Cannabis sativa has long been an important source of fiber extracted from hemp and both medicinal and recreational drugs based on cannabinoid compounds. Here, we investigated its poorly known domestication history using whole-genome resequencing of 110 accessions from worldwide origins. We show that C. sativa was first domesticated in early Neolithic times in East Asia and that all current hemp and drug cultivars diverged from an ancestral gene pool currently represented by feral plants and landraces in China. We identified candidate genes associated with traits differentiating hemp and drug cultivars, including branching pattern and cellulose/lignin biosynthesis. We also found evidence for loss of function of genes involved in the synthesis of the two major biochemically competing cannabinoids during selection for increased fiber production or psychoactive properties. Our results provide a unique global view of the domestication of C. sativa and offer valuable genomic resources for ongoing functional and molecular breeding research. Genome analyses provide new insights into the global domestication history of Cannabis sativa and its two main cannabinoids. Genome analyses provide new insights into the global domestication history of Cannabis sativa and its two main cannabinoids.
Anthropology is the study of what makes us human. Anthropologists take a broad approach to understanding the many different aspects of the human experience, which we call holism. They consider the past, through archaeology, to see how human groups lived hundreds or thousands of years ago and what was important to them.
Increasing body and brain size constitutes a key macro-evolutionary pattern in the hominin lineage, yet the mechanisms behind these changes remain debated. Hypothesized drivers include environmental, demographic, social, dietary, and technological factors. Here we test the influence of environmental factors on the evolution of body and brain size in the genus Homo over the last one million years using a large fossil dataset combined with global paleoclimatic reconstructions and formalized hypotheses tested in a quantitative statistical framework. We identify temperature as a major predictor of body size variation within Homo, in accordance with Bergmann’s rule. In contrast, net primary productivity of environments and long-term variability in precipitation correlate with brain size but explain low amounts of the observed variation. These associations are likely due to an indirect environmental influence on cognitive abilities and extinction probabilities. Most environmental factors that we test do not correspond with body and brain size evolution, pointing towards complex scenarios which underlie the evolution of key biological characteristics in later Homo.
Left-wing authoritarianism remains far less understood than right-wing authoritarianism. We contribute to the literature on the former, which typically relies on surveys, using a new social media analytics approach. We use a list of 60 terms to provide an exploratory sketch of the outlines of a political ideology (tribal equalitarianism) with origins in 19th and 20th century social philosophy. We then use analyses of the English Corpus of Google Books (over 8 million books) and scraped unique tweets from Twitter (n = 202,852) to conduct a series of investigations to discern the extent to which this ideology is cohesive amongst the public, reveals signatures of authoritarianism and has been growing in popularity. Though exploratory, our results provide some evidence of left-wing authoritarianism in two forms (1) a uniquely conservative moral signature amongst ostensible liberals using measures from Moral Foundations Theory and (2) a substantial prevalence of anger, relative to anxiety or sadness. In general, results indicate that this worldview is growing in popularity, is increasingly cohesive, and shows signatures of authoritarianism.
Radicalized beliefs, such as those tied to QAnon, Russiagate, and other political conspiracy theories, can lead some individuals and groups to engage in violent behavior, as evidenced in recent months. Understanding the mechanisms by which such beliefs are accepted, spread, and intensified is critical for any attempt to mitigate radicalization and avoid increased political polarization. This article presents and agent-based model of a social media network that enables investigation of the effects of censorship on the amount of dissenting information to which agents become exposed and the certainty of their radicalized views. The model explores two forms of censorship: 1) decentralized censorship-in which individuals can choose to break an online social network tie (unfriend or unfollow) with another individual who transmits conflicting beliefs and 2) centralized censorship-in which a single authority can ban an individual from the social media network for spreading a certain type of belief. This model suggests that both forms of censorship increase certainty in radicalized views by decreasing the amount of dissent to which an agent is exposed, but centralized "banning" of individuals has the strongest effect on radicalization.
This article provides an empirical synthesis of the existing literature on the effectiveness of restorative justice practices using meta-analytic techniques. The data were aggregated from studies that compared restorative justice programs to traditional nonrestorative approaches to criminal behavior. Victim and offender satisfaction, restitution compliance, and recidivism were selected as appropriate outcomes to adequately measure effectiveness. Although restorative programs were found to be significantly more effective, these positive findings are tempered by an important self-selection bias inherent in restorative justice research. A possible method of addressing this problem, as well as directions for future research, are provided.
