THE GHOST OF MIMICRY PAST - LABORATORY RECONSTITUTION OF AN EXTINCT BUTTERFLY RACE

Four variable traits that determine mimetic colour patterns in the but terfly, Heliconius cydno, evolved between 1908 and 1984-91. There was a decline in the frequencies of alleles and phenotypes that confer res emblance to the co-mimic, Elzunia humboldt regalis, and an increase in the frequencies of alleles and phenotypes that confer resemblance to the alternative co-mimic, Heliconius erato chestertonii. Elzunia humbo lt regalis was formerly common but is now restricted to forest fragmen ts, whereas H. e. chestertonii occurs principally in disturbed habitat s, where it is now common. Human disturbance of habitats is thought to have changed the relative abundances of the two co-mimics, and hence the selection operating on H. cydno. The form of H. cydno that is pres umed to have been a near-perfect mimic of H. h. regalis is no longer f ound in the wild: this form would have been homozygous for the rarer a lleles at all four loci. It has been possible to reconstruct this form on two occasions in the laboratory, breeding from partially heterozyg ous wild-caught female butterflies.