2016

With your coffee … With human evolution studies, we sometimes get valuable, though elusive clues (the role of Neanderthals in the human heritage), and then other times we get “‘Stay-at-home’ males fueled menopause evolution“: One of the most popular explanations put forward for the menopause is the ‘grandmother hypothesis’, which suggests that women live long past reproductive age in order to help successfully raise their grandchildren, thereby strengthening the likelihood that their own genes are passed on. Others argue that the menopause offers no selective advantage and is an evolutionary fluke or ‘mismatch’ which arose because humans were designed for shorter lifespans but now live much longer. “Designed” for shorter lifespans? Yes, that is what it says. Someone, call Darwin 9-11. Read More ›

“Your honour, it was a long time ago, and I wasn’t old enough to make a sensible decision.” Okay, seriously,  this from Science: Members of our species had sex with Neandertals much earlier—and more often—than previously believed, according to a new study of ancient DNA. As some of the first bands of modern humans moved out of Africa, they met and mated with Neandertals about 100,000 years ago—perhaps in the fertile Nile Valley, along the coastal hills of the Middle East, or in the once-verdant Arabian Peninsula. This pushes back the earliest encounter between the two groups by tens of thousands of years and suggests that our ancestors were shaped in significant ways by swapping genes with other types of Read More ›

From ScienceDaily: A new study published in Nature by a team of Tel Aviv University, Sheba Medical Center, and University of Chicago scientists finds that RNA, considered the DNA template for protein translation, often appears with an extra letter — and this letter is the regulatory key for control of gene expression. The discovery of a novel letter marking thousands of mRNA transcripts will offer insight into different RNA functions in cellular processes and contributions to the development of disease. “Epigenetics, the regulation of gene expression beyond the primary information encoded by DNA, was thought until recently to be mediated by modifications of proteins and DNA,” said Prof. Gidi Rechavi, Djerassi Chair in Oncology at TAU’s Sackler Faculty of Medicine Read More ›

From Scientific American: More than 400 years ago Renaissance scientist Nicolaus Copernicus reduced us to near nothingness by showing that our planet is not the center of the solar system. With every subsequent scientific revolution, most other privileged positions in the universe humans might have held dear have been further degraded, revealing the cold truth that our species is the smallest of specks on a speck of a planet, cosmologically speaking. A new calculation of exoplanets suggests that Earth is just one out of a likely 700 million trillion terrestrial planets in the entire observable universe. But the average age of these planets—well above Earth’s age—and their typical locations—in galaxies vastly unlike the Milky Way—just might turn the Copernican principle Read More ›

From New Scientist: We may have a complex, scientific take on the unconscious mind, but as Eliexer Sternberg’s new book shows, explanations demand a nuance befitting the subject Actually, we don’t know very much about the mind at all, and there has been legitimate doubt whether the “unconscious mind” exists. The “unconscious mind” uually means an inner consciousness of which we are unaware: “Schmeazle unconsciously wanted to avoid marrying GerdyLou. That’s why he fell down the back stairs and broke his hip the night before the wedding.” Everyone but Schmeazle is apparently conscious of the reasoning powers of his unconscious. That sort of thing did fall into disrepute, for good reasons and bad ones. We oughtn’t to confuse such a Read More ›

Salt deniers. Who knew? From Science Daily: In the debate over salt’s health effects, scientists have effectively split into two camps and are talking past each other, according to a new study. … … you might’ve started hearing some skepticism recently about whether salt is really that bad for you. The critics say health recommendations for cutting salt intake in half are lacking solid evidence. “Either it’s useless, which means it’s an expensive strategy, or it could well be harmful, which is worse,” cardiovascular disease expert Salim Yusuf told the European Heart Journal. There’s been a sharp response from salt-averse health organizations like the American Heart Association, which says sodium skeptics rely on flawed data and poorly-designed studies. The AHA Read More ›

From Christian Scientific Society: The annual meeting will once again be held in Pittsburgh, this coming April 15-16 (Friday night and Saturday morning). The theme for this year’s meeting is “Fine tuning in cosmology and biology.” Apart from the great talks and debates, the annual meetings are a great time to fellowship with like-minded Christians in science.The meeting will be held at the classic Twentieth Century Club in Pittsburgh, on the University of Pittsburgh Campus. Speakers include Robin Collins, Distinguished Professor and Chair, Department of Philosophy, Messiah College Robert Mann, Professor, Department of Physics and Astronomy, University of Waterloo Fuz Rana, Vice President of Research and Apologetics, Reasons to Believe Jerry Bergman, Adjunct Associate Professor, Medical University of Ohio Wayne Rossiter, Assistant Professor, Read More ›

