As reported in ENV by Johnathan M...ID is making impressive strides in Europe and Asia. As he reports from personal experience, the future looks particularly bright in the United Kingdom.
Hot on the heels of an arthropod with complex compound eyes from the Emu Bay Shale (in Australia) has come an even more dramatic discovery! The same lagerstatten has yielded some fossil eyes, attributed to Anomalocaris, that show just how much 'modernity' can be traced back to the Cambrian fauna.
"The number of ommatidia in the Anomalocaris eyes would almost certainly have greatly exceeded the count based on the exposed surface of the eye alone. [. . .] the total count could be substantially greater than the observed 16,000+ lenses. If this is indeed the case, few living arthropods have as many ommatidia, and these eyes would certainly have functioned with a high degree of acuity. [. . .] Throughout the geological history of Arthropoda, compound eyes have rarely exceeded this size; very large Siluro-Devonian pterygotid eurypterids and some Jurassic thylacocephalans represent some of the rare examples with eyes larger than those of Anomalocaris."
Anomalocaris and its compound eyes (source here)
Inevitably, this raises questions about the way the evolution of compound eyes has been presented in the past. Plots of ommatidia density vs geological time have been used to defend gradualism. However, most of the data was related to trilobites, which are dominated by benthic forms in the Lower Cambrian, diversifying to include nektonic species in the Late Cambrian and subsequent Periods. Now that the eyes of nektonic animals are being discovered and documented, the picture looks rather different. A whole range of eye designs were present during the Early-Middle Cambrian.
"The eyes of Anomalocaris expand the known diversity of visual adaptations in the early Cambrian: low-resolution organs with >100 ommatidia (eodiscoid trilobites), higher-resolution eyes with a distinct bright zone that might have functioned in low light, and very large eyes with a uniformly dense visual field adapted to bright environments."
It should always be remembered that eye complexity means nothing without neuronal processing capability. Light signals have to be transmitted, analysed and decoded as visual images. Modernity in these aspects must be inferred also.
"The very large size of anomalocaridid compound eyes and the visual acuity inferred from the elevated lensnumber and low interommatidial angles suggest that processing of visual information would have required the optic neuropils and brain to be of comparable complexity to crown-group (that is, modern) arthropods. In the crown group, two optic neuropils are reconstructed in the most recent commonancestor, transmitting to a protocerebrum with a median unpaired neuropil, the central body."
Discoveries like this create major challenges for advocates of Darwinian gradualism. Again and again, the source of novelty is pushed earlier into the undocumented past. Gradualism as a working concept is sustained, not by data, but by inference - but the gaps available for gradualist change are ever shrinking!
"Dense, hexagonal packing of ommatidia in compound eyes has been demonstrated to have been unequivocally present in Schinderhannes bartelsi, a Devonian species resolved as the immediate sister group to the arthropod crown group. The eyes of Schinderhannes resemble those of Anomalocaris in being large, stalked, having an ovoid outline of the visual surface, and a highly elevated number of lenses. The finding that Anomalocaris, resolved more basally than Schinderhannes in the arthropod stem group, possesses the same kind of ommatidial packing as in Schinderhannes and crown-group arthropods pushes the origin of compound eyes further down the arthropod stem group. As such, compound eyes evolved earlier than the origin of a hardened tergal exoskeleton and biramous trunk limbs (the latter characters being present in Schinderhannes but not anomalocaridids). We infer that the stalked eyes of all Radiodonta (that is, anomalocaridids) are arthropod-type compound eyes."
The same general analysis applies to all the evolutionary stories that are developed around the fossil record. As in so many research papers, the evolutionary comments are tacked on and are little more than table-talk. The last sentence of the abstract and the last sentence of the paper make the same point: the sophisticated visual system of Anomalocaris would have the consequence of enhancing selection pressures and "probably helped to accelerate the escalatory 'arms race' that began" with the Cambrian fauna.
However, justification of the 'arms race' and the way it is supposed to affect the course of evolution is left to the imagination. As an alternative scenario, consider an ecological perspective. The more we know of Cambrian faunas, the more we are finding evidence of ecosystems adapting to environmental change over time. The changes documented in the fossil record are better explained by reference to ecological concepts combined with the phenomenon of phenotypic plasticity.
Acute vision in the giant Cambrian predatorAnomalocaris and the origin of compound eyes
John R. Paterson, Diego C. Garcia-Bellido, Michael S. Y. Lee, Glenn A. Brock, James B. Jago & Gregory D. Edgecombe
Nature, 480, 237-240 (08 December 2011) | doi:10.1038/nature10689
Until recently, intricate details of the optical design of non-biomineralized arthropod eyes remained elusive in Cambrian Burgess-Shale-type deposits, despite exceptional preservation of soft-part anatomy in such Konservat-Lagerstatten. The structure and development of ommatidia in arthropod compound eyes support a single origin some time before the latest common ancestor of crown-group arthropods, but the appearance of compound eyes in the arthropod stem group has been poorly constrained in the absence of adequate fossils. Here we report 2-3-cm paired eyes from the early Cambrian (approximately 515 million years old) Emu Bay Shale of South Australia, assigned to the Cambrian apex predator Anomalocaris. Their preserved visual surfaces are composed of at least 16,000 hexagonally packed ommatidial lenses (in a single eye), rivalling the most acute compound eyes in modern arthropods. The specimens show two distinct taphonomic modes, preserved as iron oxide (after pyrite) and calcium phosphate, demonstrating that disparate styles of early diagenetic mineralization can replicate the same type of extracellular tissue (that is, cuticle) within a single Burgess-Shale-type deposit. These fossils also provide compelling evidence for the arthropod affinities of anomalocaridids, push the origin of compound eyes deeper down the arthropod stem lineage, and indicate that the compound eye evolved before such features as a hardened exoskeleton. The inferred acuity of the anomalocaridid eye is consistent with other evidence that these animals were highly mobile visual predators in the water column. The existence of large, macrophagous nektonic predators possessing sharp vision - such as Anomalocaris - within the early Cambrian ecosystem probably helped to accelerate the escalatory 'arms race' that began over half a billion years ago
Marshall, M. First top predator was giant shrimp with amazing eyes, New Scientist (7 December 2011)
From ENV...contrary to the hopes and expectations of the Darwin lobby, the post-Dover years have seen ID's scientific and cultural footprint grow only more prominent and impressive.
Critics of ID who fume on the Internet, preach in university classrooms, and feign knowledge and authority in the media love to proclaim that the ID movement is dead. As their story goes, in 2005 a federal judge ruled in the Kitzmiller v. Dover lawsuit that ID is religion and thus unconstitutional to teach in public schools. This supposedly dealt a "deathblow" to the ID movement, which according to critics, has since lost momentum and all but dissipated.
by Denyse O'Leary
In "Neanderthal home made of mammoth bones discovered in Ukraine" (PhysOrg.com December 19, 2011), Bob Yirka reports,
Up till recently, most researchers studying Neanderthals had assumed they were simple wanderers, hiding out in caves when the weather got bad. Now however, the discovery of the underpinnings of a house built by a group of Neanderthals, some 44,000 years ago, turns that thinking on its head. Discovered by a team of French archeologists from the MusÃ©um National d'Histories Naturelle, in an area that had been under study since 1984, the home, as it were, was apparently based on mammoth bones. The team's findings are to be published in the science journal Quaternary International.Why must this stuff always be a surprise?
