Ecology and evolution – Claire Ainsworth

Electricity helps fish take flight

Posted on April 30, 2021 by Claire

New Scientist, 16th March 2021

https://collections.carli.illinois.edu/cdm/singleitem/collection/nby_teich/id/428968

FLYING fish may have taken to the air when evolution tweaked electrical signals that control the size of their fins. This discovery suggests the existence of a previously unknown mechanism by which animals can change the relative size of specific body parts.

“How organs and tissues know when to stop growing at a certain size and stay there is a major mystery,” says Jake Daane at Northeastern University in Massachusetts. This scaling, known as allometry, is also a key driver of evolutionary change. The stunning variation in the fins of bony fish are a classic example, from the billowing veils of the tropical betta fish to the stumpy appendages of a mackerel.

Most dramatic of all are the wings of flying fish, which allow some species to leap from the sea and glide for 400 metres, the length of eight Olympic swimming pools. This helps fish evade underwater predators, a tactic so successful that it has evolved independently several times.

In comparisons of the genomes of nine species of flying fish and some non-flying relatives, Daane and his colleagues spotted genetic changes consistently associated with gliding, and uncovered sections of the genome being conserved by natural selection…

Fantastic beasts

Posted on November 29, 2019 by Claire

Creatures with incredible superpowers including the ability to survive being frozen and suffocated and resist ageing could revolutionise medicine, space travel and even war

IT HAS been holding its breath for months. Locked under an airless seal of ice, the extraordinary animal waits. At last, the warmth of spring brings relief. Claws twitch, a brain rouses and a beak pushes through the lake’s thawing slush to take a lungful of air. Incredibly, the western painted turtle is none the worse for having endured the kind of oxygen starvation that would normally kill a human in minutes.

At more than 100 days, the turtle holds the record among four-legged animals for surviving without oxygen. It is by no means the only creature to boast jaw-dropping talents. The constellation of powers found across the animal kingdom seems fantastical: the ability to almost completely regenerate innards, to dodge ageing or cancer, to slumber immobile for months without bone or muscle wasting, to slow biological time or even enter a state of suspended animation that can withstand all manner of trials, from freezing to bombardment with gamma rays.

Almost as implausible-sounding is the idea that humans might be able to borrow some of these abilities. Yet the discovery that these powers are underpinned by genes and biological processes we too possess makes this a distinct possibility. Some potential applications – such as putting people into a sort of hibernation for space travel – remain distant goals. But others – including keeping transplant organs fresh without cooling and developing new tactics to tackle cancer and ageing – seem feasible. In fact, the US has launched a research project to exploit animal powers that could help injured soldiers on the battlefield (see “Stop the clock”).

Image: Karunakar Rayker from India [CC BY 2.0], via Wikimedia Commons

Penguin archaeology

Posted on November 29, 2019 by Claire

It’s amazing what you can discover about a penguin when you rummage through its waste, finds Claire Ainsworth

AS EUREKA moments go, it wasn’t the most dignified. David Lambert lost his footing and face-planted into a patch of expired penguins. He had been taking blood samples from living birds at a nesting site, but as he scrambled to his feet, it dawned on him that he was standing on a mass grave. “In those penguin colonies you are literally walking on matted bodies,” he says. “When you scratch around, you just find bones after bones after bones.”

Lambert’s insight was to realise that he had stumbled on a deep-frozen archive. The remains belonged to Adélie penguins, which return to the same spots to nest year after year, often for centuries. And this was Antarctica, the coldest, driest place on the planet, offering the ideal conditions for preserving DNA. By digging into this repository, he could unearth the story of Adélies and their evolution.

That’s not all. This frozen treasure trove has the potential to give new insights into the past, present and future of the Antarctic, too. This promise is what’s drawing scientists like Lambert to the bottom of the world, braving seat-of-your-pants helicopter rides and vicious polar storms to sift through layers of mummified penguin bodies and reeking semi-fossilised bird faeces. And what they are finding has exceeded expectations. The preserved Adélie remains are providing clues about past climate conditions, changes in ice shelves and sea ice, the impact of historical human activities such as whaling, and even the mechanism of evolution itself. Not bad for a short, stout bird with a reputation for belligerent curiosity.

Image: Jerzy Strzelecki [CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)]