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Category: Biology

Where did all those structures inside complex cells come from?

Where did all those structures inside complex cells come from?

Viviane Callier writes: More than 1.5 billion years ago, a momentous thing happened: Two small, primitive cells became one. Perhaps more than any event — barring the origin of life itself — this merger radically changed the course of evolution on our planet. One cell ended up inside the other and evolved into a structure that schoolkids learn to refer to as the “powerhouse of the cell”: the mitochondrion. This new structure provided a tremendous energetic advantage to its host…

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Unique voice prints in parrots could help birds be recognized in a flock, no matter what they say

Unique voice prints in parrots could help birds be recognized in a flock, no matter what they say

Max Planck Society reports: Parrots are exceptional talkers. They can learn new sounds during their entire lives, amassing an almost unlimited vocal repertoire. At the same time, parrots produce calls so they can be individually recognized by members of their flock—raising the question of how their calls can be very variable while also uniquely identifiable. A study on monk parakeets conducted by the Max Planck Institute of Animal Behavior and Museu de Ciències Naturals de Barcelona might have the answer:…

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How NASA brought an asteroid to Earth

How NASA brought an asteroid to Earth

David W. Brown writes: On a brisk day in February, 2004, Dante Lauretta, an assistant professor of planetary science at the University of Arizona, got a call from Michael Drake, the head of the school’s Lunar and Planetary Laboratory. “I have Lockheed Martin in my office,” Drake said. “They want to fly a spacecraft to an asteroid and bring back a sample. Are you in?” The two men met that evening with Steve Price, then a director of business development…

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What makes life tick? Mitochondria may keep time for cells

What makes life tick? Mitochondria may keep time for cells

Viviane Callier writes: Just as people in different places seem to operate at different rhythms, so too do different species. They age at their own rates: Some, like the fruit fly, race to adulthood so they can reproduce before their ephemeral food source disappears, while creatures like humans mature slowly over decades, in part because building a large, complex brain requires it. And at the very beginning of an embryo’s life, small tweaks in the timing of when and how…

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Bizarre blob-like animal may hint at origins of neurons

Bizarre blob-like animal may hint at origins of neurons

Live Science reports: A sea animal so simple that it looks like a blobby pancake may hold the secret to the origin of neurons. Placozoans are one of the five major branches of animals, along with bilaterians (which include everything from worms to humans), cnidarians (corals and medusas), sponges and ctenophores (comb jellies). They’re the most basic of the bunch, consisting of millimeter-long blobs of cells without organs or body parts. They move through the water using cilia — tiny…

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‘Species repulsion’ enables high biodiversity in tropical trees

‘Species repulsion’ enables high biodiversity in tropical trees

Veronique Greenwood writes: For ecologists, tropical rainforests hold many enigmas. A single hectare can contain hundreds of tree species, far more than in forests closer to the poles. Somehow these species coexist in such dizzying abundance that, as naturalists and ecologists have sometimes noted, tropical forests can feel like botanical gardens, where every plant is something new. For such throngs of species to be packed so densely, they must coexist in a very particular balance. Evolution seems not to favor…

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Magnetism may have given life its molecular asymmetry

Magnetism may have given life its molecular asymmetry

Yasemin Saplakoglu writes: Scientists have debated why life became homochiral [that is, having molecular asymmetry], and whether it needed to happen or if it was purely a fluke. Were chiral preferences impressed on early life by biased samples of molecules arriving from space, or did they somehow evolve out of mixtures that started out as equal parts right- and left-handed? “Scientists have been mystified by this observation,” said Soumitra Athavale, an assistant professor of organic chemistry at the University of…

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All lifeforms, from worms to corals, transform the planet

All lifeforms, from worms to corals, transform the planet

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 not even…

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Do spiders dream?

Do spiders dream?

Carolyn Wilke writes: Young jumping spiders dangle by a thread through the night, in a box, in a lab. Every so often, their legs curl and their spinnerets twitch — and the retinas of their eyes, visible through their translucent exoskeletons, shift back and forth. “What these spiders are doing seems to be resembling — very closely — REM sleep,” says Daniela Rößler, a behavioral ecologist at the University of Konstanz in Germany. During REM (which stands for rapid eye…

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A basic form of numeracy is shared by countless creatures

A basic form of numeracy is shared by countless creatures

Brian Butterworth writes: You might think of counting as something that people do involving the words one, two, three and so on. But we don’t require the use of these words to enumerate a collection of objects. Indeed, some languages do not have long lists of counting words. In studies of children who speak languages with a smaller set of such words (eg, words for one, two, few and many), such as the Indigenous Australian language Warlpiri, my colleagues and I found that they were at least as accurate…

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New finding boosts Panspermia, the theory that life on Earth originated in deep space

New finding boosts Panspermia, the theory that life on Earth originated in deep space

Lina Zeldovich writes: Floating in the middle of our galaxy, near the center of the Milky Way, inside a cloud of gas that swirls at the temperature of 100 Kelvin or -279.67 Fahrenheit, a molecule essential to life on Earth has just been discovered. It sounds inconceivable that such a level of cosmic cold could harbor anything remotely related to a living organism—and yet it does. In fact, without this molecule, humans—and all other breathing, growing things on the planet—would…

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Another path to intelligence

Another path to intelligence

James Bridle writes: It turns out there are many ways of “doing” intelligence, and this is evident even in the apes and monkeys who perch close to us on the evolutionary tree. This awareness takes on a whole new character when we think about those non-human intelligences which are very different to us. Because there are other highly evolved, intelligent, and boisterous creatures on this planet that are so distant and so different from us that researchers consider them to…

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Selfish, virus-like DNA can carry genes between species

Selfish, virus-like DNA can carry genes between species

Saugat Bolakhe writes: Biologists have understood the broad contours of the rules of inheritance for more than a century: that genes are passed down from parent to child within species. But in more recent years, they have also become aware of genes that go rogue and hop laterally between species — be they frog genes in Madagascar that originally came from snakes, or antifreeze genes found in cold-water fish like herring that transferred to smelts. The mechanism facilitating this gene…

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Modern ‘sixth mass extinction’ event will be worse than first predicted, says report

Modern ‘sixth mass extinction’ event will be worse than first predicted, says report

GrrlScientist writes: Tragically, the global mass extinction event that we find ourselves in the midst of will be even worse than originally predicted, according to a recent study (ref). The international team of scientists came to their conclusion after analyzing population trends data for more than 71,000 animal species — including mammals, birds, reptiles, amphibians, fish and insects — from around the world to see how their numbers have changed since record-keeping first began. Generally, scientists agree that an extinction…

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Wild parrot chicks babble like human infants

Wild parrot chicks babble like human infants

Science reports: Babies don’t babble to sound cute—they’re taking their first steps on the path to learning language. Now, a study shows parrot chicks do the same. Although the behavior has been seen in songbirds and two mammalian species, finding it in these birds is important, experts say, as they may provide the best nonhuman model for studying how we begin to learn language. The find is “exciting,” says Irene Pepperberg, a comparative psychologist at Hunter College not involved with…

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In a fierce desert, microbe ‘crusts’ show how life tamed the land

In a fierce desert, microbe ‘crusts’ show how life tamed the land

Zack Savitsky writes: In 2017, a team of scientists from Germany trekked to Chile to investigate how living organisms sculpt the face of the Earth. A local ranger guided them through Pan de Azúcar, a roughly 150-square-mile national park on the southern coast of the Atacama Desert, which is often described as the driest place on Earth. They found themselves in a flat, gravelly wasteland interrupted by occasional hills, where hairy cacti reached their arms toward a sky that never…

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