Most people with ovaries go through menopause. But most animals do not. We are an outlier. So are whales. Beluga whales and narwhals are the latest known addition to the ranks of menopausal mammals, scientists reported in the journal Scientific Reports. That brings the total number of species to five: these two whales, plus killer whales, short-finned pilot whales and us. The new work suggests that menopause evolved independently in toothed whales three times: once in killer whales, once in short-finned pilot whales and once in the common ancestor of narwhals and belugas. Sam Ellis of the University of Exeter in Britain said that humans “are quite far away from whatever ancestral state we evolved in.” But these whales live in environments and groups similar to those of their ancestors millions of years ago, he said. If we understand the circumstances that led to whale menopause, perhaps we can better understand it in ourselves.
Plastics are failing test of time in artwork – where they are meant to last forever
The custodians of Neil Armstrong’s spacesuit at the National Air and Space Museum saw it coming. A marvel of human engineering, the suit is made of 21 layers of plastics: nylon, neoprene, Mylar, Dacron, Kapton and Teflon. The suit’s caretakers knew the neoprene would pose the biggest problem and were able to save Armstrong suit. But in other spacesuits, the neoprene shattered. An estimated 8,300 million metric tons of plastic have been produced to date, and most of us want much of that plastic to disappear. But in museums, where objects are meant to last forever, plastics are failing the test of time. Of all materials, plastics are proving to be one of the most challenging for conservators. Metal, stone, ceramic and paper have survived thousands of years, while plastics have existed for a little over 150 years. Georgina Rayner, a conservation scientist at Harvard Art Museums, said, “Plastics are reaching the end of their lifetimes.”
How idleness can contribute to success, at least among ants building tunnels
Ants don’t tend to get in traffic jams. They might butt heads (or antennae) momentarily, but ants have mastered the art of keeping things moving. But some just sit around doing nothing. Georgia Tech researchers found that ants are more successful when they are selectively industrious. The researchers studied groups of 30 color-coded ants digging tunnels. About 30 percent of the ants did 70 percent of the work. Some ants did very little or nothing. When the researchers removed the most hardworking ants, some of the previously less-active ants began working harder. It appears that industriousness is not an individual attribute but a defined role. It’s like a job title: heavy lifter. When excavating a tunnel, the deep end of the tunnel can get crowded. What the researchers noted is that some ants would leave without doing any work, limiting the potential for clogging up the works.