Feb 16, 2022 06:32 PM
How ancient plants ‘learnt’ to use water when they moved on to land – new research
https://theconversation.com/how-ancient-...rch-177009
INTRO: “Plants, whether they are enormous, or microscopic, are the basis of all life including ourselves.” This was David Attenborough’s introduction to The Green Planet, the latest BBC natural history series.
Over the last 500 million years, plants have become interwoven into every aspect of our lives. Plants support all other life on Earth today. They provide the oxygen people breathe, as well as cleaning the air and cooling the Earth’s temperature. But without water, plants would not survive. Originally found in aquatic environments, there are estimated to be around 500,000 land plant species that emerged from a single ancestor that floated through the water.
In our recent paper, published in New Phytologist, we investigate, at the genetic level, how plants have learnt to use and manipulate water – from the first tiny moss-like plants to live on land in the Cambrian period (around 500 million years ago) through to the giant trees forming complex forest ecosystems of today... (MORE - details)
Examining sudden evolutionary change
https://phys.org/news/2022-02-sudden-evolutionary.html
INTRO: When Charles Darwin first codified the theory of evolution by means of natural selection, he thought of it as a gradual process. "We see nothing of these slow changes in progress, until the hand of time has marked the long lapse of ages," he wrote in his seminal work, "On the Origin of Species."
But Darwin didn't have the full picture. "Evolution doesn't necessarily take all these small changes like Darwin proposed," said Scott Hodges, a professor in UC Santa Barbara's Department of Ecology, Evolution, and Marine Biology.
Hodges, doctoral student Zachary Cabin and their colleagues just have identified a case of a sudden evolutionary change. In the journal Current Biology, the scientists describe a population of columbines that have lost their petals, including the characteristic nectar spurs. A drastic change caused by a mutation in a single gene. The finding adds weight to the idea that adaptation can occur in large jumps, rather than merely plodding along over extended timespans.
Ever since the theory of evolution was put forward, biologists have debated whether it always occurs in small, gradual steps over long timespans or sometimes as an equilibrium punctuated by abrupt changes. Often, large morphological changes appear within short geologic timescales where intermediate forms may not have fossilized. The question then remains whether many small changes occurred in a short period of time, or perhaps whether single large-scale mutation might be responsible. So, researchers really have to catch the development in action if they hope to build a case that sudden changes can drive evolution.
Enter the Colorado blue columbine. In one population, a mutation has caused many of the plants to lose their petals with the iconic nectar spurs. While not an uncommon occurrence in columbines, spurlessness seems to have stuck around in this area: About a quarter of the plants lack the distinctive feature.
The team plumbed the plant's genome to find the source of the unusual morphology. They considered a gene, APETALA3-3, known to affect spur development. They found that this single gene controlled the entire development of the flower's spurs and nectaries.
"The gene is either on or off, so it's about as simple of a change you can get," said lead author Zachary Cabin. "But that simple difference causes a radical change in morphology." A single broken gene causes mutant plants to develop flowers with no petals or nectar spurs... (MORE - details)
https://theconversation.com/how-ancient-...rch-177009
INTRO: “Plants, whether they are enormous, or microscopic, are the basis of all life including ourselves.” This was David Attenborough’s introduction to The Green Planet, the latest BBC natural history series.
Over the last 500 million years, plants have become interwoven into every aspect of our lives. Plants support all other life on Earth today. They provide the oxygen people breathe, as well as cleaning the air and cooling the Earth’s temperature. But without water, plants would not survive. Originally found in aquatic environments, there are estimated to be around 500,000 land plant species that emerged from a single ancestor that floated through the water.
In our recent paper, published in New Phytologist, we investigate, at the genetic level, how plants have learnt to use and manipulate water – from the first tiny moss-like plants to live on land in the Cambrian period (around 500 million years ago) through to the giant trees forming complex forest ecosystems of today... (MORE - details)
Examining sudden evolutionary change
https://phys.org/news/2022-02-sudden-evolutionary.html
INTRO: When Charles Darwin first codified the theory of evolution by means of natural selection, he thought of it as a gradual process. "We see nothing of these slow changes in progress, until the hand of time has marked the long lapse of ages," he wrote in his seminal work, "On the Origin of Species."
But Darwin didn't have the full picture. "Evolution doesn't necessarily take all these small changes like Darwin proposed," said Scott Hodges, a professor in UC Santa Barbara's Department of Ecology, Evolution, and Marine Biology.
Hodges, doctoral student Zachary Cabin and their colleagues just have identified a case of a sudden evolutionary change. In the journal Current Biology, the scientists describe a population of columbines that have lost their petals, including the characteristic nectar spurs. A drastic change caused by a mutation in a single gene. The finding adds weight to the idea that adaptation can occur in large jumps, rather than merely plodding along over extended timespans.
Ever since the theory of evolution was put forward, biologists have debated whether it always occurs in small, gradual steps over long timespans or sometimes as an equilibrium punctuated by abrupt changes. Often, large morphological changes appear within short geologic timescales where intermediate forms may not have fossilized. The question then remains whether many small changes occurred in a short period of time, or perhaps whether single large-scale mutation might be responsible. So, researchers really have to catch the development in action if they hope to build a case that sudden changes can drive evolution.
Enter the Colorado blue columbine. In one population, a mutation has caused many of the plants to lose their petals with the iconic nectar spurs. While not an uncommon occurrence in columbines, spurlessness seems to have stuck around in this area: About a quarter of the plants lack the distinctive feature.
The team plumbed the plant's genome to find the source of the unusual morphology. They considered a gene, APETALA3-3, known to affect spur development. They found that this single gene controlled the entire development of the flower's spurs and nectaries.
"The gene is either on or off, so it's about as simple of a change you can get," said lead author Zachary Cabin. "But that simple difference causes a radical change in morphology." A single broken gene causes mutant plants to develop flowers with no petals or nectar spurs... (MORE - details)