Aggressive mimicry Wolf in sheep’s clothing Instances Commentary

George and Elizabeth Peckham evolution

Aggressive mimicry

• As opposed to defensive mimicry
• for which the mimic avoids harm by appearing harmful,
• aggressive mimicry harms others by appearing harmless.
• Elizabeth Peckham called defensive mimicry
• “direction protection”
• and she wrote that cases of “indirection protection”
• included spiders that mimic unpalatable creatures
• some for protection, some for capturing prey, and some for both.
• George and Elizabeth studied
• defenseless spiders of the family attidae that mimic ants,
• which helps them escape from birds that eat spiders.

Wolf in sheep’s clothing

• There are many cases of agressive mimicry.
• the wolf in sheep’s clothing intentionally deceives the sheep
• but accidentally deceives the shepherd
• who butchers the sheep for meat.
• The northern shrike mimics the songs
• of small birds
• to lure them to their death.
• The tongue of an alligator snapping turtle
• has a worm-like extension that lures fishes
• that it eats.
• The assassin bug eats spiders
• and plugs the silk of the spiders’ webs
• to mimic a bug caught in it.
• Bolas spiders lure
• male moth flies by mimicing
• the female moth flies’ sex pheromones.
• The sabre-toothed blenny mimics the dance
• of the bluestreak cleaner wrasse
• but instead of cleaning the grouper takes a bite of its fin.
• Parasitic larva of the shellfish Lampsilis
• are injected into a fish by the female shellfish
• who lures the fish using extensions that mimic tiny fish.
• The haplochromine cichlid plays dead,
• lying on its side on the lake bottom and faking a blotchy skin,
• but eats any scavenger that approaches.

Instances

• “In looking for instances of protective form and color among spiders
• we encounter one difficulty at the outset.
• The meaning of a protective peculiarity can be determined
• only when the animal is seen in its natural home.
• The number of strangely modified forms depicted
• in descriptive works on spiders is enormous.
• Bodies are twisted, elongated, inflated, flattened,
• truncated, covered with tubercles or spines,
• enclosed within chitinous plates, colored like bark,
• like lichens, like flowers of every imaginable hue,
• like bird droppings, like sand or stones,
• and in every one of these modifications
• there is doubtless an adaptation of the spider to its surroundings
• which when it is studied out of its natural relations,
• we can only guess at.” —E.G.P.
• Strangely modified forms
• are doubtless adaptions
• we can only guess at.