The Earth's Shifting Crust by Charles Hapgood - wire of information

LIFE 335
the pre-Cambrian, and therefore is incapable of making his
living in any field outside of geology, or even outside pre-
Cambrian geology, degenerate? If he starves to death, is his
extinction due to degeneration? The reasoning is analogous.
But, supposing that we allow a phenomenon of degeneration
in species, it is still true that most species disappear with-
out showing any indication whatever of a decline of their
'Vital force/' The majority of them are cut off in the vigor
of maturity, or in "youth," as in the case of the camariate
crinoids. Moreover, there is no rule as to the relative length
of the different periods. Dr. Simpson remarks:
Diversification may be brief or prolonged, and may be of limited
scope or may ramify into the most extraordinarily varied zones cover-
ing a breadth of total adaptation that would have been totally unpredictable
and incredible if we were aware only of the beginning of
the process (390:222-23).
Again, he says,
. . . Episodes of proliferation may come early, middle or late in
the history of a group. This confirms the conclusion that adaptive
radiation is episodic but not cyclic (390:235).
We have already noted that Darwin recognized that the
ordinary competition of species could not account for the
mass extinction of whole groups, of which, even then, there
were many known instances in the fossil record. Since his
day, paleontologists have found very many more cases of
apparently well-adapted species, which in some cases had
flourished for tens of millions of years and yet suddenly disappeared,
sometimes leaving their life niches empty, and at
other times giving way to inferior species as their successors.
For the Pleistocene alone, the last million years, as we have
seen, the examples of this include the mammoth, the masto-
don, the sabertooth cat, the giant beaver, the giant sloth, the
giant bison, and countless extinct varieties of still existing
forms like horses, deer, camels, peccaries, armadillos, wolves,
bears, etc. Dr. Simpson, in discussing the extinction of the
dinosaurs, remarks: