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janrinok writes:

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Arthur T Knackerbracket has processed the following story:

Arthropods belong to an evolutionary branch – the ecdysozoa – that contains about half of all animal species, and the earliest fossil evidence of the group now dates back 550 million years

21 November 2024

3D laser scan of the specimen, Uncus dzaugisi

Mary L. Droser

A worm-like creature preserved in ancient rock has just been identified as the oldest known relative of insects, spiders and crustaceans.

The ecdysozoans are a group of invertebrate animals with a tough outer coating, or cuticle, that they moult as they grow. It is clearly a successful evolutionary strategy, because today the group contains millions of species. “Some estimates suggest that about half of all known animal species are ecdysozoans,” says Ian Hughes at Harvard University. All arthropods – including insects and spiders – belong to the group, and so do …

Original Submission

Arthur T Knackerbracket has found the following story:

In the absence of biological catalysts and metabolism, can atmospheric and geochemical processes provide the substrates and conditions required for production of biological molecules? Becker et al. devised an abiotic synthetic scheme that allows for accumulation of both purine and pyrimidine nucleoside mono- and diphosphates (see the Perspective by Hud and Fialho). A key starting material for this chemistry, hydroxylamine and/or hydroxylamine disulfonate, can form under plausible early atmospheric conditions. Cycles between wet and dry conditions provide the environments necessary to complete formation of purine and pyrimidine bases essentially in one pot.

Theories about the origin of life require chemical pathways that allow formation of life’s key building blocks under prebiotically plausible conditions. Complex molecules like RNA must have originated from small molecules whose reactivity was guided by physico-chemical processes. RNA is constructed from purine and pyrimidine nucleosides, both of which are required for accurate information transfer, and thus Darwinian evolution. Separate pathways to purines and pyrimidines have been reported, but their concurrent syntheses remain a challenge. We report the synthesis of the pyrimidine nucleosides from small molecules and ribose, driven solely by wet-dry cycles. In the presence of phosphate-containing minerals, 5′-mono- and diphosphates also form selectively in one-pot reactions. The pathway is compatible with purine synthesis, allowing the concurrent formation of all Watson-Crick bases.

Original Submission

"martyb" writes:

Liliputing:

Windows 10X is Microsoft's new operating system designed for dual-screen and foldable devices, although it also has some features that could make it an interesting new option for traditional tablets and laptops.

While the operating system is still a work in progress, this week Microsoft released a set of Windows 10X development tools including a Windows 10X emulator. And in practically no time flat, folks started figuring out how to install Windows 10X on hardware that it's not supposed to run on.

If you want to play along at home, there's a set of instructions — but I'd suggest reading them all before getting started and then proceeding with caution if you still want to proceed at all.

Original Submission

SNAPI_Test writes:

Title: Unified Prebiotically Plausible Synthesis Of Pyrimidine And Purine Rna Ribonucleotides

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Arthur T Knackerbracket has found the following story:

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In the absence of biological catalysts and metabolism, can atmospheric and geochemical processes provide the substrates and conditions required for production of biological molecules? Becker et al. devised an abiotic synthetic scheme that allows for accumulation of both purine and pyrimidine nucleoside mono- and diphosphates (see the Perspective by Hud and Fialho). A key starting material for this chemistry, hydroxylamine and/or hydroxylamine disulfonate, can form under plausible early atmospheric conditions. Cycles between wet and dry conditions provide the environments necessary to complete formation of purine and pyrimidine bases essentially in one pot.

Theories about the origin of life require chemical pathways that allow formation of life’s key building blocks under prebiotically plausible conditions. Complex molecules like RNA must have originated from small molecules whose reactivity was guided by physico-chemical processes. RNA is constructed from purine and pyrimidine nucleosides, both of which are required for accurate information transfer, and thus Darwinian evolution. Separate pathways to purines and pyrimidines have been reported, but their concurrent syntheses remain a challenge. We report the synthesis of the pyrimidine nucleosides from small molecules and ribose, driven solely by wet-dry cycles. In the presence of phosphate-containing minerals, 5′-mono- and diphosphates also form selectively in one-pot reactions. The pathway is compatible with purine synthesis, allowing the concurrent formation of all Watson-Crick bases.

This is an article distributed under the terms of the Science Journals Default License.

Vol 366, Issue 6461
04 October 2019

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By Sidney Becker, Jonas Feldmann, Stefan Wiedemann, Hidenori Okamura, Christina Schneider, Katharina Iwan, Antony Crisp, Martin Rossa, Tynchtyk Amatov, Thomas Carell

Concurrent synthesis of complementary ribonucleotides from geochemical precursors can proceed via wet and dry cycles.

By Sidney Becker, Jonas Feldmann, Stefan Wiedemann, Hidenori Okamura, Christina Schneider, Katharina Iwan, Antony Crisp, Martin Rossa, Tynchtyk Amatov, Thomas Carell

Concurrent synthesis of complementary ribonucleotides from geochemical precursors can proceed via wet and dry cycles.

Vol 366, Issue 6461

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Science ISSN 1095-9203.

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