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Category: Biology

Five misunderstandings of pregnancy biology that cloud the abortion debate

Five misunderstandings of pregnancy biology that cloud the abortion debate

Science News reports: Like most aspects of biology, early human development involves many complex processes. Despite the rhetoric around these issues, clear lines — between having a heart and not having a heart or being able to survive outside of the uterus — are scarce, or nonexistent. “There aren’t these set black-and-white points for much of this,” says obstetrician-gynecologist Nisha Verma, a fellow with the American College of Obstetricians and Gynecologists in Washington, D.C. Here’s what’s known about five key…

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How the brains of social animals synchronise and expand one another

How the brains of social animals synchronise and expand one another

Sofia Quaglia writes: Humans are not the only creatures that show a refined grasp of social norms. If a group of adult male rhesus monkeys (Macaca mulatta) find themselves sitting around a turning table set with food, they will display an ‘I scratch your back, you scratch mine’ ethos of reciprocity. One monkey will offer another one a piece of fruit and, what’s more, will expect the gesture to be reciprocated. If the offer isn’t forthcoming, the first monkey is…

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Modern city dwellers have lost about half their gut microbes

Modern city dwellers have lost about half their gut microbes

Science reports: Deep in the human gut, myriad “good” bacteria and other microbes help us digest our food, as well as keep us healthy by affecting our immune, metabolic, and nervous systems. Some of these humble microbial assistants have been in our guts since before humans became human—certain gut microbes are found in almost all primates, suggesting they first colonized a common ancestor. But humans have also lost many of these helpers found in other primates and may be losing…

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How the sugars in mucus tame the body’s unruly fungi

How the sugars in mucus tame the body’s unruly fungi

Wired reports: Katharina Ribbeck’s lab collects mucus—the often gooey substance present in places like the mouth, gut, reproductive tract, and intestines. While the slimy goop may not be pretty from the get-go, a purification process can brighten it up. “Once you remove particulates and microbes, it’s a beautiful, beautiful clear gel—like egg white,” says Ribbeck, a professor of bioengineering at the Massachusetts Institute of Technology. “It’s really gorgeous.” Ribbeck cares about spit because she’s trying to deconstruct how glycans, tiny…

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How humans impact the perceptual world of other animals

How humans impact the perceptual world of other animals

Ed Yong writes: In the Tetons, as I watch [a sensory ecologist, Jesse] Barber tagging bats, mosquitoes bite me through my shirt, attracted by the smell of the carbon dioxide on my breath. While I itch, an owl flies overhead, tracking its prey using a radar dish of stiff facial feathers that funnel sound toward its ears. These creatures have all evolved senses that allow them to thrive in the dark. But the dark is disappearing. Barber is one of…

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Brain-signal proteins evolved before animals did

Brain-signal proteins evolved before animals did

Viviane Callier writes: Our human brains can seem like a crowning achievement of evolution, but the roots of that achievement run deep: The modern brain arose from hundreds of millions of years of incremental advances in complexity. Evolutionary biologists have traced that progress back through the branch of the animal family tree that includes all creatures with central nervous systems, the bilaterians, but it is clear that fundamental elements of the nervous system existed much earlier. How much earlier has…

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Cultivating a sense of wonder

Cultivating a sense of wonder

Anelise Chen writes: When the marine biologist Rachel Carson was a young girl, she discovered a fossilized shell while hiking around her family’s hillside property in Springdale, Pennsylvania. Those who knew her then would later contend that this relic sparked such intense reverie in her that she instantly felt a tug toward the sea. What was this ancient creature, and what was the world it had known? Though Carson had never seen the sea herself, she threw herself into its…

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How I started to see trees as smart

How I started to see trees as smart

Matthew Hutson writes: A couple of decades ago, on a backpacking trip in the Sierra Nevada, I was marching up a mountain solo under the influence of LSD. Halfway to the top, I took a break near a scrubby tree pushing up through the rocky soil. Gulping water and catching my breath, I admired both its beauty and its resilience. Its twisty, weathered branches had endured by wresting moisture and nutrients from seemingly unwelcoming terrain, solving a puzzle beyond my…

