67 results found.
... Science Frontiers ONLINE No. 130: JUL-AUG 2000 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Has Human Evolution Been Directed by Bacteria?With considerable fanfare, a multinational team of scientists has announced that the mtDNA (mitochondrial DNA) "squeezed" from a 29,000-year-old Neanderthal skeleton found in the northern Caucasus differs by 3.48% from the mtDNA of a 40,000-year-old Neanderthal skeleton from (fittingly) Germany's Neander Valley. Furthermore, both mtDNA samples differ from that of modern humans by a substantial 7%. These two innocent-appearing, widely publicized numbers have far-reaching implications: Modern humans and Neanderthals are only very distantly related, and they certainly never interbred, as suggested in many recent, popular articles; and Since neither Neanderthal mtDNA sample is closer to that of modern Europeans than it is any other modern human population, the so-called "multiregional" theory of human evolution and dispersion is unlikely to be correct. Thus, the out-of-Africa theory is favored;. These data and their implications stimulate several observations and comments; only one of which is mentioned in the references given below. F.H . Smith, an anthropologist from Northern Illinois University and a supporter of the multiregional theory, opines that 30,000-40,000 years ago the mtDNA of the early humans, who were mixing it up with the Neanderthals, was certainly very different from what it is today. Since mtDNA mutates rapidly, ...
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... Viruses as Ancient Artifacts HTLV-1 is a blood-borne retrovirus that causes leukemia in about 3% of those carrying it. In southern Japan, roughly 4% of the populace are afflicted with this virus, so are some isolated groups living today in Columbia and Chile. Does this correlation prove that South America received settlers from Japan in the distant past? Such a biological linkage would augment pottery evidence from Peru and, especially, Ecuador where Jomon-style pottery 4,000-5 ,000 years old has been found on the coast. However, the HTLV-1 virus also could have been introduced to South America by more recent visitors. Is there any way to fix the timing of HTLV-1 's introduction to South America? Actually, there is. The DNA in viruses is not as durable as pottery shards, but it does hang around for a while, as seen is recent efforts to ex-tract DNA from from frozen mammoths for possible "revival" of the species. A team of Japanese and Chilean scientists has been searching for DNA surviving in 104 mummies deposited in South America's arid Atacama Desert 1,200-1 ,500 years ago. Two of the mummies still retained DNA; and one of them included shards of DNA from HTLV-1 . This certainly doesn't prove trans-Pacific diffusion, but it helps. (Holden, Constance; "Backtracking a Mummy Virus," Science, 286:2071, 1999.) From Science Frontiers #128, MAR-APR 2000 . 1997 William R. ...
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... The Complexity of it All!The headlines say that the human genome has been charted and further imply that we now can read life's total blueprint. Closer study of the announcement reveals that there still remain unreadable snippets of the genome here and there. In fact, the total number of human genes is still in doubt: maybe 30,000, some say 120,000. This wide range of uncertainty does not inspire belief in the accurate readability of this biological blueprint at the present time. Usually left unsaid is the fact that the present blueprint covers only 2-3 % of the territory. That's right, 97-98% of the human genome isn't mapped at all. This uncharted territory is assumed to be "junk" or "nonsense" DNA that plays no role in heredity. Want to bet that this assumption is correct? And don't forget that genes jump around. The genome is really a moving target. Genes also work in concert. It is not one gene coding for one protein, which then has a singular role in creating an operational human being. For example, some 5,692 genes are active in breast-cancer cells. Genes may also have multiple roles. Our present blueprint of the human genome does not display all the mobility and complex interrelationships of the genes. We do know that genes are the blue-prints for the manufacture of proteins. Of these, there may be over 1,000,000 different -- more than ten times the number of genes! These multitudinous proteins ...
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... Science Frontiers ONLINE No. 131: SEP-OCT 2000 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Will mtDNA Trump C14 and Projectile Points?Do not imagine for a minute that the Clovis Police are successfully suppressing all radical notions in archeology. Revolutionaries are everywhere. Not the least of these are studying the mtDNA (mitochondrial DNA) of Native American peoples and comparing it with the mtDNAs of Asians and Europeans. The geographical distribution of mtDNA haplogroups can trace out the migratory routes of early humans in the New World and, in addition, provide rough times-of-arrival. Some of this mtDNA evidence will undoubtedly attract the attention of the Clovis Police. But do these law enforcers -- mostly archeologists -- dare to challenge genetic data? Can mtDNA lie? There are in the cells of North American Native Americans mitochondria that seem to divide these peoples into four major "haplogroups." These four groups can be readily traced back to Siberia and northeast Asia. No trouble from the Clovis Police here! But there is also a "haplogroup-X " that does not fit the Clovis paradigm. In North America, haplogroup-X is found frequently among the Algonkian-speaking tribes, such as the Ojibwa. This same haplogroup occurs in Europe and the Middle East, especially Israel. It is notably absent in Asia. Furthermore, the data suggest that haplogroup-X was resident in North America thousands of years before the Vikings and Columbus made landfall. (Schurr, Theodore G.; "Mitochondrial DNA and the ...
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... Science Frontiers ONLINE No. 132: NOV-DEC 2000 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Unidentified Cellular Object The multitudinous cells that make up our bodies are miniscule factories humming with activity. The microscope reveals mitochondria, chromosomes, centrioles, granules, and a host of entities doing their own things. But even after generations have scrutinized our cells, new objects are discovered. The latest, only recognized in 1986, look like a miniature hand grenades. Called "vaults" these objects are composed of proteins and ribosomal DNA. They exist only in the cells of the higher organisms -- like us. Biologists surmise that they are important in some way but have no idea what they do. (Anonymous; "Cell Biology Mystery," Science, 289:355, 2000.) A "vault," a mammalian cellular object of unknown purpose. From Science Frontiers #132, NOV-DEC 2000 . 2000 William R. Corliss Other Sites of Interest SIS . Catastrophism, archaeoastronomy, ancient history, mythology and astronomy. Lobster . The journal of intelligence and political conspiracy (CIA, FBI, JFK, MI5, NSA, etc) Homeworking.com . Free resource for people thinking about working at home. ABC dating and personals . For people looking for relationships. Place your ad free. ...
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... that they: Selected which of your mother's germ cells matured to produce you; Have decided your odds of living to be 100; and May influence your being afflicted with Parkinson's and Alzheimer's , as well as rarer disorders. The first item (or "force") is the most disturbing. Mitochondria (with only 35 genes), it seems, can exercise vetoes over decisions by our own genome (with its 100,000 genes). (Cohen, Philip; "The Force," New Scientist, p. 30, February 26, 2000.) The cells of higher organisms are busy places. One of this cell's mitochondria is indicated at the lower right, but there are several others in the sketch. They have their own DNA (mtDNA). Comment. It is disconcerting to realize that within each of our cells hundreds of alien entities, though helpfully supplying energy, are mutating and evolving in ways to enhance their fitness rather than ours. Like so many true parasites, mitochondria will not shrink from modifying their hosts (us!) to achieve their ends -- whatever they are. The Force seems to be with them! From Science Frontiers #130, JUL-AUG 2000 . 2000 William R. Corliss Other Sites of Interest SIS . Catastrophism, archaeoastronomy, ancient history, mythology and astronomy. Lobster . The journal of intelligence and political conspiracy (CIA, FBI, JFK, MI5, NSA, etc) Homeworking.com . Free resource for people thinking about working at home. ABC dating and ...