Nature and Scientific American think we are beginning to find out: Biologists have argued for decades over what ignited this evolutionary burst. Some think that a steep rise in oxygen sparked the change, whereas others say that it sprang from the development of some key evolutionary innovation, such as vision. The precise cause has remained elusive, in part because so little is known about the physical and chemical environment at that time. But over the past several years, discoveries have begun to yield some tantalizing clues about the end of the Ediacaran. Evidence gathered from the Namibian reefs and other sites suggests that earlier theories were overly simplistic — that the Cambrian explosion actually emerged out of a complex interplay Read More ›

From ScienceDaily: Most living vertebrate species have jaws, a development thought to have occurred sometime in the Paleozoic era. Jawed vertebrates–including humans–share many developmental characteristics that have remained unchanged for millennia. The brain’s basic developmental plan was thought by many scientists to have reached completion in jawed vertebrates because the brains of lampreys and hagfish–the only jawless fish that remain alive today–seem to lack two key domains. However, it turned out that hagfish [jawless fish] do have the required equipment. “The problem was that lampreys had not yet been shown to have a similar patterning,” explains Kuratani. “The shared pattern of brain development between hagfish and jawed vertebrates raised the possibility that the apparently primitive brain of the lamprey is Read More ›

From Evolution News & Views: Basically,  [the reearchers] claim that a single mutation “repurposed” an enzyme that made multicellularity possible. A common guanylate kinase enzyme (gk), used by all living things to regulate the supply of nucleotides for the genetic code, underwent a mutation that enabled it to learn a new function. The new GKPIDenzyme, found primarily in animals and choanoflagellates, is important for cell adhesion and spindle orientation. The mutation gave it a new shape that enabled it to bind to a different ligand. Sometime later, GKPID found a new partner in Pins, a protein on the inner membrane that (with some helper enzymes) connects to both the spindle microtubule and the complex that receives signals from neighboring cells. Read More ›

A little timeline on the second law argument, as applied to evolution (see my BioComplexity article for more detail): 1. Scientists observed that the temperature distribution in an object always tends toward more uniformity, as heat flows from hot to cold regions, and defined a quantity called “entropy” to measure this randomness, or uniformity. The first formulations of the second law of thermodynamics stated that thermal “entropy” must always increase, or at least remain constant, in an isolated system. 2. It was realized that the reason temperature tends to become more uniformly (more randomly) distributed was purely statistical: a uniform distribution is more probable than a highly non-uniform distribution. Exactly the same argument, and even the same equations, apply to Read More ›

From ScienceDaily: Fossil analysis pushes back human split from other primates by two million years A paper in the latest issue of the journal Nature suggests a common ancestor of apes and humans, Chororapithecus abyssinicus, evolved in Africa, not Eurasia, two million years earlier than previously thought. “Our new research supports early divergence: 10 million years ago for the human-gorilla split and 8 million years ago for our split from chimpanzees,” said Los Alamos National Laboratory geologist and senior team member Giday WoldeGabriel. “That’s at least 2 million years earlier than previous estimates, which were based on genetic science that lacked fossil evidence.” “Our analysis of C. abyssinicus fossils reveals the ape to be only 8 million years old, younger Read More ›

From Brendon Brewer at Quillette: I first encountered the second law as a teenager, while reading an issue of the fundamentalist Christian magazine Creation, given to me by my grandmother. Since the article’s author wanted to argue against biological evolution, it claimed that the second law of thermodynamics implies evolution is impossible. Its definition of the second law was that disorder always increases with time. At first glance, this does seem incompatible with evolution by natural selection, which can lead to more complex, “better designed” organisms over time.3 At the time, I thought it was unlikely that mainstream biology would flagrantly contradict mainstream physics, so I remained sceptical of this argument, even though I couldn’t understand the counterarguments I found Read More ›

Sound of fiftieth shoe dropping. From “skeptic” Shermer Scientific American: Although there are many proximate causes, there is but one ultimate cause—lack of political diversity to provide checks on protests going too far. … The problem is most relevant to the study of areas “related to the political concerns of the Left—areas such as race, gender, stereotyping, environmentalism, power, and inequality.” The very things these students are protesting. How does this political asymmetry corrupt social science? It begins with what subjects are studied and the descriptive language employed. Consider a 2003 paper by social psychologist John Jost, now at New York University, and his colleagues, entitled “Political Conservatism as Motivated Social Cognition.” Conservatives are described as having “uncertainty avoidance,” “needs Read More ›

In a recent post over at Why Evolution Is True, Professor Jerry Coyne addresses what he regards as the “main incompatibility between science and religion.” Coyne is confident that science is a legitimate arbiter of truth because “there’s only one brand of science, with most scientists agreeing on what’s true,” whereas “there are tens of thousands of brands of religion, many making conflicting and incompatible claims.” In today’s short post, I’d like to explain why Coyne’s assertion about science is fundamentally mistaken. First of all, “conflicting claims” and “conflicting brands” are two very different things. At any given moment, there are literally thousands of conflicting and incompatible claims being made within each field of science. That’s part of the way Read More ›