Extinction and Life and Death on Planet Earth Part 1
About the variety of life that has lived on planet Earth, the species that have become extinct, their fossil remains.
DEATH ON EARTH
Earth has been inhabited by an unbelievably diverse and ever-multiplying roster of vigorous life forms that no science-fictionist could ever have imagined. Each arrival of "new" relatives (and we must remember that all life is one close-woven family of cousins) was predicated upon planetary conditions favorable for each new species in its time, station, and comfortable adaptation to the then existing conditions on earth.
When vast changes took place, life forms were often wiped out instantaneously. Two thirds of the primitive families suddenly disappeared at the end of the Cambrian period. The greatest mass extinction took place at the end of the Permian period (midway between the Cambrian and the present), when "Nearly half the known families of animals throughout the world became extinct," as N. J. Berrill reported, in Inherit the Earth: Man on an Aging Planet. He said further, "Another major case of mass extinction occurred at the end of the Cretaceous period. . . . The dinosaurs large and small, the great marine reptiles, the flying reptiles, the ammonite mollusks of all sizes, and many other forms of terrestrial and marine animal life disappeared without a trace--at least 16 orders and superfamilies of living creatures."
During the 1970s or sometime in the 21st century sudden drastic earth changes could again wipe out families, most notably the one that concerns us, the family of man. If the earth warmed up suddenly, the Antarctic continental glacier would begin to melt, drowning millions of seaside residents. Changes in ocean currents take place occasionally, shifting the longtime migration patterns of massive schools of fish, with drastic effects on man's fishing industries. One great mystery of sudden mass death under freezing temperatures left mammoths, their tusks obtruding, frozen high inside a Siberian cliff. The mammoths were dug out by peasants, and scientists studied the instantly frozen giant herbivores, with bits of grass still delicately held across their palates. We don't know what massive rippling of the planet's skin might have taken place, how the sudden freezing cold was achieved, or if and when it may happen again.
Only about 1/3 of the 2,500 families of animals--whose fossilized remains have been found--are represented by living descendants. Man's descent comes from collateral lines of often secondary creatures who were somehow able to survive and adjust to changed conditions after one of nature's upsets. Meantime, man has advanced from a timid subordinate being to become a threat to the natural environment of the entire planet.
Two groups of Stone Age men presently face assimilation by their "civilized" neighbors--the bushmen of the South African Kalahari Desert and the aborigine population in Australia. Evidence seems fairly conclusive that the "more modern" Neolithic men of the later Stone Age, inventors of the bow and arrow and the wheel, most likely wiped out their earlier kin, Paleolithic man, wherever they encountered him. After all, these earlier Neanderthals had only primitive stone axes as weapons.
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