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... layer of complexity that people are only now starting to consider in the context of whole ocean systems . . Gel is like the dark matter of the sea. While sea gel does not impede the snorkeler, . it does herd microbes into clumps or microniches . which we cannot see either. These microbes. in effect, exist in a tangled. 3-D mesh that affects not only their movements but also those of their prey and predators. A few statistics confirm the amazing complexity of the seawater microcosm and its incredibly high microbe population density. The long strands in the oceanic gel are mostly crosslinked polysaccharides. If the polysaccharides in 1 milliliter of seawater could be placed end-to-end, they would stretch out to 5,600 kilometers! Coexisting proteins would span 310 kilometers ; DNA, 2 kilometers. This same milliliter may also contain up to a million bacteria and ten times as many virus particles. Also in this brew are, on the average, 1.000 protozoans and 100 phytoplankton. It's a microscopic metropolis, about the size of a sugar cube, and one in which you may never wish to swim again! The polysaccharides and proteins that comprise most of the thin goo are not alive, although the bacteria are. Just how this thin goo and its multitudinous inhabitants evolved has not been explained. Which came first, the goo or the bacteria? Being devoid of life's spark, the goo cannot evolve, or can it? (LaFee, Scott; "Meet Me at the Goo," New Scientist, p. 44 ...
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... Science Frontiers ONLINE No. 83: Sep-Oct 1992 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Flat-faced hominid skulls from china The "African Eve" theory of human evolution was given much play in the media a few years back. According to the "African" view, modern humans arose exclusively in Africa and, about 100,000 years ago, expanded rapidly from there into Europe and Asia, displacing "lesser" hominids. Unfortunately, the DNA studies that stimulated this conjecture have been found to be flawed. And now new fossil testimony casts further doubt. In 1989 and 1990, near the Han River, in China's Hube Province, anthropologists found hominid skulls with the characteristic flat faces of modern humans. These skulls seem to be about 350,000 years old. Although they apparently retain some primitive features, paleoanthropologist D. Erler, of the University of California, asserted, "This shows that modern features were emerging in different parts of the world." In other words, all of the evolutionary action was not confined to Africa. Proponents of the "African Eve" theory retort that the dating of the Chinese skulls is questionable and that flat faces alone are not enough to support the idea that modern humans arose separately in widely separated locales? (Gibbons, Ann; "An About-Face for Modern Human Origins," Science, 256: 1521, 1992. Also: Bower, Bruce; "Erectus Unhinged," Science News, 141:408, 1992.) Comment ...
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... Science Frontiers ONLINE No. 105: May-Jun 1996 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Mixed-up people Mother-child chimeras. Investigators have discovered cells carrying male DNA among a mother's blood cells 27 years after the birth a male child. Evidently, descendents of fetal cells escape during pregnancy and persist in the mother for years after birth. The mother thus becomes a blend of herself and her child (or, possibly, children) - a kind of chimera. The question is: Why doesn't the mother's immune system destroy these foreign cells? Some scientists speculate that these escaped and still-surviving cells may help explain why women are more susceptible than men to autoimmune diseases. (Travis, J.; "Kids: Getting under Mom's Skin for Decades," Science News, 149:85, 1996) Fatherless blood. In Britain, a male child has been found with normal skin, with each cell carrying the expected X and Y chromosomes, but "his" blood is all female. Its cells contain the mother's two X chromosomes with no paternal contribution. What happened? One theory is that the mother's unfertilized egg spontaneously divided. Then, fertilization occurred, but it was only partial. The sperm got to just one of the two or more cells derived from the egg. The embryo continued to develop but it was part all-mother and part mother-father! "Partial parthenogenesis" seems to be the proper term here ...
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... respected archeologist from the Andover Foundation for Archeological Research, has charted a 30,00040,000-year-old paleonotological record of ancient camels, horses, tapirs, and other fauna found while excavating this cave. Intermixed with the animal bones are layers of charcoal (easily carbondated) and hints of human occupation. But don't we all know that humans did not arrive in the New World until 12,000 years ago? Nevertheless, there they are: (1 ) rude human tools; and (2 ) a possible human palm print. Mainstream archeologists are stonewalling again; there must be some mistake! (Appenzeller, Tim; " A High Five from the First New World Settlers?" Science, 255:920, 1992.) Scene: Inside Amerind cells. DNA analyses of the mitochondria present in the cells of North American Indian populations indicate that the Eskimo-Aleut and Nadene populations arrived about 7,500 years ago. The more geographically widespread Amerind population, however, seems to be descended from two separate influxes; the first about 30,000 years ago, the second about 10,000 years ago. D. Wallace, from Emory University, surmises that the sharply defined rise of the Clovis culture, conventionally dated from 12,000 years ago, may have resulted from the second Amerind immigration. (Lewin, Roger; "Mitochondria Tell the Tale of Migrations to America," New Scientist, p. 16, February 22, 1992.) Comment. The 30,000-year date, however, is consistent with MacNeish' ...
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... Science Frontiers ONLINE No. 67: Jan-Feb 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Dna On Cell Surfaces DNA attached to a cell's surface? Such a notion was shocking to scientific orthodoxy in the 1970s. At that time, observations of the phenomenon were rejected. Even worse, funding to continue the work was not forthcoming. Happily, other researchers have later stumbled onto cell-surface DNA; and this startling phenomenon has been rescued from conformity's wastebasket. Now that cell-surface DNA can be talked about, we can wonder aloud where it comes from and what its significance is. First, this out-of-place DNA -- thought to amount to about 1% of a cell's total DNA -- could come from either inside the cell itself or from blood-borne cellular debris. There is considerable argument on this point. Second, this cell-surface DNA does not appear to undergo replication nor does it perform any gentic coding function. Speculation is that it may somehow be involved in the immunological response of the body; for its position on the cell surface is ideal for such a role. Some researchers think that cell-surface DNA may aid in the drug treatment of T-cell lymphoma, a type of cancer. On the other side of the coin, it may mask those molecules on tumor cells that provoke immune responses. Such divergence of opinion indicates how much there is to learn here. (Wickelgren, Ingrid; "DNA's Extended ...
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... Science Frontiers ONLINE No. 77: Sep-Oct 1991 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Do birds use genetic maps during migration?Routes taken by migrating German and Austrian blackcaps en route to Africa. Hybrids bisect these initial paths and would end up in the Alps. Many young birds migrate successfully without help from older birds who have made the trip before. The implication is that migration instructions, perhaps even some sort of map of astronomical or geo graphical references, are somehow written upon the genes inherited from their parents. Just how maps can be coded into gene structure is anyone's guess. (In fact, since the DNA in the genes seems to cody only for protein synthesis, the locations and characters of inheritable maps and other biological instructions are not immediately obvious.) The problem has been exacerbated by recent experiments with German and Austrian blackcaps. These two common European warbler species take different routes to Africa in the winter. The Ger-man blackcaps fly southwest and the Austrian southeast--routes 50 apart. A. Helbig has crossed the German and Austrian blackcaps to see what route(s ) their hybrid offspring would take. Curiously, they favored a route intermediate between those of their parents. The hybrids' route -- bisecting those of the parents' -- would take the hybrids right into the Alps, where survival would be unlikely. (Day, Stephen; "Migrating Birds Use Genetic Maps to Navigate," New Scientist, p. 21, April 21, 1991.) ...
