What'sNEW January-March 2012
For evidence of life elsewhere, NASA's Chris McKay (pictured) says, "Ultimately, you'll have to have a body." Of course, we think Richard Hoover has already produced a body in the form of fossilized germs in carbonaceous meteorites. The review is wide-ranging and enjoyable. Heidi Ledford, "Life-changing experiments: The biological Higgs" [html], Nature.com, 28 Mar 2012.Thanks for the alert, Stan Franklin. The RNA World and Other Origin-of-Life Theories has updates since 1998. Fossilized bacteria in meteorites...: Hoover's evidence, 3 Mar 2011.
X. Bonfils et al., "The HARPS search for southern extra-solar planets XXXI. The M-dwarf sample" [abstract], arXiv:1111.5019v2, 24 Nov 2011. Many billions of rocky planets in the habitable zones around red dwarfs in the Milky Way, EurekAlert! (also ScienceDaily), 28 Mar 2012. ...'Super Earths' Abound Nearby by Sid Perkins, ScienceNow, 28 Mar 2012. Life on Europa, Other Moons, Other Planets? has links to news about other (mostly nearer) possible habitats for life. No theory is too special to question — Giovanni Amelino-Camelia, p125 v438, Nature, 8 Mar 2012.
These two self-described "paleovirologists" are initially interested in reconciling the conflicting ages of viruses given by different methods. The observed mutation rate indicates they are young, but distribution among long-diverged species suggests they are old. The two researchers conclude that viruses are old: In many cases in which EVEs that are closely related to modern viruses could be dated, the minimum age inferred for the most recent ancestor of the viral family has turned out to be far older than was previously estimated using sequence data from circulating viruses. For our part, we want to know how viruses affect evolution. Feschotte and Gilbert notice a lot about that as well: Population genetics predict that, for every fixed EVE insertion, thousands must have occurred in germ cells but were lost from the host population. Nonetheless: Nearly half a million viral insertions have reached fixation in the human genome alone, whereas many more have concurrently colonized other vertebrate lineages.
Examples abound in the literature of ERV-derived sequences that have been incorporated into the 'normal' regulation of mammalian genes, most frequently as promoters, enhancers or polyadenylation signals. ...There are circumstances in which viral gene products have been usefully recruited by the host. ...Through various interactions, viruses have profoundly influenced the evolution of cellular life ever since its origin.
Cédric Feschotte and Clément Gilbert, "Endogenous viruses: insights into viral evolution and impact on host biology" [abstract], doi:10.1038/nrg3199, p283-296 v13, Nature Reviews Genetics, Apr 2012.
Almost a hundred years ago, this distinguished biologist proposed the radical idea that life comes with all of its diversity already available, originally. (The idea is more radical now than it was then, before big bang orthodoxy became dominant in the second half of the twentieth century.) Interestingly, the opening quotation begins with a dependent clause, If then we have to dispense, as seems likely, with any addition from without.... In his day, the theory that life on Earth could arrive from space was little considered, because space was believed to be completely hostile to life. But at least he mentions the possibility. The idea of "evolution as an upacking of an original complex" that comes from "without" — we call that cosmic ancestry.
Roger Sansom, Ingenious Genes, MIT Press, 2011. Bateson could not fathom the addition of inherited factors or mutations that improved their function. Genes Older Than Earth? is a possibly-related local webpage. The Beginning names others who entertained early versions of strong panspermia – a term we have abandoned in favor of simply, "cosmic ancestry." Bateson: We have done with the notion ...that large differences can arise by accumulation of small differences. Weldon, Bateson, and the origins of genetics: Reflections on the unraveling and rebuilding of a scientific community by Lea K. Davis, PLoS Gen, 27 Oct 2022.