Actually, Darwinists desperately needed an ape man, to demonstrate the fabled ascent of man, and they co-opted the Neanderthals. Who appear to have quit the job.
Over the past decade, new information regarding Neanderthals, a human ancestor that died out approximately 30,000 years ago, has come to light that tends to reverse decades of thinking. Instead of a clumsy, dim-witted people, it appears Neanderthals were more advanced than most had thought. Evidence of cooking, burying their dead, making jewelry and perhaps even speaking to one another has come to light indicating that first assumptions were a little harsh. Now, with the discovery of a home built by Neanderthals, it's clear they were far more sophisticated than anyone had imagined.
Perhaps even more interesting was the fact that some of the bones used to build the house had decorative carvings and added pigments clearly showing that those that built the house, were in fact, building a home.We told you. They quit. And their house might be worth more than yours nowadays ... well, it would get top marks for creative use of natural materials ...
One solution for the Darwinist would be to establish "ghost lineages" of ape men. They must have existed, and the speculations about them will be immune to correction by evidence.
by Denyse O'Leary
In a remarkable departure from the usual "idiot child of evolutionary biology" fare provided by evolutionary psychology, from Was Darwin Wrong About Emotions?(ScienceDaily Dec. 13, 2011), we learn,
Contrary to what many psychological scientists think, people do not all have the same set of biologically "basic" emotions, and those emotions are not automatically expressed on the faces of those around us, according to the author of a new article published in Current Directions in Psychological Science, a journal published by the Association for Psychological Science. This means a recent move to train security workers to recognize "basic" emotions from expressions might be misguided.Anyone who has managed a large number of people from diverse backgrounds will soon discover this fact. One smells lawsuits to come from security interventions based on crackpot evolution theory.
"What I decided to do in this paper is remind readers of the evidence that runs contrary to the view that certain emotions are biologically basic, so that people scowl only when they're angry or pout only when they're sad," says Lisa Feldman Barrett of Northeastern University, the author of the new paper.(Heretic!)
A very good point. Actors are expected to "show" emotions that the audience can interpret. But that's an elaborate repertoire. One reason most people "can't act" is that their real display repertoire doesn't travel well enough, and they can't master the repertoire.
But Barrett (along with a minority of other scientists) thinks that expressions are not inborn emotional signals that are automatically expressed on the face. "When do you ever see somebody pout in sadness? When it's a symbol," she says. "Like in cartoons or very bad movies." People pout when they want to look sad, not necessarily when they actually feel sad, she says.
Some scientists have proposed that emotions regulate your physical response to a situation, but there's no evidence, for example, that a certain emotion usually produces the same physical changes each time it is experienced, Barrett says. "There's tremendous variety in what people do and what their bodies and faces do in anger or sadness or in fear," she says. People do a lot of things when they're angry. Sometimes they yell; sometimes they smile.And occasionally they show no apparent reaction but later go postal ...
Hope she's got tenure.
"Textbooks in introductory psychology says that there are about seven, plus or minus two, biologically basic emotions that have a designated expression that can be recognized by everybody in the world, and the evidence I review in this paper just doesn't support that view," she says. Instead of stating that all emotions fall into a few categories, and everyone expresses them the same way, Barrett says, psychologists should work on understanding how people vary in expressing their emotions.
But she may escape the Inquisition because, we are told, Darwin's sacred text "The Expression of the Emotions in Man and Animals" does not actually contain the claim attributed to him. Barrett tells us, "Darwin thought that emotional expressions -- smiles, frowns, and so on -were akin to the vestigial tailbone -- and occurred even though they are of no use." Which is equally nonsense, but not the same nonsense.
by Denyse O'Leary
In "Are there Higgs bosons in space?" (Science on MSNBC.com, 12/14/2011), Natalie Wolchover asks,
"Rather than using a 17-mile-long collider, can't we just find them out there?", explaining, Physicists at the Large Hadron Collider, a particle accelerator near Geneva, Switzerland, report that they're hot on the trail of an elusive elementary particle known as the Higgs boson. It's only a matter of time before they'll have the infamous "God particle" in handcuffs, they say. But after years of particle- and head-bashing at the LHC, one burning question is whether there's an easier way to do this. Instead of constructing an 17-mile-long, high-energy collider to generate a Higgs particle from scratch, couldn't we just go look for one in nature?
Yet the little devils are explicitly avoiding the Large Hadron Collider ... hmmm ...
John Gunion, first author of "The Higgs Hunter's Guide" (Basic Books, 1990) and a professor of physics at the University of California, Davis, said Higgs bosons regularly pop into existence all over space.
by Denyse O'Leary
From "From whales to earthworms, the mechanism that gives shape to life" (News Mediacom, 14.10.11), we learn,
During the development of an embryo, everything happens at a specific moment. In about 48 hours, it will grow from the top to the bottom, one slice at a time â€“ scientists call this the embryo's segmentation. "We're made up of thirty-odd horizontal slices," explains Denis Duboule, a professor at EPFL and Unige. "These slices correspond more or less to the number of vertebrae we have."
Every hour and a half, a new segment is built. The genes corresponding to the cervical vertebrae, the thoracic vertebrae, the lumbar vertebrae and the tailbone become activated at exactly the right moment one after another."
The process is astonishingly simple. In the embryo's first moments, the Hox genes are dormant, packaged like a spool of wound yarn on the DNA. When the time is right, the strand begins to unwind. When the embryo begins to form the upper levels, the genes encoding the formation of cervical vertebrae come off the spool and become activated. Then it is the thoracic vertebrae's turn, and so on down to the tailbone. The DNA strand acts a bit like an old-fashioned computer punchcard, delivering specific instructions as it progressively goes through the machine.
The punch line:
"A new gene comes out of the spool every ninety minutes, which corresponds to the time needed for a new layer of the embryo to be built," explains Duboule. "It takes two days for the strand to completely unwind; this is the same time that's needed for all the layers of the embryo to be completed." This system is the first "mechanical" clock ever discovered in genetics. And it explains why the system is so remarkably precise.
The Hox clock is a demonstration of the extraordinary complexity of evolution.Or of something.
Happily, these guys don't offer a hoked-up "evolutionary" explanation.
The earliest example of a domestic dwelling built from bone has been discovered in the Ukraine. The structure is considered to be 44,000 years old and the builders were Neanderthals. The significance of this is that Neanderthals are supposed to be lacking in creativity and aesthetics, so they are usually portrayed as pragmatists dwelling in caves and rock shelters, largely devoid of characteristics we associate with humanity. Yet again, the evidence base shows the iconic Neanderthal to be a figment of the imagination.
"Neandertals are stumping for bragging rights as the first builders of mammoth-bone structures, an accomplishment usually attributed to Stone Age people. Humanity's extinct cousins constructed a large, ring-shaped enclosure out of 116 mammoth bones and tusks at least 44,000 years ago in West Asia, say archaeologist Laetitia Demay of the National Museum of Natural History in Paris and her colleagues. The bone edifice, which encircles a 40-square-meter area in which mammoths and other animals were butchered, cooked and eaten, served either to keep out cold winds or as a base for a wooden building." (source here)
Caves are portrayed as dwelling places and burial locations for Homo neanderthalensis. This scene is from Hannover Zoo. (Source here)
Finding a building made of mammoth bones is suggestive of a lifestyle that involved creativity, forward planning, cooperation and language. To build a dwelling is suggestive of them living in one place for extended periods of time. In addition, many of the bones had been decorated with carvings and ochre pigments, revealing an aesthetic sense in Neanderthals. Here is a selection of comments from Laetitia Demay, who led the research:
"It appears that Neanderthals were the oldest known humans who used mammoth bones to build a dwelling structure.
