Feathers: The Evolution of a Natural Miracle by Thor Hanson

Author:Thor Hanson [Hanson, Thor]
Language: eng
Format: epub
Tags: Nature, Nonfiction, on kindle, Popular Science, Science, To Read, Mom
Publisher: Basic Books
Published: 2011-04-19T07:00:00+00:00

With these words, Wallace began to unravel a mystery that had puzzled naturalists for centuries. His “dance party” was what biologists now call a lek, a type of communal display where groups of males gather to pose and posture in an intense competition for mates. The word derives from a Swedish verb for “play,” but there’s nothing playful about lekking males. The quality of their performance proves more than status on the dance floor; it determines just who among them will reproduce and who will remain an evolutionary wallflower. Species that lek often develop exaggerated characters or behaviors specific to the mating ritual. Certain antelope, a fish, and even a tiny white moth are known to do it, but lekking finds its greatest expression in birds of paradise, and it helps explain why they’ve developed the most varied and colorful plumage in history.

Wallace’s “magnificent golden fans” belong to the male Greater Bird of Paradise. They include hundreds of elongated contour feathers that trail from its flanks in fiery streamers, stretching two times its body length or more. From head to tail the bird’s color scheme is so ornate it’s hard to follow. A guidebook description includes no fewer than fourteen distinct feather shades, from “warm sepia” and “walnut brown” to “maroon,” “orangy yellow,” and “vinaceous pink.” And the Greater Bird of Paradise is just the beginning.

Taxonomists recognize forty-two species of paradise birds, each with a unique suite of elaborate displays and courtship regalia. Some birds puff out ebony emerald-topped feather skirts and waggle the hula. Others dangle upside down from branches or juggle iridescent-green feather coins suspended on long filaments above their heads. There are turquoise and purple ruffs that extend sideways like skinny bow ties or inflate like a lion’s mane. The King of Saxony Bird boasts two half-meter feathers jutting from the back of its head, each emblazoned with fifty sky-blue flags that sway and bounce seductively in front of prospective mates. The bent, naked tail quills of the Twelve-wired Bird look so bizarre, the first specimens brought to Europe were long dismissed as fakes. To page through a book on birds of paradise is to be astounded, to feel that nothing is left to exaggerate. From Wallace’s time onward, these birds have embodied the extremes of an evolutionary process that Darwin dubbed “sexual selection.”

Published in 1871, The Descent of Man, and Selection in Relation to Sex marked Darwin’s second major contribution to evolutionary theory. Though he intended the book as a treatise on human origins, he ended up devoting more than half of it to the idea that breeding behaviors are a potent evolutionary force. He seemed surprised by the result, as if the importance of the second topic had grown with the writing of it: “Consequently, the second part of the present work, treating of sexual selection, has extended to an inordinate length, compared to the first; but this could not be avoided.” Indeed, though Darwin’s treatment of human evolution showed his typical thoroughness and took

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