10 results found.
... Science Frontiers ONLINE No. 85: Jan-Feb 1993 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Clams Before Columbus "Zoologists and geologists agree that specimens of Mya arenaria (the American soft-shell clam) from the Holocene found in Europe first appeared in the sixteenth century, after the voyage of Columbus. But we have dated a sample from the Kattegat region on the east coast of the Skaw in northern Jutland, Denmark, that predates Columbus's voyage. This result implies that contact between America and Europe existed before the sixteenth century." In fact, one sample of the American soft-shell clam was carbon-dated by the authors of the above paragraph at 1245-1295 1 standard deviation. This particular shell was discovered in the sand barrier farthest from the Danish coast. Since it seems highly unlikely that the larvae of the American clam could have swam across the Atlantic, the authors wonder if the Vikings might have carried them home. (Petersen, K.S ., et al; "Clams before Columbus," Nature, 359:679, 1992.) Comment. Certainly the Vikings might have consumed these clams on their voyages to the New World, but why would they or any other explorer carry live clams or their larvae back to the Old World? Or was the transfer accidental in ships' ballast? From Science Frontiers #85, JAN-FEB 1993 . 1993-2000 William R. Corliss ...
Terms matched: 1 - Score: 183 - 15 May 2017 - URL: /sf085/sf085a01.htm
... Four 'clever' adaptations According to theory, many butterflies have wing patterns that evolved in response to predation. Some wing patterns blend into the background, making the butterfly hard to spot; other wings have prominent eyespots that are supposed to deter predators or trick them into striking at the wings instead of the soft, vulnerable body. But some tropi cal butterflies have a double problem; their predators change from dry to wet season. One butterfly, Orsotriena medus, masters this situation by changing wing patterns with the season. In the dry season, it is dark brown and inconspicuous; in the wet season, it switches to black wings with ostentatious eyespots and white bands. (Anonymous; "Cryptic Butterflies," New Scientist, 20, September 13, 1984.) The Asiatic freshwater clam has spread rapidly across North America since its accidental introduction about 50 years ago. In addition to its natural dispersal via its more mobile larvae, the young adult clams have a surprising method of hitchhiking rides on the water currents. Through their siphons they deploy long mucous threads. Water currents pull on these threads just as air currents catch the silken threads of migrating spiders. Given a water current of 10-20 cm/sec, the small clams manufacture and deploy their threads, and off they go downstream. (Prezant, Robert S., and Chalermwat, Kashane; "Flotation of the Bivalve Corbicula Fluminea as a Means of Dispersal," Science, 225:1491, 1984.) Australia boasts many peculiar animals and plants. One of these is an orchid that grows underground ...
Terms matched: 1 - Score: 42 - 15 May 2017 - URL: /sf036/sf036p06.htm
... Science Frontiers ONLINE No. 43: Jan-Feb 1986 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Life Seeks Out Energy Sources Wherever They May Be Life is opportunistic; it siphons off energy wherever it can find it. That life utilizes solar energy we all know. And, of course, humans have tapped the atom for energy. In just the past few years, remarkable colonies of life forms have been discovered congregated around deep-sea hydrothermal vents where sunlight is essentially nonexistent. Still more recently, similar life forms have been found clustered around oil seeps in the Gulf of Mexico. As at the hydro-thermal vents, the clams, worms, crabs, and other organisms depend mainly upon the ability of bacteria to chemosynthesize -- the primary energy source being hydrogen sulfide in the vented water. (Paull, C.K ., et al; "Stable Isotope Evidence for Chemosynthesis in an Abyssal Seep Community," Nature, 317:709, 1985; Also: Weisburd, S.; "Clams and Worms Fueled by Gas?" Science News, 128:231, 1985.) Comment. Since the earth's crust seems honeycombed with fissures and rivers of life-sustaining fluids, subterranean life may be as common as the abyssal chemosynthetic life at the vents and seeps. This versatility of life signals us that we should look for life wherever there is energy of any kind. From Science Frontiers #43, JAN-FEB 1986 . 1986-2000 William R. Corliss ...
