From ScienceDaily: Pygmies show growth plasticity is key to human evolution While the stature of pygmies is well-suited to tropical rainforests, the mechanisms underlying their growth remain poorly understood. In order to decipher these mechanisms, a team of scientists from the CNRS, IRD and UPMC studied a group of Baka pygmies in Cameroon. Their findings revealed that their growth rate differed completely from that of another pygmy cluster, despite a similar adult height, which implies that small stature appeared independently in the two clusters. This work is published on 28 July 2015 in Nature Communications. More. Sure, but so…? The scientists were thus able to show that although the body size at birth of the Baka was within normal limits, Read More ›

From RealClearScience: The pebble accretion model, as the idea is called, suggests that tiny objects first coalesce together due to drag then gravitationally collapse and form larger objects one hundred to one thousand kilometers in size. These larger objects, now referred to as planetesimals, than draw in all the remaining pebbles and become the cores of larger planets. Simulations completed last year cast doubt on this interesting theory. They suggested that — in the context of our solar system — too many planetesimals would form — as many as one hundred objects the size of Earth! Since our Solar System only contains eight planets and five recognized dwarf planets, this theory was mostly ruled out. However, a new simulation carried Read More ›

In a recent KCBS radio interview about his work for the search for extraterrestrial life, the Center for SETI research Director Seth Shostak repeatedly made claims about the simplicity of life. “Life is just chemistry,” Shostak informed …  Read more

From Texas Observer: The beast was a mammal relative with a heavy skull, a mouth full of fangs, and a tall dorsal sail made of skin stretched over long struts of bone. Sinuous as a crocodile, leathery scales shining in the hot sun, it padded along black-mud swamps and highlands shaded by swaying tree ferns. Sixty million years before the first dinosaur, it slept, basked, chased and killed. It breathed. It was alive. That would be about 280 million years ago (Early Permian). So the mystery is: Paleontologists studying the red beds puzzled over Dimetrodon’s ubiquity for years. No modern land ecosystems support that many apex predators. “If you go on a wildlife-watching tour in Africa,” Bakker said, “you will Read More ›

From Slate: Let me be clear: I love NASA. I think it represents the best of what we humans can do. I also know it is tied in knots trying to appease the whims of Congress and the White House, two winds that blow in vastly different directions. I have taken the president to task before for mysteriously and bafflingly underfunding planetary exploration, but in this case the White House has it right. I know that SLS and Orion are too big and moving forward too much to cancel now. That’s a political reality, and while I can’t make my peace with it, I can understand its truth. But this nickel and diming Commercial Crew must stop. Boeing and SpaceX Read More ›

New Scientist magazine reports on a paper by Hippke, Domainko and Learned, suggesting that fast radio bursts, which were first discovered in 2001, may be artificial signals produced by alien – or human – technology. Ten fast bursts of radio waves have been detected within the past 15 years, and the delay between the arrival of the first and last waves is always very close to a multiple of 187.5. The authors claim there is a 5 in 10,000 probability that the line-up is coincidence, and they argue that no known natural process can explain this curious fact. They conclude that if the signals are not due to “a [natural] galactic source producing quantized chirped signals” (which would be “most Read More ›

In a comment to my last post WJM states: if morality is subjective and there are no necessary consequences, why should I care about it? Why shouldn’t I just consider it an inhibiting evolutionary, emotional artifact (like any other emotion or feeling) and overcome its inhibiting interference with my capacity to act in this world for my own benefit? I made similar arguments in: Psychopath as Übermensch or Nietzsche at Columbine Follow Up on Psychopath as Übermensch The materialist response was large on howling outrage; small (as in “non-existent”) in logical rebuttal. Your statement is obviously true. Materialists deny it anyway. Add that to the list of truths you have to deny to be a materialist.

