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Category: Biology

How antidepressants help bacteria resist antibiotics

How antidepressants help bacteria resist antibiotics

Nature reports: The emergence of disease-causing bacteria that are resistant to antibiotics is often attributed to the overuse of antibiotics in people and livestock. But researchers have homed in on another potential driver of resistance: antidepressants. By studying bacteria grown in the laboratory, a team has now tracked how antidepressants can trigger drug resistance1. “Even after a few days exposure, bacteria develop drug resistance, not only against one but multiple antibiotics,” says senior author Jianhua Guo, who works at the…

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How our microbiome is shaped by family, friends and even neighbours

How our microbiome is shaped by family, friends and even neighbours

Nature reports: Most studies on how humans acquire their microbiomes have focused on people’s first contact with microbes: through their mums. “It’s key to providing a microbial starter kit,” says Hilary Browne, a microbiologist at the Wellcome Sanger Institute in Hinxton, UK. To examine how and why this starter kit changes over a person’s life, a team led by microbiome researchers Mireia Valles-Colomer and Nicola Segata at the University of Trento, Italy, analysed DNA from nearly 10,000 stool and saliva…

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How gut bacteria are controlling your brain

How gut bacteria are controlling your brain

Miriam Frankel and Matt Warren write: Your gut is a bustling and thriving alien colony. They number in their trillions and include thousands of different species. Many of these microorganisms, including bacteria, archaea and eukarya, were here long before humans, have evolved alongside us and now outnumber our own cells many times over. Indeed, as John Cryan, a professor of anatomy and neuroscience at University College Cork, rather strikingly put it in a TEDx talk: “When you go to the…

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Mobile genes from the mother shape the baby’s microbiome

Mobile genes from the mother shape the baby’s microbiome

Yasemin Saplakoglu writes: A mother gives her baby her all: love, hugs, kisses … and a sturdy army of bacteria. These simple cells, which journey from mother to baby at birth and in the months of intimate contact that follow, form the first seeds of the child’s microbiome—the evolving community of symbiotic microorganisms tied to the body’s healthy functioning. Researchers at the Broad Institute of the Massachusetts Institute of Technology and Harvard University recently conducted the first large-scale survey of…

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Using physics to describe how tiny biological components give rise to living organisms

Using physics to describe how tiny biological components give rise to living organisms

Charlie Wood writes: In a sunny lab at the Massachusetts Institute of Technology, two starfish fought over their prey. Overlapping arms pinned a hunk of thawing cocktail shrimp against the side of the tank. Thousands of suction cups rippled furiously against the glass as each echinoderm struggled to inch the prize toward its own maw. The physicist Nikta Fakhri looked on with a grin. Not many physicists keep ocean life in their labs, but Fakhri has learned to care for…

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What ants’ longevity secrets could mean for aging in other species

What ants’ longevity secrets could mean for aging in other species

Viviane Callier writes: Animals that produce many offspring tend to have short lives, while less prolific species tend to live longer. Cockroaches lay hundreds of eggs while living less than a year. Mice have dozens of babies during their year or two of life. Humpback whales produce only one calf every two or three years and live for decades. The rule of thumb seems to reflect evolutionary strategies that channel nutritional resources either into reproducing quickly or into growing more…

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Humans are still evolving thanks to microgenes

Humans are still evolving thanks to microgenes

The Scientist reports: Humans are still evolving new genes, according to a study published in Cell Reports on December 20. As our lineage evolved, at least 155 human genes sprung up from DNA regions previously thought of as “junk,” including two human-specific genes that emerged since humans branched off from chimpanzees around 4 to 6 million years ago, the researchers report. “I thought it was a great study,” says Alan Saghatelian, a biologist at the Salk Institute who was not…

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Inside ancient asteroids, gamma rays made building blocks of life

Inside ancient asteroids, gamma rays made building blocks of life

John Rennie and Allison Parshall write: In 2021, the Hayabusa2 space mission successfully delivered a morsel of the asteroid 162173 Ryugu to Earth — five grams of the oldest, most pristine matter left over from the solar system’s formation 4.5 billion years ago. Last spring, scientists revealed that the chemical composition of the asteroid includes 10 amino acids, the building blocks of proteins. The discovery added to the evidence that the primordial soup from which life on Earth arose may…