Terms matched: 1 - Score: 29 - 15 May 2017 - URL: /sf043/sf043p09.htm
... Science Frontiers ONLINE No. 42: Nov-Dec 1985 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Remarkable Distribution Of Hydrothermal Vent Animals Hydrothermal vents support a bizarre array of large clams, mussels, worms and other curious species. These biological communities are unique in that they are supported not by solar energy but rather the earth's thermal energy. What verges on the anomalous is the appearance in both Atlantic and Pacific Oceans of very similar vent communities, with similar or identical species. How did these continent-separated communities originate ? In the words of the author of the present article, "The cooccurrence of a clam, a mussel, and a vestimentiferan worm at widely separated sites in the Pacific and Atlantic represents either an unusual distribution from a single lineage or, even more remarkably, cases of parallel evolution. " (Grassle, J. Frederick; "Hydrothermal Vent Animals: Distribution and Biology, " Science, 229:713, 1985.) From Science Frontiers #42, NOV-DEC 1985 . 1985-2000 William R. Corliss ...
Terms matched: 1 - Score: 24 - 15 May 2017 - URL: /sf042/sf042p15.htm
... rarefied peaks of the Andes, one would not expect giant fossilized oysters. But there they are---over 500 of them in one location. Some are 3.5 meters in circumference (about 3.8 feet across). When alive, they probably weighed 300 kilograms (660 pounds). About 200 million years ago, according to the geologists, these oysters were thriving under Pacific waters. One must conclude that the Andes rose to their snowy magnificence in a very short period of geological time. (Mayo, Raul; "Descubren Fosiles de Ostras Gigantes en Plena Cordillera," El Comercio, February 28, 2001. Cr. R. Gabbert) Comment. The article calls the fossils "oysters" (" ostras"), but they look more like giant clams. The high Andes boast some curious marine innuendoes. Lake Titicaca is freshened by melting snows but is said to support a species of seahorse and many fish with marine affinities. It drains into lakes that are highly saline. From Science Frontiers #139, Jan-Feb 2002 . 2001 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. ...
Terms matched: 1 - Score: 15 - 15 May 2017 - URL: /sf139/sf139p10.htm
... Science Frontiers ONLINE No. 85: Jan-Feb 1993 Other pages Home Page Science Frontiers Online All Issues Last Issue Next Issue Sourcebook Project Sourcebook Subjects Contents Archaeology Clams before columbus Europe's mystery people Astronomy Heavy traffic in near-earth space WHY INTELLIGENT LIFE NEEDS GIANT PLANETS Biology Biology's big bang Singing caterpillars The lures of mussels WHEN A BIRD IN THE HAND IS WORSE THAN TWO IN THE BUSH Growth spurts in children GEOMAGNETIC STORMS AND HUMAN HEALTH Our chemical brain Geology Biogeology Two tsumani tales Geophysics A PARADE OF SPINNING PHOSPHORESCENT WHEELS BALL LIGHTNING PUNCHES CIRCULAR HOLE IN WINDOW Unclassified Three views of mortality Electronic channeling ...
Terms matched: 1 - Score: 15 - 15 May 2017 - URL: /sf085/index.htm
... 5 -7 meters in width, and 0.1 -0 .4 meters in depth. No known geological processes seem responsible. Farther east, in Nor-ton Sound, methane eruptions from buried organic matter do blow out circular craters; but the elongated pits investigated by Nelson and Johnson are gouged in sand considered too permeable for gas-crater formation. Rather surprisingly, the gray whale has become suspect as a pit excavator. They feed in the area of the pits; and the pits, before enlargement by currents, are just the size of the whales' mouths. The whales apparently dredge up sediment and, with their baleen, strain out amphipods (shrimp-like crustaceans) from the sand. The coexisting narrow furrows turn out to be the work of walruses digging for clams. (Nelson, C. Hans, and Johnson, Kirk R.; "Whales and Walruses as Tillers of the Sea Floor," Scientific American, 256:112, February 1987.) Comment. The whale tale seems a reasonable explanation of the pits described by Nelson and Johnson, but how far in time and space can it be stretched? Whales do frequent the North Sea, but we do not know whether they or methane eruptions excavate the many craters observed there. As for the much larger Carolina Bays, which exist by the thousands in sandy, coastal terrain, who can say without further study. The Carolina Bays, like the whale-made pits of the Bering Sea, are oriented. One can imagine that, when the oceans stood higher, whale pits ...
