#oldest-living-organisms

#oldest-living-organisms

"The worst place to live on Earth is actually the safest place to live on another planet," he adds.

These findings reposition the thymus as a central regulator of immune‑ mediated aging and disease susceptibility in adulthood.

Hundreds of fossils uncovered in southern China's province of Yunnan reveal that at least some of the life-forms scientists had thought arose in the Cambrian period were alive and thriving millions of years earlier, in an era known as the Ediacaran period.

Four protrusions appear to be arranged in pairs, each consisting of two connected branches surrounding a central depression. We really don't understand what any of these features represent anatomically.

Such an event, if it transpired on Earth today, would see kilometres-thick ice sheets gouging their way from the Arctic to the Bahamas. Once-diverse ecosystems and climate zones would merge into a single, uniform condition, seemingly destined to be barren. Scientists once argued that such a 'snowball' state could never have existed on Earth since global glaciation could not be reversed. Moreover, on such a world, all life, including our own ancestors, would surely have been extinguished.

Marine fossils have been discovered on mountain ranges around the world, including the Himalayas, Andes and Rocky Mountains, which scientists say were once covered by ancient seas before being pushed upward as continents collided and mountains formed.

To capture the biological impact of this extreme environment, I used a comprehensive suite of sensors and biomarker analyses. I wore a wireless electroencephalograph (EEG) system to monitor brain activity, sleep stages and neural signatures of stress and adaptation; the Oura Ring to continuously track sleep patterns, heart-rate variability and circadian-rhythm shifts; and the glucose monitor to follow metabolic responses in real time.

For example, reader David Erickson had this on his mind: If there were aliens 66 million light-years from Earth, how big a telescope would they need to see dinosaurs? Ha! I love this question. I've thought of it myself but never worked out the mathexcept to think, Probably pretty big, which turns out to dramatically underestimate the actual answer.

At first glance, it looked like Wooller and his colleagues might have found evidence that mammoths lived in central Alaska just 2,000 years ago. But ancient DNA revealed that two "mammoth" bones actually belonged to a North Pacific right whale and a minke whale-which raised a whole new set of questions. The team's hunt for Alaska's last mammoth had turned into an epic case of mistaken identity, starring two whale species and a mid-century fossil hunter.

The lava heron also has a much thicker bill than other closely related herons - an adaptation linked to feeding among sharp volcanic rocks and hard-shelled prey. "What we learned was something that hadn't been reported before," Mendales said. The discovery underscores how much remains unknown, even in iconic places like the Galápagos, said John Dumbacher, the Academy's curator of birds and mammals and Mendales' thesis adviser.

We have little physical evidence of these interactions turning violent, however, because burials were rare and carnivores were more likely to finish off their prey. That's why the embellished burial site of a 15-year-old from 27,000 years ago is an important window into the past: the teenager's bones indicate he was mauled by a bear. The finding represents some of the first evidence of its kind.