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Origin of life theory involving RNA–protein hybrid gets new support

Origin of life theory involving RNA–protein hybrid gets new support

Nature reports: Chemists say they have solved a crucial problem in a theory of life’s beginnings, by demonstrating that RNA molecules can link short chains of amino acids together. The findings, published on 11 May in Nature, support a variation on the ‘RNA world’ hypothesis, which proposes that before the evolution of DNA and the proteins it encodes, the first organisms were based on strands of RNA, a molecule that can both store genetic information — as sequences of the…

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Tiny channels discovered inside the human skull could be vital for the brain

Tiny channels discovered inside the human skull could be vital for the brain

Science Alert reports: A shortcut between the skull and the brain could be a possible way for the human immune system to bypass the blood-brain barrier. Researchers recently discovered a series of tiny channels in mice and human skulls, and in mice at least, these little pathways represent an unexpected source of brain immunity. Previously, scientists assumed that the immune system connects with the brain by slipping through a kind of neurological customs gate – a barrier separating blood channels…

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Lowly mushrooms may be key to ecosystem survival in a warming world

Lowly mushrooms may be key to ecosystem survival in a warming world

Elizabeth Pennisi writes: The red, orange, and spotted mushrooms that sprout up after it rains are doing more than adding color to the landscape. The fungi that produce them could be keeping the natural world productive and stable, according to a new study. Indeed, they may be critical to the health of Earth’s ecosystems, says Matthias Rillig, a soil ecologist at the Free University Berlin who was not involved with the work. There are 70,000 known kinds of fungi. These…

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The awake ape: Why people sleep less than their primate relatives

The awake ape: Why people sleep less than their primate relatives

Elizabeth Preston writes: On dry nights, the San hunter-gatherers of Namibia often sleep under the stars. They have no electric lights or new Netflix releases keeping them awake. Yet when they rise in the morning, they haven’t gotten any more hours of sleep than a typical Western city-dweller who stayed up doom-scrolling on their smartphone. Research has shown that people in non-industrial societies — the closest thing to the kind of setting our species evolved in — average less than…

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Ancient genes for symbiosis hint at mitochondria’s origins

Ancient genes for symbiosis hint at mitochondria’s origins

Veronique Greenwood writes: Once, long ago, the only players in the grand drama of life, predation and death were invisibly small and simple cells. Archaea and bacteria jigged and whirled through seas and ponds, assembled themselves into fortresses a few microns wide, and devoured films of organic matter. Then some of them began to change, and eventually the first eukaryote — the first organism to keep its genes locked away in a nucleus, to line its interior with ramifying compartments,…

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New evidence shows cancer is not as heritable as once thought

New evidence shows cancer is not as heritable as once thought

University of Alberta: While cancer is a genetic disease, the genetic component is just one piece of the puzzle — and researchers need to consider environmental and metabolic factors as well, according to a research review by a leading expert at the University of Alberta. Nearly all the theories about the causes of cancer that have emerged over the past several centuries can be sorted into three larger groups, said David Wishart, professor in the departments of biological sciences and…

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Jupiter’s moon Europa may have water where life could exist, scientists suggest

Jupiter’s moon Europa may have water where life could exist, scientists suggest

The Guardian reports: Subterranean pools of salty water may be commonplace on Jupiter’s moon, Europa, according to researchers who believe the sites could be promising spots to search for signs of life beyond Earth. Evidence for the shallow pools, not far beneath the frozen surface of the Jovian moon, emerged when scientists noticed that giant parallel ridges stretching for hundreds of miles on Europa were strikingly similar to surface features discovered on the Greenland ice sheet. If the extensive ice…

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Could gut microbes regulate appetite and body temperature?

Could gut microbes regulate appetite and body temperature?

Science reports: With more microbes than cells in our body, it’s not surprising that bacteria and other invisible “guests” influence our metabolism, immune system, and even our behavior. Now, researchers studying mice have worked out how bacteria in the mammalian gut can ping the brain to regulate an animal’s appetite and body temperature—and it involves the same molecular pathway the immune system uses to detect bacterial pathogens. “It’s quite an important finding,” says Antoine Adamantidis, a neuroscientist at the University…

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