While archaeological and genetic evidence suggest that Homo sapiens originated in Africa around 200,000 years ago, it is more difficult to identify when modern human behaviors emerged. Intriguingly, recent archaeological excavations in southern Africa have shown that technological innovation, linked to the emergence of culture and modern behavior, took place relatively suddenly on more than […]
Swiss astronomer Fritz Zwicky first suggested that a distant cluster of galaxies would fall apart were it not for the gravitational pull of some invisible cosmic substance, and ever since then astronomers have been trying to find evidence for this mysterious “dark matter.” Now, an international team of scientists conducting experiments in a disused Minnesota […]
A new study is the first to yield direct data on how bacteria, fungal spores and plant material influence cloud formation at high altitudes. The researchers, led by Kimberly Prather and Kerri Pratt of the University of California at San Diego, sampled water droplet and ice crystal residues at high speeds while flying through clouds […]
Looking backward in time to an instant after the big bang, physicists at the University of Wisconsin-Madison have devised a way to unlock the hidden shapes of alternate dimensions of the universe. Their study, inPhysical Review Letters, demonstrates that the shapes of extra dimensions can be “seen” by deciphering their influence on cosmic energy released […]
Research published in Science is the first in the world to demonstrate a genetic gradient – or path of gradually changing genetic traits – between two distinct species that have been isolated by distance. The research challenges the prevailing theory among evolutionary biologists that species evolve only when separated by a geographical barrier. The research […]
The world’s largest mass extinction occurred some 250 million years ago, wiping out 90 percent of marine life. While some scientists have speculated that an asteroid impact might be to blame, the cause of this great dying has remained a mystery. But a new study published inGeology provides evidence that the cause of the extinction […]
NASA, Canadian, and European satellites have observed worrying increases in the flow of glaciers into the open ocean, following the breakup of ice shelves in Antarctica. Two reports appearing in Geophysical Research Lettersused different techniques to arrive at similar results, suggesting climate warming can lead to rapid rises in sea level. Researchers from NASA’s Jet […]
Researchers from the Mayo Clinic found they could isolate and culture nanoparticles from filtered homogenates of diseased calcified human cardiovascular tissue. These cultured nano-sized particles were recognized by a DNA-specific dye, incorporated radiolabeled uridine, and after decalcification, appeared via electron microscopy to contain cell walls. The peer-reviewed paper, entitled “Evidence of Nanobacterial-like Structures in Human […]
An team of physicists has provided the best evidence to date of the existence of a new form of atomic matter, dubbed the “pentaquark.” The research team confirmed the existence of pentaquarks by using a different approach that greatly increased the rate of detection compared to previous experiments. The results are published in the journal […]
Elderly women are receiving a large number of mammograms and Pap smears with limited scientific evidence of advantage, researchers from Duke University Medical Center have reported. Such widespread, general screening in women over age 70 is a misdirected use of health-care funds that might be better utilized in higher-risk, underserved women, they said. “Cancer screening […]
