Orchids mimic alarm pheromones of bees to attract wasps

At the end of The Origin, Darwin constructed a justly famous metaphor of nature as a “tangled bank.” In the case of mimicry, the metaphor might be Walter Scott’s “tangled web,”* since the network of interspecific interaction and deception can become quite intricate. Some of the most famous examples of mimicry are those of orchids […]

The Asian giant hornet

In WEIT, I begin the chapter on natural selection with a particularly gruesome example of an adaptation: the predatory Asian giant hornet (Vespa mandarina), the world’s largest wasp and a viscious killing machine. They are horribly fricking huge, with a two-inch body (tipped with a quarter-inch stinger that injects a potent venom) and a three-inch […]

How the tapir got his spots III

by Greg Mayer The two great classes of phenomena that Darwin set out to explain were those of adaptation– the fit between an organism’s features (structure, behavior, etc.) and its conditions of existence; and unity of type — the similarities of basic structure among organisms in diverse conditions of existence (e.g., the one bone-two bones-many […]

How the tapir got his spots II

by Greg Mayer I promised baby tapirs, so here are baby tapirs! (From Zooborns.) Adult Malay tapirs, as you’ll recall, are particolored: The three other species of tapir, all from the Americas, also have spotted/striped young. Here’s a lowland tapir, found throughout much of cis-Andean tropical South America; the others are very similar in appearance. […]

How the tapir got his spots

by Greg Mayer A while back Jerry posted a video of lion cubs at the Tulsa Zoo, and noted that they have spots, remarking Many species of cats show this pattern in the cubs, even if the pattern disappears with growth.  It almost certainly reflects (as discussed in WEIT), an atavistic trait: the persistence in […]

Why toucans have big bills

If you’re like me, you’ll have asked yourself many times, “Jerry, why do toucans have such ridiculously big bills?” (See Figs. 1 and 2.)  The first answer that might strike you is that the bill — like bodies, plumage ornaments, and other traits in birds — was driven to extreme size by sexual selection.  But […]