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... -Jun 1997 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Extraterrestrial Handedness Human life forms favor right-handedness over left-handedness by a 9:1 ratio. Other terrestrial animals are also asymmetrical in various ways. But on the molecular level, terrestrial biochemistry is all left-handed. As far as scientists can determine, only left-handed amino acids are incorporated into proteins. In nonlife (if such a state really exists), amino-acid molecules are right- and lefthanded in equal numbers -- as least this has been the theory up until now. Amino acids are found in substances we assume are non-life or of abiotic origin. In fact, amino acids are present in meteorites, often in substantial amounts. ... are profuse in Australia's Murchison meteorite, a carbonaceous chondrite. However, analysis of the Murchison's amino acids indicates that there are slightly more (7 -9 %) left-handed than right-handed amino acids present. This extraterrestrial handedness is of great import to both cosmologists and biologists, because the carbonaceous chondrites are thought to have formed 4.5 billion years ago -- long before life on earth originated. Furthermore, some of the Murchison's amino acids have never been found in terrestrial life, and they are also slightly left-handed. For some unfathomed reason, chemical and biological evolution both tilt to the left! (Bada, Jeffrey L.; "Extraterrestrial Handedness?" Science, 275:942, 1997. Cronin, John R. ...
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... Sourcebook Subjects It's according to hoyle and wickramasinghe The June 17, 1994 issue of Science did not ignore it. In fact, this conservative journal devoted almost an entire page to a paper presented by Yi-Jehng Kuan and Yanti Miao at the recent Minneapolis meeting of the American Astronomical Society. Students of L. Snyder, at the University of Illinois, Kuan and Miao reported that the amino acid glycine had been detected in a molecular cloud named Sagittarius B2. Glycine has only ten atoms and is the smallest of the 20 amino acids vital to life-as-we-know-it. The Science article supposed that this discovery of extraterrestrial glycine might reignite speculation that earth life might not be unique after all. (Travis, John; "Hints of First Amino Acid outside ... System," Science, 264:1669, 1994.) Structure of the amino acid glycine What Science did not mention but New Scientist did is that F. Hoyle and C. Wickramasinghe have long predicted that the molecules of life, as well as life itself, would be found in outer space. Now, after much ridicule, they are being vindicated. "It's been a long hard struggle," said Hoyle. Wickramasinghe remarked that the discovery was "no surprise at all." "He believes it is only a matter of time before other amino acids, together with nucleotide bases, the components of nucleic acids that make up genetic material, are found in space. 'This is just the tip of the iceberg,' he says. 'I would fully ...
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... Subjects Prebiological chemistry in titan's atmosphere From the abstract of the referenced paper: "An organic heteropolymer (Titan tholin) was produced by continuous dc discharge through a 0.9 N2 / 0.1 CH4 gas mixture at 0.2 mbar pressure, roughly simulating the cloudtop atmosphere of Titan [one of Saturn's moons]. Treatment of this tholin with 6N HCl yielded 16 amino acids by gas chromatography after derivatization to N-trifluroacetyl isopropyl esters on two different capillary columns...The presence of 'nonbiological' amino acids, the absence of serine, and the fact that the amino acids are racemic within experimental error together indicate that these molecules are not due to microbiol or other contamination, but are derived from the tholin...These results suggest that episodes ... liquid water in the past or future of Titan might lead to major further steps in the probiological organic chemistry on that body." (Khare, Bishun N., et al; "Amino Acids Derived from Titan Tholins," Icarus, 68:176, 1986.) From Science Frontiers #49, JAN-FEB 1987 . 1987-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 115: Jan-Feb 1998 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Why did life take a left turn?Life-as-we-know-it is left-handed; that is, our amino acid molecules are levorotatory rather than the mirror-image dextrorotatory versions. Because humans "expect" symmetry in nature, it is taken for granted that everything else in the universe is split equally between leftand right-handed molecules. Earth life is just a fluke -- or is it? On September 28, 1969, organic-rich stones fell in Victoria, Australia. This was the Murchison meteorite, and it may carry a message. Over a decade ago, M.H . Engel ... B. Nagy reported that the organic molecules in the Murchison meteorite were not split 50:50 between left- and right-handed versions. So contrary to expectations was this finding that most scientists assumed that the analysis was contaminated by terrestrial organic molecules. Now, M.H . Engel and S.A . Macko have refined the analytical techniques and apparently avoided any taint of contamination. Their conclusion: the Murchison amino acids still lean to the left. From all this arise several intriguing possibilities: Life on earth started split evenly between left- and right-handed amino acids, but was nudged to the left by the influx of organic-laden meteorites like the Murchison. Terrestrial life actually originated elsewhere in the universe where much matter is left-handed, including life, if it ...
