ريتشارد دوكنز's Blog, page 342
November 1, 2017
Could Genetic Engineering Save the Galápagos?
By Stephen S. Hall
Invasive species have been a problem in the Galápagos Islands since mariners first arrived there. Hundreds of introduced species of plants, insects, reptiles, birds and mammals live in the archipelago, displacing and in some cases preying on native species.
Eradicating invasive species can be a brutal job. On the island of Floreana, a plan to eliminate the rodents that raid the nests of native birds and reptiles calls for 400 tons of rat poison, requiring weeks of dislocation for pets, livestock and perhaps children.
Genetic manipulation—for example, tweaking sex inheritance in rodents to produce an all-male, and thus reproductively doomed, population—is being discussed as a safer alternative to poison and bullets. But what are the risks? And would it even work?
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Small group scoops international effort to sequence huge wheat genome
By Ewen Callaway
The wheat genome is finally complete. A giant international consortium of academics and companies has been trying to finish the challenging DNA sequence for more than a decade, but in the end, it was a small US-led team that scooped the prize. Researchers hope that the genome of bread wheat (Triticum aestivum) — described in the journal GigaScience this month[1] — will aid efforts to study and improve a staple crop on which around 2 billion people rely.
The wheat genome is crop geneticists’ Mount Everest. It is huge — more than five times the size of a single copy of the human genome — and harbours six copies of each chromosome, adding up to between 16 billion and 17 billion letters of DNA. And more than 80% of it is made of repetitive sequences. These stretches are especially vexing for scientists trying to assemble the short DNA segments generated by sequencing machines into much longer chromosome sequences.
It’s like putting together a jigsaw puzzle filled with pieces of blue sky, says Steven Salzberg, a genomicist at Johns Hopkins University in Baltimore, Maryland, who led the latest sequencing effort. “The wheat genome is full of blue sky. All these pieces look like a lot of other pieces, but they’re not exactly alike.”
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Man Kills Eight People in NY Terror Attack While Shouting “Allahu Akbar”
By David G. McAfee
Earlier today, Sayfullo Saipov, a 29-year-old originally from Uzbekistan but with a green card to legally stay in the United States, drove a rental truck down a popular bike path near the World Trade Center and killed eight people. He also shouted, “Allahu Akbar,” according to local reports.
New York City’s Mayor Bill de Blasio declared the attack “an act of terror,” according to the New York Post.
“A particularly cowardly act of terror aimed at innocent civilians, aimed at innocent people going about their lives.”
[Saipov] was shot by a cop after getting out of his car at Chambers and West streets with two realistic-looking guns while screaming “Allahu Akbar” — Arabic for God is good, police sources said.
Fox News also reported that the suspect had handwritten notes in his vehicle “pledging his loyalty to the Islamic State terror network.”
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OPEN DISCUSSION – NOVEMBER 2017
This thread has been created for open discussion on themes relevant to Reason and Science for which there are not currently any dedicated threads.
Please note it is NOT for general chat, and that all Terms of Use apply as usual.
If you would like to refer back to previous open discussion threads, they can be found here (but please continue any discussions from them here rather than on the original threads):
October 31, 2017
We may have found 20 habitable worlds hiding in plain sight
By John Wenz
There could be more habitable planets out there than we thought. An analysis of data from the Kepler space telescope has revealed 20 promising worlds that might be able to host life.
The list of potential worlds includes several planets that orbit stars like our sun. Some take a relatively long time to complete a single orbit, with the longest taking 395 Earth days and others taking Earth weeks or months. The fastest orbit is 18 Earth days. This is very different to the very short “years” we see around smaller stars with habitable planets like Proxima Centauri.
The exoplanet with a 395-day year is one of the most promising worlds for life on the list, says Jeff Coughlin, a Kepler team lead who helped find the potential planets. Called KOI-7923.01, it is 97 per cent the size of Earth, but a little colder.
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Geneticists are starting to unravel evolution’s role in mental illness
By Sara Reardon
Psychiatric disorders can be debilitating and often involve a genetic component, yet, evolution hasn’t weeded them out. Now, recent work is beginning to reveal the role of natural selection — offering a peek at how the genetic underpinnings of mental illness has changed over time.
Many psychiatric disorders are polygenic: they can involve hundreds or thousands of genes and DNA mutations. It can be difficult to track how so many genetic regions evolved, and such studies require large genome data sets. But the advent of massive human genome databases is enabling researchers to look for possible connections between mental illnesses and the environmental and societal conditions that might have driven their emergence and development. Others are looking to Neanderthal genetic sequences to help inform the picture of these disorders, as well as cognitive abilities, in humans. Several of these teams presented their findings at the American Society of Human Genetics (ASHG) meeting in Orlando, Florida, in late October.