"This mammoth bone structure could be described as the basement of a wooden cover or as a windscreen.
"Neanderthals purposely chose large bones of the largest available mammal, the woolly mammoth, to build a structure.
"The mammoth bones have been deliberately selected - long and flat bones, tusks and connected vertebrae - and were circularly arranged.
"The use of bones as building elements can be appreciated as anticipation of climatic variations. Under a cold climate in an open environment, the lack of wood led humans to use bones to build protections against the wind."
People have been talking about revising our assessment of Neanderthals for some time now, but we still find them portrayed as brutish; still as sub-human; still as making noises to communicate rather than using speech. In a report on the research, Richard Gray says that the new finds "add to the growing view that Neanderthals were in fact quite advanced humans who had their own culture and may have even used language to communicate". Another comment is provided by Simon Underdown, an academic who researches Neanderthals at Oxford Brookes University, who said:
"It's another piece in the newly emerging Neanderthal jigsaw puzzle. Far from being the stupid cavemen of popular image it's becoming increasingly clear the Neanderthals were a highly sophisticated species of human. We can now add shelter building to the list of advanced behaviours that includes burying the dead, spoken language, cooking and wearing jewellery."
What is it that stops us thinking that Neanderthals were humans like us? For more on this, and an answer, go here.
Mammoths used as food and building resources by Neanderthals: Zooarchaeological study applied to layer 4, Molodova I (Ukraine)
Laetitia Demay, Stephane Pean, Marylene Patou-Mathis
Quaternary International, In Press, Available online 26 November 2011
Abstract: Considering Neanderthal subsistence, the use of mammoth resources has been particularly discussed. Apart from procurement for food, the use of mammoth bones as building material has been proposed. The hypothesis was based on the discovery made in Molodova I, Ukraine (Dniester valley). In this large multistratified open-air site, a rich Mousterian layer was excavated. Dated to the Inter-Pleniglacial (MIS 3), it has yielded 40â€ˆ000 lithic remains associated with ca. 3000 mammal bones, mostly from mammoth. Several areas have been excavated: a pit filled with bones, different areas of activities (butchering, tool production), twenty-five hearths and a circular accumulation made of mammoth bones, described as a dwelling structure set up by Neanderthals. Attested dwelling structures made of mammoth bones are known in Upper Paleolithic sites, from Ukraine and Russia, attributed to the Epigravettian tradition. [. . .] Based on anthropogenic marks, mammoth meat has been eaten. The presence of series of striations and ochre on mammoth bones are associated with a technical or symbolic use. Furthermore, mammoth bones have been deliberately selected (long and flat bones, tusks, connected vertebrae) and circularly arranged. This mammoth bone structure could be described as the basement of a wooden cover or as a wind-screen. The inner presence of fifteen hearths, lithic artifacts and waste of mammal butchery and cooking is characteristic of a domestic area, which was probably the centre of a residential camp recurrently settled. It appears that Neanderthals were the oldest known humans who used mammoth bones to build a dwelling structure.
We were saddened to hear of the passing of Christopher Hitchens at age 62.
by Denyse O'Leary
In "U.S. Will Not Finance New Research on Chimps" (New York Times, December 15, 2011), James Gorman reports,
The National Institutes of Health on Thursday suspended all new grants for biomedical and behavioral research on chimpanzees and accepted the first uniform criteria for assessing the necessity of such research. Those guidelines require that the research be necessary for human health, and that there be no other way to accomplish it.The announcement was not controversial. Not much chimp research is going on in medicine; it's expensive and usually unnecessary. And the ban exempts the usual "chimps r' us" stap of the pop science media:
For behavioral and genomic experiments, the report recommended that the research should be done on chimps only if the animals are cooperative, and in a way that minimizes pain and distress. It also said that the studies should "provide otherwise unattainable insight into comparative genomics, normal and abnormal behavior, mental health, emotion or cognition."Notably,
In making the announcement, Dr. Francis S. Collins, the director of the N.I.H., said that chimps, as the closest human relatives, deserve "special consideration and respect" and that the agency was accepting the recommendations released earlier in the day by an expert committee of the Institute of Medicine, which concluded that most research on chimpanzees was unnecessary.Of course, the key question is, what's to become of the (probably) thousands of chimps who are no longer grant attractors?
by Denyse O'Leary
Here, it was one of 2010's top ten new species picks. Turned up in South Africa; Can leap as well as a grasshopper.
File under: We warned you about cockroaches already, but you ...
by Denyse O'Leary
Here's some useful work by new Zealand scientists: By themselves, the New Caledonian crows didn't know what the thirsty crow knew in the famous Aesop's fable: He dropped pebbles into a nearly empty pitcher until the much-sought water ended up at the top. But given hints, ...
Crows saw a tube partially filled with water. Inside the tube was a bite of meat, stuck onto a piece of wood that floated below their reach. Small stones were sitting nearby. If you're thinking that you might not have been able to solve this puzzle, rest assured--the birds didn't get it either.
This suggests that smarter animals do not so much abstract a solution to a proble4m but take available hints from their environment. Makes sense.
After making sure the crows didn't naturally know how to solve the puzzle, the researchers gave the birds a hint. This time, the crows saw the same tube, floating meat, and stones. But there was a platform next to the top of the tube with a couple stones sitting on it, too. As the crows attempted to jam their beaks far enough into the tube to reach the meat, they tended to accidentally knock the stones into the tube. After doing this several times and noticing how the water level rose, all the crows eventually figured out the trick. They began dropping stones into the tube on purpose to get the meat.
by Denyse O'Leary
Well, isn't that the key epigenetics question - what we really want to know.
From "Why Does the Same Mutation Kill One Person but Not Another?" (ScienceDaily, Dec. 7, 2011), we learn:
The vast majority of genetic disorders (schizophrenia or breast cancer, for example) have different effects in different people. Moreover, an individual carrying certain mutations can develop a disease, whereas another one with the same mutations may not. This holds true even when comparing two identical twins who have identical genomes. But why does the same mutation have different effects in different individuals?Some researchers propose,
"In the last decade we have learned by studying very simple organisms such as bacteria that gene expression -- the extent to which a gene is turned on or off -- varies greatly among individuals, even in the absence of genetic and environmental variation. Two cells are not completely identical and sometimes these differences have their origin in random or stochastic processes. The results of our study show that this type of variation can be an important influence the phenotype of animals, and that its measurement can help to reliably predict the chance of developing an abnormal phenotype such as a disease ."This team's own research looked at the worm C. Elegans, the space shuttle blowup survivor. C. Elegans is too simple to feature many complicating factors.
The work suggests that, even if we completely understand all of the genes important for a particular human disease, we may never be able to predict what will happen to each person from their genome sequence alone. Rather, to develop personalised and predictive medicine it will also be necessary to consider the varying extent to which genes are turned on or off in each person.Goodbye, "genetics is destiny."