But this week..., Pani and colleagues report finding some of the genetic processes that regulate vertebrate brain development in (of all places) the acorn worm (pictured), a brainless, burrowing marine invertebrate.... "Biologists from the University of Chicago and Stanford University conclude that genes containing programs for aspects of vertebrate brain development were present among some species that existed long before the appearance of vertebrates. Although it may not, this news should astound darwinists. How does darwinism account for genes that entirely precede the features they encode? For cosmic ancestry this news is a confirmation, because genes always come first. Ariel M. Pani, Erin E. Mullarkey, Jochanan Aronowicz, Stavroula Assimacopoulos, Elizabeth A. Grove, Christopher J. Lowe, "Ancient deuterostome origins of vertebrate brain signalling centres" [abstract], doi:10.1038/nature10838, p289-294 v483, Nature, 15 Mar 2012.An Evolutionary Surprise: In a brainless marine worm, MBL researchers find the developmental 'scaffold' for the vertebrate brain, Marine Biological Laboratory (also ScienceDaily), 14 Mar 2012. Metazoan Genes Older Than Metazoa? lists many more examples of genes that apparently come first. Testing Darwinism versus Cosmic Ancestry discusses this genomic-analysis method of reconstructing the past. Genes Older Than Earth? is a possibly related local webpage. Thanks for an alert, Ken Jopp.
Also in this analysis, the two major subunits of the ribosome must have functioned independently at some earlier time (not shown in illustration). Chronologically, "We find that components of the small subunit involved in ribosomal processivity evolved earlier than the catalytic peptidyl transferase center responsible for protein synthesis." A problem for this proposal is to explain how proteins were made before there were ribosomes to make them. The researchers propose, "The very early peptide chains were most likely synthesized by primitive means, perhaps through autocatalysis and/or non-ribosomal peptide synthesis, since modern ribosomal translation had not yet evolved." The report is consistent with darwinian philosophy, which assumes that life originated from nonliving chemicals and evolved through many stages before there were cells. We suggest that without these assumptions other interpretations of the data might emerge (as hinted in box at right.) In any case, the research is comprehensive and the accompanying illustrations alone are worth seeing. Meanwhile, here's another contender among origin-of-life theories. Ajith Harish and Gustavo Caetano-Anollés, "Ribosomal History Reveals Origins of Modern Protein Synthesis" [html], doi:10.1371/journal.pone.0032776, PLoS ONE 7(3): e32776, 12 Mar 2012.Study of ribosome evolution challenges RNA World hypothesis by Diana Yates, The University of Illinois (also PhysOrg.com), 12 Mar 2012. Thanks, Stan Franklin. The RNA World... is the main related local webpage. Genes Older Than Earth? has corroboration for Caetano-Anollés' radical suggestion, "...always been the same...."
NASA's team supposes that these amino acids, found in meteorites recovered in Antarctica, were made by catalysed chemical reactions in space, even though harmful contaminants would be present. We wish NASA would at least mention the fact that life makes amino acids, and ask if they could have eventually degraded into the ones observed. Instead, NASA comments that chemically produced amino acids must be abundant in space and could provide starter ingredients for an origin-of-life almost anywhere. With resignation, we welcome this added support for pseudo-panspermia. At least it's something.
Aaron S. Burton et al., "A propensity for n-ω-amino acids in thermally altered Antarctic meteorites" [abstract], doi:10.1111/j.1945-5100.2012.01341.x, Meteoritics & Planetary Science, online 8 Mar 2012.
There is no reason to think that this mechanism would be unique to the evolution of the C4 pathway. As more genomic data accumulate for other taxa, additional cases of adaptive plant-plant nuclear gene transfers may be discovered, in a great variety of adaptive traits. In cosmic ancestry, lateral or horizontal gene transfer (HGT) supplies the genes for new features. Mainstream darwinian theory, however, expects genes for new features to be composed by trial-and-error on a virtually blank slate, during vertical inheritance. Evidence for HGT is abundant and growing rapidly. By comparison, evidence for the mainstream account of new genes seems awfully thin. We welcome pointers to counterexamples.
Pascal-Antoine Christin et al., "Adaptive Evolution of C4 Photosynthesis through Recurrent Lateral Gene Transfer" [abstract | pdf], doi:10.1016/j.cub.2012.01.054, p445-449 v22, Current Biology, 16 Feb 2012.
Ricardo Acuña, Beatriz E. Padilla et al., "Adaptive horizontal transfer of a bacterial gene to an invasive insect pest of coffee" [abstract], doi:10.1073/pnas.1121190109, Proc. Natl. Acad. Sci. USA, online 27 Feb 2012.
Marc Kaufman, First Contact: Scientific Breakthroughs in the Hunt for Life Beyond Earth [publisher's promo], ISBN: 9781439109014, Simon & Schuster, Apr 2011. "If life is found on Mars or Europa.... Feeling at home in nature suddenly has a very different, much bigger meaning" (p14).