One project found that evolution selected for DNA variants thought to protect against schizophrenia. The study, led by population geneticist Barbara Stranger of the University of Chicago in Illinois, looked at hundreds of thousands of human genomes using a statistical method that identified signals of selection over the past 2,000 years1. There were no signs of selection in genetic regions associated with any other mental illness.
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Saudi Arabia Takes Another Big Step Toward Gender Equality
By David G. McAfee
It may seem like a minor change, but it’s actually a big step on Saudi Arabia’s road to gender equality. The country, known for restricting women’s rights in the name of religion, is finally allowing women to attending sporting events in stadiums.
The move comes a month after King Salman bin Abdulaziz Al Saud issued an order allowing women in the country to drive, ending a longstanding policy that epitomized gender discrimination in the Middle East for years. Now they’re allowing women to attend sporting events in stadiums for the first time, according to the Washington Post.
Saudi Arabia’s General Sports Authority made the announcement Sunday, tweeting that preparations will begin to “accommodate families” in three stadiums in the major cities of Riyadh, Jiddah and Dammam. Two of the stadiums, the King Fahd International Stadium in Riyadh and the King Abdullah Sports City in Jiddah, hold the highest seating capacity in the kingdom.
“Sports stadiums in Saudi Arabia to open their doors to welcome women in 2018,” Princess Reema Bandar bint Al-Saud, the vice president for women’s affairs of the General Sports Authority, wrote on Twitter.
The change is part of Crown Prince Mohammed bin Salman’s “vision for 2030.″
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Judge blocks enforcement of Trump’s transgender military ban
By Ariane de Vogue
Washington (CNN)A federal judge on Monday partially blocked enforcement of key provisions of President Donald Trump’s memorandum banning transgender people serving in the military.
Judge Colleen Kollar-Kotelly blocked provisions of the memorandum concerning the enlistment and retention of transgender military service members, holding that the plaintiffs “have established that they will be injured by these directives, due both to the inherent inequality they impose, and the risk of discharge and denial of accession that they engender. “
The judge also blasted Trump’s initial abrupt announcement via Twitter that came “without any of the formality or deliberative processes that generally accompany the development and announcement of major policy changes that will gravely affect the lives of many Americans.”
In partially granting a preliminary injunction pending appeal, the judge said the plaintiffs — current and aspiring service members who are transgender — are “likely to succeed” on their due process claims.
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October 30, 2017
‘Octlantis’: Bustling Octopus Community Discovered Off Australia
By Jasmin Malik Chua
In the briny waters of Jervis Bay on Australia’s east coast, where three rocky outcrops jut out from piles of broken scallop shells, beer bottles and lead fishing lures, a clutch of octopuses gambol among a warren of nearly two dozen dens. Welcome to Octlantis.
The bustling community belies conventionally held notions of the cephalopods, once thought to be solitary and asocial.
Indeed, Octopus tetricus, known colloquially as the gloomy octopus, has always been framed as a bit of a loner, with males and females meeting only once a year to mate.
Even then, there’s barely any touching. To avoid being throttled and eaten by a hungry female, the male octopus uses a specialized arm to jettison packets of sperm called spermatophores into the giant bulb behind the female’s head, also known as the mantle.
In the site they have christened “Octlantis,” however, an international team of marine biologists, led by Alaska Pacific University’s David Scheel, observed “complex social interactions” among 10 to 15 octopuses on eight different days, as they foraged, mated and fought in close quarters.
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3D printing doubles the strength of stainless steel
By Robert F. Service
3D printing has taken the world by storm, but it currently works best with plastic and porous steel—materials too weak for hard-core applications. Now, researchers have come up with a way to 3D print tough and flexible stainless steel, an advance that could lead to faster and cheaper ways to make everything from rocket engines to parts for nuclear reactors and oil rigs.
Stainless steel was first invented nearly 150 years ago, and it remains widely popular today. It’s made by melting conventional steel—itself a combination of iron and carbon (and sometimes other metals like nickel)—and adding in chromium and molybdenum, which prevent rust and corrosion. A complex series of cooling, reheating, and rolling steps gives the material a microscopic structure with tightly packed alloy grains and thin boundaries between the grains that create a cell-like structure. When the metal is bent or stressed, planes of atoms in the grains slide past one another, sometimes causing crystalline defects to connect with each other—producing fractures. But strong boundaries can halt these defects, making the material tough, yet still flexible enough to be formed into a desired shape.
3D printing researchers have long tried to reproduce this structure. Their setup starts with a powdery layer of metal alloy particles laid on a flat surface. A computer-controlled, high-powered laser beam then advances back and forth across the surface. Particles hit by the laser melt and fuse together. The surface then drops down a step, another layer of powder is added, and the laser heating process repeats, binding the newly melted material to the layer below. By repeating this tier-by-tier addition, engineers can build complex shapes, such as rocket engines.
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