Evolution

From Carolyn Gramling at ScienceNews: Earth’s earliest land-walking vertebrates didn’t paddle about in freshwater lakes or rivers. Instead, these four-footed creatures, which appeared about 375 million years ago, lived in the brackish waters of an estuary or delta, researchers report online May 30 in Nature. Early tetrapods, such as Ichthyostega and Acanthostega, lived an amphibious existence between land and sea: They had feet, but also gills and tails made for swimming. … An ability to tolerate different salinity environments could have helped tetrapods — a group that includes today’s amphibians, reptiles and mammals — survive a mass extinction of ocean-dwellers that occurred by the end of the Devonian Period about 359 million years ago, the researchers say. More. Some life Read More ›

Well, not exactly. From ScienceDaily: Steelhead trout, a member of the salmon family that live and grow in the Pacific Ocean, genetically adapted to the freshwater environment of Lake Michigan in less than 120 years. Steelhead were intentionally introduced into Lake Michigan in the late 1800s in order to bolster recreational and commercial fisheries. In their native range, which extends from California to Russia, steelhead hatch in freshwater rivers, migrate to the ocean, and return to freshwater to spawn. This migration allows steelhead to feed in the ocean, where they can grow larger and produce more eggs than if they remained in freshwater streams for their entire lives. The steelhead introduced into Lake Michigan continue to spawn in small freshwater Read More ›

From geologist Julie Hollis at Massive: Sexual dimorphism is a result of males and females diverging down different evolutionary paths through selection processes, such as competition to reproduce. These processes happen for a variety of reasons. In some cases, strong colors in male birds are a sign of health. The elephant seal’s bulbous nose allows him to roar loudly to defend his territory – and his harem. And the moose’s antlers are used to intimidate or fight other males. Sexual dimorphism is the end result of choices made by mating partners and can increase the likelihood of reproduction: I would bet on the moose with the biggest antlers, wouldn’t you? But what about the long run? What’s the impact on Read More ›

From at ScienceDaily: The 240-million-year-old fossil, Megachirella wachtleri, is the most ancient ancestor of all modern lizards and snakes, known as squamates, the new study, published today in the journal Nature, shows. The fossil, along with data from both living and extinct reptiles — which involved anatomical data drawn from CT scans and DNA — suggests the origin of squamates is even older, taking place in the late Permian period, more than 250 million years ago. Tiago Simões, lead author and PhD student from the University of Alberta in Canada, said: “The specimen is 75 million years older than what we thought were the oldest fossil lizards in the entire world and provides valuable information for understanding the evolution of Read More ›

A new book from astrophysicist Milan M. Ćirković, The Great Silence: Science and Philosophy of Fermi’s Paradox:  The Great Silence explores the multifaceted problem named after the great Italian physicist Enrico Fermi and his legendary 1950 lunchtime question “Where is everybody?” In many respects, Fermi’s paradox is the richest and the most challenging problem for the entire field of astrobiology and the Search for ExtraTerrestrial Intelligence (SETI) studies. This book shows how Fermi’s paradox is intricately connected with many fields of learning, technology, arts, and even everyday life. It aims to establish the strongest possible version of the problem, to dispel many related confusions, obfuscations, and prejudices, as well as to offer a novel point of entry to the many Read More ›

From Horizon: the EU Research and Innovation Magazine, Our brains make sense of the world by predicting what we will see and then updating these predictions as the situation demands, according to Lars Muckli, professor of neuroscience at the Centre for Cognitive Neuroimaging in Glasgow, Scotland. He says that this predictive processing framework theory is as important to brain science as evolution is to biology. From an interview with neuroscientist Lars Muckli, ‘The main purpose of the brain, as we understand it today, is it is basically a prediction machine that is optimising its own predictions of the environment it is navigating through. So, vision starts with an expectation of what is around the corner. Once you turn around the Read More ›

Yesterday, PaV drew our attention to this story from Marlowe Hood at Phys.org: Sweeping gene survey reveals new facets of evolution Here’s another swatch from it, of interest: “another unexpected finding from the study—species have very clear genetic boundaries, and there’s nothing much in between. “If individuals are stars, then species are galaxies,” said Thaler. “They are compact clusters in the vastness of empty sequence space.” The absence of “in-between” species is something that also perplexed Darwin, he said.” More. If this replicates, it will do for textbook Darwinism what the Cambrian explosion did. Paper. See also: Startling Result–90% of Animals Less than 200 kya and Researchers: Cambrian explosion was not an explosion after all (It was just an intense Read More ›