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Strange, tentacled microbe may resemble ancestor of complex life

Strange, tentacled microbe may resemble ancestor of complex life

Science reports: By growing an unusual tentacled microbe in the lab, microbiologists may have taken a big step toward resolving the earliest branches on the tree of life and unraveling one of its great mysteries: how the complex cells that make up the human body—and all plants, animals, and many single-celled organisms—first came to be. Such microbes, called Asgard archaea, have previously been cultured—once—but the advance reported today in Nature marks the first time they’ve been grown in high enough…

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Microorganisms that expand their range by absorbing organelles

Microorganisms that expand their range by absorbing organelles

Veronique Greenwood writes: Nature, red in tooth and claw, is rife with organisms that eat their neighbors to get ahead. But in the systems studied by the theoretical ecologist Holly Moeller, an assistant professor of ecology, evolution and marine biology at the University of California, Santa Barbara, the consumed become part of the consumer in surprising ways. Moeller primarily studies protists, a broad category of unicellular microorganisms like amoebas and paramecia that don’t fit within the familiar macroscopic categories of…

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New research upends conventional wisdom about how we burn calories

New research upends conventional wisdom about how we burn calories

Herman Pontzer writes: We’re often told our metabolism speeds up at puberty and slows down in middle age, particularly with menopause, and that men have faster metabolisms than women. None of these claims is based on real science. My colleagues and I have begun to fill that gap in scientific understanding. In 2014 John Speakman, a researcher in metabolism with laboratories at the University of Aberdeen in Scotland and the Chinese Academy of Sciences in Shenzhen, organized an international effort…

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World’s oldest DNA discovered, revealing ancient Arctic forest full of mastodons

World’s oldest DNA discovered, revealing ancient Arctic forest full of mastodons

Scientific American reports: The oldest DNA ever recovered has revealed a remarkable two-million-year-old ecosystem in Greenland, including the presence of an unlikely explorer: the mastodon. The DNA, found locked in sediments in a region called Peary Land at the farthest northern reaches of Greenland, shows what life was like in a much warmer period in Earth’s history. The landscape, which is now a harsh polar desert, once hosted trees, caribou and mastodons. Some of the plants and animals that thrived…

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Ant milk — it does a colony good

Ant milk — it does a colony good

The New York Times reports: Orli Snir, a biologist at the Rockefeller University in New York, couldn’t keep her ants alive. She had plucked pupae from a colony of clonal raider ants, where the sesame seed-size offspring that looked like puffed rice cereal were being fussed over by both younger larvae and older adult ants. Then she had isolated each pupa into a tiny, dry test tube. And every time, they drowned. More specifically, each pupa was leaking so much…

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Honeybees are living half as long as they were 50 years ago

Honeybees are living half as long as they were 50 years ago

New Scientist reports: Honeybees kept under laboratory conditions in the US only live half as long as they did in the 1970s, suggesting that genetics could be contributing to colony losses, and not just environmental factors such as pesticides and sources of food. Five decades ago, the median lifespan for a worker western honeybee (Apis mellifera) that spent its adult life in a controlled environment was 34.3 days. Now, the median is 17.7 days, according to research by Anthony Nearman…

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Our planet, shaped by life

Our planet, shaped by life

Olivia Judson writes: I want to start with a proposition: if Earth had never come alive, it would be a profoundly different world. Conversely: the planet of today has, to a remarkable extent, been made what it is by the activities of lifeforms. Over the course of the planet’s long history, a history that extends back more than 4.5 billion years, lifeforms have shaped the rocks, the water, the air, even the colour of the sky. A Never-Life Earth would…

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Human exceptionalism imposes horrible costs on other animals

Human exceptionalism imposes horrible costs on other animals

Barbara J King writes: Human exceptionalism takes many forms but most share an assumption that our species displays singularly complex ways of being, thinking and feeling. On this perspective, other animals’ capacities are inferior, and so other animals’ lives are also seen as inferior. It’s only a myth, though, that other-than-human animals inevitably live moment to moment. Many mammals and birds remember and learn from past experiences, and anticipate with joy or fear what may be coming next. Recognition of…

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