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Cell biology

RNA molecules recognize each other

From ScienceDaily: In the past decade, scientists have watched protein and RNA molecules condensing into droplets, or membrane-free condensates, in many kinds of cells, from bacterial to human. They have also noted that the same proteins that form liquid droplets in healthy cells can “solidfy” in the context of disease, such as neurodegenerative disorders. But what makes certain molecules come together in the same droplet, while others are excluded, has been unexplained. This week in Science, a team shows for the first time that RNA molecules recognize one another to condense into the same droplet due to specific 3D shapes that the molecules assume. The study’s senior author, Amy S. Gladfelter of University of North Carolina, Chapel Hill, began this Read More ›

Exploring the frontiers: When biological materials behave like glass

From Suzan Mazur in a profile of and interview with computational biologist Lisa Manning at Oscillations: A half dozen or so years ago, Carl Woese and Nigel Goldenfeld characterized biology as the new condensed matter physics. More recently, Eugene Koonin advised “biology has to become the new condensed matter physics”. It’s an area of scientific research that is indeed ramping up, and not a moment too soon, after decades of puffery about a so-called selfish gene. But what exactly is meant by “the new condensed matter physics”? I decided to contact Syracuse University physicist Lisa Manning to help sort it all out in a conversation that follows. … The promo for your upcoming Simons Foundation lecture titled: “A Body Made Read More ›

Günter Blobel (1936–2018), Nobelist ‘99, found cell zip codes

From Robert D. McFadden at the New York Times: Günter Blobel, a molecular biologist who was awarded the 1999 Nobel Prize in Medicine for discovering that proteins in any living cell have virtual ZIP codes that guide them to where they can help regulate body tissues, organs and chemistry, died on Sunday in Manhattan. He was 81. … The mystery Dr. Blobel confronted was how cells control their internal traffic, so that large proteins can get through tightly sealed membranes surrounding their birthplace and then travel to sites within the cell, or even through cell walls on intercellular trips through the body, where they can find specific worksites, called organelles (little organs) and penetrate them to perform assigned tasks. More. Read More ›

Suzan Mazur has some hard questions for NASA “astrovirology” expert Ken Stedman

Yes, “astrovirology” is a new term, for the possibility that viruses originated in space. Suzan Mazur wonders at Oscillations: If viruses originated on Earth—which is NASA astrovirology chief Ken Stedman’s “best guess”—just why do we need a new field called astrovirology? That’s a very good question. If viruses originated elsewhere than Earth, the history of the origin of life would become very complex indeed. In her interview with Stedman, she asks about a recent article (paywall US$50.00) in Astrobiology, a publication with curious connections with NASA: My question is why didn’t you publish your astrovirology article independently? Why publish in a journal that despite its disclaimer is seen as a propaganda arm of NASA and “the Darwinian government”—as the late, Read More ›

Researchers: Horizontal gene transfer may have helped early microbes move out of hot springs

The microbes are archaea, not bacteria. From ScienceDaily: The first-ever analysis of DNA of a contemporary heat-loving, ammonia-oxidizing organism, published in open-access journal Frontiers in Microbiology, reveals that evolution of the necessary adaptations may have been helped by highly mobile genetic elements and DNA exchange with a variety of other organisms. Most extremophiles are microorganisms — and many of the most extreme are archaea, an ancient group of single-celled organisms intermediate between the other two domains of life, bacteria and eukaryotes. Different archaea lineages are specialized to different extreme environments, including scalding hot springs, incredibly salty lakes, sunless deep-sea trenches and frigid Antarctic deserts. Only one branch, Thaumarchaeota, has managed to colonize very successfully the Earth’s more hospitable places — Read More ›

“Evolutionists don’t know a good eye when they see one”

From molecular biologist Jonathan Wells at Salvo: In 2005, Douglas Futuyma published a textbook about evolution claiming that “no intelligent engineer would be expected to design” the “functionally nonsensical arrangement” of cells in the human retina. That same year, geneticist Jerry Coyne wrote that the human eye is “certainly not the sort of eye an engineer would create from scratch.” Instead, “the whole system is like a car in which all the wires to the dashboard hang inside the driver’s compartment instead of being tucked safely out of sight.” Like Dawkins, Williams, Miller, and Futuyma, Coyne attributed this arrangement to unguided evolution, which “yields fitter types that often have flaws. These flaws violate reasonable principles of intelligent design.” We can be Read More ›

Should NASA look for viruses in space?

