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(ALMOST) HUMAN FOSSILS • DARWINIAN CHEMISTRY • MISMANAGING RAIN FORESTS
BLACK HOLE PARADOX: DATA LOST IN COLLAPSED STARS MAY NOT BE GONE FOREVER APRIL 1997
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Why things go wrong.
Copyright 1997 Scientific American, Inc.
April 1997
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FROM THE EDITORS
8 LETTERS TO THE EDITORS
10 50, 100 AND 150 YEARS AGO
12 NEWS AND
ANALYSIS
Out of Africa Again...and Again? Ian Tattersall
IN FOCUS Microcreditors help to stem poverty.
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The story of human evolution once seemed fairly simple: after evolving in Africa, one intrepid hominid species migrated throughout the Old World and gave rise to modern people. But scrutiny of the archaeological and paleontological records pieced together from digs at many sites suggests that hominid creatures migrated out of Africa several times. Each wave of emigration sent forth a different species onto the world stage—until our own, Homo sapiens, eliminated all the others.
16 Can Sustainable Management Save Tropical Forests?
SCIENCE AND THE CITIZEN Hot spots.... Europa.... Minimizing stroke damage.... Splicing saffron.... What’s your EQ?... Electric car ride.
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Richard E. Rice, Raymond E. Gullison and John W. Reid
22 To preserve our planet’s exquisite and valuable rain forests, many experts have embraced the idea of sustainability, through the replacement of trees harvested for lumber. These conservationists explain why this seemingly logical strategy often fails.
PROFILE Dan Farmer, computer security expert, hacks up the Web.
32 TECHNOLOGY AND BUSINESS Defense cost sharing.... Drugnet: catching cholesterol.... Flexible batteries.
HORIZON: “POINT OF NO RETURN”
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Leonard Susskind
35 CYBER VIEW Is