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... Science Frontiers ONLINE No. 70: Jul-Aug 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Artificial molecule shows 'sign of life'A synthetic molecule has been found that apparently replicates itself. This seems to be a step on the road to artificial life. "Julius Rebek, Tjama Tjivikua and Pablo Ballester of the Massachusetts Institute of Technology say that their compound, an amino adenosine triacid ester (AATE), acts as a "template" which combines molecular fragments to make a copy of the original compound. This process is very similar to that used by DNA. The difference is that the biological copying usually needs an enzyme to make it work." (Emsley, John; "Artificial Molecule Shows 'Sign of Life,'" New Scientist, p. 38, April 28, 1990.) Comment. No one can say that replication is a "spontaneous" property of inorganic matter. It is truly remarkable that base matter is intrinsically self-organizing and replicating. We know! It is all because the universe just happens to be anthropic. From Science Frontiers #70, JUL-AUG 1990 . 1990-2000 William R. Corliss ...
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... operated by F. de Sarre, publishes a little journal called Bipedia . In the first issue of Bipedia , de Sarre sets out, in English, his basic thesis: Abstract. "The explanation of Man's special nature is to be sought in the original combination formed by a primordial brain, the globular form of the skull and initial bipedalism. The ape, when compared with Man, appears to be rather a vestige of Man's ancestral line than his predecessor, according to the views of Max Westenhofer, Serge Frechkop, Klaas de Snoo and Bernard Heuvelmans. The study of the human morphology allows logically to carry the problem of Man's origin back to a very early stage of the evolution, and not to which has been reached by apes. From chromosomal and DNA comparison in the cells of living apes and people, several researches argue to-day that humans are genetically more like the common ancestor than is either Chimpanzees or other apes. The array of facts and considerations should be sufficient for an unbiased mind to discount away any idea of simian antecedents in Man's ascent." The body of the article supports de Sarre's thesis with observations from embryogenesis, comparative anatomy (skull, hand, foot), and phylogenesis. (de Sarre, Francois; "Initial Bipedalism: An Inquiry into Zoological Evidence," Bipedia , 1:3 , September 1988.) Comment. Obviously, de Sarre is taking an extreme position, and any observations supporting his position are anomalous by definition. From Science Frontiers #65, SEP-OCT ...
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... virus infection may be an important factor in the ecological control of planktonic microorganisms, and that viruses might mediate genetic exchange among bacteria in natural aquatic environments." (Bergh, Oivind, et al; "High Abundance of Viruses Found in Aquatic Environments," Nature, 340:467, 1989.) A sip of water could therefore introduce a billion virus particles into your stomach! This level of virus density in natural water is about 10 million times that formerly estimated. Besides reducing your thirst, what are the implications of this discovery? First, it suggests that bacteria in natural waters are probably kept in check by viruses as well as protozoans. So far, this sounds good. Second, since viruses can ferry genetic material between organisms via transduction (i .e ., host DNA is carried to the next host). This means that genes for antibody resistance and increased bacterial virulence (as present in sewage) may be spread quickly and widely. Also, "engineered bacteria" proposed for use in agriculture, viz., the ice-minus bacterium created to protect strawberries, may die, but their new genes will soon be everywhere. (Weiss, R.; "Aquatic Viruses Unexpectedly Abundant," Science News, 136: 100, 1989.) From Science Frontiers #66, NOV-DEC 1989 . 1989-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 63: May-Jun 1989 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Language Of Life Popular writers on biology are fond of saying that the genes and their DNA carry all information necessary for the development of an organism and the transfer of inherited characteristics. With the advent of the multibillion-dollar project to map the human genome (our genetic inventory), we have been seeing this extreme claim more often. The truth is that a map of the human genome will not tell us everything. By way of confirmation, we quote the lead paragraph from a recent article in New Scientist: "In the early days of molecular biology, during the 1950s and 1960s, scientists as much as journalists fuelled the euphoria that surrounded the cracking of the genetic code. The secret of life was revealed, so many people thought. As our understanding has grown, however, so has our awareness of our ignorance. Research at the forefront of the molecular sciences has shown that we can no longer regard DNA - the stuff of genes - as a direct and complete set of instructions for the synthesis of proteins. The evidence begins to suggest that messages in the DNA are, in themselves, no more precise than the symbols and sounds with which we communicate. As in the languages with which we are familiar, the correct sense of a message written in DNA seems to depend on the rigorous checking and correction of errors, and on the context in which they are read." The final sentence of the ...
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... question that the physical world is coherent and harmonious. Yet according to the traditional scientific picture, the Universe is just a random collection of particles with blind forces acting upon them. There is, then a deep mystery as to how a seemingly directionless assembly of passive entities conspire to produce the elaborate structure and complex organisation found in nature." The author of this introductory paragraph, P. Davies, asks, as we all do, "What is the origin of this creative power?" In groping for an answer, he presents first a common example of "blind" organization: the hexagonal convection cells in a pan of heated water. Using for a stepping stone the cooperative action of atoms in a laser, he leaps to the development of an embryo from a single strand of DNA! All such systems are "open"; that is, energy can flow in and out. They are also nonlinear, which means that chaotic, unpredictable action may occur. Davies implies that such action can be "creative," almost as if they possessed free will! His final example is that of the network with large numbers of interacting sites or nodes. With random inputs, large networks do exhibit self-organization. Network theory is now very popular in the field of artificial intelligence. (Remember the computer Hal in 2001?) Davies's conclusion: ". .. Neo-Darwinism, combined with the mathematical principles emerging from network theory and related topics, will, I am convinced, explain the 'miracle' of life satisfactorily." (Davies, ...
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... Science Frontiers ONLINE No. 50: Mar-Apr 1987 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects How Cancers Fight Chemotherapy How do cancer cells develop resistance to lethal chemicals? The clues seem to reside in extrachromosomal DNA that carries drug-resistance-conferring genes from one cancer cell to another. Cancer cells dying from chemotherapy may, for example, cast off extrachromosomal DNA that carries information on how to combat the chemicals. Other factors may also be at work, but basically we have only suspicions. (Silberner, Joanne; "Resisting Cancer Chemotherapy," Science News, 131:12, 1987.) Comment. Insects and other organisms also acquire resistance to chemical poisons. Does extrachromosomal DNA play roles in these instances, too? Can Information coded in extrachromosomal DNA be passed from one species to another, say, via insect bites? From Science Frontiers #50, MAR-APR 1987 . 1987-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 41: Sep-Oct 1985 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Genetic Garrulousness It is tempting to predict that those cells with the most genetic material will belong to the most advanced organisms. One would, for example, expect to find more DNA or nucleotide pairs in human cells than the cells of bacteria or plants. In the case of the bacteria, this expectation is realized. Some plants, however, have one hundred times more DNA per cell than humans. Some fish and salamanders do, too. One reason why there is no simple relationship between a cell's genetic complement and the organism's complexity is that a lot of genetic material is apparently useless, with no known functions. Human genes, by way of illustration, possess about 300,000 copies of a short sequence called Alu. The Alu sequences seem to be simply dead weight -- functionless -- yet continuously reproduced along with useful sequences. One purposeless mouse gene sequence is repeated a million times in each cell. (Stebbins, G. Ledyard, and Ayala, Francisco J.; "The Evolution of Darwinism," Scientific American, 253:72, July 1985.) Comment. Why so much redundance? Or is there some purpose for this excess genetic material that we haven't yet descried? The "useless" sequences may merely be left over from ancient gene shufflings; or they may be awaiting future calls to action. The above tidbits come from a long review article that is ...