There is a sense in which no one can tell you why your brother died and you didn't. Perhaps some day they can point to a gene abnormality that affected him fatally and you minimally - and offer a credible explanation of the cascade of outcomes. But that's it. Some of what we need to know can only be addressed by philosophy, not science.
by Denyse O'Leary
In the recent social sciences scandals, there was an obvious "freakonomics" factor: Really weird findings that do not directly upset elite pieties get massive attention and little analysis. Now, in "Freakonomics: What Went Wrong?" (American Scientist, statistics teachers Andrew Gelman and Kaiser Fung explain, "Examination of a very popular popular-statistics series reveals avoidable errors":
In our analysis of the Freakonomics approach, we encountered a range of avoidable mistakes, from back-of-the-envelope analyses gone wrong to unexamined assumptions to an uncritical reliance on the work of Levitt's friends and colleagues. This turns accessibility on its head: Readers must work to discern which conclusions are fully quantitative, which are somewhat data driven and which are purely speculative.
Some good suggestions for avoiding stats scams.
The risks of driving a car: In SuperFreakonomics, Levitt and Dubner use a back-of-the-envelope calculation to make the contrarian claim that driving drunk is safer than walking drunk, an oversimplified argument that was picked apart by bloggers. The problem with this argument, and others like it, lies in the assumption that the driver and the walker are the same type of person, making the same kinds of choices, except for their choice of transportation. Such all-else-equal thinking is a common statistical fallacy. In fact, driver and walker are likely to differ in many ways other than their mode of travel. What seem like natural calculations are stymied by the impracticality, in real life, of changing one variable while leaving all other variables constant.
by Denyse O'Leary
From "Disappearance of the Elephant Caused Rise of Modern Humans: Dietary Change Led to Modern Humans in Middle East 400,000 Years Ago," (ScienceDaily, Dec. 12, 2011), we learn:
The elephant, a huge package of food that is easy to hunt, disappeared from the Middle East 400,000 years ago -- an event that must have imposed considerable nutritional stress on Homo erectus.There are so many holes in this story, it should be a fish net. There is considerable evidence of varied human diet from great antiquity - which we should expect, given that people can starve waiting for big game - and the longer they starve, the less capable they are.
Unlike other primates, humans' ability to extract energy from plant fiber and convert protein to energy is limited. So in the absence of fire for cooking, the Homo erectus diet could only consist of a finite amount of plant and protein and would have needed to be supplemented by animal fat. For this reason, elephants were the ultimate prize in hunting -- slower than other sources of prey and large enough to feed groups, the giant animals had an ideal fat-to-protein ratio that remained constant regardless of the season. In short, says Ben-Dor, they were the ideal food package for Homo erectus.Except for one thing: The carcass goes bad after a few days. Maybe the theory is that homo erectus didn't notice. Even the flies and worms didn't bother him. Or, even though he couldn't cook, he knew how to salt and dry pemmican?
When elephants began to die out, Homo erectus "needed to hunt many smaller, more evasive animals. Energy requirements increased, but with plant and protein intake limited, the source had to come from fat. He had to become calculated about hunting," Ben-Dor says, noting that this change is evident in the physical appearance of modern humans, lighter than Homo erectus and with larger brains.One thing their implausible thesis doesn't lack is confidence:
Not only do their findings on elephants and the Homo erectus diet give a long-awaited explanation for the evolution of modern humans, but they also call what scientists know about the "birth-place" of modern man into question.
Incidentally, if these people think elephants are dead easy to kill, they need to read George Orwell's "Shooting an Elephant."
by Denyse O'Leary
From "A Small Step for Lungfish, a Big Step for the Evolution of Walking" (ScienceDaily, Dec. 12, 2011), we learn,
Extensive video analysis, published in the Proceedings of the National Academy of Sciences, reveal that the African lungfish can use its thin pelvic limbs to not only lift its body off the bottom surface but also propel itself forward. Both abilities were previously thought to originate in early tetrapods, the limbed original land-dwellers that appeared later than the lungfish's ancestors.
The observation reshuffles the order of evolutionary events leading up to terrestriality, the adaptation to living on land. It also suggests that fossil tracks long believed to be the work of early tetrapods could have been produced instead by lobe-finned ancestors of the lungfish.
Walking fish are nothing new, but there's more to terrestrial life than that.
See also: Land-based fish helps researchers assess how animals moved to land â€“ and stayed there
Darwinists censor writer re: Fish that jump onto land unaided complicate the water-to-land transition story
by Denyse O'Leary
In "You don't really exist, do you?" (December 10, 2011), at his blog Rationally Speaking, philosopher Massimo Pigliucci,
offers reasons to reject the materialist claim that our consciousness is an illusion:
For some time I have been noticing the emergence of a strange trinity of beliefs among my fellow skeptics and freethinkers: an increasing number of them, it seems, don't believe that they can make decisions (the free will debate), don't believe that they have moral responsibility (because they don't have free will, or because morality is relative â€” take your pick), and they don't even believe that they exist as conscious beings because, you know, consciousness is an illusion.As co-author with Jerry Fodor of What Darwin Got Wrong, he might be expected to have thought of this:
... a closer look at the evidence does not bear out the increasingly persistent myth that "it's all unconscious anyway." Here very interesting work has been done by Alfred Mele at Florida State University. In his Effective Intentions: The Power of Conscious Will, Mele critically examines claims to the effect that, for instance, our brains make decisions before we become conscious of them, or that intentions don't play a role in producing actions. He finds the evidence for such extraordinary claims extraordinarily deficient and â€” to the contrary â€” lines up evidence from neurobiology for the conclusion that consciousness plays a major role in (some, most certainly not all) of our decisions, particularly when it comes to the sort of decisions we normally do attribute to conscious deliberation (like whether to change career, say, not just when to push a button on a computer screen, a la Libet experiments).As a matter of fact, the older one gets, the more likely one is to take some time to make a decision - because all aspects of one's mind are not reporting at once. Not all decisions are equally easy, or fact-rich.
That is why David Brooks' "The young and the neuro" have got it all wrong.
It's interesting how many atheists are pulling back from the materialist conclusions.
Most biological students think that adaptive radiations and Darwinism go together, and that the mechanisms of genetic mutation and natural selection explain all the data. However, in most cases, this explanation is assumed and not supported by evidence. It is assumed because of the dominance of neodarwinism in evolutionary biology and because students are very impressed with the "mountains of evidence" claimed to support the consensus. Happily, there are some biologists prepared to step outside the paradigm, and one of them is Austin Hughes from the University of South Carolina. In preparing the ground for his iconoclastic analysis, he writes:
"I will refer to this mechanism as the Neo-Darwinian mechanism; and, following general usage, I will refer to an allele that has been fixed by this process as one that has been fixed by positive Darwinian selection. The Neo-Darwinian mechanism is often assumed by biologists to be the only source of adaptive traits of organisms, to the point where 'adaptive evolution' and 'positive (Darwinian) selection' are treated as interchangeable terms in the literature."
Also, by way of preparation, he refers to the significant theoretical and evidential base for neutral evolution (Kimura, 1976). There is a phenomenon known as genetic drift involving neutral or nearly neutral mutations. There are mechanisms for fixing these genetic changes - all invisible to natural selection. These are considered to be more important than we realise, evidenced by the continuing scarcity of advantageous mutations. This was recognised in 1976 and it continues to this day.