From ScienceDaily: Biologist investigates how gene-swapping bacteria evade antibiotics “One of the prevailing theories for why bacteria make these antibiotic compounds is to fight off competition. But the bacteria that make the antibiotics have to be resistant to those antibiotics. Therefore, many encode antibiotic resistance genes against their own products.” Random genetic mutation is one way bacteria become antibiotic resistant, but another way is by exchanging antibiotic resistance genes with one another in close quarters, such as in human wounds or on hospital surfaces. In a recent study, published in June in the Journal of Bacteriology, Palmer and her colleagues shed light on a gene-swapping process called conjugation, which, she tells her students, is like bacterial sex. “These bacteria utilize Read More ›

Maybe, 10,000–40,000 years ago. From CBC News: Deep inside the Oxocelhaya cave in southern France, Canadian anthropologist Genevieve von Petzinger points at a small red marking barely noticeable on a rock wall. It looks like someone deliberately drew an X using two inverted V’s. … While cave paintings have long been cited as early evidence of human art, anthropologists are now taking a closer look at the significance of strange abstract signs – including spirals, ovals, handprints and intersecting lines – found alongside prehistoric rock art depicting animals. Von Petzinger, a PhD student at the University of Victoria who has been studying prehistoric signs in European caves for a decade, says they suggest “the first glimmers of graphic communication” among Read More ›

From ScienceDaily: Chimpanzees found to survive in degraded and human-dominated habitats (Well, given that—according to the BBC—), they have entered the Stone Age … No, but seriously, wouldn’t even reasonable people expect chimps to be at least as smart as urban raccoons? A chimpanzee population in Uganda has been found to be three times larger than previously estimated, according to research published in the open access journal BMC Ecology. The study suggests that chimpanzees may adapt to degraded habitats better than expected, but also highlights the importance of new and more focused conservation strategies. The protected Budongo and Bugoma Forest Reserves together compose approximately one quarter of the estimated total chimpanzee population in Uganda. The unprotected area between these two Read More ›

From New Scientist: Stephen Hawking says he has a way to escape from a black hole What you may not know is that physicists have been arguing for 40 years about what happens to the information about the physical state of those objects once they fall in. Quantum mechanics says that this information cannot be destroyed, but general relativity says it must be – that’s why this argument is known as the information paradox. Now Hawking says this information never makes it inside the black hole in the first place. “I propose that the information is stored not in the interior of the black hole as one might expect, but on its boundary, the event horizon,” he said today. The Read More ›

From the Independent: Black holes are a passage to another universe, says Stephen Hawking Black holes in fact aren’t as “black” as people thought and could be a way of getting through to an alternative universe. “The existence of alternative histories with black holes suggests this might be possible,” Hawking said, according to a report from Stockholm University. “The hole would need to be large and if it was rotating it might have a passage to another universe. But you couldn’t come back to our universe. So although I’m keen on space flight, I’m not going to try that. More. For some people, it might be just the ticket. Julian Assange, are you listening? The way some people talk about Read More ›

Unfortunately. Had to happen though. While I (O’Leary for News) was preparing a post on the significance of evolution via epigenetics—changes within parents’ genes in their own lifetime are passed on to offspring— this ScienceBlogs item whistled past the desk and crashed into the Later pile. Well, later is now: For those not familiar with biology, epigenetics is a new branch of genetics that describes cellular and physiologic trait variations that are not caused by changes in DNA sequence. Rather, epigenetics describes traits that are due to changes in the expression of genes; these changes may or may not be heritable. Common epigenetic processes include the methylation of DNA (a chemical modification that attaches methyl groups), a method of silencing Read More ›

Here is an example: Barry to Popperian: Anyone who cannot unambiguously condemn the practice of chopping little boys and girls up and selling the pieces like so much meat shares in the evil of those who do so. Popperian responds: Note how Barry is making my point for me. I wrote: From time to time, old words become obsolete. For an non-essentialist this is not a problem. This is because non-essentialists view words as a tool, not a Thing with a capital T. If any word ceases to function as a tool, a non-essentialists will quickly let it go and find some other new tool to solve problems with. On the other hand, an essentialist will not do this. Why Read More ›

Re the excerpt from Evolution: Making sense of life by science writer Carl Zimmer and evolutionary biologist Doug Emlen (from 2012, hardcover valued at $80): In response to the offer noted here, the reader kindly writes to say, The free download is only the first part of the chapter, not the whole thing. Most of the discussion in this excerpt is about patterns in the fossil record (species diversity temporally and geographically, rates of origination and extinction, etc.) Concerning possible mechanisms of macroevolution, the downloaded pages included this: In Chapter 13 we saw how microevolutionary processes, such as natural selection and drift, can produce new species. The only other references to possible mechanisms of macroevolution included “convergence” as an explanation Read More ›