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... the most widespread characteristic represents the primitive state. The fact that feces look so much the same from individual to individual strongly suggests that feces are the primitive condition. The variety of animal bodies, on the other hand, implies that bodies are secondary or derived features of the organisms. The expansion of genetic research in the twentieth century has led to the conclusion among many geneticists that bodies exist solely for the propagation and dispersal of genes. This perspective has been dubbed 'the selfish gene theory'. While the author acknowledges the insight and creativity that went into the selfish gene theory, it must be pointed out that the idea has not been carried far enough by the geneticists. Where did the genes come from in the first place? Who ever heard of a sea bottom made up of DNA ooze? It is obvious from the fossil data that feces were teeming in the Precambrian oceans well before DNA appeared on the face of the earth, and that feces were therefore the original driving force of life. Bodies exist for the propagation and dispersal of feces, and genes are simply the instructions used by feces in the manufacture of those bodies. This concept is best described as the 'selfish feces theory'." (Sager, J. Curt; "The Origin of Feces," Journal of Irreproducible Results," p. 20, 1986.) From Science Frontiers #46, JUL-AUG 1986 . 1986-2000 William R. Corliss ...
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... just one simple memory, the brain will quickly use up all available cells. It must be that individual brain cells can participate in the storage of many different memories. The conventional mem-ory-trace theory would have to be replaced by a new type of memory architecture. (Bower, Bruce; "Million-Cell Memories," Science News, 130:313, 1986) Comment. Our thinking about biological memory may be controlled by our preoccupation with the two-dimensional circuits of computer memories. Biological memories might be three-dimensional, or of even higher order. Some scientists have ventured that memory might entail electrical charge distribution patterns in the brain; such need not be limited to two dimensions. The same thinking can be applied to the storage of genetic information. While DNA, RNA, etc., may be pieces in the puzzle, the complete solution may include the ways in which these molecules are bent, twisted, convoluted, arrayed, juxtaposed, and so on. In a letter relating to the above article, P.J . Rosch points out that John's results are consistent with the holographic theory of brain function supported by Pribram and Bohm. "In a hologram, every element of the subject is distributed throughout the photographic plate, making it possible to reconstruct the entire original image from any portion of the picture. In this paradigm, the brain stores memory and deals with interactions by interpreting and integrating frequencies, retaining the data not in a localized area but dispersed throughout its substance." (Rosch, Paul J.; " ...
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... of atoms in constant interchange with atoms on the crystal surface. The clouds of gold atoms extended up to 9A from the crystal surface, continually changing their shape and density." The remarkably dynamic nature of solid surfaces, as now revealed, has many implications. (Bovin, J. -O ., et al; "Imaging of Atomic Clouds Outside the Surfaces of Gold Crystals by Electron Microscopy," Nature, 317:47, 1985.) The problem of snowflake growth (SF#38) is probably solvable in terms of clouds of water molecules surrounding crystal nuclei with electrostatic fields guiding the symmetric deposition of molecules. Biological structures, too, are probably encompassed by clouds of atoms and molecules; viz., the crystal-like, polyhedral viruses. Does the highly ordered DNA structure also possess an aura of molecules constantly swapping places ? Such would not be inconsistent with "jumping genes" and M. Kimura's Neutral Theory of Evolution (SF#41). (WRC) From Science Frontiers #42, NOV-DEC 1985 . 1985-2000 William R. Corliss ...
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... own, how do the prions multiply? Recent laboratory work suggests that the prions subvert a gene that normally dwells in the brain. With the help of this gene, an endless stream of prions emerges, and the animal is sick. In hamsters, which are employed in laboratory research on scrapie, a gene demarcated PrP has been implicated in scrapie. PrP is present in both healthy and infected hamster brains, but no one knows what its normal function is, if indeed it has one. (Anonymous; "Prion Gene," Scientific American, 253:60, July 1985.) Comment. One can make an immediate connection between the traitorous PrP genes in the hamster brains and the excess genetic material in humans and all life forms. Biologists commonly call excess genetic material "nonsense DNA" which only means that they haven't devined its purpose. But, as already sugested, these unused blueprints may have had some past purpose or will be called into action in the future. The purpose may be insidious, as in the case of scrapie, or vital to the organism's survival in some unrecognized biological Armageddons. From Science Frontiers #41, SEP-OCT 1985 . 1985-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 34: Jul-Aug 1984 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Dna Even More Promiscuous It was a surprise when DNA sequences from mitochondria in yeast cells were discovered setting up shop in the nuclear genomes (i .e ., the normal genetic endowment of the cell nucleus). Now biologists find that DNA sequences in many species regularly and frequently hop from one genome to another. Genetic material from cell chloroplasts mix with that of the mitochondria and that of the normal nucleus in what seems to be a free-for-all. This genome hopping has earned DNA the adjective "promiscuous." The significance of DNA promiscuity is to be found in the general belief that the cell's mitochondria and chloroplasts were once independent biological entities that, in the course of life's development, invaded or were captured by cells and have led a symbiotic life ever since. The mitochondria and chloroplasts perform certain important functions in the cell but were thought, until now, to retain considerable genetic independence. (Lewin, Roger; "No Genome Barriers to Promiscuous DNA," Science, 224:970, 1984.) Comment. The promiscuity of DNA raises speculation that other DNA-bearing entities that invade the body, especially the viruses, may transfer their DNA to the host, and conceivably vice versa. With DNA apparently much more promiscuous than believed earlier, the role of disease in the development of life takes on a new importance. In other words, all species can potentially exchange genetic ...
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... Science Frontiers ONLINE No. 25: Jan-Feb 1983 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Promiscuous Dna The cells of plants (photosynthetic eukaryotes) are genetically the most complex that biologists have discovered. Each cell has three genetic systems: its own, that of the chloroplasts; and that of the mitochondria. It is supposed that the chloroplasts and mitochondria were once free-living cells that linked up with the embryonic plant cell to form a symbiotic partnership, with the host "plant" cell being the dominant member. Up until now, the three genetic systems were thought to be discrete, each going down its own pathway. But chloroplasts genes have now been found inside plant mitochondria, overturning conventional wisdom. To sum it all up, DNA seems promiscuous -- no respecter of privacy and breaking down all isolating genetic barriers. This discovery at once raises a dozen questions. For example, are mitochondria genes in chloroplast cells? How far does this promiscuity go? Can the same thing happen in higher organisms; say, with humans and symbiotic microorganisms or even not-so-symbiotic disease organisms? Is there no stopping this DNA? (Ellis, John; "Promiscuous DNA -- Chloroplast Genes inside Plant Mitochondria," Nature, 299:678, 1982.) From Science Frontiers #25, JAN-FEB 1983 . 1983-2000 William R. Corliss ...
