Adaptation and evolution in Gallotia lizards from the Canary Islands: age, growth, maturity and longevity

Abstract

Abstract Qualitative and quantitative comparisons of histological data recorded from growing bone from seven extant and extinct taxa of Gallotia show that these lizards do not have the same longevity, reach sexual maturity at various ages and probably have different growth rates which are in reverse proportion to the specific size of individuals in each taxon. In term of relative growth, the highest rate is seen in the smallest taxon (G. atlantica) and the lowest in the largest taxon (G. goliath). It appears that differences between the maximum size reached, irrespective of the size of hatchlings, are only the consequence of changes in longevity allowing a more or less protracted growth; they are not due to differences in growth rates. On the basis of these data we discuss some points relating to adaptive strategies and evolutionary features of these lizards.