Informal social hierarchies within small human groups are argued to be based on prestige, dominance, or a combination of the two (Henrich & Gil-White, 2001). Prestige-based hierarchies entail the ordering of individuals by the admiration and respect they receive from others due to their competence within valued domains. This type of hierarchy provides benefits for subordinates such as social learning opportunities and both private and public goods. In contrast, dominance-based hierarchies entail the ordering of individuals by their capacity to win fights, and coerce or intimidate others. This type of hierarchy produces costs in subordinates due to its aggressive and intimidating nature. Given the benefits and costs associated with these types of social hierarchies for subordinates, we hypothesised that prestige and dominance cues are better recalled and transmitted than social rank cues that do not elicit high prestige or dominance associations (i.e. medium social rank cues). Assuming that for the majority of the population who are not already at the top of the social hierarchy it is more important to avoid the costs of dominance-based hierarchies than to obtain the benefits of prestige-based hierarchies, we further hypothesised that dominance cues are better transmitted than prestige cues. We conducted a recall-based transmission chain experiment with 30 chains of four generations each (N = 120). Participants read and recalled descriptions of prestigious, dominant, and medium social rank footballers, and their recall was passed to the next participant within their chain. As predicted, we found that both prestige cues and dominance cues were better transmitted than medium social rank cues. However, we did not find support for our prediction of the better transmission of dominance cues than prestige cues. We discuss whether the results might be explained by a specific social-rank content transmission bias or by a more general emotional content transmission bias.
Previous research has sought to explain the rise of right-wing populist leaders in terms of the evolutionary framework of dominance and prestige. In this framework, dominance is defined as high social rank acquired via coercion and fear, and prestige is defined as high social rank acquired via competence and admiration. Previous studies have shown that right-wing populist leaders are rated as more dominant than nonpopulist leaders, and right-wing populist / dominant leaders are favoured in times of economic uncertainty and intergroup conflict. In this paper we explore and critique this application of dominance-prestige to politics. First, we argue that the dominance-prestige framework, originally developed to explain inter-personal relationships within small-scale societies characterised by face-to-face interaction, does not straightforwardly extend to large-scale democratic societies which have frequent anonymous interaction and complex ingroup-outgroup dynamics. Second, we show that economic uncertainty and intergroup conflict predict not only preference for dominant leaders, but also prestigious leaders. Third, we show that perceptions of leaders as dominant or prestigious are not fixed, and depend on the political ideology of the perceiver: people view leaders who share their ideology as prestigious, and who oppose their ideology as dominant, whether that ideology is liberal or conservative. Fourth, we show that political ideology is a stronger predictor than economic uncertainty of preference for Donald Trump vs Hillary Clinton in the 2016 US Presidential Election, contradicting previous findings that link Trump‟s success to economic uncertainty. We conclude by suggesting that, if economic uncertainty does not directly affect preferences for right-wing populist leaders, other features of their discourse such as higher emotionality might explain their success.
Cultural evolutionary theories define prestige as social rank that is freely conferred on individuals possessing superior knowledge or skill, in order to gain opportunities to learn from such individuals. Consequently, information provided by prestigious individuals should be more memorable, and hence more likely to be culturally transmitted, than information from non-prestigious sources, particularly for novel, controversial arguments about which preexisting opinions are absent or weak. It has also been argued that this effect extends beyond the prestigious individual’s relevant domain of expertise. We tested whether the prestige and relevance of the sources of novel, controversial arguments affected the transmission of those arguments, independently of their content. In a four-generation linear transmission chain experiment, British participants (N = 192) recruited online read two conflicting arguments in favour of or against the replacement of textbooks by computer tablets in schools. Each of the two conflicting arguments was associated with one of three sources with different levels of prestige and relevance (high prestige, high relevance; high prestige, low relevance; low prestige, low relevance). Participants recalled the pro-tablets and anti-tablets arguments associated with each source and their recall was then passed to the next participant within their chain. Contrary to our predictions, we did not find a reliable effect of either the prestige or relevance of the sources of information on transmission fidelity. We discuss whether the lack of a reliable effect of prestige on recall might be a consequence of differences between how prestige operates in this experiment and in everyday life.