Horse genetics, archaeology, and the beginning of riding - Science | AAAS

In archaeology, discoveries typically prompt more questions than answers. For Max Lehman, who studies Pre-Columbian art history, what we don’t know—and may never—about ancient peoples and civilizations is what makes the discipline so compelling. The ancient Mayans, for example, bedecked their elaborate temples with images on carved rock slabs, and the Aztec sun stone, or calendar stone, is a remarkable example of Mexica sculpture. Lehman’s work has one foot in the advanced civilizations of the past and another in the distant future, a time long after today’s developments around robotic and machine learning technologies. His current show Ancestral Androids at Hecho a Mano delves into a kind of future past inspired by science fiction, where modern tech and prehistoric visual culture merge in unexpected and idiosyncratic ways.

)The immortal jellyfish is capable of winding back its lifecycle to become young again. Scientists are unlocking its cellular secrets for new strategies to treat diseases of old age. The tiny translucent jellyfish Turritopsis dohrnii is surprisingly hard to kill. The marine biologist Maria Miglietta of Texas A&M University at Galveston has cut them, boiled them, starved them, overloaded their tanks with salt or plopped them in fresh water – but the nifty creatures seem to cheat death every time. Under duress, they stop in their tracks and fall to the bottom of their tank. Then something astonishing happens: the animals transform into balls of cells that bear no resemblance to the tentacled umbrella shape of adult jellyfish, known as the medusa. Within one to three days, a structure called a polyp – an early jellyfish life stage – buds off from this ball of cells and then grows into a colony, which will eventually sprout new medusae. "From one jellyfish that doesn't die, then you get this colony that can form hundreds more," Miglietta says.

Much like sushi or political humor, badly needed donor organs tend to have a pretty short shelf life. By current estimates, vital organs like a heart or a lung need to be transplanted into their waiting human recipient within six hours or less, while the most hardy of these organs, the kidney, can only remain viable for up to 36 hours before surgery. These unforgiving expirations dates have helped keep over 100,000 Americans (and counting) stuck on the waiting list for a new organ—but surgeons and medical researchers at the University of Minnesota have just reported a breakthrough that might finally get this line moving. A university team, co-led by transplant surgeon Erik Finger, says it has effectively kept pig kidneys in cold storage for months, and in one case over a year, managing to gently thaw, test, and successfully transplant these warmed-over organs into test pig recipients. The research, published as a pre-print with bioRxiv while it awaits peer review, confirmed that the once-frozen organs had both regained their color and helped the test pigs produce urine: critical signs that restored blood flow and organ function had been achieved.