THE CORAL SNAKE “MIMIC” PROBLEM IN PANAMÁ

Abstract

student of evolution, if his attention is called to contemporary phenomena in Animal Kingdom, cannot fail to note cases of extraordinary superficial resemblance between animals of quite diverse relationships. term and voluminous body of literature has resulted. In most general terms may be called word to describe situation (or an evolutionary problem) in. which external appearance, confined to certain area and certain size range, is shared by species of diverse ancestry. In many of these situations (and coral snake problem is case in point) some species are definitely venomous, poisonous, or distasteful as food while others are innocuous and edible. In all these situations evolutionary problem of superficial resemblance (the observational data) challenges evolutionary student. An almost complete acquaintance with history, facts, and status of coral snake mimic problem may be gained by perusal of four papers; those of Cope 1860, Wallace 1867, Gadow 1911, and Sternfeld 1913. Cope first called attention to existence of problem in following words (p. 262): The subject of prevalence of peculiar shades and arrangements of colors throughout certain geographical districts is one of much interest to zoologists, the Elaps of South America is represented in same region by black and red ringed Oxyrhopes, Erythrolamprus, Pliocercus, Lampropeltis, etc. Wallace, in discussing problem, proposed solution: a very remarkable and instructive case of true Gadow, writing after extensive field experience in Mexico, objected to idea of mimicry on number of grounds as follows: There are more mimickers . . . than species of Elaps, there are large districts of unquestionably Elaps-terrain where harmless species and individuals form great majority. The range of harmless species in typical dress of Elaps often extends far beyond that of nearest species of Elaps. have not yet come across single instance of what may be called occurrence by side. This in spite of fact that he had previously written (1908) several kinds of harmless snakes, belonging to different groups, inhabit same districts together with poisonous coral snake, and, what is more, they lead same kind of life under rotten stumps and in ants nests. He proposed two other solutions, as follows: (1) at dusk . . . black, alternating with red produces an effacive blur; i.e., coloration of these snakes is concealing; and (2) because America [sic] environment favours production of red in snakes . . . Scientist . . . means, but does not like to say: loci. Sternfeld's paper is defense of mimicry against some of Gadow's criticisms, and an attack on second of Gadow's solutions. He suggests that superiority in number of species of mimics over coral snakes is point in favor of, not against, mimicry. He claims that coincidence of range is much better than Gadow implied, and adds important point of coincidence in size, coral snake coloration being manifested only in snakes of coral snake dimensions. Gadow's by side criticism he considers absurd, and ridicules it in most amusing paragraph I have ever read in scientific paper. With regard to environment in America and Genius loci he says, concerning this geheimii-