What'sNEW April–June 2009
More than 20% of diatom genes were apparently recruited from red and green algae. The process probably began with endosymbiosis, when the algae were engulfed as organelles within cells ancestral to diatoms, but the recruited genes are now incorporated into the diatoms' nuclear genomes. Endosymbiosis is horizontal gene transfer (HGT) in wholesale form, and the subsequent migration of organellar genes into the eukaryotic nucleus is a well known phenomenon. However, other more piecemeal forms of HGT might also account for some of the transferred genes, according to an international research team. Examples of HGT in any form are consistent with evolution by cosmic ancestry.
...Some microbes thrive at ...10 times the salinity of seawater.
The tree of life was always a net. Nature was always a genetic engineer.  Stefan Helmreich, Alien Ocean: anthropological voyages on microbial seas, ISBN-10: 0520250613, University of California Press, 5 Jan 2009. (p 103) The Tree of Life is a related webpage.
A novel bacterium that has been trapped more than three kilometres under glacial ice in Greenland for over 120,000 years, may hold clues as to what life forms might exist on other planets. This is what astrobiologists are saying about Herminiimonas glaciei, recently found and cultured by a team at Penn State. The bacteria are small enough to pass through a normal sterilizing filter, and culturing them was tedious. But could their hardiness enable them to survive on a place like Europa? These extremely cold environments are the best analogues of possible extraterrestrial habitats, said team leader Jennifer Loveland-Curtze.
...Metabolically active microbes were reported in 111-million-year-old sediments buried as deep as 1.6 kilometres below the seabed. This is among the surprises in a recent article about prokaryotes that can survive in harsh deep environments. Some of them may reproduce only once per thousand years. Some can persist solely on energy that comes from radioactivity. Astrobiologists are wondering why they couldn't live on other planets. We think they probably could.
Formic acid ...has been found at record levels on a meteorite that fell onto a frozen Canadian lake in 2000. The University of Alberta's meteorite curator Chris Herd (pictured with sample) reported this finding to the American Geophysical Union in Toronto in May. The Tagish Lake meteorite is an especially pristine one; organic compounds in it are unlikely to be earthly contaminants. Organics from space are usually called "prebiotic", but we think they could as well be "postbiotic".
Astrobiologist Richard Hoover discusses his work in a new short video. In five minutes he describes extremophiles that could apparently survive in ice on Mars or Europa, and microfossils that resemble microbial life, found inside carbonaceous meteorites (see example). One microfossil in the Murchison meteorite was seen for the first time as the video was being filmed.
The enemy has become more diverse, says anthropologist Eugenie Scott, executive director of the National Center for Science Education. "Darwin's golden retriever," as she likes to be known, Scott was recently interviewed for Science magazine. In the quoted phrase she may be acknowledging the fact that some who see problems with the mainstream theory of evolution have no agenda beyond science. But she categorizes them all as "the enemy," keeping the discussion strongly polarized and superficial. This tactic impedes scientific progress. 
The mainstream theory of evolution has no credible acount of the origin of life, certainly. Acknowledging this, Scott stubbornly says, "Not yet." Alchemists trying to turn lead into gold said the same thing. Also unexplained are the genetic programs contained within DNA. Darwinan mutation-and-natural-selection is supposed to compose them, but direct evidence for this composing is lacking. Instead, darwinan mutation-and-natural-selection can be seen only to toggle, shuffle and optimize programs that are already present in a given genome. New genetic programs often appear suddenly during evolution; many are known to arrive by gene transfer (HGT). But Scott would minimize the importance of HGT and assert that evidence for the mainstream account of new genetic programs is abundant. In a similar manner, Galileo's opponents held that Ptolemaic astronomy was perfectly adequate. Given the described shortcomings, it is no surprise that a majority of Americans are not satisfied with the mainstream theory of evolution. Apparently, the National Center for Science Education sees a majority of Americans as "the enemy." Such animosity from the science establishment is unwarranted and, to our knowledge, unprecedented.