We have long thought that "immune warfare" like this is analogous to code-breaking and the defenses against it. Code-breaking uses exhaustive search to find the combination or key, and the best defense is frequently-changed keys. Those cyber-activities do nothing that would compose new programs for new features.
However, the molecular biologists conducting this experiment, including Richard Lenski and members of his group at Michigan State University, think more has happened. They believe that host-recognition proteins on the surface of a virus are analogous to the full multitude of enzymes catalyzing all of the reactions in life. If so, a newly evolved one would illustrate how all of those enzymes could have evolved. In this case anyway, we suspect not. If, for example, the observed phenomenon of "directed mutation" were acting on the correct 5 nucleotides, only 4^5 = 1,024 trials would likely produce the needed combination of mutations. If it were focussed even on ten nucleotides (4^10 = about a million), the right combination might still be within reach. (To us, directed mutation is further implicated in this experiment, because out of 40 mutations that became fixed in the alleles of the subject gene —most of them several times— all were nonsynonymous. If the mutations were strictly random, this is highly unlikely.) In our opinion, this change would fall into the category of microevolution, which is capable of code-breaking, of which this development appears to be an example. This evolution is quite different, we believe, from the discovery of most of life's enzymes. In general, each enzyme exists in a family which is itself removed from other families by, not 5 or 10, but up to hundreds of nucleotide substitutions, additions or deletions. That means that the number of needed trials to probably derive a new one from an existing one could be 4^hundreds = far too many. The report begins, "The processes responsible for the evolution of key innovations, whereby lineages acquire qualitatively new functions that expand their ecological opportunities, remain poorly understood." Later it states, "...Natural selection is critical for the process of adaptation, yet its role in producing key innovations is less clear because, by fixing variants that improve existing functions, selection might strand populations on local adaptive peaks and thereby prevent them from discovering new functions." Apparently, not everyone had gotten the word before now. We should mention that the article is largely about coevolution between the virus and its host, on which we scarcely comment. For an analysis that comments fully on it, by an expert in biochemistry, we recommend Michael Behe's, linked below. Finally, we think that quarantined experiments in biology are the best way to explore the power and range of strictly darwinian evolution in life, and that Richard Lenski's group conducts the best ones of them. That's why we pay attention to their reports.
Justin R. Meyer et al., "Repeatability and Contingency in the Evolution of a Key Innovation in Phage Lambda" [abstract], doi:10.1126/science.1214449, p428-432 v335, Science, 27 Jan 2012.
Svetlana Yashina et al., "Regeneration of whole fertile plants from 30,000-y-old fruit tissue buried in Siberian permafrost" [abstract], doi:10.1073/pnas.111838610, Proc. Nat. Acad. Sci., USA, online 21 Feb 2012.
"The answer might come from NASA's Mars Science Laboratory rover, called Curiosity, scheduled to land on Mars in August 2012, carrying with it the Sample Analysis at Mars (SAM) suite, which will measure a multitude of trace constituents and isotopes from gas and solid samples. ...A more comprehensive test is planned in 2016 with the ExoMars Trace Gas Orbiter (TGO), which will be part of the joint ESA/NASA dual mission ExoMars Program. The TGO will scan the atmosphere for exotic trace gases, such as methane." Of course, we think Mars' methane could come from methanogenic life there. NASA: "The Conditions for the Emergence of Life were Present on Mars – Period, End of Story", The Daily Galaxy, 17 Feb 2012.Life on Mars! is a related local webpage. Search for "methane". Thanks, Stan Franklin.
Earthlike extrasolar planets are one of Sasselov's specialties, and he easily gets the reader up to speed about them by recounting the relevant developments in history, chemistry, astronomy and other related fields. I thought I already knew this stuff, but I had never heard of, for example, ice VII, ice X and ice XI that are denser than liquid water and would be found on oceanic super-Earths. Most of the extrasolar planets discovered so far are gas giants, like Jupiter. These would be unlikely to harbor life, at least not life as we know it. Our kind of life needs minerals and a variety of things found only on rocky, "Earthlike" planets. That's why they especially interest Sasselov. And he has helped to pioneer methods for detecting them. Beyond finding them, he has thought deeply about how life would flourish on them. He concludes that life would have an easier time on ones that are larger than Earth — hence, "super-Earths." Sasselov also knows big bang cosmology thoroughly, and describes the universe as "young." If so, the minerals needed for life are even younger, and life must originate from nonlife, as is the consensus. He overrates the progress of the RNA World, writing, "RNA ...is capable of catalyzing its own replication" (p136). At best, these would be very short strands, in entirely unnatural environments. And he says nothing about the software aspect of the origin-of-life problem, but this is wise, because there is nothing to say. Notably, he finds interplanetary panspermia "quite plausible" (p157).