"In the ensuing decades, a vast amount of molecular sequence data, including complete genome sequences of many organisms, has become available to test for the evidence of positive selection at the molecular level. However, the number of well-established cases has not increased greatly in comparison with those known in the mid-1970s. It is true that a very large number of papers have been published in recent years purporting to show evidence of positive selection on the basis of various statistical methods. However, the vast majority of these cases cannot be considered well established. [. . .] Moreover, in almost all of the putative cases of positive selection identified by statistical analysis of sequence data alone, the biological basis of the supposed selection and even the phenotypic effects, if any, of the supposedly selected nucleotide substitutions have not been addressed."
Hughes has previously pointed out difficulties in identifying evidence for positive selection, yet there appears to be plenty of evidence for purifying selection (the elimination of deleterious variants).
"The predominance of purifying selection was predicted by Kimura and Ohta (1974), and the fact that their prediction has been proved to be correct is the cornerstone of many routine methods of modern bioinformatics, whereby evolutionary conservation of a sequence element (the consequence of purifying selection) is taken as evidence of that element's functional importance."
So, in view of the meagre evidential support for "the Neo-Darwinian mechanism", Hughes turns his attention to the thought that adaptive phenotypes might arise by alternative routes. This has been considered by a few other authors, but the field is wide open. Consequently, Hughes proposes one such mechanism: the plasticity - relaxation - mutation (PRM) mechanism. He argues that the evidential base for this concept is already in existence in the biological literature.
"I examine some predictions of this theory and summarize evidence relating to those predictions. The present hypothesis does not deny that the Neo-Darwinian mechanism operates in certain cases. Rather, based on what we can learn from the known cases of positive selection, I conclude that the phenomenon of positive selection may be of relatively minor importance in phenotypic evolution. Instead, phenotypic plasticity and changes in the direction and nature of purifying selection, combined with the chance fixation of neutral or nearly neutral mutations, are proposed to be the major factors in the evolution of adaptive phenotypes."
Much of the paper provides clarification of the PRM mechanism and justifies the claim that the concept has a track record in the literature. The emerging scenario is that organisms typically have an ability to adapt to environmental inputs in ways that change and fix the phenotype. This is a variability that does not depend on mutations for new genetic information, although mutations may be involved in the fixing of the phenotype. The genomic architecture is already present that supports adaptation in a variety of directions. Influences may come from neutral mutations and genetic drift, and they may involve epigenetic mechanisms. After reviewing a variety of evidences, Hughes concludes:
"The PRM mechanism provides unification to the biological sciences by uniting observations at the genomic level (where purifying selection and genetic drift predominate) with those at the phenotypic level (where adaptive characters are well known). As mentioned above, some known examples are suggestive of the action of the PRM mechanism, but it is not yet known how widespread this mechanism is. However, I would predict that the PRM mechanism is likely to be a major mechanism for the origin of evolved adaptations, and perhaps more common than the Neo-Darwinian mechanism."
Let's look at some of the applications of the PRM concept.
First, a comment on the general picture. Adaptive radiations in the fossil record appear to have been rapid, followed by stasis. This pattern is quite unlike the branching illustration found in On the Origin of Species.
"In some cases, the time frame seems rather short for a Darwinian process to have occurred, and in other cases, the effective population sizes of the species in question are small, suggesting that there is unlikely to have been extensive genetic variation in the population prior to selection. However, none of these factors are problematic if these cases of apparent rapid evolution in fact represent cases of phenotypic plasticity, perhaps in some cases rendered heritable through germline DNA methylation. Thus, rather than the paradoxical observation of Darwinian evolution over ecological time, we may be merely seeing incipient evolution by the PRM mechanism, which is expected to operate over ecological time."
Second, the specific case of cichlid fishes is of interest, because these radiations do not have the luxury of extensive time.
"The PRM mechanism provides a simple explanation of such comparatively recent adaptive radiations as that of the cichlids of the East African Great Lakes. The oldest of these lakes, Lake Victoria, is no more than 200,000 years old, and others are still more recent. The diversity of species in these lakes is problematic for Neo-Darwinism, but is easily explained by the PRM mechanism if prior to the divergence of ecotypes the ancestral species showed a phenotypic plasticity similar to that described in sticklebacks."
Third, consider that classic example of adaptive radiation: the Galapagos finches.
"Perhaps ironically, the PRM mechanism can likewise account readily for the radiation of Darwin's finches in the Galapagos Islands. The natural history of Darwin's finches provides many examples where it is plausible that phenotypic plasticity preceded morphological change; a striking example involves the sharper bill shape of a population of the ground finch Geospiza diffilis that feeds on the blood of boobies."
Fourth, the topic of artificial selection is of interest - not least because Darwin (and modern textbooks) portrayed artificial selection as directly relevant to natural selection, whereas Wallace thought it was irrelevant. There is no doubt that artificial selection produces rapid phenotypic change, but we already know that most of this does not involve mutations.
"The same process [incipient evolution by the PRM mechanism] might also be involved in rapid responses to artificial selection, for instance in accelerated domestication."
The significance of this research for the study of biological variation surely deserves our attention. We are not here considering a theory that claims to explain the concept of common descent from a single cell, but it has the more modest aim of explaining adaptive radiations from ancestral populations. However, the main critique that has been advanced is that the PRM hypothesis "does not explain why the ancestral state should be phenotypically plastic, or why this plasticity should be adaptive in the first place." The critique is not a fair one, because the new theory is proposed to explain observations of biological variation, rather than to explain the origin of all species.
The perspective provided by Hughes is one that is based on both theory and empirical data, and it stands up to testing very well. This model of variation provides an understanding that differs markedly from the Darwinism and the Neo-Darwinism of most textbooks. It is time for evolutionists to cease claiming all examples of variation and adaptation as evidence for Darwinian mechanisms of evolution. This is bad science and it is the perpetuation of a consensus by repetition rather than by hypothesis testing and validation. Hughes concludes thus:
"The hypothesis proposed here has the advantage of explaining the available data regarding adaptive evolution on the levels of genomics, ecology and paleontology, without invoking any mechanisms other than the commonly observed phenomena of phenotypic plasticity, purifying selection, mutation and genetic drift. Although it may represent a new perspective to biologists schooled in Neo-Darwinism, this view of life in its own way is not without 'a certain grandeur.'"
Evolution of adaptive phenotypic traits without positive Darwinian selection
A L Hughes
Heredity, advance online publication 2 November 2011 | doi: 10.1038/hdy.2011.97
Recent evidence suggests the frequent occurrence of a simple non-Darwinian (but non-Lamarckian) model for the evolution of adaptive phenotypic traits, here entitled the plasticity-relaxation-mutation (PRM) mechanism. This mechanism involves ancestral phenotypic plasticity followed by specialization in one alternative environment and thus the permanent expression of one alternative phenotype. Once this specialization occurs, purifying selection on the molecular basis of other phenotypes is relaxed. Finally, mutations that permanently eliminate the pathways leading to alternative phenotypes can be fixed by genetic drift. Although the generality of the PRM mechanism is at present unknown, I discuss evidence for its widespread occurrence, including the prevalence of exaptations in evolution, evidence that phenotypic plasticity has preceded adaptation in a number of taxa and evidence that adaptive traits have resulted from loss of alternative developmental pathways. The PRM mechanism can easily explain cases of explosive adaptive radiation, as well as recently reported cases of apparent adaptive evolution over ecological time.
