Charles Lyell, Historian of Time's Cycle - Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time - page 144

turists, breeders, and fanciers—to invisible events of grander scale in nature,
his otherwise eccentric beginning makes sense. Ernst Mayr (1963) began our
most important modern book on species and their origin with an empirical
list of sibling species, 7 not with general theories or global frameworks. When
we grasp Mayr's major aim—to substitute a dynamic view of species as
natural populations defined by interbreeding and ecological role for the old
taxonomist's idea of dead things that look alike in a museum drawer—we
recognize that his choice for starters embodies his book's program: for sibling
species are the test case of his vision—perfectly good species by the new
criterion, unrecognizable under the old.
Following five historical chapters that tout the factual and moral benefits of
nondirection, Lyell begins his substantive brief with three chapters on climate
in the northern hemisphere and one on the hypothesis of progression in life's
history. Chapter 6 of volume I bears the title "Proofs that the climate of the
Northern hemisphere was formerly hotter." And so—mark the oddity—the
first substantive chapter in a three-volume brief for time's cycle admits as its
central theme the most favorable datum that Lyell's opponents, advocates of a
directionally cooling earth, could possibly muster.
Chapter 7, "on the causes of vicissitudes in climate," then argues that varying
distributions of land and sea are the most evident and easily ascertainable
causes of climatic change. (A vast ocean dotted with a few small islands will
bring warmer and more equable climates than a massive continent with little
surrounding water at the same latitudes.) Chapter 8 bears an extended title:
"Geological proofs that the geographical features of the northern hemisphere,
at the period of the deposition of the carboniferous strata, were such as
would, according to the theory before explained, give rise to an extremely hot
climate." And now we understand the point and the program.
Carboniferous rocks are old. They represent a time of great swamps and lush
tropical vegetation; their fossil remains supply
7. Sibling species are morphologically indistinguishable populations as
clearly separated by behavior in nature as others more visually distinct.