Science

[:es]In the past 2000 years, Earth has drifted in and out of extended periods of warmer- and cooler-than-normal climate, including the so-called Medieval Warm Period and the Little Ice Age. Scientists long thought that during these hot and cold spells, temperatures rose and fell in sync across the globe. In fact, Earth warmed and cooled…

[:es]Dark matter, the mysterious substance that makes up most of the mass of the universe, has proved notoriously hard to detect. But scientists have now proposed a surprising new sensor: human flesh.[:]

[:es]Looking a squid in the eye is eerily like looking in a mirror. Squids, octopuses, and other cephalopods are on a very different part of the tree of life from vertebrates. But both have evolved sophisticated peepers that rely on a lens to focus light and provide excellent vision. This independent evolution of such complexity…

[:es]A collaboration of Chinese and Japanese astrophysicists has reported the highest energy photons ever seen: gamma rays with energies up to 450 trillion electron volts (TeV).[:]

[:es]As a schoolgirl in Israel, Michal Feldman learned that the ancient Philistines, who lived between present-day Tel Aviv and Gaza during the Iron Age, were «the bad guys.» In the Bible, they were the archenemies of the Israelites, who fought Samson’s armies and sent Goliath into battle against David. «Philistine» is still a slur for…

[:es]The idea that chemical tags on genes can affect their expression without altering the DNA sequence, once surprising, is the stuff of textbooks. The phenomenon, epigenetics, has now come to messenger RNA (mRNA), the molecule that carries genetic information from DNA to a cell’s proteinmaking factories. At a conference here last month, researchers discussed evidence…

[:es]Fast radio bursts (FRBs)—intense blasts of radio waves from distant galaxies—have perplexed astronomers since they were first detected a dozen years ago. The bursts are so brief, only about one-thousandth of a second, that it’s usually impossible to pinpoint their origins—or their cause, be it a supernova, a neutron star, or something even more exotic.[:]

[:es]The perpetual shortage of human organs for transplant has researchers turning to farm animals. Several biotech companies are genetically engineering pigs to make their organs more compatible with the human body. But some scientists are pursuing a different solution: growing fully human organs in pigs, sheep, or other animals, which could then be harvested for…

[:es]In what may be a cautionary tale for citizen scientists trying to save North America’s iconic monarch butterfly, new research has found that butterflies raised in captivity are sometimes unable to migrate—some as a result of missing genes and others for want of the right environmental cues.[:]