Early Large Spiral Galaxy Resembles Milky Way

first_imgAstronomers using adaptive optics at the Very Large Telescope (VLT) in Paranal, Chile took spectra of a galaxy at red-shift 2.38 described as an “early young galaxy” that must have, according to current theory, formed very rapidly, because it looks like the Milky Way.  The observations by Genzel et al., published in Nature,1 were described by Robert C. Kennicutt (editor of Astrophysical Journal) in the same issue of Nature2 this way:On page 786 of this issue1, Genzel et al. present remarkable observations of what appears to be a newly formed spiral galaxy, observed when the Universe was just a fifth of its current age.  The result is doubly significant: first, it provides the most detailed glimpse so far of the formation of a galaxy similar to our own Milky Way; second, it demonstrates the power of a new generation of high-resolution instruments that use adaptive optics to study the information and evolution of far-off galaxies.Though Kennicutt claims that our growing catalog of deep-space observations have given rise to “a self-consistent picture of the evolution of galaxies,” he did find it remarkable that such a distant galaxy would look so familiar:The authors’ observations of BzK-15504 reveal it to be a giant spiral galaxy, with a size and mass similar to that of the Milky Way, but observed just 3 billion years after the Big Bang.  It shows many similarities to present-day spiral galaxies, with rotational properties that, again, are nearly identical to those of the Milky Way.  These similarities are notable because they imply that at least some large disk galaxies were broadly in place even at these early cosmic epochs.He says that the spectra imply a rapid burst of star formation in this galaxy 50 times greater than that assumed in our own.  The authors of the paper, after stating the “framework” of galaxy evolution, admitted to some anomalies in the picture:It remains unclear, however, over what timescales galaxies were assembled and when and how bulges and disks—the primary components of present-day galaxies—were formed.  It is also puzzling that the most massive galaxies were more abundant and were forming stars more rapidly at early epochs than expected from models.Everyone thought large spiral galaxies formed late in the evolution of the cosmos.  Kennicut said, “large spiral galaxies with well-developed disks similar to the Milky Way are conspicuously absent in both observations and models of the early Universe.  These large spirals are expected to form rather late, so one would not expect to find many of them at early times,” he added.  But why there are any galaxies this large and mature at such an early age?  “Both these and other results from the same programme are challenging theorists to account for the existence of such massive and well-formed galaxies at such early cosmic epochs, he added, changing the subject to the promise of adaptive optics to answer that question.1Genzel et al., “The rapid formation of a large rotating disk galaxy three billion years after the Big Bang,” Nature 442, 786-789(17 August 2006) | doi:10.1038/nature05052; Received 25 April 2006; Accepted 6 July 2006.2Robert C. Kennicutt, Jr., “Astronomy: Young spirals get older,” Nature 442, 753-754(17 August 2006) | doi:10.1038/442753a; Published online 16 August 2006.The juxtaposition of cockiness about their models and head-scratching about the particulars is what is puzzling.  To keep the model together, they have to have this galaxy, which is surely representative of billions more, forming stars and evolving so rapidly that it looks mature at one-fifth the assumed age of the universe.  This pattern of early maturity is the Cambrian Explosion of cosmology, also known as the Lumpiness Problem.  The early universe shows much more structure (lumpiness) than expected from a nearly homogeneous expansion of an initially uniform particle soup (uniform, that is, to within one part in a hundred thousandth of a degree temperature of the cosmic background radiation).  Astronomers seem to take their lumps in stride.  Sometimes, however, discretion is the better part of valor.(Visited 9 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Exploring the Malleability of Evolutionary Explanation

first_imgMetal bars can be rated on how much they are malleable (able to be hammered) or ductile (able to be stretched) without breaking.  Is evolutionary theory just a very malleable and ductile idea, able to adapt to changing observations, or should it be described as a strong theory, powerful in its explanatory breadth?  Maybe some recent examples can illuminate the issue. MSNBC News announced this nonchalantly with a pretty picture of a swamp sparrow singing away.  Yes, it all began long ago: “The pattern started to evolve when lungfishes started to gulp and swallow air,” an evolutionary biologist “explained”.  “Heads up, ‘American Idol’,” reporter Jennifer Viegas chirped.  “Findings may lead to better human singing.”  Thank your inner fish. Hardwired metaphysics:  Why do some people tend to see religion and science at conflict?  Obviously, we must have evolved that tendency.  Robin Lloyd for MSNBC News explained that we can only handle one deep thought at a time.  She spoke more about the Galileo affair and the “ongoing effort of U.S. creationists to inject doubt about evolution into science classrooms in public schools,” but the tenor of the article is that humans are hardwired to act that way.  “Experiments headed up by psychologist Jesse Preston of the University of Illinois at Urbana-Champaign and her colleague Nicholas Epley of the University of Chicago provide some data to support the argument that the conflict is inherent, or hard-wired,” she said.  “They found that subjects apparently cannot easily give positive evaluations to both God and science as explanations for big questions, such as the origin of life and the universe, at the same time.”  Apparently the hard wiring can be short-circuited by conscious choice.  Presumably science is a shunt around the hardwiring.  She did not say whether conscious choice evolved, or why scientists should combat a group of people (like creationists) who only do what they are hardwired to do.  If they are products of evolution, could they not be considered more fit? Scorpius:  The “book lungs” of scorpions (so called because they look superficially like the leaves of a book) have been imaged by scientists at high detail at the American Museum of Natural History.  Science Daily shows a photo and claims it “gives insight into the evolutionary relationships among scorpions.”  How does it do that?  Apparently this is the first time since 1926 that someone examined book lungs for clues to where scorpions fit on Darwin’s tree of life.  “Scorpions were traditionally placed at the base of the phylogenetic tree, as a sister group to all other arachnids, but molecular data has complicated this picture by suggesting that scorpions move higher on the tree, closer to sun spiders and daddy long legs,” the article said.  “Consequently, the question of whether the book lung evolved once, at the base of the arachnid phylogenetic tree, or more than once, as arachnids adapted to life out of water, is unresolved.”  Did the new pictures of 200 specimens help, then?  For one thing, they found a “tremendous diversity” of structures.  They did claim a match to progressive tree-like variation: “The finding suggests that a significant change in the structure of the respiratory apparatus must have occurred early in the evolution of modern scorpions.”  The book lungs, however, all have the same basic parts, just in varied forms of sculpting of the lamellae.  The differences seem as trivial as those between human hairstyles. Extended construction:  An old idea by Richard Dawkins didn’t fare so well for awhile, but is now enjoying a resurgence.  Science Daily said the Extended Phenotype model which Dawkins developed in 1982 is gaining acceptance among the European Science Foundation.  The attendees at a recent ESF workshop worked out a compromise with proponents of niche construction, often considered a rival hypothesis.  “However there was lively debate between Dawkins and proponents of niche construction over the role of evolution within closely coupled ecosystems,” the article said, leading into an unfinished discussion of how the rival ideas interact and what questions remain. Pair o’ sites:  Which genes are involved in the evolution of parasitism?  Science Daily reported on discussions of competing signal pathways that, though “evolutionarily conserved” (i.e., unevolved, “unchanged during the course of evolution”), might have played roles in the development of parasitism.  The word “conserved” appears four times in the short article.  First line said: “Today, 150 years after Darwin’s epochal ‘On the Origin of Species,’ many questions about the molecular basis of evolution are still waiting for answers.” Swimmin’ lizards:  New Zealand paleontologists have a conundrum on their hands.  Remnants of a group of lizards that went extinct in the Age of Dinosaurs abide as “living fossils” in New Zealand (03/10/2006).  Problem: the islands were supposed to be almost submerged in between the time of the dinosaurs and now.  Science Daily has a humorous picture of a lone tuatara trying to survive on a tiny rock out in the ocean.  Unless these relatively delicate reptiles (03/31/2002) swam from South America after New Zealand rose above the waves, some of its land mass must have remained above the surface.  Even so, they would have had to survive major climate upheavals.  An entry last year 03/24/2008 claimed that tuatara genes seem to be running in place. Twists and turns:  A triumphant-sounding article on EurekAlert claims that the evolutionary process has been explored in greater detail than ever before – in yeast.  Describing how “Mother Nature sorts things out,” a team at Texas A&M claimed they could watch beneficial mutations take hold in succeeding generations, just like Darwin said.  “We’re gaining a comprehensive understanding of the way a microorganism adapts to its environment as it fights to survive,” Katy Kao announced in good Malthusian form.  “We’re demonstrating that the evolutionary journey has many more ‘twists and turns’ than we once thought.”  She did not elaborate on how the twisty path might make it difficult to discern an evolutionary track millions of years later.  After all, she was watching just a few generations of yeast in the present – and at the end of the experiment, they were still yeast. Darwin in space:  Space.com has a lively discussion on whether human spaceflight is driving evolution, or evolution is driving human spaceflight.  “It’s about culture and the human desire to evolve and expand,” said one German spokesperson, apparently oblivious to the usual Darwinian principle that organisms do not normally exercise free will in the matter.  Darwinist professor Will Provine, for instance, has long preached dogmatically that there is no free will in a Darwinist world.  Evolution must have programmed him to say that.  The Space.com statement implies progress – a no-no in evolutionary theory, according to Michael Ruse and other leading Darwinists. It’s hard to be purposeless:  Two Japanese scientists reported their findings about RNA interference in Nature1  Although their work concerned “mechanisms” that involve “fine-tuning and networking of complex suites of gene activity, thereby specifying cellular physiology and development,” they took advantage of opportunities to speculate about how these complex systems came to be.  Teleological language is supposed to be verboten in Darwinian explanations, but it’s hard to avoid: “the core PIWI and piRNA machinery might have evolved to produce small RNAs and silence targets by different strategies,” they said.  They also speculated on how silencing RNAs might have originated in plants.  Phrases might evolve and could be evolutionary intermediates seasoned their speculation.  In one sentence, “It is possible that such an adaptive switch could also occur,” the word occur substituted for an unspecified lucky outcome of mindless chance.  They also stated flatly that “Argonaute proteins have diversified over evolutionary timescales, evolving a range of functions.”  As an encore, they claimed, “Such changes might have contributed to many processes, including human evolution” – even though they were the only humans in the room. Freak show:  A new book is out, Freaks of Nature: What Anomalies Tell Us About Development and Evolution by Mark Blumberg (Oxford, 2009).  Jerry Coyne was quick to jump on it and assure readers of Nature that orthodox Darwinism is safe.2    Blumberg, an advocate of evo-devo, argues that genetics only plays a minor role in evolution.  Coyne enjoyed some things about the book, but stood religiously with the old guard: “In his anxiety to boost the status of evo-devo in the pantheon of evolutionary subdisciplines, Blumberg has short-changed orthodoxy,” he said.  “Not only does the traditional view of evolution explain far more than he allows, but Blumberg shapes his own vision of development to inflate its challenge to neo-Darwinism.” Braining the mind:  Which came first, the brain or language?  If language, it would be too shifty a platform for natural selection to work on, argued three psychologists and cognitive neuroscientists in PNAS.3  Darwin to the rescue: “The genetic basis of human language acquisition and processing did not coevolve with language, but primarily predates the emergence of language.  As suggested by Darwin, the fit between language and its underlying mechanisms arose because language has evolved to fit the human brain, rather than the reverse.”  Note: they did not claim this was the origin of the proverb, “use it or lose it.” Gunning the governor:  How can you overcome the anti-evolutionary force of “stabilizing selection,” a force that tries to keep genomes stable?  Harvard evolutionary biologists Bedford and Hartl tackled that conundrum in PNAS.  “It is generally assumed that stabilizing selection promoting a phenotypic optimum acts to shape variation in quantitative traits across individuals and species,” they began.  “Although gene expression represents an intensively studied molecular phenotype, the extent to which stabilizing selection limits divergence in gene expression remains contentious.”  To provide relief from contention, they invented a “theoretical framework for the study of stabilizing and directional selection using data from between-species divergence of continuous traits.”  They used Brownian motion as an analogue – that continuous random jiggling of particles visible under a microscope.  Their model first showed that “gene-expression divergence is substantially curtailed by stabilizing selection.”  That could be bad for Darwin.  So they tweaked some parameters and got better results: These findings highlight the power of natural selection to shape phenotype, even when the fitness effects of mutations are in the nearly neutral range.” Darwinian altruism?  No problemo:  Human altruism has been one of the most challenging phenomena to explain by evolution.  Why would natural selection favor a soldier jumping on a grenade to save his friends, or an elderly woman giving money for the relief of poor Africans she will never see?  It seems these and a thousand other actions could not possibly help spread the genes of the altruists.  Not a problem, claim Fletcher and Doebeli, writing “A simple and general explanation for the evolution of altruism” for the Royal Society.4  Kin selection is no longer a requirement, they claimed.  In their model, “even suicidal aid can theoretically evolve without help ever being exchanged among genetically similar individuals.”  Wow; how is that?  Deploying some mathematics and game theory, they rigged a “theoretical framework” and then proposed a thought experiment using bacteria (not humans) whose genes produce some “common good” (presumably, preservation of the group).  They assumed this common good could be produced by gene regulation pathways.  If the altruism gene gets assorted among members of the group, individuals possessing it can be preserved even if some commit suicide.  