Genetic influences on male and female variance in reproductive success and implications for the recovery of severely endangered mountain caribou

Spatial familial networks to infer demographic structure of wild populations

“…We used five centrality measures in our network analysis of familial networks (Figure 3) and found that alpha, betweenness, and eccentricity centrality were the most informative measures of individual centrality (Figure 1). McFarlane et al (2018) found significant difference between fitness level in mountain caribou and showed that there could be genetic predisposition to higher fitness levels, with evidence of inbreeding avoidance. Maternal social rank influenced reproductive success in reindeer (R. tarandus), with higher fitness females having higher fecundity and earlier offspring date of birth than lower fitness females (Holand et al, 2004).…”

“…With a wide spectrum of mating systems present in wildlife species (Clutton-Brock, 1989), almost all species present pedigree networks, with multiple partners and/or offspring attributed to each individual, therefore creating a complex network of familial relationships (Morrison, 2016). Although caribou present varying levels of individual fitness (McFarlane et al, 2018) and their distribution is spatially clustered across the range, our network does not appear to be vulnerable to sudden population crashes resulting from changes in population structure, isolation, and inbreeding. Our network was highly connected as a result of the polygamous mating system of caribou and ability for long range dispersal.…”

“…In comparison with association networks, in familial networks, only the sampled individuals are known or observed, and the edges between individuals and the unsampled individuals (parents) are inferred by the data analysis (Morrison, 2016). Reconstructing a familial network from genetically derived pedigree data gives valuable information about the number of mating partners, the number of offspring, and the structure of the reproductive network of a population (McFarlane et al, 2018;Pemberton, 2008). Pedigrees represent historical and evolutionary connections between generations; these relationships have long been recognized as reticulating but are instead commonly presented as simplified trees instead of networks, where reticulations caused by inbreeding are absent (Morrison, 2016).…”

“…In parallel, pedigree reconstructions have been done to inform on demographic parameters (Creel et al, 2003;Gobush et al, 2009;Lucena-Perez et al, 2018;McFarlane et al, 2018), yet network analyses and genetically derived pedigrees have been used as two separate methodological frameworks. Here, we suggest that the combination of these methods may highlight the interconnectedness between individuals (Escoda et al, 2019;Morrison, 2016), differences in reproductive success (McFarlane et al, 2018), and ultimately inform on the demographic structure of a population.…”

“…More recently, graph-theoretic approach has been used to assess population genetic structure (Dyer & Nason, 2004), investigate sex-specific dispersal processes and network structures in landscape genetics (Bertrand et al, 2017), and analyze spatial patterns of genetic variation across a species' range (Fortuna et al, 2009). In parallel, pedigree reconstructions have been done to inform on demographic parameters (Creel et al, 2003;Gobush et al, 2009;Lucena-Perez et al, 2018;McFarlane et al, 2018), yet network analyses and genetically derived pedigrees have been used as two separate methodological frameworks. Here, we suggest that the combination of these methods may highlight the interconnectedness between individuals (Escoda et al, 2019;Morrison, 2016), differences in reproductive success (McFarlane et al, 2018), and ultimately inform on the demographic structure of a population.…”