Geoscience Reference
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Clemens that such a gap was only to be expected when rare crea-
tures had suddenly gone extinct, yet Clemens stubbornly refused to
accept the obvious. Luis's description of his attempt to persuade his
"friend" goes on for four dense pages; its detail suggests that there
must have been something more than friendship and science behind
it—Alvarez seems to be trying to show Clemens up not only as
wrong but as unreasonable, even unscientific: "I really cannot con-
ceal my amazement that some paleontologists prefer to think that
the dinosaurs, which had survived all sorts of severe environmental
changes and flourished for 140 million years, would suddenly, and
for no specified reason, disappear from the face of the earth ... in a
period measured in tens of thousands of years. I think that if I had
spent most of my life studying these admirable and hardy creatures,
I would have more respect for their tenacity and would argue that
they could survive almost any trauma except the worst one that has
ever been recorded on earth—the impact of the K-T asteroid."
1
2
Shortly after he gave his talk, the review article by Archibald and
Clemens in
American Scientist
13
appeared, just in time for Alvarez
to incorporate a critique of it as an afterword to his written remarks.
According to Alvarez, after they had ignored the iridium evidence
and pooh-poohed impact, Archibald and Clemens offered only two
alternatives as the cause of the K-T extinction: supernova explosion
and the spillover of Arctic seawater (which would have lowered
global temperatures). Alvarez said that he was "quite puzzled to see
that in 1982, two knowledgeable paleontologists would show such
a lack of appreciation for the scientific method as to offer as their
only two alternative theories to that of the asteroid, a couple of out-
moded theories. . . . Today, both of them are as dead as the phlogis-
ton theory of chemistry."
1
4
To accuse a scientist not only of being
wrong, but of being ignorant of the proper use of the scientific
method, is the deadliest of scientific insults—tantamount to saying
that the person in question is not truly a scientist. Such a remark
would certainly strain any friendship.
Polls do not decide scientific matters, but since our interest is
not only in what caused the K-T extinction, but in how scientists
reacted to the Alvarez theory, it is useful to consider the results
(normalized to equal 100 percent) of a poll taken in the summer of
1984 of over 600 paleontologists, geophysicists, and other geologists
from six countries:
• 24 percent agreed that an extraterrestrial impact at the K-T
boundary caused the mass extinction.
• 38 percent thought that a K-T impact had occurred but that
other factors caused the mass extinction.