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... the adjective "organic" may be premature, but in light of the next item, maybe not. (2 ) Carbonaceous chondrites . This well-known class of meteorites sometimes appears tarry and is characterized by carbon contents of up to 2% and more. The Japanese have just reported the analysis of Yamoto 791198, a carbonaceous chondrite picked up in the Antarctic. This meteorite is loaded with amino acids, 20 kinds of them. These extraterrestrial amino acids are not considered biogenic because they are half left-handed and half right-handed; whereas all amino acids synthesized by terrestrial animals, plants, etc. are left-handed. [This is obviously presumptious because we have no notion how extraterrestrial life works, assuming it exists at all.] (3 ) The rings of ... . Voyager photos reveal that these rings are composed of unknown dark material quite unlike that in the high-albedo (bright) rings of Saturn. References. (Kerr, Richard A.; "A Comet's Heart May Be Big But Black," Science, 229:372, 1985. Also: Emsley, John; "Amino Acids from Outer Space," New Scientist, p. 30, December 19/26, 1985. Also: Anonymous; "Fine Particles Viewed in Uranus' Rings Leave Scientists 'Happily Bewildered'." Baltimore Sun, January 28, 1986.) Comment. How and where is star sludge manufactured? Again we have to venture that the venerable "primordial soup" in which life mysteriously assembled itself is located in outer space rather than ...
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... high iridium concentrations at the Cretaceous-Tertiary (K -T ) boundary, some 65 million years ago, has led to the widely accepted notion that an extraterrestrial projectile slammed into the earth at that time, wreaking geological and biological havoc. But the K-T boundary is anything but simple chemically and paleontologically. To illustrate, J.L . Bada and M. Zhao have found unusual amino acids in sediments laid down before and after this geological time marker. "They find that Danish sediments spanning the narrow boundary layer contain two amino acids, alpha-aminoisobutyric acid and isovaline, that are relatively uncommon in biological materials but abundant in the organicrich meteorites. They suggest that the body which collided with Earth 65 million years ago and left the telltale iridium residue may have been organic- ... , perhaps like a C-type asteroid or a comet. Such a possibility has interesting implications for the extinction and related atmospheric effects, and supports the idea that impact events could have supplied the Earth during a much earlier period with the raw materials for organic chemical evolution." Actually, the above quotation is pretty much in line with present mainstream thinking. Perhaps so, but Bada and Zhao identified two troubling anomalies. First, the amounts of amino acids found were surprisingly high. How could these complex molecules survive the searing temperatures engendered by high-velocity impact? Second, the amino acids may be abundant tens of centimeters above and below the K-T boundary clay containing the iridium, but they are virtually absent in the clay itself! (Cronin, John R.; " ...
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... 1987 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Meteorites Also Transport Organic Payloads Excerpts from the Abstract of a paper printed in Nature: "Much effort has been directed to analyses of organic compounds in carbonaceous chondrites because of their implications for orgainc chemical evolution and the origin of life. We have determined the isotopic composition of hydrogen, nitrogen and carbon in amino acid and monocarboxylic extracts from the Murchison meteorite. .. .. . "These results confirm the extraterrestrial origin of both classes of compounds, and provide the first evidence suggesting a direct relationship between the massive organo-synthesis occurring in interstellar clouds and the presence of pre-biotic compounds in primitive planetary bodies." (Epstein, S., et al; "Unusual Stable Isotope Ratios ... Amino Acid and Carboxylic Acid Extracts from the Murchison Meteorite," Nature, 326:477, 1987.) From Science Frontiers #52, JUL-AUG 1987 . 1987-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 117: May-June 1998 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Terrestrial Life Is Ambidextrous But only slightly so! In SF#115, we asked whether right-handed organic molecules can be found in any terrestrial life forms. E. Clark answered as follows: "D -amino acids [right-handed amino acids] do occur fairly often in bacterial cell walls and other microbial products such as antibiotics. When I was first introduced to this fact, I was intrigued and I wondered if the presence of D-amino acids in these large molecules might indicate that there was something special about the way they were synthesized -- perhaps, for example, that they essentially assembled themselves without the need ... individual synthetic enzymes at each synthetic step." (Clark, Ed; personal communication, February 28, 1998.) Comment. So, right-handed molecules are not forbidden on earth, but we are still faced with that great preponderance of left-handed molecules. What "force" is at work here, or is this just the way things are? We should not settle for the latter interpretation. From Science Frontiers #117, MAY-JUN 1998 . 1998-2000 William R. Corliss ...
