Evolution of biometric and life-history traits in lizards (Gallotia) from the Canary Islands

Abstract

The aim was to study as to how biometric and life‐history traits of endemic lacertids in the Canary Islands (genus Gallotia) may have evolved, and possible factors affecting the diversification process of this taxon on successively appearing islands have been deduced. To that end, comparative analyses of sexual dimorphism and scaling of different body, head and life‐history traits to body size in 10 species/subspecies of Gallotia have been carried out. Both Felsenstein's independent contrasts and Huey and Bennett's ‘minimum evolution’ analyses show that male and female snout‐vent length (SVL) changed proportionally (sexual size dimorphism not changing with body size) throughout the evolution of these lizards and all within‐sex biometric traits have changed proportionally to SVL. Life‐history traits (size at sexual maturity, clutch size, hatchling SVL and mass, and life span) are highly correlated with adult female body size, the first two being the only traits with a positive allometry to female SVL. These results, together with the finding that the slope of hatchling SVL to female SVL regression was lower than that of SVL at maturity to female SVL, indicates that larger females reach maturity at a larger size, have larger clutches and, at the same time, have relatively smaller hatchlings than smaller females. There was no significant correlation between any pair of life‐history traits after statistically removing the effect of body size. As most traits changed proportionally to SVL, the major evolutionary change has been that of body size (a ca. threefold change between the largest and the smallest species), that is suggested to be the effect of variable ecological conditions faced by founder lizards in each island.

Sex‐specific differences in ecomorphological relationships in lizards of the genus Gallotia

“…Analyses were run for males and females separately as Gallotia are known to be dimorphic (Herrel et al . ; Molina‐Borja ; Molina‐Borja & Rodríguez‐Domínguez ; Molina‐Borja et al . ).…”

Morphology, performance and fighting capacity in male lizards, Gallotia galloti

“…Gallotia galloti is a medium‐sized diurnal (average snout–vent length, SVL, ? = 107 mm, / = 88 mm, Molina‐Borja & Rodríguez‐Domínguez 2004) omnivorous lizard endemic to the Canary Islands of Tenerife and La Palma (Spain). The species is sexually dimorphic in body size, head dimensions and coloration.…”

Adaptive trait evolution in random environment

“…In the table 10, the OUBMCIR, and OUOUCIR models are the best models or the second best model in our collect data. [27] lizard oubmcir ououcir oubmbm ououbm [28] fish oubmbm oubmcir ououbm ououcir [29] lizard oubmcir oubmbm ououcir ououbm [30] lizard oubmcir oubmbm ououcir ououbm [30] lizard oubmcir oubmbm ououcir ououbm [31] coral oubmcir oubmbm ououcir ououbm [32] foram ououbm ououcir oubmcir oubmbm [33] fig ououbm oubmbm ououcir oubmcir [34] For foram data in [33], the best model is OUBMBM, the second best model is OUOUCIR, the third model is OUBMBM and the last model is OUBMCIR. Their Bayes factors is shown in We use the range of K values proposed by [26] to compare the support between models for foram data in [33].…”