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... Science Frontiers ONLINE No. 69: May-Jun 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Extinction Countdown Some plants may, as described below, have environment-sensitive genes that help them adjust to external pressures. Amphibians and birds do not seem to be so pliable. The worldwide precipitous decline of amphibian populations is alarming. Her-petologists are literally seeing species disappear before their eyes. Here is a typical anecdote: "In 1974, Michael Tyler of the University of Adelaide, Australia, described a newly discovered frog species that broods its young in its stomach. The frog was once so commo 'an agile collector could have picked up 100 in a single night,' Tyler says. By 1980 it had completely disappeared from ... Science Frontiers ONLINE No. 69: May-Jun 1990 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Extinction Countdown Some plants may, as described below, have environment-sensitive genes that help them adjust to external pressures. Amphibians and birds do not seem to be so pliable. The worldwide precipitous decline of amphibian populations is alarming. Her-petologists are literally seeing species disappear before their eyes. Here is a typical anecdote: "In 1974, Michael Tyler of the University of Adelaide, Australia, described a newly discovered frog species that broods its young in its stomach. The frog was once so commo 'an agile collector could have picked up 100 in a single night,' Tyler says. By 1980 it had completely disappeared from ...
Terms matched: 2 - Score: 169 - 15 May 2017 - URL: /sf069/sf069b05.htm
... Predation BBC2 Conspicuous Plumage Advertises Unpalatability BBC3 Why Did Stinking Birds Evolve? BBC4 Poisonous Birds and Poison Dart Frogs: Convergent Evolution? BBC5 Are Ratites More Primitive Than Flying Birds? BBC6 Did Australian Songbirds Evolve Earlier than European Songbirds? BBC7 Are Birds More Closely Related to Mammals Than to Reptiles? BBC8 The Inability of Some Birds to Synthesize Ascorbic Acid BBD DISTRIBUTION OF BIRDS IN SPACE AND TIME BBD1 Discontinuous Populations of Birds BBD2 Uncolonized Areas: Unfilled Niches BBD3 Land Birds Observed Far at Sea BBD4 Late Survival of Moas and Passenger Pigeons BBD5 Distribution Curiosities BBE THE FOSSIL RECORD OF BIRDS BBE1 The Fossil Record of Birds and Associated Paradigms BBE2 Evidence against the Dinosaur Origin of Birds BBE3 Protoavis: A Pre-Archaeopteryx Bird? BBE4 Unresolved Nature of Archaeopteryx BBE5 The Apparent Absence of Transitional Forms of Feathers BBE6 Fossils ... Tears BHF31 The Lack of Any Measurable Biochemical Value of Sleep BHF32 Lunar Control of the Sleep Cycle BHF33 Voluntary Suspended Animation BHF34 Human Mortality Correlated with Geomagnetic Activity BHF35 Nearly-Simultaneous Deaths of Twins BHF36 Curious Attitudes after Death Geophagy in Pregnancy and Health Evolution of Menopause Uncertain Purpose of REM Sleep Curious Nature of Anesthesia Evolution of Menstruation Fetal Growth Correlated with Solar Activity Evolution of Sex Purpose of Life after Menopause Decline in Sperm Counts Fetus Signals Timing of Birth How Embryo Development Is Controlled and Effected Cycles in Autistic Births Rhythms in Growth Evolution of Lactose Tolerance Twins and Occurrence of Nightmares Timing of the End of Sleep BHG HUMAN GENETICS BHG1 Human Chromosomes Less Evolved Than Ape Chromosomes BHG2 The Presence of Introns in Human Chromosomes BHG3 Human Chromosomes Lack the "Baboon Marker" BHG4 Y-Chromosome Analysis Suggests First Humans Were ...
Terms matched: 2 - Score: 160 - 15 May 2017 - URL: /cat-biol.htm
... no particular interval. Pairs of workers, confined together, also do not show periodicity in activity level. One worker can stimulate another worker to become active, thus coupling their movement-activity patterns. As ants are placed in larger groups, the variation in the interval between activity peaks declines in a manner predicted by coupled oscillator theory. It is argued that the colony can be regarded as a population of 'excitable subunits.," Activity records from two ant colonies. Time (horizontal axis) is measured in 30-second intervals. (Cole, Blaine J.; "Short-Term Activity Cycles in Ants: Generation of Periodicity by Worker Interaction," American Naturalist, 137:244, 1991.) Comment. The author also pointed out the "formal" or mathematical ... workers do not show the pattern of periodic changes in activity level. Single workers become active spontaneously, but at no particular interval. Pairs of workers, confined together, also do not show periodicity in activity level. One worker can stimulate another worker to become active, thus coupling their movement-activity patterns. As ants are placed in larger groups, the variation in the interval between activity peaks declines in a manner predicted by coupled oscillator theory. It is argued that the colony can be regarded as a population of 'excitable subunits.," Activity records from two ant colonies. Time (horizontal axis) is measured in 30-second intervals. (Cole, Blaine J.; "Short-Term Activity Cycles in Ants: Generation of Periodicity by Worker Interaction," American Naturalist ...
Terms matched: 2 - Score: 129 - 15 May 2017 - URL: /sf076/sf076b06.htm
... have been accompanied by worldwide volcanic upheavals and reorganization of tectonic plates that would have played havoc with anything living in the Late Cretaceous period, 65 million to 99 million years ago. Although the notion that an asteroid was the immediate cause of dinosaur extinction about 65 million years ago has won wide acceptance, many paleontologists have argued that volcanic activity may have played a role in changing the climate and sending populations of the giant creatures into decline. (Bowman, Lee; "Scientist's Say Earth's Magnetic Field Shifted Rapidly in Time of Dinosaurs," Dallas Morning News, January 21, 2000. Cr. Phelps) Comment. Coincidentally (honest!), we are offering with this mailing a reprint of C.H . Hapgood's The Path of the Pole. From ... Frontiers #128, MAR-APR 2000 . 1997 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: 2 - Score: 120 - 15 May 2017 - URL: /sf128/sf128p08.htm