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... Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Mind Before Life For some years S.W . Fox, at the Institute for Molecular and Cellular Evolution, University of Miami, has been experimenting with possible precursors of life. So-called "microspheres" are hot items in Coral Gables these days. Fox and his colleagues make microspheres by preparing a heated stew of various amino acids. These amino acids form long polymer chains spontaneously. Then, when water is added and the mixture reheated (or processed in some other way), the polymers organize themselves, again spontaneously, into spheres a few microns in diameter. Each sphere consists of a two-layer membrane with residual material trapped inside. Although thicker, the microsphere membrane is very similar to the lipid bi ... layer enclosing normal living cells. The relatively stable microspheres could, in theory, have formed sheltered environments for the evolution of the more complicated parts of living cells. The microspheres absorb sunlight and, with the addition of this energy, display some of the electrical characteristics of biological neurons, like those in the brain. The implication is that some components of "mind" may have existed in the very earliest life forms. (Peterson, Ivars; "Microsphere Excitement," Science News, 125:408, 1984.) Comment. Two comments here: First, the word "spontaneous" is customarily employed when describing how atoms unite to form molecules and molecules combine into polymers, which then gather into microspheres. The word "spontaneous" seems to imply chance is operating rather than design ...
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... 48: Nov-Dec 1986 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Cosmic Chemistry Of Life C. Ponnamperuma, at the University of Maryland, speculates that the genetic code employed by earth life may, in fact, reflect a universal chemistry. His lab data "suggest that the formation and linking of life's building blocks -- amino acids and nucleotides -- may have been all but inevitable, given the starting chemistry of earth's 'primordial soup.'" Going even further Ponnamperuma believes that "if there is life elsewhere in the universe, chemically speaking it would be very similar to what we have on earth." (Raloff, J.; "Is There a Cosmic Chemistry of Life?" Science ... , 130:182, 1986.) From Science Frontiers #48, NOV-DEC 1986 . 1986-2000 William R. Corliss ...
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... far beyond his previous thesis, which in essence declared that from statistical considerations life could not have arisen and evolved on earth. Rather, life had to come from outer space, probably in the form of bacteria and viruses. Evolution was and is dependent upon new information arriving from outer space on tiny bits of life. Hoyle now greatly extends his theory: "But where did a knowledge of amino acid chains of enzymes come from? To use a geological analogy, the knowledge came from the cosmological equivalent of a previous era, from a previously existing creature if you like, a creature that was not carbon-based, one that was permitted by an environment that existed long ago. So information is handed on in a Universe where the lower symmetries of physics -- and characteristics of ... and atoms -- are slowly changing, forcing the manner of storage of the information to change also in such a way as to match the physics. It is this process that is responsible for our present existence, and it is the one which our descendants would be fated to continue." To continue his search for the ultimate, Hoyle recognizes that, contrary to what transpires in the inorganic world, life as-a -whole is actually gaining order and information. He sees life leading the universe forward to a remarkable future: "That biological systems are able in some way to utilise the opposite time-sense in which radiation propagates from future to past. Biology works backwards in time. Living matter responds to quantum signals from the future, instead of the Universe being committed to ...
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... , this research bore severe scrutiny. Objections and arguments against directed mutation arose, but the original research was never shown to be faulty. New experiments along this line, by B. Hall at the University of Rochester, have supported the original Harvard work and refuted some of the objections that had been leveled. Working with a special strain of Escherichia coli , Hall starved the bacteria of a certain amino acid, (tryptophan) that they usually got from the environment and could not synthesize. In the days that followed, many of the bacteria mutated so that they could synthesize their own tryptophan. Hall concluded: "Mutations that occur more when they're useful than when they're not: That I can document any day, every day, in the laboratory." Rather than ... any "conscious" goal-seeking attributes to the bacteria, Hall prefers to think that the environmental stress induced a state of "hypermutation." In this state all sorts of mu-tations occurred in abundance. Only those that synthesized tryptophan survived the starvation program; even potentially favorable mutations died quickly. (Stolzenburg, W.; "Hypermutation: Evolutionary Fast Track," Science News, 137:391, 1990.) Comment. Besides the implication that environmental stresses have initiated the mutations that gave us today's fauna and flora, we see that the idea of hypermutation is merely an acceleration of standard evolutionary processes. But how do environmental stresses turn on the biological switch that starts the mutation machine going? What sort of environmental stresses would cause humans to mutate? What would ...