The whole problem reduces, therefore, to how genes that favor altruism get sorted in a population.  Their model, and others, depend on certain assumptions: that genes determine altruistic behavior, and that they know what fitness is.  It’s all theoretical: “Put bluntly,” they said in conclusion, “based on the concept of assortment, we would be able to fully understand the evolution of cooperation in a world in which the concepts of kin and group selection are absent.”  They did not explain how concepts evolve, but they must have cooperated on the paper – maybe taking their cues from bacteriaq.  They also did not test their ideas with experiments – e.g., throwing themselves on the railroad tracks to protect a fallen comrade, or giving money to help North Korean refugees.  Undoubtedly it would be difficult to link such actions to the particular genes when some humans do it and others don’t. As a footnote, Darwin is even being invoked by astronomers.  Martin Rees wrote in Nature last week,5 Darwin closes On the Origin of Species with these famous words: ‘whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning, forms most beautiful and most wonderful have been, and are being, evolved.’  This ‘simple’ beginning–the young Earth, orbiting a rather ordinary star–is itself very complicated, geologically and chemically.  Astronomers aim to probe further back and set our entire solar system in a broader expanse of space and time. Whether we are really approaching an understanding, or just fooling ourselves by limiting our explanatory resources to natural causes, is a lively debate among philosophers and theologians – but not scientists, who presume by default that they do understand.  They are scientists, aren’t they?center_img 1.  Siomi and Siomi, “Insight: On the road to reading the RNA-interference code,” Nature 457, 396-404 (22 January 2009) | doi:10.1038/nature07754. 2.  Jerry Coyne, “Evolution’s Challenge to Genetics,” Nature 457, 382-383 (22 January 2009) | doi:10.1038/457382a. 3.  Chater, Riali and Christiansen, “Restrictions on biological adaptation in language evolution,” Proceedings of the National Academy of Sciences USA, published online before print January 21, 2009, doi: 10.1073/pnas.0807191106. 4.  Fletcher and Doebeli, “A simple and general explanation for the evolution of altruism,” Proceedings of the Royal Society B, Volume 276, Number 1654 / 07 January 2009, pp 0962-8452, 10.1098/rspb.2008.0829. Sometimes the Darwinian silliness comes in so fast we have no choice but to provide snippets of it.  Darwinians really, really need to take some classes in philosophy of science.  Maybe they would understand the deeper issues and controversies about scientific explanation.  If you think scientific explanation must relate to truth about the world, it is highly doubtful that is even attainable through science.  Van Fraasen does not even believe that explanation is even a part of science – this after decades of debates between empiricists and theoreticians over what constitutes an explanation.  Consider the strong possibility that the “scientific explanations” in these articles have no more validity than a bedtime story dressed up in highfalutin jargon.  Scientific realists, who believe their explanations provide valid knowledge about reality, have a very difficult task defending that position in this post-Kuhn intellectual climate.  Without the connection, though, they have no claim to epistemic privilege.     Somehow, the art of storytelling has become honored practice in our scientific institutions.  Look at these waffly, wobbly, insipid excuses for scientific explanations.  The one about altruism is as evil as it is stupid.  Can you imagine the reaction of fellow soldiers in Iraq to the sacrifice of their friend Ross McGinnis (see L.A. Times), if they were told that Ross did what he did only because he got the altruism gene in his genome by chance, just like it had “emerged” in some bacterium by chance in a senseless, godless, material world?  Yet that is exactly what these armchair storytellers said.  If it makes the Darwinists comfortable to invent such fantasies, and then pat themselves on the back that they somehow “understand the world” better thanks to “Darwinian thinking,” you have found no better candidates for the label CLUELESS.  It never enters their thought processes that their explanation cannot possibly be right.  Why?  Because it undermines their own credibility.  Reason disappears.  They were hardwired to publish that paper because they inherited the CLUELESS gene.  It forced them to become Darwinian storytellers.  They could not discern this because CLUELESS produces a mental illness (the Yoda Complex).     We’ve given you a Baker’s dozen of examples to illustrate that evolution is as malleable and ductile as Gumby.  It can fit any possible combination of observations or theoretical conflicts.  Darwinists like to call this explanatory power.  We call it busy work for storytellers.  Storytelling is highly prized in Darwinian circles – within limits.  As long as you never stray outside the boundaries of purposeless, undirected causes, you will have a blossoming sinecure career as A Scientist.  Weep for Francis.  He brought home the Bacon only to have it rot while his heirs gorged on junk food in front of the boob tube.(Visited 16 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more