Octopuses as team leaders for fish; the universe confuses the standard model; extremely old cheese

This week, biologists found a mysterious group of orcas near Chile; Hubble has spotted a black hole jet that causes stars to erupt along its path; and researchers explained the mysterious craters that began appearing in Siberian permafrost in the 2010s. But you’re probably here for the cheese, cosmology, and octopuses, so here goes:

Eight arms to hit you

Octopuses tend to be solitary creatures, like Boo Radley, living and hunting alone before eventually mating, developing a strange brain deterioration similar to Alzheimer’s disease, and then dying. But sometimes they interact socially and even cooperatively in interspecific networks, hunting with groups of fish.

Researchers from the University of Konstanz conducted an underwater field observation during which they used three-dimensional field tracking and collected 100 hours of images of Octopus cyanea individuals during collaborative hunts with groups of several species of fish, discovering hidden leadership mechanisms and complex mechanisms. social dynamics.

The groups of reconnoitering fish provided an extended sensory network for the octopus, which was better able to locate and identify its prey. In all cases observed, the octopus was the de facto leader of the group, eating its prey before the fish and inflicting corporal punishment on insufficiently docile subordinate fish.

Previous observations of similar octopus and fish hunting parties raised questions about the group’s leadership and exploitation: were the fish exploiting the octopus easier to catch prey? But the researchers found that, among species in hunting groups, the octopus was the main interspecific regulator of the group, striking exploitative fish partners with a tentacle to move them to the outer edge of the group.

Universe going against the grain for physicists: Drop Dead

If you’re a fan of things that defy prediction once observed directly, the universe will truly blow your mind. For years, the standard model of physics has predicted things like the expansion rate of the universe, the age of the universe, and the likely date of birth of the first stars and galaxies. to make observations, the universe says “haha, no”.

This week, a multi-institutional group of astronomers published a paper suggesting that it may be time for new physics to reconcile recent observations acquired through the Dark Energy Spectroscopic Instrument regarding neutrinos.

DESI creates the deepest and most accurate map of the universe, providing baryonic acoustic oscillation measurements that, in combination with cosmic microwave background measurements, allow physicists to calculate the absolute mass scale of the neutrino. Neutrinos, among the most abundant particles in the universe, are extremely difficult to study, and by determining their mass scale, physicists can discover how matter has grouped together throughout cosmic evolution.

However, while cosmologists expected to see an inhibition of matter clustering, as predicted by the Standard Model, actual DESI observations revealed increased clustering. “Explaining this improvement could indicate a problem with the measurements, or require new physics not included in the standard model of particle physics and cosmology,” says Joel Meyers, associate professor of physics at Southern Methodist University.

Old cheese identified

Chinese researchers extracted and analyzed DNA from cheese samples contained in ancient snack packets discovered 20 years ago among mummies in the Tarim Basin in northwest China.

The mummies and cheese date from around 3,300 to 3,600 years ago. Their analysis revealed cow and goat DNA. Microorganisms comprising a white substance confirmed that it was kefir cheese, containing Lactobacillus kefiranofaciens and Pichia kudriavzevii, both constituents of modern kefir grains. Researchers report that the microorganisms are most closely related to modern Tibetan kefir.

“Our observation suggests that kefir culture has been maintained in northwest China’s Xinjiang region since the Bronze Age,” said Qiaomei Fu, a researcher at the Institute of Paleontology and Paleoanthropology of China. Vertebrates of the Chinese Academy of Sciences.

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