From Anna Azvolinsky at The Scientist: In a study published last week (January 3) in eLife, Burchard and colleagues showed that about 75 percent of methylation signatures could be explained by the children’s genetic ancestry. The other 25 percent, however, is likely due to social or environmental factors that co-vary with self-identified race/ethnicity. The study is among the first to probe how the epigenome is influenced by genetic ancestry. Additional investigations are needed to better understand to what extent race and ethnicity are interchangeable with genetic ancestry, experts say. … It is challenging to draw conclusions from methylation analyses like this one because “a lot of the variation can be explained by background genetic variation of individuals,” noted Conley. In Read More ›

Taking issue wth paleontologist Simon Conway Morris, astrobiologist Dirk Schulze-Makuch writes at Air and Space Smithsonian: Since we doubtlessly did originate from animal ancestors, the gap between us and them must have been bridged at some point in time. Perhaps it was not a jump, but a continuous evolution. Were the mental abilities of the cavewoman or caveman really as advanced as today’s humans? How much ability for abstraction and appreciation of complex numbers did they have? Since modern humans are the evidence that bridging the gap is possible, we might ask why it wasn’t bridged earlier, perhaps by an intelligent octopus, a smart dinosaur, a dolphin, or another ape? They’ve had millions more years to evolve than we have, Read More ›

After the asteroid hit. The extinction of the dinosaurs is, in certain ways, the pop science equivalent of the falls of great houses in ancient literature. It’s  fascinating and it accommodates dozens of plausible explanations and hundreds of possible ones. Good for business. From ScienceDaily: “It became cold, I mean, really cold,” says Brugger. Global annual mean surface air temperature dropped by at least 26 degrees Celsius. The dinosaurs were used to living in a lush climate. After the asteroid’s impact, the annual average temperature was below freezing point for about 3 years. Evidently, the ice caps expanded. Even in the tropics, annual mean temperatures went from 27 degrees to mere 5 degrees. “The long-term cooling caused by the sulfate Read More ›

From ScienceDaily: As they were able to see, the catalysis of the reaction took place when the fatty acids formed compartments. As they are in an aqueous medium, and due to the hydrophobic nature of lipids, they tend to join with each other and form closed compartments; in other words, they take on the function of a membrane; “at that time the membranes obviously weren’t biological but chemical ones,” explained Ruiz-Mirazo. In their experiments they were able to see that the conditions offered by these membranes are favourable for amino acids. “The Montpellier group had the prebiotic reactions of the formation of dipeptides very well characterised, so they were able to see that this reaction took place more efficiently in Read More ›

From Mike Wall at Space.com: A new analysis of lunar rocks brought to Earth by Apollo astronauts suggests that the moon formed 4.51 billion years ago — just 60 million years after the solar system itself took shape. Astronomers think the Moon took shape from a collision between Earth and a Mars-size body but just when is unclear, from the jumbled rock samples available to be gathered by astronauts: “You don’t have pristine, old rock preserved on the moon,” Barboni said. “That’s one of the biggest problems — the whole-rock record on the moon is not there.” But zircon samples collected by Apollo 14 appear to provide reasonably clear information. The moon’s advanced age also makes sense from a dynamics Read More ›

From the Daily Galaxy: On Earth, simple life appears to have formed quickly, but it likely took many millions of years for very simple life to evolve the ability to photosynthesize. “The early Earth certainly wasn’t a hellish, dry, boiling planet; we see absolutely no evidence for that,” said Harrison [UCLA]. “The planet was probably much more like it is today than previously thought.” UCLA geochemists have found evidence that life likely existed on Earth at least 4.1 billion years ago — 300 million years earlier than previous research suggested. The discovery indicates that life may have begun shortly after the planet formed 4.54 billion years ago. The new research suggests that life existed prior to the massive bombardment of Read More ›

As new techniques arise in sequence analysis, as well as in genetic engineering, new frontiers open up to test the direction and power of natural selection. A new such experiment has been performed by a team including Joe Thornton. Here’s the opening sentences from the paper: We generated a large alignment of ADH sequences, determined the best-fit evolutionary model, inferred the maximum likelihood phylogeny and calculated the posterior probability distribution of amino acid states at key ancestral nodes. We synthesized coding sequences for the maximum a posteriori sequence of AncMS, which was inferred with high confidence and only one ambiguously reconstructed amino acid (Fig. 1b, Supplementary Fig. 1), and for an alternative version of AncMS (Alt-AncMS), which contained the other plausible Read More ›

