gideon Lewis-Kraus writes: [Kathryn Paige] Harden understands herself to be waging a two-front campaign. On her left are those inclined to insist that genes don’t really matter; on her right are those who suspect that genes are, in fact, the only things that matter. The history of behavior genetics is the story of each generation’s attempt to chart a middle course. When the discipline first began to coalesce, in the early nineteen-sixties, the memory of Nazi atrocities rendered the eugenics…

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The complex truth about ‘junk DNA’

The complex truth about ‘junk DNA’

Jake Buehler writes: Imagine the human genome as a string stretching out for the length of a football field, with all the genes that encode proteins clustered at the end near your feet. Take two big steps forward; all the protein information is now behind you. The human genome has three billion base pairs in its DNA, but only about 2% of them encode proteins. The rest seems like pointless bloat, a profusion of sequence duplications and genomic dead ends…

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Animals count and use zero. How far does their number sense go?

Animals count and use zero. How far does their number sense go?

Jordana Cepelewicz writes: An understanding of numbers is often viewed as a distinctly human faculty — a hallmark of our intelligence that, along with language, sets us apart from all other animals. But that couldn’t be further from the truth. Honeybees count landmarks when navigating toward sources of nectar. Lionesses tally the number of roars they hear from an intruding pride before deciding whether to attack or retreat. Some ants keep track of their steps; some spiders keep track of…

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Do wild animals get PTSD? Scientists probe its evolutionary roots

Do wild animals get PTSD? Scientists probe its evolutionary roots

By Sharon Levy, Knowable Magazine Every few years, snowshoe hare numbers in the Canadian Yukon climb to a peak. As hare populations increase, so do those of their predators: lynx and coyotes. Then the hare population plummets and predators start to die off. The cycle is a famous phenomenon among ecologists and has been studied since the 1920s. In recent years, though, researchers have come to a startling conclusion: Hare numbers fall from their peak not just because predators eat…

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