Part of sparrow's brain massively expands in preparation for mating

When it’s time to find a mate, the parts of songbird brains that are responsible for singing get bigger — and then shrink down again at the end of the season. But none do it quite like the Gambel’s white-crowned sparrow (Zonotrichia leucophrys gambelii). In males of the species, a brain area called the HVC nearly doubles in size, expanding from 100,000 neurons to 170,000. How the bird pulls off this feat is still a mystery — but it might one day point to ways of treating anomalies in the human brain.

The most powerful cosmic ray since the Oh-My-God particle puzzles scientists

Scientists have detected the highest-energy cosmic ray since the Oh-My-God particle in 1991. Cosmic rays are high-energy subatomic particles that often originate from a stellar explosion or black hole. The latest turbocharged particle, dubbed Amaterasu, seems to have come from a void-like region in space. One explanation could be that Amaterasu actually came from a different region and scientists’ models of what influences the course of cosmic rays are off. Another possibility is that the rays are produced by unknown physics.

Wi-Fi for neurons: first map of wireless nerve signals unveiled in worms

Researchers have charted a long-distance ‘wireless’ nerve network in Caenorhabditis elegans worms for the first time. The nervous system can be thought of as a web of neurons that pass on messages through direct links, called synapses. But neurons can also communicate over longer distances by releasing molecules called neuropeptides, which are intercepted by other neurons some distance away. Incorporating both ‘wired’ synaptic connections and wireless signalling better predicts how signals travel in the worm than does a model using synaptic connections alone.

Mysterious ‘Tasmanian devil’ space explosion baffles astronomers

Astronomers have observed an unprecedented space explosion that, months after the initial event, briefly flared at peak brightness more than a dozen times. Nicknamed the Tasmanian devil, it is one of several similar events whose cause remains unknown. The phenomena could be failed supernovae — massive stars that run out of fuel and collapse into a dense neutron star or a black hole before they can explode. The flashes could be caused by powerful jets of energy firing from their poles.

Earliest bird signs in southern hemisphere

Footprints preserved in the rocks of Australia’s south coast might have been left by ancient birds 128 million years ago — the earliest evidence for birds in the southern hemisphere. The 27 tracks would have been made when Australia was part of the Gondwana supercontinent; this particular bit of land was close to the South Pole. Features such as widely spread toes and a distinctive perching claw suggest the animals were birds, not dinosaurs.

AI Robot chemist could make oxygen on Mars

A robotic chemist powered by artificial intelligence (AI) can make oxygen from water using only materials found on Mars’s surface. The refrigerator-sized machine separated and analysed ore from Martian meteorites, and then found an effective oxygen-generating catalyst among the more than three million possible compounds — all without human intervention. A similar robot could be sent to Mars to remove the need for astronauts to carry oxygen, or the materials to generate it, from Earth.

Human migrations recorded in lice

One animal has accompanied humans on all of our great migrations: the louse (Pediculus humanus capitis). Its genetics might help to reveal the full extent of our travels. Researchers looked at the genetic variation in lice from around the world and found signs of a genetic link between lice in Asia and those in Central America that might be the mark of ancient humans’ arrival in the Americas. Supporting that theory, louse DNA seems to accurately reflect the known timeline of European settlers mingling with Indigenous Americans.

The rise of brain-reading technology

Prototype brain–computer interfaces have helped paralysed people to speak in their own voices, type at unprecedented speeds and walk smoothly. And companies are working on wearable brain-reading products that aim to help users to control their mental state or to interact with computers. Beyond the hype, researchers are well-aware of the risks: from the spectre of big-brother brain surveillance to the commodification of “the sanctuary of our identity”.

An asteroid with its own moon

NASA’s Lucy spacecraft has spotted the tiny 790-metre asteroid Dinkinesh’s even tinier companion, about 220 metres wide. Lucy is on a 12-year mission to take a close-up look at Trojan asteroids, which orbit the Sun near Jupiter.

Strange blobs in Earth’s mantle are relics of a massive collision

Two mysterious blobs of rock in Earth’s mantle could be remnants of the planetary smash-up that formed the Moon. The formations sit in the layer between the crust and the core, are thousands of kilometres long and are slightly denser than their surroundings. Computer simulations suggest that they are from the protoplanet Theia, which smashed into Earth 4.5 billion years ago. Some of Theia’s remnants were flung into orbit, where they coalesced into the Moon.

The Social Exchange Of Value In Plants

This video shows chemical signals passing along the leaves of an Arabidopsis thaliana plant as it senses the airborne volatile organic compounds, which are released by damaged plants. The signals are carried by calcium ions. The plants’ ability to detect their neighbours’ warning messages allows them to activate defences against herbivores. (Reference: Nature paper)

Lampreys had flesh-eating ancestors

Two superbly preserved Jurassic fossils suggest that the ancestors of lampreys — one of two surviving lineages of the once-diverse group of jawless fishes — were fearsome, flesh-eating predators. The discovery also hints that lampreys have evolved different life strategies over time.

Consciousness is still a mystery

The scientific debate around consciousness is livelier than ever: what it is, where it comes from and whether machines can have it. Cognitive neuroscientist Liad Mudrik reviews three books that tackle these thorny questions. The authors — philosopher Daniel Dennett, geneticist Kevin Mitchell and neuroscientist Joseph LeDoux — agree that consciousness gave humans an evolutionary edge. Dennett and LeDoux argue that consciousness can exist only in biological beings, but Mitchell suggests that artificial systems could follow our evolutionary trajectory: embodiment, sensing, acting, with some motivation and learning abilities, and a drop of indeterminacy. Whether this is a good idea, writes Mudrik, is a different question.

Blogger Comments:

From the perspective of Systemic Functional Linguistic Theory, human consciousness is the construal of experience as meaning and the enactment of the self in social relations as meaning. The content of consciousness is the content plane of language, with mental processes projecting meaning and verbal processes projecting wording. Language provided human consciousness and intelligence, not the reverse.

Did dust from the Chicxulub asteroid impact kill the dinosaurs?

Dust might have been responsible for the deadly dinosaur-killing global winter that came after an asteroid slammed into Earth 66 million years ago. Climate simulations suggest that the impact kicked up enough fine particles to block out the Sun and prevent plants from photosynthesising for up to two years. The dust might have stayed in the atmosphere for some 15 years, which resulted in global temperatures dropping by as much as 15 ℃.