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... Science Frontiers ONLINE No. 18: Nov-Dec 1981 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects The Burgess Shale Puzzle In British Columbia, a middle Cambrian (550 million years BP) formation called the Burgess Shale has miraculously preserved a vast assemblage of soft-bodied sea creatures, especially arthropods. Does this rich and unusual deposit help elucidate arthropod evolution? No, it has complicated the problem. Few of the fossil arthropods can be easily related to groups now living. The Burgess Shale arthropod population is primitive in some ways but remarkably specialized in others. Some of the fossils have body segments like those in one recognized arthropod group but display limbs resembling those of an entirely different group. (Fortey, R.A .; " ... Burgess Shale: A Unique Cambrian Fauna," Nature, 293: 189, 1981.) Comment. It appears that Nature was shuffling the gene deck, or that there was rampant hybridization, or that confusing programs for evolutionary change were drifting in from the cosmos a la Hoyle and Wickramasinghe! From Science Frontiers #18, NOV-DEC 1981 . 1981-2000 William R. Corliss ...
Terms matched: 2 - Score: 445 - 15 May 2017 - URL: /sf018/sf018p08.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 Treasures In A Toxonomic Wastebasket The Burgess Shale, in British Columbia, ia all that is left of a Middle Cambrian mudbank that adjoined a massive algal reef. Here, many "experimental" forms of life prospered and succumbed. The Burgess Shale is probably the world's greatest depository of fossils of softbodied creatures. Quoting Stephen Jay Gould: "The Burgess (fortunately for us) occupies a crucial time in life's history. It represents our only 'window' upon the first great radiation of complex life on earth. All but one or two modern phyla originated in a burst of evolutionary activity associated with the so-called ... explosion some 570 million years ago. The Burgess provides our only peek at the soft-bodied forms of this first flowering. All other soft-bodied fossil assemblages are much younger; they represent faunas well past the initial burst and sorting out of Cambrian times." The morphological diversity of the Burgess Shale, incorporating many bizarre forms of life, represents a true biological revolution. Here are found a dozen genera that do not fit into any modern phylum. Most of the novelties never survived into modern times. (Gould, Stephen Jay; "Treasures in a Taxonomic Wastebasket," Natural History, 94:24, December 1985.) Comment. Somewhere on today's earth, there must be mudbanks washed by nutrient-rich waters and bathed in tropical sunlight. Is some ingredient ...
Terms matched: 2 - Score: 276 - 15 May 2017 - URL: /sf043/sf043p11.htm
... -Dec 1981 Other pages Home Page Science Frontiers Online All Issues Last Issue Next Issue Sourcebook Project Sourcebook Subjects Contents Archaeology The Senegambian Megalithic Monument Complex A Celtic Frontier Site in Colorado? Astronomy A Bump in the Cosmic Background Phoebe Not Locked to Saturn Biology Descent of Man -- or Ascent of Ape? Life's Origin Within the Earth? Or Did it Drift in From Without? Geology The Burgess Shale Puzzle Iridium-rich Layers and Catastrophism Geophysics The Long Arms of Venus and Jupiter Giant Thunderstorm Clusters Offshore Booms Are Still with Us Psychology Dreams More Real Than Reality Warts on Demand? ...
Terms matched: 2 - Score: 173 - 15 May 2017 - URL: /sf018/index.htm
... average 50 x 110 microns and are the size and shape of fecal pellets produced by microscopic animals today. Pellets occur in dark gray and black rocks that were deposited in the facies that also preserves sulfide minerals and that represent environments analogous to those that preserve fecal pellets today. Rocks containing pellets and algal microfossils range in age from 0.53 to 1.9 gigayears (Gyr) and include Burgess Shale, Greyson and Newland Formations, Rove Formation, and Gunflint Iron-Formation. Similar rock types of Archaean age, ranging from 2.68 to 3.8 Gyr, were barren of pellets. If the Proterozoic microfossils are fossilized fecal pellets, they provide evidence of metazoan life and a complex food chain at 1.9 Gyr ago. This occurrence predates macroscopic metazoan body fossils in ... Science Frontiers ONLINE No. 46: Jul-Aug 1986 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects Which came first?The advent of complex life keeps getting pushed back farther and farther in time, as evidenced by the following abstract: "Microfossils resembling fecal pellets occur in acid-resistant residues and thin sections of Middle Cambrian in Early Proterozoic shale. The cylindrical microfossils average 50 x 110 microns and are the size and shape of fecal pellets produced by microscopic animals today. Pellets occur in dark gray and black rocks that were deposited in the facies that also preserves sulfide minerals and that represent environments analogous to those that preserve fecal pellets today. Rocks containing pellets and algal microfossils range in age from 0.53 to 1.9 gigayears ...
Terms matched: 2 - Score: 165 - 15 May 2017 - URL: /sf046/sf046p14.htm