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... has become quite respectable. The cladists, however, are now fighting among themselves. One camp draws their "cladograms" (see illustration) using evolutionary theory as a guide. The other side believes that the cladograms should be drawn up first, based only upon actual characters and ignoring the theory of evolution -- let the species fall where they may. When evolutonary theory is omitted in the deliberations, radically different cladograms result. Mammals then seem more closely related to birds than reptiles, for example, as expressed in the illustration. A key connecting character here is mutual warmbloodedness. The shifting of a few lines in a cladogram may seem trivial to the nonbiologist, but saying that man is more closely related to a chicken than a lizard is pretty controversial stuff to the conservative evolutionist. DNA analysis supports the contention that humans are more closely related to birds than reptiles. Paleontological evidence, however, supports the opposite view. The fight rages on. (Benton, Mike; "Is a Dog More Like a Lizard or a Chicken?" New Scientist, p. 18, August 16, 1984.) Comment. It all seems to boil down to morphology in the end. Which is a more faithful record of the development of life through the long eons, the phenotype (what the organism looks like) or the genotype (what the DNA looks like)? This may be a dangerous simplification. Why? Because life just may be shaped by more than DNA. Standard evolution cladogram (left). Cladogram based only on characters (right). The numbers ...
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... Science Frontiers ONLINE No. 36: Nov-Dec 1984 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Evolution Of Man And Malaria Malarial parasites are customarily classified according to the species infected and then further subdivided by morphology and biological characteristics. The two assumptions implicit in this classification procedure, which is supposed to mirror actual historical evolution, are: Malarial parasites evolved in parallel with their hosts; and Morphology is a measure of evolutionary relatedness. With modern biochemical techniques it is possible to test these assumptions by comparing the DNA structures of the different malarial parasites. P. falcipa rum, the parasite transmitting the most deadly human malaria, turns out to be more closely related to rodent and avian malaria than the other primate malarias. Therefore, assumption #1 above is in correct in this view. Assumption #2 is also wrong because some species of malaria parasites which are very similar morphologically are quite different DNAwise. (McCutchan, Thomas F., et al; "Evolutionary Relatedness of Plasmodium Species as Determined by the Structure of DNA," Science, 225:808, 1984.) Comment. The article does not draw attention to still another assumption; namely, that similarities are measures of evolutionary relatedness. If this as sumption isn't correct, evolutionary family trees based on bodily structure, which means most of the family trees in the textbooks, may not truly reflect what really happened in the development of life. Further, if malarial parasites did evolve along with their hosts, hu man evolution seems farther removed from the evolution ...
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... big challenge is getting the arthropod eaten by a vertebrate. In most instances, it alters the behavior of the arthropod in a way that makes it more conspicuous to the predators. For example, infested pill bugs do not hide from birds, as they normally do, and are snapped up. Infested crustaceans move towards the light where ducks consume them. No one knows how a parasite floating in the body cavity of its host can control the host's behavior. (Moore, Janice; "Parasites That Change the Behavior of Their Host," Scientific American, 250:108, May 1984.) Comment. One cannot but wonder if human behavior is somehow controlled by parasites. Obviously we deny such dominance. Yet, some have speculated that our urge for space travel is only DNA's way of expanding its dominion. A thorny-headed worm that cycles between ducks and crustaceans. (Adapted from Scientific American). From Science Frontiers #34, JUL-AUG 1984 . 1984-2000 William R. Corliss ...
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... Its Time," Nature, 309:400, 1984.) Comment. This is an appropriate time to suggest that "psychoevolution" may be physiologically possible. If the brain can fight disease and even control cell growth, why not a role for the mind in stimulating the development of new spe cies, perhaps in response to extreme environmental pressures, and perhaps not on the conscious level? The body's sensory system would detect great external stresses, the brain would process the information, and direct some astute genetic shuffling. The genetic inheritance of an organism is not sacrosanct. Radiation, chemicals, and various others mutagens are recognized. There seems to be no a priori reason why the brainbody combination cannot generate mutagens -- possibly not randomly but intelligently! (We ignore here selfish DNA and Sheldrake's morphogenic fields.) Does this mean that if we wish to mutate, we can? Well, it's probably not as simple as wishing warts away, but Maddox's editorial underscores the complexity and subtlety of the brain-body combination. From Science Frontiers #35, SEP-OCT 1984 . 1984-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 25: Jan-Feb 1983 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Learning By Injection The following abstract is taken from the Psychological Record. "In an attempt to replicate previous findings that learned information could be transferred from trained donor animals to untrained recipient animals by means of brain extracts, two groups of rats were trained to approach a food cup in response to a discriminative stimulus (click or light). RNA extracted from the brains of these animals was injected intraperitoneally into untrained rats. The two untrained groups showed a significant tendency to respond specifically to the stimulus employed during the training. The results support the conclusion that acquired behaviors can be transferred between animals by transferring brain DNA, and further suggest that the transfer effect is dependent upon and specific to the learning of the donors." (Oden, Brett B., et al; "Interanimal Transfer of Learned Behavior through Injection of Brain RNA," Psychological Record, 32:281, 1982.) Comment. Of course, morphogenic fields, as described in R. Sheldrake's A New Science of Life, could also explain this effect. From Science Frontiers #25, JAN-FEB 1983 . 1983-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 10: Spring 1980 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Dynamic Dna Smugness over our discovery of the genetic code and some simple features of biological synthesis has recently been undermined by the recognition that the so-called nonsense segments in genes may be important after all. Now comes the realization that the DNA molecule may not be a staid, static construction. Travelling kinks and other disturbances seem to play some unknown role in biological recognition. Some biochemists have even suggested that DNA winds and unwinds or "breathes" like a living thing as it helps to manufacture biological substances. (Spencer, Michael; "Bent DNA," Nature, 281:631, 1979.) Comment. The addition of the time dimension to biological synthesis evokes thoughts of oscillating systems, frequency dependence, filters, etc. Perhaps Nature has invented something better than the silicon chip. From Science Frontiers #10, Spring 1980 . 1980-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 11: Summer 1980 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Hierarchies Of Evolution All organisms from man to mouse to amoeba are merely DNA's way of manufacturing still more DNA -- so goes the modern ramification of molecular biology and the Genetic Code. In other words, DNA and genes are selfish, and ultimate parasites, directing the evolution of life only to maximize the production of DNA. This theme is not the subject of this paper by Doolittle and Sapienza. Rather, they wonder about those nonsense DNA sequences that do not code for protein. The presence of these "useless" bits of genetic material is often explained in terms of gene "expression." Emphasis is always on maximizing the "fitness" of the organism (phenotype). Perhaps this seemingly excess genetic material actually maximizes the fitness (survivability) of the DNA itself. Evolution thus occurs at DNA and gene (genome) levels, despite what transpires at the organism (phenotype) level. (Doolittle, W. Ford, and Sapienza, Carmen; "Selfish Genes, the Phenotype Paradigm and Genome Evolution," Nature, 284:601, 1980.) Comment. We know that mitochondria and chloroplasts have their own genetic material; evolution may be occurring at this level, too, independent of pressures for change on the organisms. Waxing speculative, may there not be other hierarchies where systems are trying to maximize their own survivability, even at molecular, atomic, and subatomic levels? Don't laugh! ...
