Enzyme polymorphism, wing pattern variability, and geographical isolation in an endangered Butterfly species
Auteurs : Descimon (Henri) et Napolitano (Michel)
Année de publication : 1993
Publication : Biological Conservation
Volume :
66
Fascicule : 2
Pagination : 117-123
Résumé :
A study of the variation of allozyme genetic diversity and phenotypic diversity of wing pattern was conducted in the endangered montane butterfly Parnassius mnemosyne in southern France. A decrease of gene flow in peripheral isolated colonies was detected by the analysis of electrophoretic data. The same methods disclosed a marked reduction of gene diversity in the same populations, correlated with reduced habitat area and distance to the continuous core of the species' distribution. Wing pattern variability was not affected in the same way: overall variation range did not regularly decrease with isolation, but the shape of the distribution changed This modification may be interpreted as a loss of phenotype canalization power, resulting from a decrease of diversity at the level of polygenic morphological characters. This overall loss of gene diversity may seriously reduce the ability of peripheral colonies surviving precariously on montane islands to face climate fluctuations in the future