Population structure of the yellow-footed rock-wallaby Petrogale xanthopus (Gray, 1854) inferred from mtDNA sequences and microsatellite loci

The yellow-footed rock-wallaby Petrogale xanthopus is considered to be potentially vulnerable to extinction. This wallaby inhabits naturally disjunct rocky outcrops which could restrict dispersal between populations, but the extent to which that occurs is unknown. Genetic differences between populations were assessed using mitochondrial DNA (control region) sequencing and analysis of variation at four microsatellite loci among three geographically close sites in south-west Queensland (P. x. celeris) and, for mtDNA only, samples from South Australia (P. x. xanthopus) as well. Populations from South Australia and Queensland had phylogenetically distinct mtDNA, supporting the present classification of these two groups as evolutionarily distinct entities. Within Queensland, populations separated by 70 km of unsuitable habitat differed significantly for mtDNA and at microsatellite loci. Populations separated by 10 km of apparently suitable habitat had statistically homogeneous mtDNA, but a significant difference in allele frequency at one microsatellite locus. Tests for Hardy-Weinberg equilibrium and microgeographical variation at microsatellite loci did not detect any substructuring between two wallaby aggregations within a colony encircling a single rock outcrop. Although the present study was limited by small sample sizes at two of the three Queensland locations examined, the genetic results suggest that dispersal between colonies is limited, consistent with an ecological study of dispersal at one of the sites. Considering both the genetic and ecological data, we suggest that management of yellow-footed rock-wallabies should treat each colony as an independent unit and that conservation of the Queensland and South Australian populations as separate entities is warranted

Why and when employees like to speak up more under humble leaders? The roles of personal sense of power and power distance

Research investigating the underlying mechanisms and boundary conditions under which leader humility influences employee voice remains underdeveloped. Drawing from approach–inhibition theory of power and leader humility literature, we developed a moderated-mediation model in which personal sense of power (i.e., employees’ ability to influence other individuals such as their leader) was theorized as a unique mechanism underlining why employees feel motivated to speak up under the supervision of humble leaders. Additionally, the cultural value of power distance was proposed to be a relevant boundary condition to influence such relationship. We tested the model using time-lagged supervisor–subordinate matched data. Results of mixed models analyses provided support for our hypotheses confirming that employees’ personal sense of power mediates the relationship between leader humility and employee voice, and such relationship was found to be stronger when employees’ power distance was lower rather than higher