During Earths 4.6 billion year history,
the surface of our planet has undergone numerous
transformations. These transformations have had
a profound impact on the evolution of life on
Earth. When plates move they carry living organisms
along with them like passengers on a slow moving
ice floe. As a plates relative position
to the equator changes over time, organisms well
adapted to a polar environment, for example, must
either evolve through adaptations or perish as
the plate migrates into a tropical environment.
Did you ever wonder why elephants are only found
in Africa and Asia? With plate tectonics as a
guiding principle, the answer becomes moderately
clear. As India broke away from Africa 20 million
years ago it very likely ferried some unsuspecting
elephants (along with many other organisms) northward
to Asia. The Asian and African elephants have
slight physical variations, but they are clearly
cut from the same genetic mold.
Another very interesting theory to emerge recently
concerns, perhaps, the greatest of all mysteries
- the origins of life on earth. The predominant
theory held that life had its origins in warm
ponds or similar small bodies of water protected
from the harsh environment of the early earth
and far from the escaping heat of the deep sea-floors.
But now scientists have discovered organisms that
thrive in these hellish conditions and appear
to have been around long before the earliest known
organisms previously known. Could the hot vents
at mid-ocean ridges have been the incubators of
life on this planet?