Levi, P.J. No Positive Selection, No Darwin: A New Non-Darwinian Mechanism for the Origin of Adaptive Phenotypes, Evolution News & Views (November 14, 2011)
Tyler, D. Rodents evolve - but does the evidence suggest phenotypic plasticity? ARN Literature Blog (18 November 2011)
Tyler, D. A call for an end to Pseudo-Darwinian hype, ARN Literature Blog (11 September 2008)
by Denyse O'Leary
Natural Science is now in grave disrepute. It survives in its present from only because of a media- and academia-generated program of propaganda which needs the constant distractions of novelties, spurious discoveries, outright fraud, and smokescreens of personal invective, all of which are designed to keep the punters guessing, and ordinary people from asking the most fundamental of philosophical questions about cause and effect, reason and purpose, and loss and gain. ... This is not science. This is unmitigated wickedness.
Strong stuff. But spend a while on the "The Aliens are really OUT There!" desk and you'll find it harder to disagree.
- Metamorphosis, p. 52 (a companion book to the film, Metamorphosis
by Denyse O'Leary
A long time ago Here.
by Denyse O'Leary
Speaking of Dawkins, "I watch from the sidelines with engaged curiosity, and I shall not be surprised if within the next few years, chemists report that they have successfully midwifed a new origin of life in the laboratory." - The God Delusion, 2006, p. 165. Anyone remember which year it was that the great breakthrough occurred?
by Denyse O'Leary
In "Life on Earth: Is our planet special?" (BBC News , 9 December 2011), Howard Falcon-Lang tells us,
Far from being unique, many now regard Earth as an ordinary lump of space rock and believe that life "out there" is almost inevitable. But could the truth be somewhat more complex?
On Friday, top scientists are meeting at the Geological Society in London to debate this very issue, posing the question: "Is the Earth special?". What emerges is that aspects of our planet and its evolution are remarkably strange.
Prof Monica Grady is a meteorite expert at the Open University. She explained in what sense the Earth could be considered special.
It gets better.
"Well, there are several unusual aspects of our planet," she said. "First is our strong magnetic field. No one is exactly sure how it works, but it's something to do with the turbulent motion that occurs in the Earth's liquid outer core. Without it, we would be bombarded by harmful radiation from the Sun."
A key barrier to determining the odds of the habitability of other planets has been the need to minimize the ways in which Earth is special. "Special" doesn't mean that no other planets could be like Earth, but that we need to assess our chances rationally.
As opposed to pointless speculation like "Could exoplanets support life that has a different chemical composition?" Absent the proposed composition, who knows?
Year-end Donation Opportunity: Support ARN today and receive the Phillip Johnson Greatest Hits collection celebrating the 20th Anniversary of Darwin on Trial.
Greetings from the ARN Staff. In case you haven't heard, 2011 is the 20th Anniversary of Phillip Johnson's seminal book Darwin on Trial. With this book the Law Professor from UC Berkeley made it intellectually respectable to be a Darwinian Skeptic and helped launch the intelligent design movement. Discovery Institute is celebrating the occasion with a website honoring the man and the book. At ARN we are celebrating the occasion by releasing two Phillip Johnson archive DVDs, one containing 10 of his best video lectures, debates and interviews in digital format (.mp4 files), and the other containing 25 of his best audio lectures, debates and interviews in digital format (.mp3 files). For a listing of the contents of each DVD go to Phillip Johnson Greatest Video Hits and Phillip Johnson Greatest Audio Hits. These archives are designed to be played on digital media players such as your computer, iphone, ipad, ipod, etc., and most likely will NOT play on your standard DVD or CD player. Our standard products are still available for those formats, but with the digital age upon us, this is a great way to get Philâ€™s fabulous presentations available to a wider audience in a compact format. Even if you own some of the original DVD lectures, this archive set will certainly become a collectorâ€™s item in years to come.
Initially these two DVDs will only be available on a donation basis. We want to thank you for your support of ARN over the years. We depend on your product purchases and donations to make ARN one of the leading information portals on Intelligent Design. In appreciation for a $50 donation or more received by December 31, 2011, we would like to send you either the Video or Audio DVD Collection. For a donation of $100 or more we will be happy to send you both.
Donations may be made online at http://www.arn.org/arnproducts/donation.htm. Specify either Audio DVD or Video DVD in the comment field when you check out (or Audio & Video DVD if your donation is $100 or more). Credit card donations can also be made by phone by calling 888-259-7102 and leaving your information on our secure answering machine or with our office manager, Sarah. Of course old fashion checks are always welcome which you can send to ARN, PO Box 38069, Colorado Springs, CO 80937. Donations sent by mail must be postmarked by 12/31/2011 in order to receive a charitable contribution receipt for 2011.
Merry Christmas and Happy New Year from the ARN Staff.
Dennis Wagner, Executive Director
by Denyse O'Leary
Here's Physorg on those recently found tintinnids from 635-715 million years ago. In "New fossils reveal oldest known ciliates" (November 16, 2011), Jennifer Chu reports,
Anyone who has taken high school biology has likely come into contact with a ciliate. The much-studied paramecium is one of 7,000 species of ciliates, a vast group of microorganisms that share a common morphology: single-celled blobs covered in tiny hairs, or cilia. These cilia â€” Greek for "eyelash" â€” are used to propel a microbe through water and catch prey.
Now, geologists at MIT and Harvard University have unearthed rare, flask-shaped microfossils dating back 635 to 715 million years, representing the oldest known ciliates in the fossil record. The remains are more than 100 million years older than any previously identified ciliate fossils, and the researchers say the discovery suggests early life on Earth may have been more complex than previously thought. What's more, they say such prehistoric microbes may have helped trigger multicellular life, and the evolution of the first animals.
"These massive changes in biology and chemistry during this time led to the evolution of animals," says Tanja Bosak, the Cecil and Ida Green Career Development Assistant Professor in MIT's Department of Earth, Atmospheric and Planetary Sciences. "We don't know how fast these changes occurred, and now we are finding evidence of an increase in complexity."
This is not the Darwin forced on us in school. It's not Darwin at all.
Nicholas Butterfield, a lecturer in paleobiology at the University of Cambridge in the U.K., says the group's findings provide convincing evidence for ancient organisms that are "significantly similar" to modern ciliates. However, in his view, the fossils mark a minimum date for the evolutionary appearance of tintinnids â€” the hairy organisms could have been floating about hundreds of millions of years earlier.
See also: Why do some life forms never really die?
by Denyse O'Leary
In "Can physicists crack the big puzzle?" ( MSNBC Cosmic Log, November 30, 2011), Alan Boyleinterviews Oxford physicist Frank Close on his new book, The Infinity Puzzle , wherein we learn that "an even bigger puzzle remains: Why is the cosmos built the way it is?" Meanwhile,
Q: When it comes to the Higgs boson, the question has arisen as to whether it actually exists. One of my colleagues has joked that if it's found, that's worth a Nobel. And if it's ruled out, that's worth a Nobel as well. Is that the way it works?
