title: Phylogenetic reconstruction of Bantu kinship challenges Main Sequence Theory of human social evolution.
abstract: Kinship provides the fundamental structure of human society: descent determines the inheritance pattern between generations, whereas residence rules govern the location a couple moves to after they marry. In turn, descent and residence patterns determine other key relationships such as alliance, trade, and marriage partners. Hunter-gatherer kinship patterns are viewed as flexible, whereas agricultural societies are thought to have developed much more stable kinship patterns as they expanded during the Holocene. Among the Bantu farmers of sub-Saharan Africa, the ancestral kinship patterns present at the beginning of the expansion are hotly contested, with some arguing for matrilineal and matrilocal patterns, whereas others maintain that any kind of lineality or sex-biased dispersal only emerged much later. Here, we use Bayesian phylogenetic methods to uncover the history of Bantu kinship patterns and trace the interplay between descent and residence systems. The results suggest a number of switches in both descent and residence patterns as Bantu farming spread, but that the first Bantu populations were patrilocal with patrilineal descent. Across the phylogeny, a change in descent triggered a switch away from patrifocal kinship, whereas a change in residence triggered a switch back from matrifocal kinship. These results challenge "Main Sequence Theory," which maintains that changes in residence rules precede change in other social structures. We also indicate the trajectory of kinship change, shedding new light on how this fundamental structure of society developed as farming spread across the globe during the Neolithic.
authors.affiliation: Department of Anthropology, University College London, London WC1H 0BW, United Kingdom; kit.opie@ucl.ac.uk.
authors.forename: Christopher
authors.initials: C
authors.lastname: Opie
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom;
authors.forename: Susanne
authors.initials: S
authors.lastname: Shultz
authors.affiliation: Department of Psychology, University of Auckland, Private Bag 92019, Auckland, New Zealand; and.
authors.forename: Quentin D
authors.initials: QD
authors.lastname: Atkinson
authors.affiliation: Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9FE, United Kingdom.
authors.forename: Thomas
authors.initials: T
authors.lastname: Currie
authors.affiliation: Department of Anthropology, University College London, London WC1H 0BW, United Kingdom;
authors.forename: Ruth
authors.identifier: http://orcid.org/0000-0002-6137-7739
authors.initials: R
authors.lastname: Mace
mesh_terms: D017954:Africa South of the Sahara / Q000208:ethnology; D001499:Bayes Theorem; D005075:Biological Evolution; D044383:Black People; D005260:Female; D005843:Geography; D006801:Humans; D007802:Language; D008297:Male; D008393:Marriage; D009010:Monte Carlo Method; D010802:Phylogeny; D011336:Probability; D012111:Residence Characteristics; D012919:Social Behavior
keywords: Bantu; Bayesian; Neolithic; kinship; phylogenetics