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When did life begin on earth? Harvard Paleobotanist Elso S. Barghoorn and his onetime student, J. William Schopf, discovered a possible answer to that intriguing question several years ago, when they found microscopic fossils in ancient South African rocks. These tiny traces of life indicated that single-celled creatures existed as long as 3.1 billion years ago. Now a team headed by Schopf himself has found evidence that could push the dawn of life back at least another 200 million years...

Author: /time Magazine | Title: Science: Dating the Dawn of Life | 6/19/1972 | See Source »

Chemical Choice. That sudden change in carbon ratios was highly significant to Schopf and his collaborators, Dorothy Z. Oehler of U.C.L.A. and Keith A. Kvenvolden of NASA'S Ames Research Center. In a recent report in the journal Science, they proceed to explain...

Author: /time Magazine | Title: Science: Dating the Dawn of Life | 6/19/1972 | See Source »

...discovery of photosynthetic organisms so early in the earth's history has important implications, Schopf and Barghoorn state in an article in the current issue of Science. It means either that life emerged much earlier than suspected -- maybe even as far back as 4 billion years ago -- or that once it did arise complex forms evolved much faster than believed...

Author: By James C. Dinerstein, | Title: Biologists Find Oldest Fossil; Push Back Age of Photosynthesis | 5/1/1967 | See Source »

...earth is about 4.5 billion years old and, according to Schopf, until around eight years ago, scientists thought life went back no further than 1.5 billion years at most...

Author: By James C. Dinerstein, | Title: Biologists Find Oldest Fossil; Push Back Age of Photosynthesis | 5/1/1967 | See Source »

...emergence of photosynthetic organisms was a key link in the evolution of life, said Schopf. The oxygen released in the process enabled higher, oxygen-breathing plants and animals to appear...

Author: By James C. Dinerstein, | Title: Biologists Find Oldest Fossil; Push Back Age of Photosynthesis | 5/1/1967 | See Source »

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