A: The idea that has led to the Higgs boson is a piece of beautiful mathematics. Whether nature actually does it is a question that only experiments can answer. Although the theorists are the ones that get all the press ... the Einsteins and the other names that trip off the tongue ... it's ultimately the experiments that decide. That's where we are at the moment.
The idea that there should be a Higgs boson, or something else that masquerades as that particle, has been around for a long time. It's only now that are finally able to do the experiments that will tell us one way or the other if that is the case. And if it is the case, we might find out exactly how nature plays this particular trick. When Peter Higgs and a group of other people first put the idea forward, they were trying to solve a particular conundrum, and they came up with the simplest way of doing it â€” that is, that there was a single particle known as the Higgs boson. That was 50 years ago. Since then, people have refined those original ideas, based on the discoveries we have made.
There are several possible ideas as to how nature might actually do this conjuring trick. It might be there's a whole family of particles called Higgsinos and other weird names. It might not be a simple particle. It might be a compound â€” just as an atom has a nucleus that's made of protons and neutrons, which are made of smaller things called quarks, there might be new sorts of particles waiting to be found, called techniquarks, which collectively act as if they were a single boson.
We didn't know that nature was a personality who could know anything, but we didn't know about Higgsinos and such ...
It might be those, it might be something else. We simply don't know. And that's the exciting thing. Nature knows the answer at the moment, and we're trying to find out at last what it is.
by Denyse O'Leary
From "The Driver of Human Evolution Isn't the Climate Around You, It's the Worms Inside You" (Discover Crux blog, December 2, 2011), we learn what one team of researchers concluded:
the authors found that adaptation to pathogens exhibited particularly strong signals of local adaptationâ€”in particular, adaptations to varieties of worms. This aligns with the deduction of some evolutionary biologists that host-parasite interactions drive much of adaptive evolution in complex organisms. Why the local adaptation with worms? The authors posit that worms evolve slower than bacteria, and are also more localized in distribution. Climate and diet? Not so much effect. At least for humans the public perception is close to 100% wrong. Humans adapt to local biological forces, not to the local natural environment.
Well, that might be the reason so much of Darwinist evolutionary biology is a mess. On the other hand, it could be growing incoherence in the face of mounting disconfirmation. By 2011, they weren't even doing reigns of terror well any more.
Finally, this should perhaps allow us to reconceptualize adaptation. It's not due to something out there, but something in there. Biological organisms by and large aren't reacting to geological forces, but to other biological entities. This is what makes biology such a frustrating science when you're faced with the beauty and linearity of physics. The planets may move, but they move regularly. In contrast, as organisms trace evolutionary paths they exhibit chaotic creativity, responding to each other's dodges and jabs. Evolution is not a smooth gradual geological process, but a noisy and scattered perpetual re-oganization of living organisms again and again in kaleidoscopic patterns.
by Denyse O'Leary
From "Astronomers Find 18 New Planets: Discovery Is the Largest Collection of Confirmed Planets Around Stars More Massive Than the Sun" (ScienceDaily, Dec. 2, 2011) , we learn:
Discoveries of new planets just keep coming and coming. Take, for instance, the 18 recently found by a team of astronomers led by scientists at the California Institute of Technology (Caltech).
So many of them might not exist?
"It's the largest single announcement of planets in orbit around stars more massive than the sun, aside from the discoveries made by the Kepler mission," says John Johnson, assistant professor of astronomy at Caltech and the first author on the team's paper, which was published in the December issue of The Astrophysical Journal Supplement Series. The Kepler mission is a space telescope that has so far identified more than 1,200 possible planets, though the majority of those have not yet been confirmed.
By searching the wobbly stars' spectra for Doppler shifts -- the lengthening and contracting of wavelengths due to motion away from and toward the observer -- the team found 18 planets with masses similar to Jupiter's.Question: These planets are unlikely to support life, and no one has suggested they do. But what if we find 18,000 planets that don't support life and none that do? Would it be time for a revisit of the basic "They're Out There" hypothesis?
"They" may very well be out there. Or not. But at what point would we be justified in using cold analysis - as opposed to brave, faint hopes - to make a decision?
It is universally claimed that the early Earth had a reducing atmosphere. Models have been proposed for the gases to have accumulated after outgassing of volatiles from volcanism. This reducing atmosphere was originally thought to have been dominant throughout the Precambrian, but signs of oxygenation have pushed it back earlier than the earliest rocks that researchers have discovered. The earlier claims for a reducing atmosphere have other explanations, such as resulting from the action of hydrodynamic fluids. This has put severe constraints on theories of abiogenesis, because the proposed mechanisms typically presuppose a reducing atmosphere. By the earliest Archaean, the atmosphere was at least neutral - so abiogenesis is inferred to have occurred even earlier. But moving back earlier brings us to the Late Heavy Bombardment which is generally deemed to have obliterated all traces of any life that may have been present. So there is a little window in the Hadean that is deemed to have offered a reducing atmosphere free from the destructive bombardment.
"For decades, scientists believed that the atmosphere of early Earth was highly reduced, meaning that oxygen was greatly limited. Such oxygen-poor conditions would have resulted in an atmosphere filled with noxious methane, carbon monoxide, hydrogen sulfide, and ammonia. To date, there remain widely held theories and studies of how life on Earth may have been built out of this deadly atmosphere cocktail." (Source here)
Artist's impression of the Hadean Earth (source here)
The evidence for a Hadean reducing atmosphere has been entirely theoretical. It does not rest on empirical evidence because there has been so little to work with. However, a new study of zircon crystals has reported some fascinating results that allow speculation about the Hadean black box to be replaced by empirical evidence. Zircons have been identified that carry signatures identifying them with the Hadean - and zircons are remarkably stable once formed. Using zircons dated to almost 4.4 Ga, the researchers have analysed their redox state (a measure of the degree of oxygenation of the mineral). This gives a handle on the type of gases that would have been outgassed by the magmas, and so, according to these models of Earth history, the type of atmosphere that would have been formed.
"Unlike other materials that are destroyed over time by erosion and subduction, certain zircons are nearly as old as Earth itself. As such, zircons can literally tell the entire history of the planet - if you know the right questions to ask. The scientists sought to determine the oxidation levels of the magmas that formed these ancient zircons to quantify, for the first time ever, how oxidized were the gases being released early in Earth's history. Understanding the level of oxidation could spell the difference between nasty swamp gas and the mixture of water vapor and carbon dioxide we are currently so accustomed to, according to study lead author Dustin Trail, a postdoctoral researcher in the Center for Astrobiology. "By determining the oxidation state of the magmas that created zircon, we could then determine the types of gases that would eventually make their way into the atmosphere," said Trail." (Source here)
It is important to realise what was predicted by prevailing theories: the redox state of the magmas with which the zircons were associated was expected to be strongly reducing. This prediction is a necessary part of the Earth having a reducing atmosphere in the Hadean. The research findings did not confirm the prediction. Here is the comment of the authors of a News & Views commentary in Nature:
"[In] this issue, Trail et al. report their analysis of the sole mineral survivors of the Hadean, zircon samples more than 4 billion years old. Their findings allowed them to determine the 'fugacity' of oxygen in Hadean magmatic melts, a quantity that acts as a measure of magmatic redox conditions. Unexpectedly, the zircons record oxygen fugacities identical to those in the present-day mantle, leading the authors to conclude that Hadean volcanic gases were as highly oxidized as those emitted today."
