Mutant, parasitic impostor queens lurk in ant colonies. Is a ‘supergene’ to blame?
News and notes about science
To thrive, ant colonies rely on everyone pulling their weight. For raider ants, this means diligent scouts track down other nests, then direct hundreds of savage foragers to attack. They return with pincers gripping dead young ants to feed the settlement. Clones are produced. The colony thrives.
But raider ants are among about 50 species plagued by impostors: parasitic ants that resemble queens. They greedily eat the colony’s food, but shirk their own foraging duties, and can only hatch more parasites instead of workers when they reproduce. How the fake queens emerge has long puzzled scientists.
“It’s a real mystery how these things arrive,” said Ken Ross, an evolutionary geneticist at the University of Georgia.
A new study offers a solution: A “supergene” that mutates rapidly, between a single generation of raider ants, is likely responsible for the royal impostors. The discovery arose from an observation in a lab at Rockefeller University, where Waring Trible and his graduate adviser, Daniel Kronauer, studied raider ants.
“These weird, mutant queens just showed up,” said Trible, now at Harvard University, who led the study. Isolated from the rest of the colony in a petri dish, it was plain to see: Several of the ants had wings.
It’s a typical trait for queens in many species, but it was odd because raider ants don’t normally have wings — or queens.
“Seeing these winged females was very shocking, very striking, right away,” Trible said. “I immediately thought it was something genetic.”
He set about sorting through the 10,000-ant colony. His needle-in-a-haystack search found 14 impostor queens, which he then let reproduce. Their progeny were always the winged parasites.
Trible and his colleagues devoted years to studying the mutants and trying to figure out their origin. Another geneticist, Sean Mckenzie, compiled the regular ants’ whole genome, while Trible analyzed the mutants’ genome. Comparing the genomes let Trible see where the regular and mutant ants differed.
— Rebecca Dzombak
Dunk was chunky, but still deadly
With a bite that could split a shark in two, Dunkleosteus was one of Earth’s earliest apex predators, terrorizing subtropical seas 360 million years ago. By some estimates, the monster fish measured as long as a school bus.
However, a new study is taking a sizable bite out of Dunkleosteus’ estimated size. Russell Engelman, a paleontologist pursuing his doctorate at Case Western Reserve University, recently compared the proportions of Dunkleosteus’ armor-clad head with the skull sizes of hundreds of living and fossil fish. In the journal Diversity, Engelman concluded that these ancient fish maxed out at only 13 feet and were shaped more like stocky tuna than svelte sharks.
For the study, Engelman examined several Dunkleosteus terrelli specimens at the Cleveland Museum of Natural History. Many of these fossils were discovered nearby in cliffs along the Rocky River. But little research had been done on Dunkleosteus’ size, and past measurements seemed fishy to Engelman.
According to Engelman, head length is a reliable proxy for body size in fish: Short fish species generally have shorter heads, and long fish species longer heads. He focused on the region between a fish’s eye and the back of its head.
— Jack Tamisiea
Stuck in neutral
In an impressive feat, China landed its Zhurong rover on Mars in May 2021, joining NASA in exploring the red planet’s surface. But China has not provided recent updates, and images from orbit show the vehicle fixed in the same place. Something seems to have gone wrong.
Zhurong went into hibernation last May, as planned, to conserve energy with the onset of winter. In December, it was supposed to revive when the Martian days became longer and warmer.
While no news has come from China, NASA’S Mars Reconnaissance Orbiter periodically passes overhead while studying the Martian surface. Its images show that Zhurong has not moved from last September to February this year.
The NASA orbiter has documented other mishaps. Schiaparelli, a European Space Agency spacecraft, was sent to Mars to test landing technologies. But, arriving in 2016, it crashed at 330 mph, leaving a new scar.
The spacecraft has also spotted signs of success, like the parachute that helped slow NASA’S Perseverance rover en route to a safe landing in 2021. The images help engineers analyze the performance of their designs.
NASA also has eyes on the moon’s surface, using the Lunar Reconnaissance Orbiter.
A number of spacecraft have attempted — and failed — to land on the moon in recent years. An Israeli spacecraft, Beresheet, came close, but its engine was inadvertently shut off, and it crashed.
Indeed, in the 21st century so far, only China has successfully put spacecraft on the moon in one piece. And NASA’S observer in orbit has been keeping watch on those. — Kenneth Chang
Who’s using vocal fry in the ocean?
Dolphins, pilot whales and sperm whales use echolocation clicks to hunt and subdue their prey. But the animals, known as toothed whales, also produce other sounds for social communication, like grunts and highpitched whistles. For decades, scientists speculated that something in the nasal cavity was responsible for this range of sounds, but the mechanics were unclear.
Now, researchers have uncovered how structures in the nose, called phonic lips, allow toothed whales to produce sounds at different registers, similar to the way the human voice functions, all while conserving air deep beneath the ocean’s surface. And the animals use the vocal fry register for echolocation. Yes, that vocal fryyyy. The work was published in the journal Science recently.
Coen P.H. Elemans, a biologist in Denmark, and colleagues inserted endoscopes into the nasal cavities of trained Atlantic bottlenose dolphins and harbor porpoises to get high-speed footage during sound production. They found that sound was indeed being produced in the nose. But to confirm that the phonic lips were involved they created an experimental setup with deceased (beached or bycatch) harbor porpoises, filming the phonic lips as air was pushed through the nasal complex. They saw that the phonic lips would briefly separate and then collide back together, causing a tissue vibration that would release sound into the surrounding water.
— Sam Jones