Abstract: As a result of the process of descent with modification, closely related species tend to be similar to one another in a myriad different ways. In statistical terms, this means that traits measured on one species will not be independent of traits measured on others. Since their introduction in the 1980s, phylogenetic comparative methods (PCMs) have been framed as a solution to this problem. In this paper, we argue that this way of thinking about PCMs is deeply misleading. Not only has this sowed widespread confusion in the literature about what PCMs are doing but has led us to develop methods that are susceptible to the very thing we sought to build defenses against — unreplicated evolutionary events. Through three Read More ›

From ScienceDaily: With individuals weighing in at more than 140 pounds, the critically endangered Chinese giant salamander is well known as the world’s largest amphibian. But researchers reporting in the journal Current Biology on May 21 now find that those giant salamanders aren’t one species, but five, and possibly as many as eight. The bad news as highlighted by another report appearing in the same issue is that all of the salamanders — once thought to occur widely across China — now face the imminent threat of extinction in the wild, due in no small part to demand for the amphibians as luxury food. … “We were not surprised to discover more than one species, as an earlier study suggested, Read More ›

 Berlinski, an agnostic mathematician, is author of The Devil’s Delusion, a riposte to Richard Dawkins’ The God Delusion. See also: Darwinian biologist Jerry Coyne takes on skeptical mathematician David Berlinski

From Nathan H. Lents, author of Human Errors: A Panorama of Our Glitches, from Pointless Bones to Broken Genes, at Undark: Of course there’s an explanation (sperm like to develop at lower temperatures). But really: What intelligent designer could have come up with this? It sounds as though Lents has never heard of the concept of “optimal”: best possible solution in given environment, as opposed to best theoretical solution as an abstraction. The fact is that there is no good reason that sperm development has to work best at lower temperatures. It’s just a fluke, an example of poor design. If nature had an intelligent designer, he or she would have a lot to answer for. But since natural selection Read More ›

The book, Darwin’s Secret Sex Problem: Exposing Evolution’s Fatal Flaw: The Origin of Sex, by Bible commentator F. Lagard Smith,m is endorsed by emeritus biology prof (Cedarville University), John E. Silvius. From the publisher at Amazon: Darwins Secret Sex Problem What Darwin Ignored . . . For all his revolutionary insight into the fascinating processes of evolution so useful to current scientific research, health care, and technology, Darwin never seriously confronted the crucial, insurmountable gap in his grand theory between asexual replication and sexual reproduction. Nor could Darwins famed natural selection have provided simultaneous on-time delivery of the first male/female pair of millions of sexually unique species required for evolutions bedrock premise of common descent, a fundamental flaw fatal to Read More ›

From Ryan F. Mandelbaum at Gizmodo: A team of researchers from the United States and New Zealand took a look at how likely species were to go extinct and how likely new species were to appear during a 60-million-year period, long before humans evolved. Upon analyzing fossil data, it seemed to them as if astronomical cycles led to climactic effects that ultimately aligned with new species of plankton appearing and going extinct on Earth. “Our results… show that known processes related to the mechanics of the Solar System were shaping marine macroevolutionary rates comparatively early in the history of complex life,” the authors write in the study published today in the Proceedings of the National Academy of Sciences. More. It certainly Read More ›

From David Klinghoffer at ENST: If you ever encounter a horseshoe crab on the beach, you are a looking at a creature that would not have appeared out of place hundreds of millions of years ago. Arthropods breathtakingly similar to this, says paleontologist Günter Bechly, go back “almost a half billion years without significant morphological change. And you really have to let this number sink in.” Some want to get rid of the category. At the Guardian, Mark Carnall says, Although the idea of living fossils flourished after Darwin introduces the idea, it was never formally defined and was used as a catch all for apparently any organism that has an interesting fossil record. In a paper on rates of Read More ›

From Suzan Mazur at Oscillations: The mechanics of morphogenesis is something European scientists, in particular, seem to find intriguing. However, physical biology is an approach many classical biologists in America have had a difficult time in the past understanding as well as accepting, as evidenced by vociferous attacks in the blogosphere on scientists working in that area. Fortunately, this is changing with America’s new generation of scientists, with project support from organizations like the Simons Foundation, and with publicly funded research in Europe that continues to explore along those lines. French scientists, in particular, have been central to the inquiry into the mechanics of shape in developmental biology. An inspiring example is the current work of Jean-Léon Maître, who is Read More ›