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evolutionary biology

Hair vs. Fur

“Adam catched Eve by the fur below,” goes an old English song from the swampy fens of Norfolk, “and that’s the oldest catch I know.” The ditty may not be suitable for work or for younger audiences, but it points to a tricky matter of trichoid distinction: namely, the finer-than-frog’s-hair distinction between hair and fur.

Of Marsupials and Placentals

Why are there no giant tree-climbing, carnivorous kangaroos in the stately magnolias and maples of Central Park?

It’s a question of what might have been. To be fair, those lethal hoppers—called marsupial lions, less for their gross anatomy than for their sharp teeth—have been absent from Australia for 40,000 years, too. Gone are their giraffe-like cousins, which browsed on the branches of eucalyptus trees. Gone are the giant-fanged sparassodonts of South America. Gone is Thylacosmilus, the saber-toothed opossum, which weighed about as much as the average American male today—a lot, in other words.

Illustration by Angela Cockayne

Of Hounds and Dogs


All hounds are dogs. All dogs are not hounds, a fact for which dog trainers everywhere are no doubt grateful.

Every one of the world’s 400 dog breeds has its origins in Canis lupus, the wolf, domesticated on the trash middens of the ancient world, their archetype not the wolf but something like the ur-dogs that inhabit the landfills and industrial edgelands of the world today: small, scruffy, tan.

Humans and Canis lupus, in its familiaris form, have thus been together for thousands of years. In that time humans have tinkered, as they have with other plants and animals around them, to make dogs more useful. Five thousand–odd years ago, the Egyptians bred something like the greyhound. At about that time, far away on the islands recently separated from the European mainland by rising seas that inundated the aptly named Doggerland, ancestral Britons were breeding familiaris for guarding livestock and hunting.


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