Well, that didn’t take long. They’re not stunned any more, they’re mad. Mad as stink. From Phillip Williamson at New Scientist: Ocean acidification is an inevitable consequence of increasing carbon dioxide in the atmosphere. That’s a matter of fact. We don’t know exactly what will happen to complex marine ecosystems when faced with the additional stress of falling pH, but we do know those changes are happening and that they won’t be good news. UK journalist James Delingpole disagrees. In an article for The Spectator in April 2016, he took the sceptical position that all concerns over ocean acidification are unjustified “alarmism” and that the scientific study of this non-problem is a waste of money. He concluded that the only reason Read More ›

From Tracy Vence at The Scientist: Foamy-like endogenous retroviruses (FLERVs), which are found in fish and amphibian genomes, may have originated with their vertebrate hosts more than 450 million years ago, according to a study published in Nature Communications this week (January 10). … “They date back to the origins of vertebrates, and this gives us the context in which we should consider their present-day activity and interactions with their hosts.” More. Maybe they were all part of a package with the fish and amphibians who hosted them? See also: Endogenous retroviruses made us human? Note the role of supposed junk DNA. and Stasis: When life goes on but evolution does not happen very much Follow UD News at Twitter!

From Anna Azvolinsky at The Scientist: The human genome is peppered with the DNA of extinct hominins—Neanderthals and Denisovans—as a result of interbreeding with early Homo sapiens. According to some reports, the Neanderthal and Denisovan DNA retained at specific loci, such as immune system-related genes, likely conferred adaptive advantages against infectious microorganisms. In a study published last month (November 29) in Genome Biology, researchers provide strong evidence that the Neanderthal DNA present at one such locus within the modern human genome is likely the result of positive selection. The study authors also suggest that this Neanderthal haplotype is not unique to Neanderthals. Rather, interbreeding reintroduced the beneficial genetic variant present in early African humans that had been lost during the Read More ›

From Colin Barras at New Scientist: The team discovered that male and female baboons each produce four vowel-like sounds. Females produce one that males don’t, and vice versa, so in total there are five distinct vowels. They correspond to the second syllable in “roses”, and the vowel sounds in “you”, “thought”, “trap” and “ah”. … “We believe that one of the major advantages of our study is that we worked on real vocalisations, which were spontaneously produced by baboons in a social context,” says Fagot. But Philip Lieberman at Brown University in Providence, Rhode Island, is not convinced. He thinks the researchers have unwittingly processed the baboon calls in a way that accentuates the fundamental frequency of the call and Read More ›

From ScienceDaily: This research challenges the classically accepted view that reduction of tooth size in hominins is linked with having a larger brain. The reasoning is that larger brains allowed hominins to start making stone tools and that the use of these tools reduced the need to have such large chewing teeth. But recent studies by other authors found that hominins had larger brains before chewing teeth became smaller, and they made and used stone tools when brains were still quite small, which challenges this relationship. The new study evaluates this issue by measuring and comparing the rates at which teeth and brains have evolved along the different branches of the human evolutionary tree. “The findings of the study indicate Read More ›

From O’Leary for News at MercatorNet: Social media are no more dangerous than life generally. But they require different interpretation skills from what we need for face-to-face contact. So do books, telephone, radio, and TV. And the current angst isn’t a new phenomenon. It normally follows the introduction of new communications technologies. One example is the anxiety that resulted from printing, especially of Bibles. The anxiety was not baseless; widespread literacy was one driver of the Reformation and the Counter-Reformation. But would suppressing the printing press have been any help? Was controlling it much of a help? The seething anger already existed and would lead to wars in any event. Literacy helped many people understand their problems in terms of Read More ›

From John Mooallem at New York Times: Neanderthals Were People, Too “New research shows they shared many behaviors that we long believed to be uniquely human. Why did science get them so wrong?” Friends have noted that the piece is a refreshing change from the snark or (worse) odious virtue signaling that infests science writing today. Mooallem really does want to know why we might have got it wrong. The real surprise of these discoveries may not be the competence of Neanderthals but how obnoxiously low our expectations for them have been—the bias with which too many scientists approached that other Us. One archaeologist called these researchers “modern human supremacists.” The correct answer, which no one gives with complete honesty Read More ›

We are excited to report that we have received a steady stream of submissions to AM-Nat Biology over the last few weeks. If you haven’t submitted your abstract, please do so soon.
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