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... major review article in Nature, see a two-fold problem: (1 ) identifying the source of the raw materials; and (2 ) identifying the source(s ) of energy required for the synthesis of complex organic chemicals. First, they point to the steady drizzle of tiny, organic-rich particles drifting down to earth from cometary debris. These particles, which even carry spacesynthesized amino acids down to the earth's surface, seem likely chemical precursors of life. However, the atmosphere is also a potential source of prebiotic chemicals -- providing energy sources are available. Chyba and Sagan suggest as sources: lightning, ultraviolet radiation, and the shock energy derived from meteorite/asteroid/comet impacts. Together these energy sources, especially ultraviolet light, might synthesize thousands of ... of complex organic compounds each year. (Chyba, Christopher, and Sagan, Carl; "Endogenous Production, Exogenous Delivery and Impact-Shock Synthesis of Organic Molecules: An Inventory for the Origins of Life," Nature, 355:125, 1992. Also: Henbest, Nigel; "Organic Molecules from Space Rained Down on Early Earth," New Scientist, 2. 27, January 25, 1992.) Comment. Little is said in either of the above articles about the nature of and impetus for that final elusive step from organic chemicals to the simplest life forms. Everyone assumes that it happened, but did it? One can always imagine a universe in which matter, energy, and life have always existed. From Science Frontiers #80, MAR-APR 1992 . ...
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... entire surface into a unique pattern. Finally, the patterns decay and the system dies, as secondary reactions drain the flow of the primary reaction." From this starting point, the implication is made that all manner of biological "reactions" are analogous and therefore reducible to nought but physics and chemistry. Some examples given of self-organizing biological phenomena are: (1 ) the sequencing of amino acids into selfreplicating structures; (2 ) slime-mold organization; and (3 ) the origin of the lens structure of the firefly. All of these claims are accompanied by computer simulations of self-organizing reactions. (Madore, Barry F., and Freedman, Wendy L.; "Self-Organizing Structures," American Scientist, 75:252, 1987.) Comment ... The article introduced by this unqualified assertion about the evolution of the universe is really about self-organizing chemical reactions. We classify it under biology because the authors imply that some biological phenomena are self-organizing. The famous Belousov-Zhabotinskii reaction is used as the prime example of chemical self-organization. First, one takes a shallow dish filled with a solution of bromate ions in a highly acidic medium. Here's what happens: "A dish, thinly spread with a lightly colored liquid, sits quietly for a moment after its preparation. The liquid is then suddenly swept by a spontaneous burst of colored centers of chemical activity. Each newly formed region creates expanding patterns of concentric, circular rings. These collide with neighboring waves but never penetrate. In some rare cases rotating one ...
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... brief summers of searching, these massive finds have posed unexpected questions. Here is a sampling. The terrestrial ages (times since arrival on earth) measure between 1,000 and 700,000 years, implying that the Antarctic ice sheet may be at least 700,000 years old. This is unfortunate for several proposed scenarios of recent catastrophism, which envision an iceless Antarctica. At least 20 amino acids appear in the more than 40 carbonaceous chondrites picked up with sterile equipment. These meteorites are dated as 4.5 billion years old, or 1 billion years older than the earliest terrestrial life found in the rocks. These finds highlight the old question: Did meteorites seed life on earth? The much-publicized "lunar" meteorite, supposedly blasted out of the moon's crust ... asteroid impact, thence falling to earth, shows little evidence of mechanical shock. If this meteorite, with a composition so similar to the Apollo samples is not from the moon, where did it come from? (Marvin, Ursula B.; "Extraterrestrials Have Landed on Antarctica," New Scientist, 97:710, 1983.) From Science Frontiers #27, MAY-JUN 1983 . 1983-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 92: Mar-Apr 1994 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The World Before Our World Genetically speaking, modern terrestrial life is bilingual in the sense that it employs two chemical languages. Function is written in the 20 amino-acid "alphabet" of proteins, while information is conveyed in sequences of four nucleotide "letters" called codons. We need go no further with the genetics lesson because our purpose here is to speculate a bit about the monolingual world that is believed to have preceded ours. This older world is commonly termed the "RNA World." It was and is monolingual because both function and information are carried on a single molecule. It is customary to call the RNA World " ... ," meaning that it was all chemistry and no life. But, one does wonder whether that was all there was to it. Catalysis and replication of genetic information occurred in the RNA World. What besides a chemical soup might have existed before "life-as-we-know-it" arrived upon the scene? A science fiction writer like H.P . Lovecraft could certainly come up with an ominous entity based upon RNA alone. Be that as it may, a book is now on the market bearing the title The RNA World (R .F . Gesteland and J.F . Atkins, eds., Cold Spring Harbor Laboratory Press, 1993) Nature reviewed the book in its January 20 issue. In addition, the RNA World was discussed recently in Science ...
