Feb 10, 2025 06:54 PM
(This post was last modified: Feb 10, 2025 09:59 PM by C C.)
The mysterious network of plants may be nastier than we thought
https://www.sciencealert.com/the-mysteri...we-thought
EXCERPTS: . . . Plants can send and receive chemical signals, aided by the mycorrhizal fungal networks that connect their roots below ground. This phenomenon was described by forest ecologist Suzanne Simard and her colleagues nearly three decades ago, and is now known affectionately as the 'wood-wide web'.
When a caterpillar takes a bite out of a tomato leaf, for instance, scientists have observed that a neighboring plant, connected to the first by a mycorrhizal network, will ramp up production of the bug-repellent enzymes in its genetic arsenal.
It's easy to assume the plant under attack is actively emitting a warning signal to its neighbors, like a horror movie character stuck in a trap: "forget about me – save yourselves!" And that's how many have interpreted this phenomenon.
But a trio of biologists from the University of Oxford and the Vrije Universiteit Amsterdam (VU) suspect this view of plant communications may be a little too rosy.
"There is no dispute that information is transferred. Organisms are constantly detecting and processing information about their environment," says VU evolutionary biologist Toby Kiers. "The question is whether plants are actively sending signals to warn each other. Maybe just like gossiping neighbors, one plant is simply eavesdropping on the other."
[...] the plant issuing that signal doesn't necessarily benefit from this interaction. The team's modeling showed that giving its neighbors such an advantage could actually do the plant more harm than good. Evolutionary pressures in their modeling, like competition with neighboring plants for nutrients and sunlight, actually selected against such an altruistic trait.
"Indeed, selection is often more likely to push plant behavior in the opposite direction – with plants signaling dishonestly about an attack that has not occurred, or suppressing a cue that they have been attacked," the authors write.
[...] The new research was published in Proceedings of the National Academy of Sciences (PNAS)... (MORE - missing details)
Boosting evolution: How humans unintentionally altered the skulls of pigs
https://pressemitteilungen.pr.uni-halle....pm_id=5859
PRESS RELEASE: Short snouts and a flat profile - within a span of 100 years, humans have significantly changed the shape of the skulls of German domestic pigs. According to a team from Martin Luther University Halle-Wittenberg (MLU), this is likely down to new breeding practices introduced at the beginning of the 20th century.
Their findings have been published in the journal Royal Society Open Science. The researchers analysed 3D scans of 135 skulls of wild boars and domestic pigs from the early 20th and 21st centuries. Surprisingly, the same effects can even be observed in species that were kept separately.
Humans have been keeping pigs as livestock for several centuries. During this time, the animals have changed considerably. For example, they have become larger and have lost their black and brown bristles and darker skin tone.
"The demand for pork in Germany increased significantly at the beginning of the 20th century and breeders were encouraged to optimise their animals. They needed them to grow quickly, provide good meat, and be fertile," explains Dr Renate Schafberg, Head of the Domestic Animal Collection at MLU.
For the current study, she and Dr Ashleigh Haruda from Oxford University analysed 135 skulls from three different breeds: Deutsches Edelschwein, Deutsches Landschwein - and wild boars, who acted as a control group. The skulls were either from the early 20th century or were only a few years old.
The two domestic pig breeds exhibited significant changes: the animals’ snouts became significantly shorter and flatter, while the skulls of the more contemporary animals no longer had a slightly outwardly curved forehead. "We didn’t expect such pronounced differences to appear within a span of only 100 years," says Schafberg.
Remarkably, both breeds of domestic pig underwent the same changes, despite being kept separately. "These changes occurred even though breeders did not select the animals specifically for their skull shape, as this trait was not important for breeding. Instead, the changes appear to be an unintended by-product of selecting the desired traits," says Schafberg.
Another reason for the alterations could be related to changes in the animals’ diet. Nutrition is known to influence the growth and development of animals. Today, pigs are mainly fed pellets that are high in protein. In contrast, the skulls of wild boars, who remain omnivores, have not undergone such changes.