Finally he promotes synthetic biology as one of the three great milestones in human history. Now we can create a new kind of life with its own separate tree. His enthusiasm for it is palpable. In all, the book tells an enjoyable, entertaining, informative story. I am going to read it again. Dimitar Sasselov is a Professor of Astronomy at Harvard University and the founding director of the Harvard Origins of Life Initiative. Dimitar Sasselov, The Life of Super-Earths: How the Hunt for Alien Worlds and Artificial Cells Will Revolutionize Life on Our Planet [publisher's promo], ISBN-10: 046502193X, 240 pages, Basic Books, 24 Jan 2012.Dimitar Sasselov discusses his book..., Harvard Book Store, 17 Feb 2012. Thanks for a link, Pam Pacelli.
Instruments, Methods, and Missions for Astrobiology XV, San Diego Convention Center, San Diego CA, USA, 12-16 Aug 2012.
The poster isolates a single filament cropped from one of Hoover's photographs, while the original, uncropped FESEM image shows a dozen or so filaments. These have sizes and detailed morphologies that are consistent with known genera and species of cyanobacteria — far more convincing evidence than a single filament. But Fries compares this one (top) to an extrusion of clay squeezed through the perforated cap of a plastic soda bottle (bottom). The cropping from Hoover's photo also omits the scale bar, allowing the clay extrusion to look smaller, although it is actually larger by three orders of magnitude. If the clay extrusion were imaged with a Scanning Electron Microscope at comparable magnification and resolution, the superfucial resenblance would vanish entirely. Yet, following this comparison, Fries claims that the microfossils in Orgueil, which Hoover interprets as the remains of cyanobacteria, are merely extrusions from magnesium sulfate veins in the stone. It is hard to take this criticism seriously. We think Fries must be joking. Richard Hoover's photographs of fossilized microorganisms in carbonaceous meteorites have been studied by the world's leading experts on cyanobacteria and micropaleontology and identified as biological. NASA astrobiologist Chris McKay, for one, commented, "If these structures had been reported from sediments from a lake bottom there would be no question that they were classified correctly as biological remains." We urge anyone who may be curious to look closely at the full evidence.
Marc Fries, "'Life in CI Chondrites': Not Life, Not Extraterrestrial, Not Even Interesting." [6035.pdf], presented at the Planetary Sciences Institute's Conference on Life Detection in Extraterrestrial Samples, San Diego CA, 12-15 Feb 2012.
Do Alien Civilizations Inevitably 'Go Green'? by Paul Scott Anderson, Universe Today, 8 Feb 2012.
The drilling took 20 years, and preventing contamination of the lake was a major concern. When the lake was penetrated, water rushed upward into the borehole as expected, flushing the drilling fluid and its potential contamnants away. This water then quickly froze, sealing contaminants out. The testing of water samples is postponed until spring returns to Antarctica. Drilling successful as scientists break through into lake buried miles under Antarctic ice by Rob Cooper and Thomas Durante, The Daily Mail, 9 Feb 2012.Lake Vostok, Antarctica's Hidden Lake, Reached By Russia, AP, Huffington Post, 8 Feb 2012. Russians Drill Into Subglacial Antarctic Lake Vostok by Carolyn Gramling, ScienceInsider, 8 Feb 2012. In scientific coup, Russians reach Antarctic lake by Vladimir Isachankov, AP, Physorg.com, 8 Feb 2012. Lake Vostok, Antarctica's Largest Subglacial Body Of Water, Reportedly Drilled By Russians, Huffington Post, 6 Feb 2012. Scientists close to entering Vostok, Antarctica's biggest subglacial lake by Marc Kaufman, The Washington Post, 31 Jan 2012. Life on Europa, Other Moons, Other Planets? is a related local webpage. Carolyn Gramling, "A Tiny Window Opens Into Lake Vostok, While a Vast Continent Awaits" [summary], p788-789 v335, Science, 17 Feb 2012. Thanks for an alert and a link, Stan Franklin.
