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Category: Evolution

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 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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Why the coronavirus has changed as it has, and what it means going forward

Why the coronavirus has changed as it has, and what it means going forward

STAT reports: It’s impossible to say how the coronavirus will continue to evolve. Those changes, after all, are a result of random mutations. But there are some fundamental principles that explain why the virus has morphed as it has, principles that could guide our understanding of its ongoing evolution — and what that means for our future with the pathogen. The great fear is that nature could spit out some new variant that completely saps the power of vaccines and…

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How will the coronavirus evolve?

How will the coronavirus evolve?

Dhruv Khullar writes: In 1988, Richard Lenski, a thirty-one-year-old biologist at UC Irvine, started an experiment. He divided a population of a common bacterium, E. coli, into twelve flasks. Each flask was kept at thirty-seven degrees Celsius, and contained an identical cocktail of water, glucose, and other nutrients. Each day, as the bacteria replicated, Lenski transferred several drops of each cocktail to a new flask, and every so often he stored samples away in a freezer. His goal was to…

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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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Great ape interactions indicate that bonobos and chimps follow certain social customs, much like humans

Great ape interactions indicate that bonobos and chimps follow certain social customs, much like humans

Gizmodo reports: You don’t walk up to a coworker without some sort of greeting, and you don’t end conversations simply by turning heel. There are rules to the game of social behavior, and now a research team studying chimpanzees and bonobos say those great apes have social habits that look a lot like what we humans call “hello” and “goodbye.” The research team observed over 2,000 interactions between chimpanzees as well as bonobos, another ape species closely related to humans….

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What misspellings reveal about cultural evolution

What misspellings reveal about cultural evolution

Helena Miton writes: Something about me must remind people of a blind 17th-century poet. My last name, Miton, is French, yet people outside of France invariably misspell it as “Milton”—as in the famed English author, John Milton, of the epic poem Paradise Lost. It is not uncommon for people to misspell an unfamiliar name—yet 99 times out of 100 people misspell mine as “Milton.” That is the name that shows up on everything from my university gym card to emails…

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When did humans start experimenting with psychoactive drugs?

When did humans start experimenting with psychoactive drugs?

Nicholas Longrich, Author provided By Nicholas R. Longrich, University of Bath Humans constantly alter the world. We fire fields, turn forests into farms, and breed plants and animals. But humans don’t just reshape our external world – we engineer our internal worlds, and reshape our minds. One way we do this is by upgrading our mental “software”, so to speak, with myths, religion, philosophy and psychology. The other is to change our mental hardware – our brains. And we do…

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Cats’ genomes are surprisingly similar to humans’

Cats’ genomes are surprisingly similar to humans’

Katherine J. Wu writes: The genome of a mouse is, structurally speaking, a chaotic place. At some point in its evolutionary past, the mouse shuffled its ancestral genome like a deck of cards, futzing up the architecture that makes most other mammalian genomes look, well, mammalian. “I always consider it the greatest outlier,” Bill Murphy, a geneticist at Texas A&M University, told me. “It’s about as different from any other placental mammal genome as you can find, sort of like…

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As little as 1.5% of our genome is ‘uniquely human’

As little as 1.5% of our genome is ‘uniquely human’

Live Science reports: Less than 10% of your genome is unique to modern humans, with the rest being shared with ancient human relatives such as Neanderthals, according to a new study. The study researchers also found that the portion of DNA that’s unique to modern humans is enriched for genes involved with brain development and brain function. This finding suggests that genes for brain development and function are what really set us apart, genetically, from our ancestors. However, it’s unclear…

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DNA has four nucleotide bases. Some viruses swap in a fifth

DNA has four nucleotide bases. Some viruses swap in a fifth

Jordana Cepelewicz writes: All life on Earth rests on the same foundation: a four-letter genetic alphabet spelling out a repertoire of three-letter words that specify 20 amino acids. These basic building blocks — the components of DNA and their molecular interpreters — lie at biology’s core. “It’s hard to imagine something more fundamental,” said Floyd Romesberg, a synthetic biologist at the pharmaceutical company Sanofi. Yet life’s foundational biochemistry can be full of surprises. A few decades ago, researchers found viruses…

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When bacteria kill us, it’s more accident than assassination

When bacteria kill us, it’s more accident than assassination

Ed Yong writes: The classic novel by H G Wells, The War of the Worlds (1898) – a tale of England besieged by Martian conquerors – ends not with a rousing and heroic victory but an accidental one. The aliens subjugate humanity with heat rays and black smoke but, at the height of their victory, they die. Their machines come to a standstill amid the ruins of a deserted London, and the birds pick at their rotting remains. The cause…

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‘Social’ mitochondria, communicating between cells, influence health

‘Social’ mitochondria, communicating between cells, influence health

Katarina Zimmer writes: During his doctoral research on the ties between aging and mitochondria, Martin Picard frequently saw micrographs of those energy-producing organelles. Yet it wasn’t until fairly late in his graduate work that he first watched sped-up video of mitochondria moving inside live human cells, and the sight came as a revelation. Tagged with fluorescent dye, the mitochondria were neon squiggles crawling through the soupy interior of the cells — stretching and contracting, fusing together and splitting up again,…

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Beyond coronavirus: the virus discoveries transforming biology

Beyond coronavirus: the virus discoveries transforming biology

Nature reports: Mya Breitbart has hunted novel viruses in African termite mounds, Antarctic seals and water from the Red Sea. But to hit pay dirt, she has only to step into her back garden in Florida. Hanging around her swimming pool are spiny-backed orbweavers (Gasteracantha cancriformis) — striking spiders with bulbous white bodies, black speckles and six scarlet spikes that make them look like a piece of medieval weaponry. Even more striking for Breitbart, a viral ecologist at the University…

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Discovery of ‘Dragon Man’ skull in China may add species to human family tree

Discovery of ‘Dragon Man’ skull in China may add species to human family tree

The New York Times reports: Scientists on Friday announced that a massive fossilized skull that is at least 140,000 years old is a new species of ancient human, a finding that could potentially change prevailing views of how — and even where — our species, Homo sapiens, evolved. The skull belonged to a mature male who had a huge brain, massive brow ridges, deep set eyes and a bulbous nose. It had remained hidden in an abandoned well for 85…

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