Later On

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Archive for August 19th, 2015

Making genes from junk DNA

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Very interesting article in Quanta by Emily Singer:

Genes, like people, have families — lineages that stretch back through time, all the way to a founding member. That ancestor multiplied and spread, morphing a bit with each new iteration.

For most of the last 40 years, scientists thought that this was the primary way new genes were born — they simply arose from copies of existing genes. The old version went on doing its job, and the new copy became free to evolve novel functions.

Certain genes, however, seem to defy that origin story. They have no known relatives, and they bear no resemblance to any other gene. They’re the molecular equivalent of a mysterious beast discovered in the depths of a remote rainforest, a biological enigma seemingly unrelated to anything else on earth.

The mystery of where these orphan genes came from has puzzled scientists for decades. But in the past few years, a once-heretical explanation has quickly gained momentum — that many of these orphans arose out of so-called junk DNA, or non-coding DNA, the mysterious stretches of DNA between genes. “Genetic function somehow springs into existence,” said David Begun, a biologist at the University of California, Davis.

This metamorphosis was once considered to be impossible, but a growing number of examples in organisms ranging from yeast and flies to mice and humans has convinced most of the field that these de novo genes exist. Some scientists say they may even be common. Just last month, research presented at the Society for Molecular Biology and Evolution in Vienna identified 600 potentially new human genes. “The existence of de novo genes was supposed to be a rare thing,” said Mar Albà, an evolutionary biologist at the Hospital del Mar Research Institute in Barcelona, who presented the research. “But people have started seeing it more and more.”

Researchers are beginning to understand that de novo genes seem to make up a significant part of the genome, yet scientists have little idea of how many there are or what they do. What’s more, mutations in these genes can trigger catastrophic failures. “It seems like these novel genes are often the most important ones,” said Erich Bornberg-Bauer, a bioinformatician at the University of Münster in Germany.

The Orphan Chase

The standard gene duplication model explains many of the thousands of known gene families, but it has limitations. It implies that most gene innovation would have occurred very early in life’s history. According to this model, the earliest biological molecules 3.5 billion years ago would have created a set of genetic building blocks. Each new iteration of life would then be limited to tweaking those building blocks.

Yet if life’s toolkit is so limited, how could evolution generate the vast menagerie we see on Earth today? “If new parts only come from old parts, we would not be able to explain fundamental changes in development,” Bornberg-Bauer said.

The first evidence that a strict duplication model might not suffice came in the 1990s, when . . .

Continue reading.

Written by LeisureGuy

19 August 2015 at 11:37 am

Posted in Evolution, Science

Making surfaces that will remain dry when submerged

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Quite interesting. Includes a video.

Written by LeisureGuy

19 August 2015 at 10:11 am

Posted in Science, Technology

Semogue, Stirling, and the NEW

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SOTD 19 Aug 2015

An extremely smooth shave today, thanks to the NEW.

The Semogue is still breaking in, and either because it’s not completely broken in or because I failed to load the brush adequately, I did have to reload for the third pass. That’s not a problem, but it usually doesn’t happen. Stirling’s Spice shaving soap has quite a nice fragrance, and the lather was slick.

The Gillette NEW head is on a UFO handle, and with three very comfortable passes my face was BBS. A good splash of Ginger’s Garden Havana Cognac aftershave and the day begins. I do like this aftershave quite a bit.

Yesterday I learned how to use the alum block as a styptic. You do not, as I had assumed, simply glide it over the nick or cut. You hold it against the nick or cut for a moment. I’m told that works extremely well and I’m eager to try it, but this morning I was nickless and cutless and unable to test. But sooner or later I’ll get a nick and test it. If you have an opportunity to try that, let me know how it works.

Written by LeisureGuy

19 August 2015 at 9:05 am

Posted in Shaving

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