Rick Potts writes:
"A deep current of cold water now surrounds Antarctica, and
information from ocean cores suggests that it developed around 20 million
years ago. Today, the current guards the coast of the enormous Antarctic
ice fields and buffers any marine or atmospheric current from infiltrating
and landing even a minor battalion of heat from the lower latitudes. It is
believed that this current was critical in the growth of perpetual ice on
the continent even during the Miocene. A hot equator was companioned by a
frigid South Pole. A steep gradient of heat linked the two regions, and
the distinction between warm and cold times of the year---annual
seasons--became larger all over the world." ~Rick Potts, Humanitiy's
Descent, (New York: Avon Books, 1996), p. 61
What other evidence is there of this?
"Out of some 20 groups of ttrees and shrubs making up the southern
temperate forests, two trees, the southern beech (Nothofagus) and a
southern conifer (Auraucaria), together with associated insect communities,
are especially interesting. Today they live only south of the equator, and
are closely adapted to cool, humid climatic conditions. Yet they are
widely separated (i.e., disjunctive) across seemingly insurmountable water
barriers. Nothofagus seeds are carreid by wind only a few hundred meters,
even during gails; the tree has failed to populate islands only a few tens
of kilometres offshore from New Zealand. This is in spite of the fact that
Nothofagus forests lie in the strongest wind zone on earth. Experiments
show that in sea water the seeds soon become water-logged and sink. Yet
Nothofagus logs are known to drift from Chile to Tasmania (note the
currents in Fig. 17.48)? Could seeds have been transported on drifting
logs? It is judged unlikely that birds dispersed these particular trees
because oceanic species rarely frequent the Nothofagus forests."
"The Cenozoic record in the northern Antarctic Peninsula contains marine
and terrestrial fossils, including giant Miocene penguins. Important plant
fossils include both Araucaria and Nothofagus. These and related plants
have lived since Cretaceous time in widely scattered Southern Hemisphere
lands. Their presence in Antarctica leads to two important conclusions.
First, some means of biologic dispersal was possible among Australia, New
Guinea, New Zealand, Antarctica, and Southern America in Cretaceous or
early Cenozoic time; in all probability, Antarctica served as a land
bridge. Since then, however, these lands have become more ecologically
isolated. Second, the climate, at least in the relatively low-latitude
Antarctic Peninsula, still was temperate enough until mid-Cenozoic time
(Miocene) for forests to thrive. Continental glaciation then brought to
extinction all indigenous land life in Antarctica."~ ~ Robert H. Dott,
Jr., and Roger L. Batten, Evolution of the Earth, (New York: McGraw-Hill,
1988), p. 564-565
To conclude, since the warmer the temperature the more species can inhabit
a region, without the circum antarctic current, we could probably have an
even more magnificent biosphere.
glenn
Adam, Apes and Anthropology
Foundation, Fall and Flood
& lots of creation/evolution information
http://www.isource.net/~grmorton/dmd.htm