Jp. Bogart et Sb. Hedges, RAPID CHROMOSOME EVOLUTION IN JAMAICAN FROGS OF THE GENUS ELEUTHERODACTYLUS (LEPTODACTYLIDAE), Journal of zoology, 235, 1995, pp. 9-31
Chromosomes from all 17 species of native Jamaican Eleutherodactylus a
s well as introduced E.johnstonei were subjected to computer-assisted
analyses. Diploid chromosome numbers of 24, 26, 28, 30 and 32 were fou
nd and no two species had identical karyotypes. Karyotypic data were s
uperimposed on a phylogeny derived from allozyme and immunological dat
a in order to assess karyotypic changes that occurred in lineages of J
amaican Eleutheronactylus. Chromosome number changes have occurred at
least nine times on the island and have involved both fission and fusi
on mutational events. C-bands and the sites of secondary constrictions
varied and provide very little phylogenetic information. In most inst
ances, karyotypically determined interspecific evolutionary relationsh
ips corresponded with the molecular data. The combination of karyologi
cal analyses and molecular data clarified lineages which involved conv
ergent chromosome numbers or extremely divergent karyotypes. Karyotypi
c changes in Jamaican Eleutherodactylus are best explained by chromoso
me fission, fusion, translocations and inversions which arose in isola
ted demes and have been fixed through inbreeding and genetic drift. Ra
tes of karyotypic evolution among Jamaican Eleutherodactylus are much
faster than previous published rates for frogs. Karyotypic evolution a
ppears to be dictated by behavioural factors and effective population
sizes irrespective of taxonomic groupings.