Beet breakthrough could apply off the dinner table
As the seasons change, a riot of red shows up in the world around us, showcasing some of the most vivid hues that plant biochemistry can create. The red pigments in maple leaves, called anthocyanins, are the same kind that light up the cranberries you might cook for a Thanksgiving feast or the ruddy apples you’d put in a pie.
But beets have evolved another way of being red. In a paper published in New Phytologist, biologists recently reported that they have discovered a key step in the evolution of this process, which not only helps explain the origins of a brilliant natural color but also could have uses far beyond brightening your dinner table.
The pigments that give red beets their incandescent hue are called betalains. They’re made using an amino acid called tyrosine, the starting material for thousands of compounds made by plants.
Plants modify tyrosine by adding other molecules to create an enormous array of useful substances. This is how morphine is made in the opium poppy, and mescaline in cactuses. Intrigued by this process, Hiroshi Maeda, a professor at the University of Wisconsin and senior author on the paper, collaborated with beet experts to study how the plants make betalains from tyrosine.
A tyrosine-making enzyme, which in most plants gets turned off after a certain amount is made, stays on longer in beets and some related species, producing an overload of the amino acid. This, it turns out, is likely the pivotal change that gave beets the starting material they would need to develop their special red.
At first, there would have been no use for the extra tyrosine. Eventually, however, some plants started to find a way to make something out of it.
At a later stage in their evolutionary history, red beets developed enzymes that use the extra tyrosine to create the rich scarlet we know so well. Scientists do not know exactly why this ability helped beets thrive. While some research suggests betalains may help plants weather stress, perhaps their primary usefulness is that humans — and presumably other creatures, like pollinators — love the way they look, Maeda said.
The discovery of an enzyme that increases the tyrosine used to make morphine could have effects on how that drug and others are made. The team is working to see whether they can boost tyrosine levels in other plants by giving them the enzyme found in beets.
Chimps share personality traits with humans
In the late 1950s and early 1960s, Jane Goodall started attributing personalities to the chimpanzees she followed in Gombe National Park in what is now Tanzania. In her descriptions, some were more playful or aggressive, affectionate or nurturing.
Many scientists at the time were horrified, she recalled. Considered an amateur — she didn’t yet have her Ph.D. — they contended she was inventing personality traits for animals.
Goodall, now 83, said in a phone interview from her home in England that scientists thought “I was guilty of the worst kind of anthropomorphism.”
But time has borne out her insights. Chimpanzees in the wild have personalities similar to those in captivity, and both strongly overlap with traits that are familiar in humans, a new study published in Scientific Data confirms.
The new examination of chimpanzees at Gombe updates personality research conducted on 24 animals in 1973 to include more than 100 additional chimps that were evaluated a few years ago. The animals were individually assessed by graduate students in the earlier study, and in the latest by Tanzanian field assistants, on personality traits like agreeableness, extroversion, depression, aggression and self-control.
Researchers used different questionnaires to assess the chimps’ traits in the two studies, but most of the personality types were consistent across the two studies.
These traits seen among wild chimps matched ones seen among captive animals, the study found, and are similar to those described in people.
Goodall, who is promoting a new documentary, “Jane,” about those early days of her research, said she’s not surprised. She knew from childhood experiences with guinea pigs, tortoises and her favorite dog, Rusty, that animals have personalities that are quite familiar.
“I honestly don’t think you can be close to any animals and not realize their very vivid personalities,” she said.
Oysters probably wish we would clam up
Like anyone with rowdy neighbors, oysters may be feeling stressed thanks to the growing problem of underwater noise pollution and are trying to filter out the racket.
New research published Oct. 25 in PLoS One reveals that oysters will close their shells when exposed to noises along a range of frequencies that includes the sounds emitted by known noise polluters like cargo ships and underwater oil exploration.
In oysters, closed shells are an indicator of distress. Under optimal conditions, bivalve mollusks will keep their shells open, and they are thought to shut them only when feeling stressed or threatened. Clamping their shells to screen out noise pollution or other artificial irritants could prevent oysters from perceiving important biological cues, said the authors of the study.
Oysters “must be able to hear breaking waves and water currents,” which could trigger their biological rhythms, said Jean-Charles Massabuau, research director at the French National Center for Scientific Research and an author of the study. “To hear the current arriving could prepare them for eating and digesting, possibly as when we hear and smell that somebody is preparing dinner.”
Not being able to detect other natural events, like rainfall or thunderstorms, could also prevent them from knowing when it is time to spawn, Massabuau said.
Noise pollution has been a growing problem in the oceans and other large bodies of water for decades. Commercial shipping, oil exploration, recreation and even scientific research are all raising the decibel levels within marine habitats, adding to naturally occurring rackets like earthquakes, crashing waves and tidal changes. And because sound travels farther in water than air, each new source has an outsize effect.
Such noise has already been shown to have adverse effects in fish, whales and other marine mammals as well as cephalopods. But little is known about its effects on most invertebrates.
“We must think that noise pollution could affect many more animals” than we thought, Massabuau said.
Skull may be earliest known tsunami victim
In 1929, an Australian geologist named Paul Hossfeld was investigating the northern coast of Papua New Guinea for petroleum. He found bone fragments embedded in a creek bank about 7 miles inland and about 170 feet above sea level.
At first, Hossfeld believed that the specimen was from the skull of Homo erectus, an extinct relative of modern humans. Later analysis would show it belonged to a modern human who lived about 6,000 years ago.
Now recent research suggests the remains — known as the Aitape skull — could be something more: the earliest known victim of a tsunami.
The findings, published Oct. 25 in the journal PLoS One, may offer useful historical context for how ancient humans living along the Pacific Ocean’s coasts faced fierce natural hazards.
“Here we start to see human interaction with some nasty earthquakes and tsunamis,” said James Goff, a retired geologist at the University of New South Wales Sydney and author of the study.
Papua New Guinea occupies the eastern half of a large, bountiful island just north of Australia (the western side is part of Indonesia). In 1998, after decades of relative geological quiet, a devastating tsunami rocked the country, killing more than 2,000 people.
Following the tsunami, Goff and some colleagues went to the country to assess the damage. The visit helped spark his interest in investigating whether there was a link between ancient tsunamis and the Aitape skull.
Hossfeld had left detailed notes about where he had found the skull, which helped guide Goff and his team as they collected samples from the same sediment layer at a nearby river-cut cliff. Back at the lab, they performed geochemical analysis to determine whether the sediment level had been deposited by a tsunami 6,000 years ago.
They found that the sediment collected from the skull site contained fossilized deep sea diatoms. These microscopic organisms were a telltale sign that ocean water had drowned the area at some point.
The geochemistry analysis supported the authors’ conclusions, another scientist not involved in the study said, although he added that it did not contribute much to our understanding of the dangers posed by tsunamis.
“It is more of an intriguing geological snapshot of an ancient catastrophic event,” said Iain Stewart, a geologist at the University of Plymouth in England.
— New York Times News Service