...In 1995, Craig Thompson, then at the University of Chicago in Illinois, formally proposed that the DNA now encoding RAG1 and RAG2 was once a mobile genetic element called a transposon. ...In 2006, a team led by Jonathan Rast of the University of Toronto in Canada and Sebastian Fugmann of the National Institute on Aging in Bethesda, Maryland, analyzed the genome of the purple sea urchin and found genes that closely resemble RAG1 and RAG2, the first time they've been uncovered in invertebrates. In cosmic ancestry, evolutionary innovations depend on genetic programs acquired by various means of horizontal gene transfer (HGT). These programs must necessarily reside silently somewhere before they arrive in species that can use them. The programs would need a means of transfer such as viral or bacterial infection. And they would need tools and systems within the acquiring genome to place and assemble them correctly. Of course, every element of this scenario is already well observed. If evolutionary innovations emerge as cosmic ancestry predicts, the immune system of jawed vertebrates makes a striking example.
And an international team proposes that dissolved minerals can explain saline liquid water activity on the surface of Mars at mean global temperatures well below 273 K.
A renowned physicist, Dyson was among nine distnguished scientists who spoke at a two-day public symposium sponsored by The Harvard-Smithsonian Center for Astrophysics and The Harvard Origins of Life Initiative, held during the Cambridge Science Festival. Others speakers included Harvard Astronomy Professor David Charbonneau (left), and University of Washington paleontologist Peter Ward (right). Panspermia was favorably mentioned by several of the speakers, including Dimitar Sasselov, who heads the Harvard Origins Initiative. Because impacts can launch life-bearing material into space, he said, "Panspermia is the future of the galaxy."
Inserting RNA molecules into an RNA First scenario without explaining how they got there seems to us an inadequate foundation for an origin theory. The RNA molecule is too complex, requiring assembly first of the monomeric constituents of RNA, then assembly of strings of monomers into polymers. As a random event without a highly structured chemical context, this sequence has a forbiddingly low probability and the process lacks a plausible chemical explanation, despite considerable effort to supply one.
The hope is that when a full theory is available, we will see the formation of life as an inevitable outcome of basic thermodynamics, like the freezing of ice cubes or the formation of magnets. We admire the optimism and imagination of origin-of-life theorists, but we have questions:
James Trefil, Harold Morowitz and Eric Smith, "The Origin of Life," doi:10.1511/2009.78.206, American Scientist, Mar-Apr 2009. What Is Life? is a related local webpage. The RNA World is our main webpage about origin-of-life theories. The Second Law of Thermodynamics is a related local webpage. Thanks, Stan Franklin.
It's hard to imagine a planet's surface exhibiting handedness without the presence of self assembly, which is an essential component of life — Thom Germer, physicist, the National Institute of Standards and Technology. A team at NIST is working on a system for detecting life on other planets by looking at the light reflected from their surfaces. If the light exhibits a biased circular polarity, it is probably coming from living surfaces, they believe. They think this signal would be present even if the life there is chemically unlike Earthly life. Chirality has already been studied in carbonaceous meteorites. In a recent study of six of them, all six contained amino acids that were predominantly left-handed, like Earthly life. We think NIST's logic for planets should apply to meteorites as well. The chiralty observed in them is easily understood if their parent bodies once harbored Earth-like life whose amino acid remnants still bear traces of left-handedness.
Complex organic molecules were once thought to come from only biological processes, so finding them in space, beginning in the 1960s, was a surprise. Now more than a hundred different ones have been observed, and nonbiological processes to explain them are being proposed. We think biological processes should be considered. Life is far more efficient than nonlife at making organic molecules.
DNA analysis reveals that the pool contains species similar to known marine microorganisms, but they must be ones that can survive "without the food and light sources available in the open ocean." By logic, the genetic programs enabling the necessary new metabolic processes must have become effective promptly when food and light were sealed out by the glacier. Otherwise — even if the various species could remain viable by going dormant — metabolism and evolution would cease. Their prompt availability suggests to us that the programs were pre-existing. The research team wonders if similar life could survive, "perhaps even on other icy planets in the solar system such as below the Martian ice caps or in the ice-covered oceans of Jupiter's moon Europa." Why not?