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... Science Frontiers ONLINE No. 17: Fall 1981 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Why conserve junk?A. Jeffries, working at Leicester University with globin genes from man and related primates, has been studying how these genes direct the blood cells to make the alpha and beta chains of hemoglobin. Jeffries' analyses seem to indicate that the genes now coding for these hemoglobin chains are almost identical to those existing in human ancestors some 500 million years ago. Two curious facts have cropped up, however. First, about 200 million years ago, these genes were modified very slightly and relocated to entirely different chromosomes. Second, 95% of the DNA associated with these genes is "junk" -- with no known use. Why did nature conserve junk for 500 million years? Are vital genes in the habit of jumping from one chromosome to another? (Yanchinski, Stephanie; "DNA: Ignorant, Selfish and Junk," New Scientist, 91:154, 1981.) From Science Frontiers #17, Fall 1981 . 1981-2000 William R. Corliss ...
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... Science Frontiers ONLINE No. 22: Jul-Aug 1982 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Nomads Within Us It was originally believed that human chromosomes were fixed at conception and all subsequent organic development proceeded from the instructions encoded on them. Biologists have recently discovered that genes grasshopper about, constantly modifying genetic instructions -- at least that's the current thinking. Additional modification of genetic instructions seems to be accomplished by entities called "nomads" or "mobile dispersed genetic elements." One type of nomad is a simple ring of DNA called a plasmid. Plasmids seem to be identical to a kind of virus called a retrovirus, which can penetrate into cells and tamper with gene expression; that is, the way genetic instructions are interpreted. Plasmids have been discovered in maize, fruit flies, bacteria, and, now, humans -- and healthy people at that. No one is quite sure what these plasmids do. Even though they look like retroviruses, they may not be associated with illness, but rather help organisms adapt to changing environments. But no one really knows. (Anonymous; "Human Wandering Genes Can Live on Their Own," New Scientist, 94:18, 1982.) Comment. So, the human body is not only beset by new genetic instructions and the static introduced by invading viruses and other disease agents, but it has an indigenous population of nomads continually fiddling with our cells' genetic instructions. Our bodies seem more like Grand Central Station with trains loaded with new biological ...
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... Science Frontiers ONLINE No. 150: Nov - Dec 2003 Other pages Home Page Science Frontiers Online All Issues Last Issue Next Issue Sourcebook Project Sourcebook Subjects Contents Archaeology Australians First in the New World? Origin of Clovis Culture Disputed A "Magic Number" Encoded in Three of the World's Major Pyramids Astronomy Mapping and Analyzing Dark Matter Biology Frog Poison Factory Puffin Tongue Trick? Human-chimp DNA Dissimilarities Four-Dimensional Biology A Squid's Eyes that Look Up and Down Tuberculosis and the Extinction of the Megaforna Dark Matter in our Genome Unknown Source of Animal Diversity Communication among Bacteria Geology When the Earth Gets Cracking Subduction Doesn't Check Out Chicxulub Didn't Do It! Geophysics Squishy Ball Lightning Far-Floating Fowl Psychology Natural-Born Readers Physics Mixed Anomalies ...
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... Science Frontiers ONLINE No. 158: Mar - Apr 2005 Other pages Home Page Science Frontiers Online All Issues Last Issue Next Issue Sourcebook Project Sourcebook Subjects Contents Archaeology Untranslatable Mohenjo-Daro Script? A very Early Compound Machine Khufu's Secret Burial Chamber: A Phony Discovery? Astronomy Allez Allez Old Galaxies in a Young Universe Biology Do Dolphins Sense the Coriolis Force? Disappearing Animals Wayward DNA: Does it Affect the Shapes of Family Trees? Geology Bermuda Triangles in the Desert! Plate-techtonics 'theory' is slowly and inevitably Dyning Geophysics Hum Update Psychology Motherese: A precursor of Human Language? Unclassified Multimedia Communications in the Cosmos Computer Bacteria ...
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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 The Unread Biotic Message We have been selling ReMine's book The Biotic Message in which he asserts that life itself is a message of transcendental nature. Every bacterium and human is a cosmic statement. Shifting from the macroscopic to the microscopic (phenotype to genotype), we recall that all macroscopic "statements" are really expressions of DNA -- the genetic code. But when we examine DNA, we find that only about 3% of the DNA in human cells codes for protein manufacture. The remaining 97% is termed "nonsense" or "junk" DNA. But there may actually be sense in nonsense DNA. Statistical analysis of nonsense-DNA "words" (3 -8 bases long) reveals considerable redundancy. Long stretches of nonsense DNA are definitely not random. In fact, the structure of nonsense DNA resembles that of language. The coding or "sense" DNA, on the other hand, lacks this language structure. The implication is that coding and nonsense DNAs carry different kinds of messages. The former consists simply of blueprints; the latter is couched in a language that we have not yet learned to read. (Flan, Faye; "Hints of a Language in Junk DNA," Science, 266:1320, 1994.) Comment. On the microscopic level, we can read only 3% of the biotic message! From Science Frontiers #117, MAY-JUN 1998 . 1998 ...
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... Science Frontiers ONLINE No. 109: Jan-Feb 1997 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Biology Heavy Paleontology vs. DNA. The so-called Cambrian Explosion has been the subject of two SF items (SF#60/187 and SF#85/ 187). A paleontological fact of life is that all known body plans (phyla) seem to have evolved suddenly -- within a few million years -- after the onset of the Cambrian period some 545 million years ago. Evolutionists are understandably uncomfortable with such a high rate of evolutionary innovation. Nothing like the Cambrian Explosion appears in the hundreds of millions of years of geological strata that followed. So rapid was speciation during the Cambrian Explosion that doubt is cast upon the accepted mechanisms of evolution: slow, stepwise accumulation of mutations plus natural selection. (Refs. 1 and 2) But G.A . Wray and colleagues seem to have rescued Darwinism. They have analyzed the DNA sequences of seven genes found in living animals. Assuming that these genes mutate at constant rates and working backwards in time, they calculate that animal diversification (i .e ., when chordates diverged from invertebrates) actually began about 1 billion years ago, rather than about 545 million years ago. This expansion of the time frame gives accepted evolutionary processes much more time to innovate and create all those new body plans. The evolutionists are pleased. The paleontologists, however, are in a quandry. They see nothing -- or very little -- in the Precambrian fossil ...