From Alex Barash at Slate: The not-quite life forms have a bad rap. But they’re a reliable sign of life, and it would be exciting to find them in space. For one thing, viruses are an excellent indicator for life itself: Wherever there’s life on Earth, there are viruses, too, and almost invariably in far greater numbers. Some scientists think that’s been true from the very beginning. While we know that RNA, the genetic material that makes up some viruses, came before DNA, the genetic material required by everything else, the fact that all modern viruses depend on cells to reproduce has led to something of a chicken-or-the-egg scenario. The NIH’s Eugene V. Koonin has spent decades investigating the evolution Read More ›

Evolution News: Don’t be fooled by protein design claim

From Andrew Jones at Evolution News & Science Today,: After many thousands of man-hours of research, and zillions of CPU-hours on borrowed computers, biochemist David Baker of the University of Washington claims we have basically nailed it. “There are subtleties going on in naturally occurring proteins that we still don’t understand,” Dr. Baker said. “But we’ve mostly solved the folding problem.” He thinks that natural proteins are not designed, and so we should be able to do better: “There’s a lot of things that nature has come up with just by randomly bumbling around,” he said. “As we understand more and more of the basic principles, we ought to be able to do far better.” Don’t be fooled. If it’s Read More ›

Guest Post — Template-Assisted Ligation: A New OOL Model

Dr E. Selensky occasionally requests that UD posts an article on his behalf. What follows is his latest: ______________ Arguably, the RNA world model is excessively complex: it operates too complex structures and involves too complex interactions. The origin of life, some researchers believe, must have been simpler.In an attempt to close the gap between chemistry and life by naturalistic means a new model has been proposed recently, yet another one of many, that seeks to explain the rise of RNAs. This model is called template-assisted ligation. It has been proposed by Alexey Tkachenko and Sergei Maslov at American Institute of Physics. They hope it can help shed light on what could have preceded the RNA world.The crux of the Read More ›

Human brain cells live long but acquire thousands of mutations along the way

From Ruth Williams at The Scientist: Two studies in Science today (December 7)—one that focuses on prenatal development in humans, the other on infancy to old age—provide insights into the extent of DNA sequence errors that the average human brain cell accumulates over a lifetime. Together, they reveal that mutations become more common as fetuses develop, and over a lifetime a person may rack up more than 2,000 mutations per cell. … Within the now burgeoning field of somatic mutation analyses, the brain is a particular area of interest. That’s because unlike organs such as the skin and gut where cells are replaced daily, the brain’s neurons, once established in the fetus, for the most part stick around for life. Read More ›

More news from the decline: Revealing responses to creationist’s wrongful dismissal over soft dinosaur tissue discovery

From Colleen Flaherty at Inside Higher Education: California State University at Northridge has settled a lawsuit brought by a former employee who said he was fired for sharing news of an archaeological discovery that supported his young-Earth creationist beliefs. The university says it settled for $399,500 to avoid a protracted legal battle, but some scientists say the outcome has implications for how scientists critique creationist colleagues going forward. … Armitage published his findings in 2013 in Acta Histochemica, a peer-reviewed journal, leaving out his interpretation of the tissue’s age. If Armitage really found soft dinosaur tissue, his interpretation of their age would be irrelevant to others’ subsequent work. It would be irrelevant if he believed that dinosaurs were specially created Read More ›

Who controls Whom in science and what it means for new thinking and new discoveries – a lawyer talks

Reader Edward Sisson writes to tell us of his encounter with the Who–Whom of science, in connection with the recent Armitage soft dinosaur tissue case:  It reminds me of an idea I had in about 2003, when I was at Arnold & Porter representing (pro bono, with firm authorization) ID organizations and people, for a study and book based on the study, working title “Who Controls Whom in Science.” The basic idea was to research and chart the individuals in power-relationships within academic science — editors of journals, persons on tenure committees, persons who have mentored PhD candidates, persons who sit on PhD thesis defense committees, etc. The research would be updated and published annually. This identifies the individuals in Read More ›

Rethinking biology: What role does physical structure play in the development of cells?

That’s structuralism, in part. Further to Evelyn Fox Keller’s comment that the landscape of biological thought is being “radically reconfigured,” a cancer geneticist writes to say that a tumor’s physical environment fuels its growth and causes treatment resistance: The forces of cancer In vitro experiments showing that cancer cells actively migrate in response to fluid flow have supported the hypothesis that fluid escaping from the boundary of a tumor may guide the invasive migration of cancer cells toward lymphatic or blood vessels, potentially encouraging metastasis. There remains controversy over how the fluid forces induce the migration; the cells may respond to chemical gradients created by the cells and distorted by the flowing fluid,8 or the fluid may activate cell mechanosensors. Read More ›

Flagellum gives bacteria a sense of touch. Behe is right.

Irreducible complexity. From ScienceDaily: Although bacteria have no sensory organs in the classical sense, they are still masters in perceiving their environment. … Swimming Caulobacter bacteria have a rotating motor in their cell envelope with a long protrusion, the flagellum. The rotation of the flagellum enables the bacteria to move in liquids. Much to the surprise of the researchers, the rotor is also used as a mechano-sensing organ. Motor rotation is powered by proton flow into the cell via ion channels. When swimming cells touch surfaces, the motor is disturbed and the proton flux interrupted. The researchers assume that this is the signal that sparks off the response: The bacterial cell now boosts the synthesis of a second messenger, which Read More ›