The Sixth Extinction: An Unnatural History

Sagan decided to try to model the effects of an all-out war and came up
with the concept of “nuclear winter,” which, in turn, generated its own
wave of media coverage.
But among professional paleontologists, the Alvarezes’ idea and in
many cases the Alvarezes themselves were reviled. “The apparent mass
extinction is an artifact of statistics and poor understanding of the
taxonomy,” one paleontologist told the New York Times.
“The arrogance of those people is unbelievable,” a second asserted.
“They know next to nothing about how real animals evolve, live, and
become extinct. But despite their ignorance, the geochemists feel that all
you have to do is crank up some fancy machine and you’ve revolutionized
science.”
“Unseen bolides dropping into an unseen sea are not for me,” a third
declared.
“The Cretaceous extinctions were gradual and the catastrophe theory
is wrong,” yet another paleontologist stated. But “simplistic theories will
continue to come along to seduce a few scientists and enliven the covers
of popular magazines.” Curiously enough, the Times’ editorial board
decided to weigh in on the matter. “Astronomers should leave to
astrologers the task of seeking the cause of earthly events in the stars,”
the paper admonished.
To understand the vehemence of this reaction, it helps to go back,
once again, to Lyell. In the fossil record, mass extinctions stand out, so
much so that the very language that’s used to describe earth’s history is
derived from them. In 1841, John Phillips, a contemporary of Lyell’s who
succeeded him as president of the Geological Society of London, divided
life into three chapters. He called the first the Paleozoic, from the Greek
for “ancient life,” the second the Mesozoic, meaning “middle life,” and the
third the Cenozoic, “new life.” Phillips fixed as the dividing point between
the Paleozoic and the Mesozoic what would now be called the end-
Permian extinction, and between the Mesozoic and the Cenozoic, the end-
Cretaceous event. (In geologic parlance, the Paleozoic, Mesozoic, and