HATCHERIES: A group of scientists proposes the pools formed form
vented geothermal steam, pictured here, may have provided the
perfect environment for life's early cells. Image: Courtesy of
National Park Service Earth started as a violent place, its
surface churned by continuous volcanic eruptions and cloaked in
an atmosphere that would have been poisonous to today's life-
forms. Furthermore, the thin primeval atmosphere may have
provided only scant protection from the young sun's harsh
ultraviolet glare. Given these inhospitable conditions,
scientists have long wondered: How did the first cells come to
be nearly four billion years ago? Conventional scientific wisdom
holds that life arose in the sea. But a new study suggests that
the first cells—or at least the ones that left descendants still
extant—got their start in geothermal pools, like those seen at
Yellowstone National Park and other geologic hot spots today.
The argument rests on one indisputable observation—enzymes
common to all archaea and bacteria a