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... Science Frontiers ONLINE No. 112: Jul-Aug 1997 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects You May Become What You Eat When we scarf down a hamburger, we ingest bovine DNA. The textbooks say that this alien DNA is destroyed during digestion. Otherwise, it might "somehow" be incorporated into our own DNA, leading in time to our acquisition of some bovine characteristics! You'll recall that cannibals thought to acquire the virtues of their slain enemies by grabbing a bite or two! But this all sounds pretty farfetched, doesn't it? Maybe not. When W. Doerfler and R. Schubbert, at the University of Cologne, fed the bacterial virus M13 to a mouse, snippets of the M13's genes turned up in cells taken from the mouse's intestines, spleen, liver, and white blood cells. Most of the alien DNA was eventually rejected, but some was probably retained. In any event, alien DNA in food seems to make its way to and survive for a time in the cells of the eater. (Cohen, Philip; "Can DNA in Food Find Its Way into Cells?" New Scientist, p. 14, January 4, 1997.) Comment. We are only half-kidding when we ask if food consumption could affect the evolution of a species. After all, our cells already harbor mitochondria, which are generally admitted to have originally been free bacteria that were "consumed" by animal cells. The process even has a name ...
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... Science Frontiers ONLINE No. 111: May-Jun 1997 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Chromosome Choreography Every biology student has seen sketches of the "dance of the chromosomes" that is performed when eukaryote (nucleuscontaining) cells divide. Because chromosomes are composed of genes and their DNA -- the information carriers of inheritance -- it reasonable to suppose that they are the "dance-masters." This expectation is enhanced if one holds that the genes are "selfish;" that is, they have their own evolutionary agendas, and all life forms exist only to execute their "will." But cell division would not occur at all without the action of the cell's bipolar spindle. This spindle is composed of microtubules -- rods of the protein "tubulin." Somehow , when cells are about to divide, they synthesize these microtubules, which then seem to organize themselves into orderly arrays (the bipolar spindles). Then, the microtubules sort out and separate the two sets of chromosomes required for the two new cells. So, far, our description conforms to what biologists have known and accepted for decades; but there is something more mysterious going on. In 1996, researchers discovered that they can actually substitute DNAcovered beads for the chromosomes, and the microtubules will still go through the motions of sorting and separating the chromosome-less strands. Actually, the microtubules will perform their act even without the DNA-covered beads. In a sense, the bipolar spindle is a puppetmaster, and the ...
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... Science Frontiers ONLINE No. 114: Nov-Dec 1997 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Gene Wars In past issues, we have mentioned: Sperm wars. Where an animal's sperm are polymorphic; some of which attack alien sperm, some dash directly to the eggs, etc. (SF#78) Selfish DNA. Where animals are merely mechanisms by which DNA perpetuates itself and expands its domain. In other words, DNA calls the shots -- not us! (SF#11) Now we learn about "gene wars." As is well known, genes are thought to control much of what goes on in a living organism. But are they only carriers of hereditary information? Not according to a long, very technical paper by L.D . Hurst et al. It seems that, like selfish DNA, genes have their own agendas. The insidiousness of this is seen in the first sentence of the paper's abstract: "Self-promoting elements (also called ultraselfish genes, selfish genes, or selfish genetic elements) are vertically transmitted genetic entities that manipulate their "host" [as in "us'] so as to promote their own spread, usually at a cost to other genes within the genome." You may not sense it, but your genes are struggling with each other, and you and/or your progeny will carry out the dictates of the victors of the "gene wars." (Hurst, Laurence D., et al; " ...
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... 9,300 years old." (Ref. 2) Actually, the skeleton may well be that of a "pioneer" but one who came from the direction of the setting sun instead of the rising sun. Of course, it is perfectly all right for Asians to have crossed the Bering Strait into North America over 9,000 years ago, but a Caucasian raises scientific and emotional problems. "If Kennewick Man were actually Caucasian, it would be a startling discovery. So far, all of the oldest North American skeletons have been of Asian descent, although features on a few skulls have been controversially interpreted as Caucasoid. Another possibility is that the first Americans -- and their Asian ancestors -- had features that were Caucasoid. The real test of these theories would be DNA, which can pinpoint which modern populations are most closely related to the skeleton and so help identify the ancestors of early Americans and perhaps give clues to their migration patterns." (Ref. 3) But science may not get the opportunity to make the desired DNA tests. The local Umatilla Indians insist that the bones of Kennewick Man be surrendered to them for immediate reburial, as stipulated by the North American Graves Protection Act of 1990. But if the bones are truly those of a Caucasian, does the Act apply? And when does the scientific value of a skeleton outweigh native tradition? Ironically, the Umatilla Indians scoff at the idea of Asian diffusion across the Bering Strait. They claim that they have always lived in the Pacific Northwest! (Ref. 4) Comment. Perhaps ...
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... The Evolution Of Computers So, you thought this item was going to be about advances in chips, modems, and related hardware? It's not about software either. It's about bioware. The title of a recent article in Science began with: "Genomic Cis-Regulatory Logic." That's obscure enough to make you move on to the next article, particularly when you see that sea urchins are involved. But buried in all the technical jargon is a profound discovery: The genes of all living things, from sea urchins to humans, are in reality systems consisting of thousands of simple computational devices. Very, very briefly, the regulatory regions for animal genes, are termed "promoters." Promoters typically consist of a few hundred to several thousand bases of DNA. In the work of Yuh et al, the article's authors, these promoters are seen to perform as logic circuits, just like those bits of silicon in your PC. These tiny, DNA-based biological logic circuits determine how genes are interpreted (each gene may be interpreted in several ways), and, in the end, how lifeforms develop from embryo to adult. (Yuh, Chiou-Hwa, et al; "Genomic CisRegulatory Logic: Experimental and Computational Analysis of a Sea Urchin Gene," Science, 279:1896, 1998. Also: Wray, Gregory A.; "Promoter Logic," Science, 279:1871, 1998.) Comment. Figuring out how your PC's hardware evolved is child's play compared to elucidating ...
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... Advancement of Science (AAAS) in Philadelphia, anthropological heresies ran rampant. T. Dillehay, who directed the Monte Verde work, declared that there were 15-20 other South American sites older than 11,500 years. Monte Verde itself may have been founded 33,000 years ago. D. Stanford, Smithsonian curator of archeology, opined that there were probably several waves of prehistoric immigration into the Americas across the Arctic, the Pacific Ocean (! ), and possibly even the Atlantic (! !) . [This is heresy no longer.] Supporting early Atlantic crossings are several dozen artifacts found in the eastern U.S . that closely resemble some found in France and Iberia. Stanford said, "We don't know yet what that means." Studies of DNA diversity among New World Indian populations find such large differences that at least 30,000 years would have been needed for these differences to develop. (Assuming, of course, a relatively homogeneous group of initial colonists.) Linguist, J. Nichols, from Berkeley, sees a similar diversity in the languages of New World peoples. Some 140 language families -- half the world total -- are found in the Americas. Nichols estimates that it would have taken a minimum of 40,000 years for such diversification. (Again assuming initial homogeneity.) Nichols also pointed out strong similarities in languages all around the Pacific Rim, from New Guinea north to Siberia, around Alaska, and down the west coast of the Americas. The implication is that many of these peoples derived from ...
