As any good high school student should know, the beaks of Galápagos “finches” (in fact the islands’ mockingbirds) helped Darwin to develop his ideas about evolution. But few people realize that the polar bear, too, informed his grand theory.
Letting his fancy run wild in On the Origin of Species, the man accustomed to thinking in eons hypothesized “a race of bears being rendered, by natural selection, more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale.”
Darwin based this speculation on a black bear the fur trader-explorer Samuel Hearne had observed swimming for hours, its mouth wide open, catching insects in the water.
If the supply of insects were constant, Darwin thought, and no better-adapted competitors present, such a species could well take shape over time.
Systematic approaches to animals and their respective niches had long fertilized the intellectual landscape.
Georges-Louis Leclerc, Comte de Buffon, in his Histoire Naturelle (published serially between 1749 and 1788) clearly distinguished a “land-bear” from a “sea-bear”. But his land-bear category was still muddled: it included a “white bear of the forest” as well as a brown bear.
The count would have likely heard of polar bears in the boreal zone of southern Hudson Bay and he thought them a separate species: his “white bear of the forest”.
In a 1754 publication of coloured plates used in Buffon’s Histoire Naturelle, his white land-bear looks different from his sea-bear, clearly showing the shorter neck and snout characteristic of brown bears and black bears.
Perhaps the count knew about British Columbia’s white black bears or “spirit bears,” which could have confused him. (Other contributions by Buffon were significant. He discovered the first principle of biogeography, noticing that despite similar environments, different regions have distinct plants and animals.)
Buffon’s L’ours blanc, the “White Bear”, featured in a 1754 publication of coloured plates used in his Histoire Naturelle.