Terms matched: 1 - Score: 14 - 15 May 2017 - URL: /sf050/sf050p09.htm
... Science Frontiers ONLINE No. 85: Jan-Feb 1993 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Biology's big bang Representatives of three body plans (phyla): jellyfish (coelenterata); aphid (arthropoda); eohippis (chordata); The title refers to the so-called "Cambrian explosion," that period that began some 570 million years ago, during which all known animal phyla that readily fossilize seem to have originated. The biological phyla are defined by characteristic body plans. Humans, for example, are among the Chordata . Some other phyla are the Arthropoda (insects, crustaceans), the Mollusca (clams, squids), the Nemotada (roundworms), etc. All of these phyla trace their ancestries back to that biologically innovative period termed the Cambrian explosion. Even at the taxonomic level just below the phylum, the class (i .e ., the vertebrates), most biological invention seems to stem from the Cambrian. J.S . Levinton, in a long article in the November 1992 Scientific American, explores the enigma of the Cambrian explosion. Did some unknown evolutionary stimuli prevail 570 million years ago that made the Cambrian different from all periods that followed? Or, has something damped evolutionary creativity since then? Levinton holds that biological innovation has continued unabated at the species level since the Cambrian explosion, but that new body plans; that is, new phyla; have not evolved for hundreds of millions of years. Therefore, something special and very mysterious -- some highly creative ...
Terms matched: 1 - Score: 13 - 15 May 2017 - URL: /sf085/sf085b05.htm
... frigid biological desert -- endless plains of sterile muck, broken once in a while by oasis-like deepsea vents, where weird tube worms thrive amidst clouds of chemosynthetic bacteria. This is a highly misleading portrayal. The situation, in fact, recalls what happened when biologists first released clouds of insecticides in rain forest canopies, thus precipitating a deluge of uncataloged insects into collecting nets waiting below. Now, instead of a mere million species of insects worldwide, entomologists are thinking perhaps 10 million or more. Will the same diversity prevail in the deepsea muck? C.L . Van Dover believes so: "Away from the vents, in the great ocean plains, life is much less dramatic and often scaled down to minute proportions -- threadlike worms, tiny snails, delicate, transparent clams. Yet, the diversity of animals in the cold abyssal muds, it now appears, may rival the celebrated biodiversity of the tropical rain forests." We now know virtually nothing about this fauna, how it survives, and how it evolved. Millions of undescribed species may be awaiting discovery by research submersibles and deep dredging. (Van Dover, Cindy Lee; "Depths of Ignorance," Discover, 14:37, September 1993.) Comment. Preconceptions about life and its talents have often blinded science as to the extent of life's domains. More revelations are sure to come when biologists begin looking at crevicular life -- those multitudinous species prospering in the earth's deep pores and crevices, where they draw energy from the earth's heat and chemicals. ...
Terms matched: 1 - Score: 13 - 15 May 2017 - URL: /sf090/sf090b98.htm
... made recently in deep ocean waters. First, abundant plant life has been found at depths of up to 268 meters, well beyond the 200-meter limit biologists had set based on the availability of sunlight. It wasn't difficult to discount photosynthetic life at 268 meters, because light there is only 0.0005% that at the surface. But there it was; and it may be found even deeper now that we've taken off the blinders. (Littler, Mark M., et al; "Deepest Known Planet Life Discovered on an Uncharted Seamount," Science, 227:57, 1985.) The second discovery came at 10,000 feet in the Gulf of Mexico. There, scientists in the submersible Alvin found a well-developed community of large clams, crabs, mussels, and tube worms, which closely resembles those around the Pacific hydrothermal vents. These life colonies do not use sunlight at all, nor do they depend on other life forms based on solar energy. They employ chemosynthesis, and the hydrogen sulfide and other substances in the vented waters replace sunlight. Although there are no obvious vents at the Gulf of Mexico site, the waters there contain plenty of hydrogen sulfide, indicating seepage from somewhere. The life forms are all new to science, although they resemble those in the Pacific. (Anonymous; "Worms without Vents," Oceans, 17:50, September/October 1984.) Comment. Question: how do non-mobile life forms travel the great distances from one vent or seepage locale to another? ...
Terms matched: 1 - Score: 13 - 15 May 2017 - URL: /sf038/sf038p10.htm