To keep the reducing atmosphere theoretical approach, the timescales must again shrink. The window is now less that 150 Ma - right at the beginning of Earth history - preceding the Late Heavy Bombardment. If life appeared so early, it must have been pulverised before the Archaean provided an environment stable enough for single-celled organisms to survive.
"Their findings extend the mantle's oxidized realm to almost 4.4 billion years ago. Although somewhat tenuous, this is the first direct evidence of the redox state of the earliest Earth. If the zircons analysed by the authors are representative of the Hadean eon, this result shrinks the duration of the reduced era of Earth's mantle to less than 150 million years. It also increases the lag time between the oxidation of the mantle and the subsequent oxidation of the atmosphere [. . .]." (source here)
The authors are well aware of the implications of their research. We need to discard theories that require a reducing atmosphere on Earth - if interest in these theories is to be perpetuated, then locations should be sought outside the Earth.
"The calibrations reveal an atmosphere with an oxidation state closer to present-day conditions. The findings provide an important starting point for future research on the origins of life on Earth. [. . .] Despite being the atmosphere that life currently breathes, lives, and thrives on, our current oxidized atmosphere is not currently understood to be a great starting point for life. Methane and its oxygen-poor counterparts have much more biologic potential to jump from inorganic compounds to life-supporting amino acids and DNA. As such, Watson thinks the discovery of his group may reinvigorate theories that perhaps those building blocks for life were not created on Earth, but delivered from elsewhere in the galaxy." (Source here)
There are two points worth making here. The first concerns the importance of empirical evidence in developing theory. The problem for any historical science is that it is relatively easy for speculation to become dominant because testing hypotheses by reference to empirical data is often a challenge. Abiogenesis is a case in point. The reducing atmosphere scenario and the mechanisms for turning simple chemicals into self-replicating cells have received theoretical development that has gone far beyond the evidential base. So confident have researchers become that they have created the delusion that it is unscientific to even challenge the consensus! Yet they have had to retreat before the evidence. The Archaean atmosphere was realised not to be reducing, so the theorists retreated to the Hadean where data is almost non-existent. They could just about live there - until this week! Now, they must revise their theories to make it all happen in the first 150 Ma of Earth history (and somehow miraculously survive bombardment) or move it "elsewhere in the galaxy". If you are aware of "god of the gaps" reasoning, this case seems to fit the pattern pretty well - the argument is from theory unsupported by evidence and there is a progressive retreat in response to evidence to a place where the theory looks untenable.
The second point is that science has not demonstrated self-correction as it is supposed to do. Evidence has been around for 30 years that the Earth's early atmosphere was not reducing. Jonathan Wells has summarised the research evidence against the reducing atmosphere in Icons of Evolution (2000). He refers to geologists who declared the concept to be mere "dogma" in 1982. Yet the reducing atmosphere has persisted in textbooks, the media, and in the research community to this day! The new research findings bring a renewed challenge to the science community: it is time to revise the textbooks and to follow the evidence wherever it leads.
The oxidation state of Hadean magmas and implications for early Earth's atmosphere
Dustin Trail, E. Bruce Watson & Nicholas D. Tailby
Nature, 480, 79-82, (01 December 2011) | doi:10.1038/nature10655
Magmatic outgassing of volatiles from Earth's interior probably played a critical part in determining the composition of the earliest atmosphere, more than 4,000 million years (Myr) ago. Given an elemental inventory of hydrogen, carbon, nitrogen, oxygen and sulphur, the identity of molecular species in gaseous volcanic emanations depends critically on the pressure (fugacity) of oxygen. Reduced melts having oxygen fugacities close to that defined by the iron-wustite buffer would yield volatile species such as CH4, H2, H2S, NH3 and CO, whereas melts close to the fayalite-magnetite-quartz buffer would be similar to present-day conditions and would be dominated by H2O, CO2, SO2 and N2. Direct constraints on the oxidation state of terrestrial magmas before 3,850 Myr before present (that is, the Hadean eon) are tenuous because the rock record is sparse or absent. Samples from this earliest period of Earth's history are limited to igneous detrital zircons that pre-date the known rock record, with ages approaching ~4,400 Myr. Here we report a redox-sensitive calibration to determine the oxidation state of Hadean magmatic melts that is based on the incorporation of cerium into zircon crystals. We find that the melts have average oxygen fugacities that are consistent with an oxidation state defined by the fayalite-magnetite-quartz buffer, similar to present-day conditions. Moreover, selected Hadean zircons (having chemical characteristics consistent with crystallization specifically from mantle-derived melts) suggest oxygen fugacities similar to those of Archaean and present-day mantle-derived lavas as early as ~4,350 Myr before present. These results suggest that outgassing of Earth's interior later than ~200 Myr into the history of Solar System formation would not have resulted in a reducing atmosphere.
Redox state of early magmas
Bruno Scaillet & Fabrice Gaillard
Nature, 480, 48-49 (01 December 2011) | doi:10.1038/480048a
A study of cerium in zircon minerals has allowed an assessment of the redox conditions that prevailed when Earth's earliest magmas formed. The results suggest that the mantle became oxidized sooner than had been thought.
Setting the Stage for Life: Scientists Make Key Discovery About the Atmosphere of Early Earth, ScienceDaily (30 November 2011)
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Evolution has become a favorite topic of the news media recently, but for some reason, they never seem to get the story straight. The staff at Discovery Institute's Center for Science and Culture started this Blog to set the record straight and make sure you knew "the rest of the story".
A blogger from New England offers his intelligent reasoning.
We are a group of individuals, coming from diverse backgrounds and not speaking for any organization, who have found common ground around teleological concepts, including intelligent design. We think these concepts have real potential to generate insights about our reality that are being drowned out by political advocacy from both sides. We hope this blog will provide a small voice that helps rectify this situation.
Website dedicated to comparing scenes from the "Inherit the Wind" movie with factual information from actual Scopes Trial. View 37 clips from the movie and decide for yourself if this movie is more fact or fiction.
Don Cicchetti blogs on: Culture, Music, Faith, Intelligent Design, Guitar, Audio
Australian biologist Stephen E. Jones maintains one of the best origins "quote" databases around. He is meticulous about accuracy and working from original sources.
Most guys going through midlife crisis buy a convertible. Austrialian Stephen E. Jones went back to college to get a biology degree and is now a proponent of ID and common ancestry.
Complete zipped downloadable pdf copy of David Stove's devastating, and yet hard-to-find, critique of neo-Darwinism entitled "Darwinian Fairytales"
Intelligent Design The Future is a multiple contributor weblog whose participants include the nation's leading design scientists and theorists: biochemist Michael Behe, mathematician William Dembski, astronomer Guillermo Gonzalez, philosophers of science Stephen Meyer, and Jay Richards, philosopher of biology Paul Nelson, molecular biologist Jonathan Wells, and science writer Jonathan Witt. Posts will focus primarily on the intellectual issues at stake in the debate over intelligent design, rather than its implications for education or public policy.
A Philosopher's Journey: Political and cultural reflections of John Mark N. Reynolds. Dr. Reynolds is Director of the Torrey Honors Institute at