A new microscope is giving researchers an unprecedented view of how mammals are built, cell by cell. Light sheet microscopes use ultrathin laser beams to illuminate sections of a specimen while cameras record those lit-up sections. Previous iterations of the device have captured detailed portraits of living zebra fish and fruit fly embryos as they […]

For the first time, researchers have created mice with two dads. No female contributed to the rodents’ genetic makeup. This unusual reproduction took place in a lab where researchers gathered fathers’ stem cells, and used them to produce embryos that were implanted into surrogate mothers. The technique required scientists to edit the animals’ genes in […]

A faint, fleeting supernova may be the key to understanding how neutron star duos are born. Astronomers have spotted what seems to be an ultrastripped supernova: a massive star in its death throes after its outer layers of gas have been siphoned off slowly by a compact companion such as a neutron star or black […]

Yeast intentionally stuffed with bacteria may teach scientists something about the origins of cells’ powerhouses. Cellular power-generating organelles, called mitochondria, are thought to have once been bacteria captured by archaea, single-celled microbes that are one of the earliest forms of life. Now, almost all eukaryotic cells (cells with a nucleus) contain mitochondria. At first, the […]

Puny particles have given scientists a glimpse inside the Earth. For the first time, physicists have measured the planet’s mass using neutrinos, minuscule subatomic particles that can pass straight through the entire planet. Researchers also used the particles to probe the Earth’s innards, studying how the planet’s density varies from crust to core. Typically, scientists […]

The Gray Fossil Site, a sinkhole in northeastern Tennessee, is full of prehistoric treasures. Between 7 million and 4.5 million years ago, rhinoceroses, saber-toothed cats and other creatures, even red pandas, perished here by the edge of a pond. But that bounty of fossils pales next to the site’s biggest find: a mastodon’s skeleton, nearly […]

Scientists have unraveled some of the mechanical mysteries behind the pokes and prods of cacti. Like porcupine quills, the barbed spines of some cactus species easily puncture their prey but are difficult to remove. Smooth spines, however, puncture flesh easily and are removed just as readily, researchers report in the Nov. 21 Proceedings of the […]

VANCOUVER — Adult female mosquitoes could be surfing air currents high above the West African Sahel. This traffic, at least 40 meters up, might be troubling news for efforts to control malaria. Traps attached to balloons flown over villages in Mali caught close to 3,000 mosquitoes at heights between 40 and 290 meters above the […]

A Chinese scientist’s surprise announcement on the eve of an international human gene-editing summit that he has already created the world’s first gene-edited babies has led to swift condemnation. Jiankui He is expected to discuss his work November 28 in Hong Kong at the second International Summit on Human Genome Editing. But in an interview […]

A massive series of volcanic eruptions in Earth’s distant past left ocean creatures gasping for breath. Greenhouse gases emitted by the volcanoes dramatically lowered oxygen levels in the oceans, a deadly scenario that may have been the main culprit in the Great Dying, researchers report. Earth scientist Justin Penn of the University of Washington in […]