NEW PAPER: landscape genomics reveal that oviparous and viviparous lizards have innately different population patterns
In a neat mix of some spatial genetic autocorrelation analyses (which I got excited about during my PhD on leaf litter frogs) and life history strategies, we have published a new paper on oviparous and viviparous lizards. We find that even in the same environment, ie at the same site, the different parity modes have different scales of dispersal and different population densities. See details below.
To do this study we reanalysed population level data collected in the study Hans led on the genomic basis of parity mode phenotypes now looking only at pure ovi/vivi individuals. This is unusual because most often these lineages are found in very different environments, which is a confound if we wanted to explore contrasts in their life histories and demographies.
Parity-specific differences in spatial genetics and dispersal in the common lizard
Abstract: Dispersal is a key demographic parameter that plays an important role in determining spatial population dynamics and genetic structure. Linking differences in dispersal patterns to life-history traits is often confounded by inconsistent environmental pressures experienced by different populations. To explore the relationship between dispersal and life history, we focus on a site where oviparous and viviparous lineages of the common lizard (Zootoca vivipara) are found adjacent to each other. We take advantage of this shared environment to investigate parity-specific dispersal patterns using high-resolution, individual-level spatial-genetic autocorrelation and population genomic approaches (11,726 single nucleotide polymorphisms; 293 oviparous and 310 viviparous individuals). We found isolation-by-distance patterns to be present in both the oviparous and viviparous populations. Density was 2.5 times higher in the oviparous population than the viviparous one, though heterozygosity and genetic diversity measures were similar in the two populations. We found marked differences in the extent of genetic neighbourhoods between the lineages, with the viviparous population showing both dispersal (σ) and spatial-genetic autocorrelation (Moran’s I) at 2-fold greater geographic distances than the oviparous population. We found clear evidence of male-biased dispersal from genetic estimates in the viviparous population. In the oviparous population, evidence of male-biased dispersal was weak or absent. These differences are likely to be closely linked to specific requirements of the alternative reproductive strategies and may be the demographic consequences of mother–offspring interactions. Fine-scale geographic and individual-level measures are essential to understanding parity mode differences at microevolutionary scales and to better identifying their ecological and evolutionary impacts.
Darren Hunter, Jean Clobert, Kathryn R Elmer - find the paper here in Journal of Evolutionary Biology
