Genetic record for domestic dogs pushed back by 5,000 years

Researchers have identified the earliest known dog genomes, which push the genetic record for dogs back by more than 5,000 years. They recovered these genomes from remains of between 14,000 and 16,000 years old found at archaeological sites that span Europe and the Middle East. The team also identified an early domestic dog population (Canis lupus familiaris) that spanned Western Eurasia and was kept by diverse human hunter-gatherer groups. The findings show that dogs were exported and exchanged by various human groups, underlying dogs’ importance to early communities with different ways of living.

‘Nuclear clocks’ tick closer to reality

After decades of research, physicists are confident that the first tick of a ‘nuclear clock’ is imminent. This device would keep time by measuring energy transitions in the radioactive isotope thorium-229, which could make it the most precise clock on the planet. Last week, scientists at the American Physical Society Global Physics Summit compared notes on their progress toward assembling the clock’s components, including efforts to build a laser that can make the clock ‘tick’.

Debate explodes over age of key South American archæological site

An archæological site that overturned the history of humans in South America might just do it again. Radiocarbon dating pegged artefacts from Monte Verde, in southern Chile, at 14,500 years old — suggesting that people arrived along the continent’s coast, before the ‘Clovis people’ travelled through an ice-free corridor in North America. Not so, says a new study: those artefacts were mis-dated and originated no more than 8,200 years ago.

New psychedelic fungus rewrites origins of magic mushrooms

A newly described species of ‘magic mushroom’ could upend a popular theory of when psychedelic fungi popped up around the world. Researchers had thought that the magic mushrooms that grow in southern Africa were Psilocybe cubensis, the same species that grows in the Americas. However, closer inspection revealed that the African mushrooms are a separate species, now named Psilocybe ochraceocentrata, and last shared a common ancestor with P. cubensis approximately 1.5 million years ago. These findings scupper the hypothesis that P. cubensis was inadvertently introduced to the Americas by 16th-century settlers, but the research offers no clues as to its origins across the Atlantic.

‘Virtual cell’ captures most-basic process of life: bacterial division

Researchers have created a 3D simulation that models DNA replication, cell division and nearly every chemical reaction in a living bacterial cell. This ‘virtual cell’ isn’t a totally faithful recreation of the organism — the team used placeholders for some genes with unknown functions, for example. But it could help researchers understand how the mix of molecules in a cell gives rise to actual life, says computational biophysicist and study co-author Zane Thornburg.

First ‘half Möbius’ carbon chain could unlock strange physical properties

Chemists have synthesised a new type of carbon-based molecule with an unprecedented twist in its structure. The team calls the looped molecule a ‘half-Möbius’, inspired by the Möbius strip — a twisted loop with one continuous surface. In the half-Möbius molecule, the chain of atoms is twisted by 90° to make the loop, instead of the full 180º seen in a standard Möbius strip. The molecule can exist in two versions depending on whether it twists left or right. The versions differ in chirality, meaning that they are mirror images of each other.

Galileo’s handwritten notes found in ancient astronomy text

Around 1590, Galileo Galilei filled the margins of a copy of Ptolemy’s The Almagest with his musings — and they have just been rediscovered. Historian Ivan Malara recognized the storied astronomer’s handwriting in the book, which was held in a library in Florence. The contents, including a transcribed psalm, could shed light on the intellectual origins of Galileo’s groundbreaking view of the Solar System.

Earth’s oldest crystals suggest an early start for plate tectonics

Chemical evidence from ancient crystals suggests that Earth’s tectonic plates had already started moving 3.3 billion years ago, relatively early in our planet’s history. By analysing zircon crystals recovered from Western Australia — the oldest-known fragments of Earth rocks — researchers also found that the ancient Earth could have contained more oxygen, and possibly more water, than suspected. The movement of tectonic plates and higher-than-expected oxygen levels suggest that conditions on Earth could have been more conducive to life during this period than previously thought.

Why ‘quantum proteins’ could be the next big thing in biology

Researchers have found ways to turn fluorescent-protein labels — coloured tags used to track the inner workings of a cell — into qubits, the basic units of quantum information. In this form, they can be used as quantum sensors, which could reveal cellular activity and detect molecules associated with disease with unprecedented detail. The development of protein quantum sensors is at an early stage, but could progress quickly, experts say: the approach has been shown to work in principle and the necessary equipment is standard fare.

Neanderthal dad, Sapiens mum: study reveals ancient procreation pattern

Genetic evidence from three Neanderthal (Homo neanderthalensis) specimens suggests female Homo sapiens and male Neanderthals mated more often than did male H. sapiens and female Neanderthals — an imbalance that helped to shape the human genome. Researchers found that the X chromosomes from the specimens had, on average, 62% more sapiens DNA than non-sex chromosomes, which could be explained by a bias in mating. The bias could have been down to mate availability or cultural sanctions for certain combinations, says population geneticist Sohini Ramachandran.

Blogger Comments:

Here's a hint for these geneticists from anthropology: In tribal warfare, the victors kill the men and absorb the women into their tribe.