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... polycyclic aromatic hydrocarbons (PAHs) from interstellar dust clouds." This article continues with an acknowledgement that F. Hoyle did predict way back in the 1950s that some of earth's organic matter came from outer space. And that he was roundly scoffed at. Next, more evidence is presented suggesting that the universe is full of the basic ingredients of life: Recently, the spectrum of the amino acid glycine was detected near the center of our galaxy. (Hecht, Jeff; "Stardust Brought Down to Earth," New Scientist, p. 17, March 23, 1996) Cross reference. IN SF#101, we related how PAHs were found in meteorite ALH84001, which was picked up in the Antarctic, and which is believed to have originated on Mars. From Science ... #106, JUL-AUG 1996 . 1996-2000 William R. Corliss ...
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... present article to making a spectroscopic case for their theory, but near the end they shake the Temple of Science a bit: "Precious little in the way of biochemical evolution could have happened on the earth. It is easy to show that the two thousand or so enzymes that span the whole of life could not have evolved on the Earth. If one counts the number of trial assemblies of amino acids that are needed to give rise to the enzymes, the probability of their discovery by random shufflings turns out to be less than 1 in 1040000." They conclude that the genes that control the development of terrestrial life must have evolved on a cosmic scale, where there has been more time and much more room for shufflings. (Hoyle, Fred, and Wickramasinghe, Chandra; " ... Microbes Boldly Went," New Scientist, 91:412, 1981.) Comment. Could not the "new" bacteria that appeared in the Mt. St. Helens area, as described in LIFE'S ORIGIN WITHIN THE EARTH? , have drifted down through the atmosphere into the lakes and ponds -- a sort of modern, ever-continuing panspermia? It is interesting to note here that even Hoyle, who has espoused the Steady State theory of the cosmos, seems to require the creation of life followed by evolution. This need for an origin of life is a human philosophical weakness. In principle, matter and life, too, could have always existed. From Science Frontiers #18, NOV-DEC 1981 . 1981-2000 William R. Corliss ...
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... becoming constantly more complex and richer in formation." (Tucker, Wallace, and Tucker, Karen; "Against All Odds: Matter and Evolution in the Universe," Astronomy, September 1984.) Comment. Now Layzer's statement seems a clear denial of the Second Law. It says, rather, that there is something intrinsic in the universe that creates order (spiral galaxies, amino acids, humans). We don't explain this tendency (assuming it really exists) just by identifying Belousov-Zhabotinsky reactions and saying, "That's the way things are." We can go one step further and say that the fundamental particles of physics have just the right properties so that they fall together into atoms, molecules, galaxies, and life forms. Can ... go any further? From Science Frontiers #36, NOV-DEC 1984 . 1984-2000 William R. Corliss ...
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... !) This is seen as a cop-out by most scientists who are searching for "natural" (designerless) explanations for those "emergent" properties of matter -- such as life. To this end, H. Frauenfelder and P. Wolynes, both at the University of California at San Diego, have been mapping the "energy landscape" of proteins as these long chains of amino acids fold into the incredibly complex shapes required by their functions in life forms. They find energy peaks and valleys are crossed as the chains writhe and fold-- often with blinding speed -- from one energy state to another, the nascent proteins "funnel" toward the minimum energy states that characterize the proteins that are capable of taking on biological tasks. This funnelling is an emergent property ... matter that leads to the final "dominant state": a protein or some other biochemical. (Irion, Robert; "Say the Magic Words," New Scientist, p. 32, June 7, 2001.) Comment. Proteins are the workhorses of terrestrial life forms. By gross extrapolation of the protein energy-landscape model, we could say that life forms are merely complexes of multitudinous dominant states and are, in effect, superdominant-states. This speculation is fun, but the WHY of this whole business still eludes us. And we wonder if "emergent property" really doesn't mean "life force"! From Science Frontiers #138, NOV-DEC 2001 . 2001 William R. Corliss Other Sites of Interest SIS . Catastrophism, archaeoastronomy, ancient history ...
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