...Why So Many Homeless Planets? by Bruce Dorminey, ScienceNow, 17 Jan 2012. Chandra Wickramasinghe says billions of Alien Planets discovered imply life everywhere by Walter Jayawardhana, The Sinhalaya News Agency, Colombo, Sri Lanka, 22 Jan 2012. Some Planets Are Alien Invaders by Ken Croswell, ScienceNOW, 21 Feb 2012. Smadar Naoz et al., "Hot Jupiters from secular planet-planet interactions" [abstract], doi:10.1038/nature10076, p187-189 v473, Nature, 12 May 2011. 'Homeless' Planets May Be Common in Our Galaxy by Jon Cartwright, ScienceNow, 18 May 2011. Life on Europa, Other Moons, Other Planets? is a local webpage with links about possible life on nearby moons and planets. How Is It Possible? cites telescopic evidence for a planet expelled from its orbit, but this case was not sustained.
A. Cassan et al., "One or more bound planets per Milky Way star from microlensing observations" [abstract], doi:10.1038/nature10684, p167-169 v481, Nature, 12 Jan 2012. Robert Lee Hotz, "An Otherworldly Discovery: Billions of Other Planets" [4+ min. video], pA2, The Wall Street Journal, 12 Jan 2012. Planets around stars are the rule rather than the exception by Anne M Stark, Lawrence Livermore National Laboratory, 11 Jan 2012. Life on Europa, Other Moons, Other Planets? is a related local webpage with links about possible life on nearby moons and planets. Thanks, EurekAlert!
Much of what living cells do is carried out by "molecular machines" - physical complexes of specialized proteins working together to carry out some biological function. How the minute steps of evolution produced these constructions has long puzzled scientists, and provided a favorite target for creationists. To probe this puzzle, Thornton and his team reconstructed the evolution of one such molecular machine, a "proton pump" that maintains acidity in cellular compartments in many species. This machine includes a subunit made of six proteins forming a ring (colored in figures). These six proteins usually exist in two kinds, but in fungi the ring has three kinds of proteins. How did the increased complexity of the fungal version evolve, they ask. This evolutionary step apparently took place more than 800 million years ago, so it is obscured in the deep past. We admire their work to make this reconstruction plausible. The geneticists conclude that, following gene duplications, paralogs of an original protein underwent mutations and diverged slightly. Only one or two amino acid substitutions reduced their capability to link together as before — a loss-of-function. After that, the proteins could link together only in a specific order to complete the ring structure. That is the likeliest explanation for the complication of the fungal version of the six-protein ring. (The logic is well illustrated in commentary by molecular biologist W. Ford Doolittle, and further elaborated in a subsequent article by Deeds et al.) Following this reconstruction of events, Thornton comments, "Gene duplications happen frequently in cells, and it's easy for errors in copying to DNA to knock out a protein's ability to interact with certain partners. It's not as if evolution needed to happen upon some special combination of 100 mutations that created some complicated new function." Thornton proposes that the accumulation of simple, degenerative changes over long periods of times could have created many of the complex molecular machines present in organisms today. (John Eastman, press release, linked below.) We are relieved to know that darwinists have been puzzled by something nontrivial, but we think the new analysis does not justify Thornton's broad conclusion. First, the slightly more complicated fungal protein pump does no more than the simpler version did, so no new function was gained. More importantly, the conclusion ignores something obvious. Paralogs that vary slightly from the original are ubiquitous and easy to explain, but the first version, the "original," remains unexplained. While paralogs relate to each other, the whole family usually lies well-isolated (>100 mutations removed?) in nucleotide sequence space. If it were not so, identifying and naming gene families would be much more difficult. In brief, the divergence of paralogs does nothing to explain the existence of a paralog family. And the divergence of these specific proteins does not in any way account for the creation of the proton pump of which they are parts. This research is quite commendable, but its implications are being exaggerated. The apparent motive for this exaggeration it to suppress criticism, as hinted in the media release. But understanding the world is the proper motive for science. When understanding is adequate, criticism does not need suppression.
Gregory C. Finnigan, Victor Hanson-Smith et al., "Evolution of increased complexity in a molecular machine" [abstract], doi:10.1038/nature10724, Nature, online 9 Jan 2012. | ||||||||||||||||||||||||||||||
COSMIC ANCESTRY | Quick Guide | Site Search | What'sNEW - Later - Earlier - Index | by Brig Klyce | All Rights Reserved |