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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 Genes vs. memes Vital to the concept of "gene wars" (mentioned in SF#114) is the assumption that our destiny is controlled by "selfish genes" (or "selfish DNA"). The idea that evolution works only at the gene level has been championed by R. Dawkins, and today it dominates much evolution philosophy. However, this "genetic imperialism" is now being challenged by some scientists who insist that culture also affects an organism's evolution, be it a human or an insect. In fact, it was Dawkins himself who first proposed the term "meme" for the cultural counterpart of the gene. A meme, in other words, is an "element" of culture that can be passed along to progeny by imitation and/or cultural pressures. In reductionist thinking, environmental challenges are met by gene mutations plus natural selection. In meme theory, the same challenges are confronted by cultural changes (meme "mutation") plus natural selection. The meme approach is holistic rather than reductionist and is appealing because it allows us some control over our destiny. There are several phenomena in which some scientists profess to see memes overpowering the genes: Generations of female infanticide have led to more male births than female births. In dairy-farming societies, 90% of the population has the enzyme lactase that allows individuals to digest cows' milk. In other societies, 80% ...
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... Science Frontiers ONLINE No. 116: Mar-Apr 1998 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Eco-Darwinism: Diffuse Individuals Epigenetic phenomena -- those phenomena beyond the pale of DNA -- are seen in "diffuse individuals" such as fungi, where it is difficult to separate individual units of life. To illustrate, some fungi may be 1,000 years old and extend for 35 acres (15 hectares) and yet possess a single, still unmodified genome. In his review of A. Rayner's new book Degrees of Freedom: Living in Dynamic Boundaries , T. Wakeford writes: "So, like the World Wide Web, a fungal network is decentralized. There is no central region capable of exerting control over the rest of the network. Rayner's own work suggests that the growth patterns of fungal filaments are forged as much by the environment that they encounter as by their genes. He believes that epigenetics, the process whereby opportunities in an organism's surroundings dictate which genes are expressed, is the norm in microorganisms. Genetic determinism is thus turned on its head." (Wakeford, Tom; "We Are the Fungus," New Scientist, p. 49, May 10, 1997.) Comment. Looking at the above situation from an information viewpoint, as one must these days, it seems that the environment can somehow "interpret" genes as the situation demands. In other words, genes are not "single-message" information carriers, but can be " ...
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... Science Frontiers ONLINE No. 94: Jul-Aug 1994 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Our genes aren't us!Almost without exception, biology textbooks, scientific papers, popular articles, and TV documentaries convey the impression that an organism's genes completely specify the living animal or plant. In most people's minds, the strands of DNA are analogous to computer codes that control the manufacture and disposition of proteins. Perhaps our current fascination with computers has fostered this narrow view of heredity. Do our genes really contain all the information necessary for constructing human bodies? In the April 1994 issue of Discover, J. Cohen and I. Stewart endeavor to set us straight. The arguments against the "genes-are-everything" paradigm are long and complex, but Cohen and Stewart also provide some simple, possibly simplistic observations supporting a much broader view of genetics. Mammalian DNA contains fewer bases than amphibian DNA, even though mammals are considered more complex and "advanced." The implication is that "DNA-as-a -message" must be a flawed metaphor. Wings have been invented at least four times by divergent classes (pterosaurs, insects, birds, bats); and it is very unlikely that there is a common DNA sequence that specifies how to manufacture a wing. The connections between the nerve cells comprising the human brain represent much more information than can possibly be encoded in human DNA. A caterpillar has the same DNA as the butterfly it eventually becomes. Ergo, something ...
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... Science Frontiers ONLINE No. 100: Jul-Aug 1995 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects When Humans Were An Endangered Species At one point during the last 400,000 years, the human population worldwide was reduced to only about 10,000 breeding men and women -- the size of a very small town. What caused this population "bottleneck"? Did a population crash engulf the entire globe. If not, who was spared? Such questions arise from a surprising observation: Human DNA is remarkably uniform everywhere humans are found. This hidden genetic uniformity is difficult to believe if one strolls through a cosmopolitan city like New York or Paris. Nevertheless, compared to the DNA of the great apes, whose mutation rates should be close to ours, human genes on the average show far fewer mutations. Human DNA from Tokyo and London is more alike than that from two lowland gorillas occupying the same forest in West Africa. Harvard anthropologist M. Ruvolo has commented: "It is a mystery that none of us can explain." The clear implication is that humans recently squeezed through a population bottleneck, during which many accumulated mutations were wiped out. In a sense, the human race began anew during the last 400,000 years. Unfortunately, DNA analysis cannot say where the very grim reaper came from. (Gibbons, Ann; "The Mystery of Humanity's Missing Mutations," Science, 267:35, 1995.) Comment. The hand that wiped the slate clean, or nearly so ...
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... as well as we thought it did. In particular, the major phylogeny of the animal kingdom as estimated from adult characters doesn't fir very well with that estimated from larvae. Such a discrepancy for different stages has occasionally been reported within families of insects, and it has an apparent resemblance to the discordance occasionally found between phylogenies inferred from morphological and molecular characters. In such cases, the usual conclusion (I ignore data chauvinists) is that we should somehow use all the available information to infer the correct phylogeny. After all, there was just one real phylogeny that occurred in the past, and we want to find it as closely as we can." Comment inserted by the compiler. Van Valen is saying that three evolutionary Trees of Life can be drawn from adult morphology, DNA structure, and larval morphology, and that they may not look the same. Caterpillars may yield a family tree different from that inferred from the butterflies. Which is correct, or are they all correct? Back to the review. Waxing heretical, Williamson points out that an organism may have more than one phylogeny ! Larvae may have ancestries different from the adults. How heretical can one get? But in the ocean, spermatozoa often cannot find an egg of the correct species. They may then fertilize eggs of a distantly related species. In such "wide hybrids," the larvae may resemble one parent and the adults the other. There is much more. The gist of it all is that evolution has been much more than random mutation and natural selection. Hybridization and outright mergers ...
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... to the biological needs for survival. This assumption is enshrined in R. Dawkins' book The Blind Watchmaker . Catchy though this title is, it looks more and more like the Watchmaker sees something. For over a decade, experiments have hinted that those mutations that are helpful to an organism's survival occur more often than those that are not "adaptively useful." This controversial phenomenon is termed "adaptive mutation." (SF#64 and SF#96*) A recent issue of Science presents two more papers that seem to confer the gift of sight on the old Watchmaker. Biochemist J.A . Shapiro, in a commentary accompanying the two Science papers, highlights a significant feature of adaptive mutation in bacteria: The genetic changes involved are multicellular. In other words, DNA rearrangements in one cell are actually transferred to other cells. But most profound of all for the whole science of biology is his sentence: "The discovery that cells use biochemical systems to change their DNA in response to physiological inputs moves mutation beyond the realm of 'blind' stochastic events and provides a mechanistic basis for understanding how biological requirements can feed back onto genome structure." (Shapiro, James A.; "Adaptive Mutation: Who's Really in the Garden?" Science, 268:373, 1995.) Comment. Random mutation has been a linchpin of Neo-Darwinism because it is "scientific"; that is, non-supernatural. We see in adaptive mutation that other scientific mechanisms may indeed exist that make biological evolution more than just a plaything of ...
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