Geoscience Reference
In-Depth Information
reign might have stretched to 225 million years—and they would
still be alive today. If 65 million years ago the mammals had found a
no vacancy sign, I would not be writing and you would not be read-
ing—our species would not exist.
This view of life in the solar system suggests that evolution can
be more a matter of chance than inevitability. The dinosaurs did not
expire because of a fatal flaw while the flawless mammals lived on.
Dinosaurian genes were not inferior to mammalian ones. Life after
the K-T event was not an improvement on life before and did not
necessarily represent Progress with a capital P. It may be instead
that, after the fall, our small, furtive ancestors survived by skulking
in burrows and crevices and eating the remains of other creatures,
many of whom might have seemed superior to them.
Even the discovery of the Alvarez theory might itself have been
due largely to chance. Whether we think it was depends on how we
see the work of Jan Smit. The discovery of iridium in the Gubbio
boundary clay by the Alvarezes was serendipitous to be sure, but
Smit was on the right trail. Had the Alvarezes not gotten there first,
would the high iridium levels in his Caravaca samples, hidden in the
archives at Delft, ever have come to light, and led him to propose
the Smit theory? That we shall never know.
Y
OUNG
T
URKS
AND
O
UTSIDERS
Thomas Kuhn said that those "who achieve . . . fundamental inven-
tions of a new paradigm have been either very young or very new
to the field whose paradigm they change."
5
The former are often
known as young turks, the latter as outsiders. The history of science
is full of examples of the vital role both play. Take geology: Alfred
Wegener was an outsider—a meteorologist and polar explorer—
who conceived the idea of continents floating through the mantle as
he watched icebergs drift across the arctic seas. Although continents
do not float in the mantle, in the largest sense he was right—they do
move—but it took half a century for insiders to wake up to it. Luis
Alvarez was a physicist without whose intrusion we might still be
saying (if not really believing) that sea level changes killed off the
resilient dinosaurs.
Outsiders can provide an indispensable point of view. With few
exceptions, scientists work within the current paradigm, which per-
meates construction of their theories, even their approach to think-
ing about their subject. They know which old questions need not be
asked again, and fail to see which new ones might fruitfully be
