The End of the RNA World Is Near, Biochemists Argue
https://www.quantamagazine.org/the-end-o...-20171219/
EXCERPT: For decades, an origin-of-life story starring RNA has prevailed. New research may be shaking that theory’s hold on our understanding of life’s beginnings. Four billion years ago, the first molecular precursors to life emerged, swirling about in Earth’s primordial soup of chemicals. Although the identity of these molecules remains a subject of fractious debate, scientists agree that the molecules would have had to perform two major functions: storing information and catalyzing chemical reactions. The modern cell assigns these responsibilities to its DNA and its proteins, respectively — but according to the narrative that dominates origin-of-life research and biology-textbook descriptions today, RNA was the first to play that role, paving the way for DNA and proteins to take over later.
This hypothesis, proposed in the 1960s and dubbed the “RNA world” two decades later, is usually viewed as the most likely explanation for how life got its start. Alternative “worlds” abound, but they’re often seen as fallback theories, flights of fancy or whimsical thought experiments. That’s mainly because, theorizing aside, the RNA world is fortified by much more experimental evidence than any of its competitors have accumulated. Last month, Quanta Magazine reported on an alternative theory suggesting that protein-like molecules, rather than RNA, may have been the planet’s first self-replicators. But its findings were purely computational; the researchers have only just begun experiments to seek support for their claims.
Now, a pair of researchers has put forth another theory — this time involving the coevolution of RNA and peptides — that they hope will shake the RNA world’s hold. Recent papers published in Biosystems and Molecular Biology and Evolution delineated why the RNA world hypothesis does not provide a sufficient foundation for the evolutionary events that followed. Instead, said Charles Carter, a structural biologist at the University of North Carolina, Chapel Hill, who co-authored the papers, the model represents “an expedient proposal.” “There’s no way that a single polymer could carry out all of the necessary processes we now characterize as part of life,” he added.
And that single polymer certainly couldn’t be RNA, according to his team’s studies. The main objection to the molecule concerns catalysis....
MORE: https://www.quantamagazine.org/the-end-o...-20171219/
The shape and fate of the Universe
https://plus.maths.org/content/shape-and-fate-universe
EXCERPT: . . . According to Einstein's general theory of relativity massive objects curve space (see here to find out more). Based on this theory and some additional assumptions, cosmologists have worked out that there are three possibilities for the shape of the Universe, depending on how much matter there is within it....
Europe Unveils Its Vision for a Quantum Future
https://www.technologyreview.com/s/60979...um-future/
EXCERPT: The race to conquer the quantum world is among the most fiercely competitive in technology. China and the U.S. have both invested billions in developing new ways to exploit the strange laws of physics that quantum effects give access to. The promise is a new era of computing and communication and, of course, undreamed-of riches.
In all the excitement, one part of the world is being left behind. Europe has a rich history of innovation in quantum physics but has begun to fall behind its global competitors in recent years.
That’s why the European Commission announced in 2016 that it was investing one billion euros in a research effort known as the Quantum Technology Flagship. The goal for this project is to develop four technologies: quantum communication, quantum simulation, quantum computing, and quantum sensing. After almost two years, how is it going?
MORE: https://www.technologyreview.com/s/60979...um-future/
https://www.quantamagazine.org/the-end-o...-20171219/
EXCERPT: For decades, an origin-of-life story starring RNA has prevailed. New research may be shaking that theory’s hold on our understanding of life’s beginnings. Four billion years ago, the first molecular precursors to life emerged, swirling about in Earth’s primordial soup of chemicals. Although the identity of these molecules remains a subject of fractious debate, scientists agree that the molecules would have had to perform two major functions: storing information and catalyzing chemical reactions. The modern cell assigns these responsibilities to its DNA and its proteins, respectively — but according to the narrative that dominates origin-of-life research and biology-textbook descriptions today, RNA was the first to play that role, paving the way for DNA and proteins to take over later.
This hypothesis, proposed in the 1960s and dubbed the “RNA world” two decades later, is usually viewed as the most likely explanation for how life got its start. Alternative “worlds” abound, but they’re often seen as fallback theories, flights of fancy or whimsical thought experiments. That’s mainly because, theorizing aside, the RNA world is fortified by much more experimental evidence than any of its competitors have accumulated. Last month, Quanta Magazine reported on an alternative theory suggesting that protein-like molecules, rather than RNA, may have been the planet’s first self-replicators. But its findings were purely computational; the researchers have only just begun experiments to seek support for their claims.
Now, a pair of researchers has put forth another theory — this time involving the coevolution of RNA and peptides — that they hope will shake the RNA world’s hold. Recent papers published in Biosystems and Molecular Biology and Evolution delineated why the RNA world hypothesis does not provide a sufficient foundation for the evolutionary events that followed. Instead, said Charles Carter, a structural biologist at the University of North Carolina, Chapel Hill, who co-authored the papers, the model represents “an expedient proposal.” “There’s no way that a single polymer could carry out all of the necessary processes we now characterize as part of life,” he added.
And that single polymer certainly couldn’t be RNA, according to his team’s studies. The main objection to the molecule concerns catalysis....
MORE: https://www.quantamagazine.org/the-end-o...-20171219/
The shape and fate of the Universe
https://plus.maths.org/content/shape-and-fate-universe
EXCERPT: . . . According to Einstein's general theory of relativity massive objects curve space (see here to find out more). Based on this theory and some additional assumptions, cosmologists have worked out that there are three possibilities for the shape of the Universe, depending on how much matter there is within it....
Europe Unveils Its Vision for a Quantum Future
https://www.technologyreview.com/s/60979...um-future/
EXCERPT: The race to conquer the quantum world is among the most fiercely competitive in technology. China and the U.S. have both invested billions in developing new ways to exploit the strange laws of physics that quantum effects give access to. The promise is a new era of computing and communication and, of course, undreamed-of riches.
In all the excitement, one part of the world is being left behind. Europe has a rich history of innovation in quantum physics but has begun to fall behind its global competitors in recent years.
That’s why the European Commission announced in 2016 that it was investing one billion euros in a research effort known as the Quantum Technology Flagship. The goal for this project is to develop four technologies: quantum communication, quantum simulation, quantum computing, and quantum sensing. After almost two years, how is it going?
MORE: https://www.technologyreview.com/s/60979...um-future/