Contents lists available at ScienceDirect Evolution and Human Behavior journal homepage: www.elsevier.com/locate/ens Explaining marriage patterns in a globally representative sample through socio-ecology and population history: A Bayesian phylogenetic analysis using a new supertree Riana Minocher a,b , Pavel Duda c , Adrian V. Jaeggi a,1, ⁎ a Department of Anthropology, Emory University, 1557 Dickey Drive, Atlanta, GA 30322, USA b Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig 04103, Germany c Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czechia ARTICLE INFO Keywords: Cultural evolution Marriage Phylogeny Polygyny Sexual selection Standard Cross-Cultural Sample ABSTRACT Comparative analyses have sought to explain variation in human marriage patterns, often using predictions derived from sexual selection theory. However, most previous studies have not controlled for non-independence of populations due to shared ancestry. Here we leverage a phylogenetic supertree of human populations that includes all 186 populations in the Standard Cross-Cultural Sample (SCCS), a globally representative and widely- used sample of human populations. This represents the most comprehensive human phylogeny to date, and allows us not only to control for non-independence, but also to quantify the role of population history in ex- plaining behavioral variation, in addition to current socio-ecological conditions. We use multiple imputation to overcome missing data problems and build a comprehensive Bayesian phylogenetic model of marriage patterns with two correlated response variables and eleven minimally collinear predictors capturing various socio-eco- logical conditions. We show that ignoring phylogeny could lead to both false positives and false negatives, and that the phylogeny explained about twice as much variance as all the predictors combined. Pathogen stress and assault frequency emerged as the predictors most strongly associated with polygyny, which had been considered evidence for female choice of good genes and male intra-sexual competition or male coercion, respectively. Mixed support was found for a polygyny threshold based on variance in male wealth, which is discussed in light of recent theory. Barring caveats, these findings refine our understanding of the evolution of human marriage systems, and highlight the value of combining population history and current socio-ecology in explaining human behavioral variation. Future studies using the SCCS should do so using the present supertree. 1. Introduction 1.1. Explaining variation in human marriage patterns Marriage patterns vary widely within and across human societies, with most societies allowing polygyny yet most marriages being monogamous (Marlowe, 2003; White, 1988), calling for a comprehen- sive explanatory framework. Sexual selection theory accounts for the distribution of mating patterns across species (Clutton-Brock & Vincent, 1991; Emlen & Oring, 1977; Kokko & Jennions, 2008; Trivers, 1972), and may thus provide insights to human marriages. For instance, polygynous mating is prevalent when variance in male quality is high, such that a few males can either directly control access to multiple females and exclude other males, or offer better genes or more re- sources relevant for female fitness (Emlen & Oring, 1977). In the latter case, females may choose to mate polygynously rather than mono- gamously if this offers greater expected fitness benefits, which is known as the polygyny threshold model (Borgerhoff Mulder, 1988, 1990). Conversely, monogamous mating may prevail in male-biased or widely dispersed populations as a form of mate-guarding, or when there are high returns to male parental investment (Kokko & Jennions, 2008; Lukas & Clutton-Brock, 2013; Marlowe, 2000; Schacht & Borgerhoff Mulder, 2015). More recently, this theory has been expanded explicitly for humans to include mutual mate choice and distinguish between https://doi.org/10.1016/j.evolhumbehav.2018.11.003 Received 12 August 2018; Received in revised form 26 October 2018; Accepted 6 November 2018 ⁎ Corresponding author. E-mail address: adrian.jaeggi@iem.uzh.ch (A.V. Jaeggi). 1 Current affiliation: Institute of Evolutionary Medicine, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland. Evolution and Human Behavior xxx (xxxx) xxx–xxx 1090-5138/ © 2018 Elsevier Inc. All rights reserved. Please cite this article as: Minocher, R., Evolution and Human Behavior, https://doi.org/10.1016/j.evolhumbehav.2018.11.003