The kinship matrix: inferring the kinship structure of a population from its demography

Christophe Coste (1) , François Bienvenu (2, 3, 4) , Victor Ronget (5) , Juan‐pablo Ramirez‐loza (6) , Sarah Cubaynes (6) , Samuel Pavard (5)

1 IBI NTNU - Department of Biology [Trondheim]
2 UMR ISEM - Institut des Sciences de l'Evolution de Montpellier
3 UMR AGAP - Amélioration génétique et adaptation des plantes méditerranéennes et tropicales
4 Department of Statistics [Oxford]
5 EA - Éco-Anthropologie
6 CEFE - Centre d’Ecologie Fonctionnelle et Evolutive

The familial structure of a population and the relatedness of its individuals are determined by its demography. There is, however, no general method to infer kinship directly from the life cycle of a structured population. Yet, this question is central to fields such as ecology, evolution and conservation, especially in contexts where there is a strong interdependence between familial structure and population dynamics. Here, we give a general formula to compute, from any matrix population model, the expected number of arbitrary kin (sisters, nieces, cousins, etc) of a focal individual ego, structured by the class of ego and of its kin. Central to our approach are classic but little-used tools known as genealogical matrices. Our method can be used to obtain both individual-based and population-wide metrics of kinship, as we illustrate. It also makes it possible to analyse the sensitivity of the kinshipstructure to the traits implemented in the model.

Keywords: Familial structure; Kinship demography; Population projection matrices; Relatedness; Structured populations

Domains: Biodiversity and Ecology; Demography; Mathematics [math]

Christophe Coste, François Bienvenu, Victor Ronget, Juan‐pablo Ramirez‐loza, Sarah Cubaynes, et al.. The kinship matrix: inferring the kinship structure of a population from its demography. Ecology Letters, 2021, 24 (12), pp.2750-2762. ⟨10.1111/ele.13854⟩. ⟨mnhn-03426026⟩