The findings demonstrate how strongly humans can influence the evolution of animals. "Charles Darwin assumed that long periods of time - millions of years - are required for major changes to take place. Our work is further proof that humans can greatly accelerate this process through selective breeding," says co-author Dr Frank Steinheimer, Head of the Central Repository of Natural Science Collections at MLU.
https://www.sciencealert.com/the-mysteri...we-thought
EXCERPTS: . . . Plants can send and receive chemical signals, aided by the mycorrhizal fungal networks that connect their roots below ground. This phenomenon was described by forest ecologist Suzanne Simard and her colleagues nearly three decades ago, and is now known affectionately as the 'wood-wide web'.
When a caterpillar takes a bite out of a tomato leaf, for instance, scientists have observed that a neighboring plant, connected to the first by a mycorrhizal network, will ramp up production of the bug-repellent enzymes in its genetic arsenal.
It's easy to assume the plant under attack is actively emitting a warning signal to its neighbors, like a horror movie character stuck in a trap: "forget about me – save yourselves!" And that's how many have interpreted this phenomenon.
But a trio of biologists from the University of Oxford and the Vrije Universiteit Amsterdam (VU) suspect this view of plant communications may be a little too rosy.
"There is no dispute that information is transferred. Organisms are constantly detecting and processing information about their environment," says VU evolutionary biologist Toby Kiers. "The question is whether plants are actively sending signals to warn each other. Maybe just like gossiping neighbors, one plant is simply eavesdropping on the other."
[...] the plant issuing that signal doesn't necessarily benefit from this interaction. The team's modeling showed that giving its neighbors such an advantage could actually do the plant more harm than good. Evolutionary pressures in their modeling, like competition with neighboring plants for nutrients and sunlight, actually selected against such an altruistic trait.
"Indeed, selection is often more likely to push plant behavior in the opposite direction – with plants signaling dishonestly about an attack that has not occurred, or suppressing a cue that they have been attacked," the authors write.
[...] The new research was published in Proceedings of the National Academy of Sciences (PNAS)... (MORE - missing details)
Boosting evolution: How humans unintentionally altered the skulls of pigs
https://pressemitteilungen.pr.uni-halle....pm_id=5859
PRESS RELEASE: Short snouts and a flat profile - within a span of 100 years, humans have significantly changed the shape of the skulls of German domestic pigs. According to a team from Martin Luther University Halle-Wittenberg (MLU), this is likely down to new breeding practices introduced at the beginning of the 20th century.
Their findings have been published in the journal Royal Society Open Science. The researchers analysed 3D scans of 135 skulls of wild boars and domestic pigs from the early 20th and 21st centuries. Surprisingly, the same effects can even be observed in species that were kept separately.
Humans have been keeping pigs as livestock for several centuries. During this time, the animals have changed considerably. For example, they have become larger and have lost their black and brown bristles and darker skin tone.
"The demand for pork in Germany increased significantly at the beginning of the 20th century and breeders were encouraged to optimise their animals. They needed them to grow quickly, provide good meat, and be fertile," explains Dr Renate Schafberg, Head of the Domestic Animal Collection at MLU.
For the current study, she and Dr Ashleigh Haruda from Oxford University analysed 135 skulls from three different breeds: Deutsches Edelschwein, Deutsches Landschwein - and wild boars, who acted as a control group. The skulls were either from the early 20th century or were only a few years old.
The two domestic pig breeds exhibited significant changes: the animals’ snouts became significantly shorter and flatter, while the skulls of the more contemporary animals no longer had a slightly outwardly curved forehead. "We didn’t expect such pronounced differences to appear within a span of only 100 years," says Schafberg.
Remarkably, both breeds of domestic pig underwent the same changes, despite being kept separately. "These changes occurred even though breeders did not select the animals specifically for their skull shape, as this trait was not important for breeding. Instead, the changes appear to be an unintended by-product of selecting the desired traits," says Schafberg.
Another reason for the alterations could be related to changes in the animals’ diet. Nutrition is known to influence the growth and development of animals. Today, pigs are mainly fed pellets that are high in protein. In contrast, the skulls of wild boars, who remain omnivores, have not undergone such changes.
The findings demonstrate how strongly humans can influence the evolution of animals. "Charles Darwin assumed that long periods of time - millions of years - are required for major changes to take place. Our work is further proof that humans can greatly accelerate this process through selective breeding," says co-author Dr Frank Steinheimer, Head of the Central Repository of Natural Science Collections at MLU.