Genetic evidence for male‐biased dispersal in theQinghai toad‐headed agamidPhrynocephalus vlangaliiand its potential link to individual social interactions

Abstract

Sex-biased dispersal has profound impacts on a species' biology and several factors have been attributed to its evolution, including mating system, inbreeding avoidance, and social complexity. Sex-biased dispersal and its potential link to individual social interactions were examined in the Qinghai toad-headed agamid (Phrynocephalus vlangalii). We first determined the pattern of sex-biased dispersal using population genetic methods. A total of 345 specimens from 32 sites in the Qaidam Basin were collected and genotyped for nine microsatellite DNA loci. Both individual-based assignment tests and allele frequency-based analyses were conducted. Females revealed much more genetic structure than males and all results were consistent with male-biased dispersal. First-generation migrants were also identified by genetic data. We then examined eight social interaction-related morphological traits and explored their potential link to sex-biased dispersal. Female residents had larger heads and longer tails than female migrants. The well-developed signal system among females, coupled with viviparity, might make remaining on natal sites beneficial, and hence promote female philopatry. Dominant females with larger heads were more likely to stay. Contrary to females, male migrants had larger heads and belly patches than residents, suggesting that dispersal might confer selective advantages for males. Such advantages may include opportunities for multiple mating and escaping from crowded sites. Large belly patches and several other morphological traits may assist their success in obtaining mates during dispersal. Furthermore, a relatively high relatedness (R = 0.06) among females suggested that this species might have rudimentary social structure. Case studies in “less” social species may provide important evidence for a better understanding of sex-biased dispersal.

Morphological species and discordant mtDNA: A genomic analysis of Phrynocephalus lizard lineages on the Qinghai-Tibetan Plateau

“…The total lake circumference is generally reported as around 360km (e.g., Virkutyte and Sillanpää, 2006) so our results suggest gene flow is sufficiently restricted to allow local divergence between populations separated by (on average) around 45 km. The closely-related P. vlangalii on the QTP also appears to show low dispersal, leading to detectable genetic structure (in microsatellites) over even shorter distances (20 km) (Qi et al, 2013). Other similar microsatellite studies of ectothermic vertebrates have detected isolation-bydistance over similar spatial scales (e.g., Arizona treefrogs; Mims et al, 2016).…”

Extreme mito-nuclear discordance in a peninsular lizard: the role of drift, selection, and climate

“…For example, in Lacerta , Olsson et al (1997) found that in both males and females, fitness was a strong component for dispersal and that males dispersed farther if relatedness was higher with respect to their neighbors. Similarly, Qi et al (2013) found clear genetic evidence of male-biased dispersal and strong female phylopatry in Phrynocephalus . In terms of female behavior, levels of aggression are higher in females with higher levels of paternity acquisition in the social lizard Egernia (While et al 2009).…”

Cenozoic aridization in Central Eurasia shaped diversification of toad-headed agamas (Phrynocephalus; Agamidae, Reptilia)

“…Further, male-biased dispersal favors mitochondrial genome introgression ( Toews & Brelsford, 2012 ) and Phrynocephalus appears to have male-mediated gene flow. Discordant breaks in mtDNA and nuDNA markers occur in at least for four species: Phrynocephalus vlangalii – Phrynocephalus putjatai Bedriaga, 1909-groups ( Noble, Qi & Fu, 2010 ; Qi et al, 2013 ), and in the P. przewalskii–P. frontalis -groups ( Urquhart, Wang & Fu, 2009 ).…”