Conventional scientific wisdom has it that plants and other
creatures have only lived on land for about 500 million years, and that
landscapes of the early Earth were as barren as Mars.
A new study, led by geologist Gregory J. Retallack of the University
of Oregon, now has presented evidence for life on land that is four times as
old — at 2.2 billion years ago and almost half way back to the inception of the
planet.