Length of activity season drives geographic variation in body size of a widely distributed lizard

Abstract

a These authors contributed equally to this work. These authors contributed equally to this work. AbstractUnderstanding the factors that drive geographic variation in life history is an important challenge in evolutionary ecology. Here, we analyze what predicts geographic variation in life-history traits of the common lizard, Zootoca vivipara, which has the globally largest distribution range of all terrestrial reptile species. Variation in body size was predicted by differences in the length of activity season, while we found no effects of environmental temperature per se. Females experiencing relatively short activity season mature at a larger size and remain larger on average than females in populations with relatively long activity seasons. Interpopulation variation in fecundity was largely explained by mean body size of females and reproductive mode, with viviparous populations having larger clutch size than oviparous populations. Finally, body size-fecundity relationship differs between viviparous and oviparous populations, with relatively lower reproductive investment for a given body size in oviparous populations. While the phylogenetic signal was weak overall, the patterns of variation showed spatial effects, perhaps reflecting genetic divergence or geographic variation in additional biotic and abiotic factors. Our findings emphasize that time constraints imposed by the environment rather than ambient temperature play a major role in shaping life histories in the common lizard. This might be attributed to the fact that lizards can attain their preferred body temperature via behavioral thermoregulation across different thermal environments. Length of activity season, defining the maximum time available for lizards to maintain optimal performance, is thus the main environmental factor constraining growth rate and annual rates of mortality. Our results suggest that this factor may partly explain variation in the extent to which different taxa follow ecogeographic rules.

Reversals in complex traits uncovered as reticulation events: Lessons from the evolution of parity‐mode, chromosome morphology, and maternal resource transfer

“…Zootoca vivipara is the terrestrial squamate species with the largest natural distribution, ranging from northwest Spain and Ireland in the West to the Peninsula of Sakhalin (Russia) and Hokkaido (Japan) in the East, and from the southern Balkan (Bulgaria) and the Pyrenees in the south to the Arctic Circle. It has seven well‐defined clades (Surget‐Groba et al, ), a bimodal reproductive pattern, and is a model species for the study of evolution, population dynamics, behavior, coloration, and physiology (Fitze & Le Galliard, ; Gonzalez‐Jimena & Fitze, ; Horvathova et al, ; San‐Jose, Peñalver‐Alcázar, Milá, Gonzalez‐Jimena, & Fitze, ). Because the existing genetic coverage was not sufficient for the envisaged analyses, we amplified three nuclear (nZV1, nZV2, and nZV3; Horreo, Peláez, Suárez, & Fitze, ) and three mitochondrial gene fragments (16S rDNA, 16S: Clary & Wolstenholme, ; cytochrome B, cytB: Smith & Patton, ; and NADH dehydrogenase 2, ND2: Macey, Larson, Ananjeva, Fang, & Papenfuss, ) in 24 individuals belonging to all extant clades (three individuals per clade; Surget‐Groba et al, ), except for clade B, from which 9 individuals were used, three per subclade; Horreo, Palaez, Breedveld, et al, ; Mila, Surget‐Groba, Heulin, Gosá, & Fitze, ) and two outgroups (Tables S2 and S3) following original protocols (Horreo, Peláez, Suárez, & Fitze, ).…”

Mate availability affects the trade-off between producing one or multiple annual clutches

“…The time of emergence from hibernation and the reproductive phenology are temperature dependent (Breedveld & Fitze, 2015;Licht, 1972) and vary between and within populations, due to interpopulation differences and annual variation in climatic conditions, respectively (Horv athov a et al, 2013). This fact, together with the temperature dependence of sperm maturation (Gavaud, 1991), indicates that changing environmental conditions could produce a mismatch in the reproductive phenology of males and females, thereby potentially resulting in unsuccessful reproduction due to low density of mates (Mugabo, Perret, Legendre, & Le Galliard, 2013), or to females encountering males outside their period of receptivity (Breedveld & Fitze, 2015) or males that do not have mature sperm (Breedveld & Fitze, 2016b).…”

“…The common lizard is ideal for investigating these questions, since it exhibits a polygynandrous mating system (Fitze, Le Galliard, Federici, Richard, & Clobert, 2005), and females produce up to three annual clutches (Horv athov a et al, 2013). Within a reproductive season, females can store sperm over longer periods, and can use sperm obtained prior to the production of the first clutch to fertilize the second clutch (Heulin, 1988).…”

GEOGRAPHIC BODY SIZE AND SHAPE VARIATION IN A MAINLAND Anolis (SQUAMATA: DACTYLOIDAE) FROM NORTHWESTERN SOUTH AMERICA (COLOMBIA)

“…Calderón-Espinosa ML, Barragán-Contreras LA (Anguilleta, 1998;Horváthová et al, 2013). For instance, microgeographic body size variation in A. mariarum appears to be due to differences in precipitation levels among localities (Bock et al, 2009).…”