Still, darwinists maintain that HGT is of minor importance among eukaryotes. But important examples have now been documented too often to keep count. The studied marine algae simply add to the evidence that HGT is crucial for eukaryotic evolution as well. As genomic databases grow, darwinists expect the number of genes without known orthologs to decrease. This is not happening. Also, darwinists expect genes for given features to be found only in organisms that exhibit those features. Otherwise, the unnecessary genes would lack the pressure of natural selection and degrade. Moreover, they would never have had the benefit of natural selection to help them form in the first place. Yet many examples of such unnecessary genes have been documented. The recent analysis adds to that list. In cosmic ancestry, all genes are very old. They would naturally be sometimes found in species that don't use them. Among eukaryotes, processes like gene conversion may help to preserve the silent genes from degradation. By HGT, species that can use them may eventually acquire the genes, and an evolutionary advance may ensue. We think the evidence supports this scenario. The recent analysis of marine algae does not surprise us.
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COSMIC ANCESTRY | Quick Guide | What'sNEW - Later - Earlier - Index | by Brig Klyce | All Rights Reserved |
A Survivor in Greenland: A Novel Bacterial Species is Found Trapped in 120,000-Year-Old Ice
In what has been called the "big bang of immunology," most vertebrates later evolved a second form of immunity, in which white blood cells exquisitely targeted to a specific pathogen are rallied and then maintained in the body as an immune memory. This "adaptive" arm seemed to have appeared out of nowhere some 450 million years ago and may be the serendipitous outcome of invading DNA introduced by a virus or microbe infecting a fishlike creature.
Rivers flowed on Mars more recently than once believed. To ascertain this a team at Brown University studied high-resolution images of the Lyot crater taken by the Mars Reconnaissance Orbiter. Although it was formed only about a billion years ago, the crater contains river channels up to 50 km long. The crater floor is 7,000 meters deep, so surface air pressure would likely have been high enough for meltwater from underground glaciers to persist in a liquid state. Liquid water would have allowed life to grow on Mars.
Freeman Dyson thinks panspermia is more likely if life can adapt to the vacuum of space. In Cambridge MA on May 2, he went on to say that we should look for forms of extraterrestrial life that are easiest to find, not ones that we consider most likely to exist. For example, plant-like life on the surface of a dimly lit planet or moon would need a light-concentrating aparatus such as a parabolic mirror or a lens. Such life would shine brightly when viewed from the direction of its source, like a deer's eyes in the headlights, suggested Dyson (pictured, center).
In their Metabolism-First scenario a simplified version of the Krebs cycle originally ran backward, using carbon dioxide and hydrogen to produce water and acetate (right). They believe that this cycle could arise naturally, and could acquire "further elaborations" enabling it to produce more complex organic molecules. Hopefully, a way to exclude the harmful byproducts will become apparent, they note. Later the system could come under the control of RNA molecules and begin to resemble life as we know it. They suggest that, this way, "the early stages in the emergence of life are no more surprising, no more accidental, than water flowing downhill."
Two new complex organic molecules have been seen toward the center of our galaxy. Ethyl formate (right) and n-propyl cyanide were detected by astronomers analysing spectra gathered at the 30-meter IRAM telescope in southern Spain.
Microbial life trapped in darkness under ice accounts for the "Blood Falls" at the snout of Taylor Glacier in Antarctica. An international interdisciplinary team shows that the staining brine leaks from a hidden pool of iron-rich, oxygen-poor, hyper-saline seawater. The pool was trapped some 1.5 to 4 million years ago when the glacier closed over it. To account for the chemicals and isotope ratios observed in the discharge, the team proposes that a metabolically active ecosystem, with microbes converting ferric iron to ferrous iron, creates food and energy in the pool. When the brine episodically leaks onto the surface 4 km away, the ferrous iron "rusts" and turns red.
