The origins of human cumulative culture: from the foraging niche to collective intelligence

Various studies have investigated cognitive mechanisms underlying culture in humans and other great apes. However, the adaptive reasons for the evolution of uniquely sophisticated cumulative culture in our species remain unclear. We propose that the cultural capabilities of humans are the evolutionary result of a stepwise transition from the ape-like lifestyle of earlier hominins to the foraging niche still observed in extant hunter–gatherers. Recent ethnographic, archaeological and genetic studies have provided compelling evidence that the components of the foraging niche (social egalitarianism, sexual and social division of labour, extensive co-residence and cooperation with unrelated individuals, multilocality, fluid sociality and high between-camp mobility) engendered a unique multilevel social structure where the cognitive mechanisms underlying cultural evolution (high-fidelity transmission, innovation, teaching, recombination, ratcheting) evolved as adaptations. Therefore, multilevel sociality underlies a ‘social ratchet’ or irreversible task specialization splitting the burden of cultural knowledge across individuals, which may explain why human collective intelligence is uniquely able to produce sophisticated cumulative culture. The foraging niche perspective may explain why a complex gene-culture dual inheritance system evolved uniquely in humans and interprets the cultural, morphological and genetic origins of Homo sapiens as a process of recombination of innovations appearing in differentiated but interconnected populations. This article is part of a discussion meeting issue ‘The emergence of collective knowledge and cumulative culture in animals, humans and machines’

Genome sequence of Enterococcus mundtii EM01, isolated from Bombyx mori midgut and responsible for flacherie disease in silkworms reared on an artificial diet

The whole genome sequence of Enterococcus mundtii strain EM01 is reported here. The isolate proved to be the cause of flacherie in Bombyx mori. To date, the genomes of 11 other E. mundtii strains have been sequenced. EM01 is the only strain that displayed active pathological effects on its associated animal species

Development of social learning and play in BaYaka hunter-gatherers of Congo.

High-fidelity transmission of information through imitation and teaching has been proposed as necessary for cumulative cultural evolution. Yet, it is unclear when and for which knowledge domains children employ different social learning processes. This paper explores the development of social learning processes and play in BaYaka hunter-gatherer children by analysing video recordings and time budgets of children from early infancy to adolescence. From infancy to early childhood, hunter-gatherer children learn mainly by imitating and observing others' activities. From early childhood, learning occurs mainly in playgroups and through practice. Throughout childhood boys engage in play more often than girls whereas girls start foraging wild plants from early childhood and spend more time in domestic activities and childcare. Sex differences in play reflect the emergence of sexual division of labour and the play-work transition occurring earlier for girls. Consistent with theoretical models, teaching occurs for skills/knowledge that cannot be transmitted with high fidelity through other social learning processes such as the acquisition of abstract information e.g. social norms. Whereas, observational and imitative learning occur for the transmission of visually transparent skills such as tool use, foraging, and cooking. These results suggest that coevolutionary relationships between human sociality, language and teaching have likely been fundamental in the emergence of human cumulative culture

Deep history of cultural and linguistic evolution among Central African hunter-gatherers

Human evolutionary history in Central Africa reflects a deep history of population connectivity. However, Central African hunter-gatherers (CAHGs) currently speak languages acquired from their neighbouring farmers. Hence it remains unclear which aspects of CAHG cultural diversity results from long-term evolution preceding agriculture and which reflect borrowing from farmers. On the basis of musical instruments, foraging tools, specialized vocabulary and genome-wide data from ten CAHG populations, we reveal evidence of large-scale cultural interconnectivity among CAHGs before and after the Bantu expansion. We also show that the distribution of hunter-gatherer musical instruments correlates with the oldest genomic segments in our sample predating farming. Music-related words are widely shared between western and eastern groups and likely precede the borrowing of Bantu languages. In contrast, subsistence tools are less frequently exchanged and may result from adaptation to local ecologies. We conclude that CAHG material culture and specialized lexicon reflect a long evolutionary history in Central Africa

Population interconnectivity over the past 120,000 years explains distribution and diversity of Central African hunter-gatherers

The evolutionary history of African hunter-gatherers holds key insights into modern human diversity. Here, we combine ethnographic and genetic data on Central African hunter-gatherers (CAHG) to show that their current distribution and density are explained by ecology rather than by a displacement to marginal habitats due to recent farming expansions, as commonly assumed. We also estimate the range of hunter-gatherer presence across Central Africa over the past 120,000 years using paleoclimatic reconstructions, which were statistically validated by our newly compiled dataset of dated archaeological sites. Finally, we show that genomic estimates of divergence times between CAHG groups match our ecological estimates of periods favoring population splits, and that recoveries of connectivity would have facilitated subsequent gene flow. Our results reveal that CAHG stem from a deep history of partially connected populations. This form of sociality allowed the coexistence of relatively large effective population sizes and local differentiation, with important implications for the evolution of genetic and cultural diversity in Homo sapiens. Significance We combined ethnographic, archaeological, genetic, and paleoclimatic data to model the dynamics of Central African hunter-gatherer populations over the past 120,000 years. We show, against common assumptions, that their distribution and density are explained by changing environments rather than by a displacement following recent farming expansions, and that they have maintained large population sizes and genetic diversity, despite fluctuations in niche availability. Our results provide insights into the evolution of genetic and cultural diversity in Homo sapiens

Influência da palha no controle químico de plantas daninhas no sistema de cana crua

In the mechanical harvesting system of sugarcane, without previously burning (raw sugarcane), a straw layer is left over the soil, that may overcome up to 20 t ha-1, what  represents a difficulty for germination and emergence of some weed species being possible to  affect herbicides leaching and efficacy. This way, considering this environmental change, herbicides used for weeds control in pre-emergence conditions, in raw sugarcane system, must present some specific physicochemical characteristics to be effective on weeds control such as high solubility in water, low vapor pressure and low Kow. Furthermore, it is important to consider straw amount and distribution in the field and rainfall intensity after herbicide application, since these factors determine how much of the applied product is intercepted by straw, do not reaching the soil, its final destination. According to this information, the present review aims to elucidate how straw presence on soil surface may influence the chemical weeds control and herbicides behavior in areas cultivated with sugarcane crop.No sistema de colheita mecanizada sem a queima prévia do canavial (cana crua) é deixada sobre o solo uma camada de palha que pode superar até 20 t ha-1, o que representa uma barreira para germinação e emergência de algumas espécies daninhas e pode afetar a lixiviação e eficácia dos herbicidas. Portanto, diante dessa alteração, os herbicidas utilizados na pré-emergência das plantas daninhas, no sistema de cana crua, precisam apresentar algumas características físico químicas especificas para que sejam eficazes no controle de plantas daninhas, tais como: alta solubilidade em água, baixa pressão de vapor e baixo Kow. Além disto, é importante considerar a quantidade e distribuição de palha no campo e a intensidade de chuva após a aplicação dos herbicidas, já que estes fatores determinam o quanto do produto é interceptado pela palha, não atingindo o solo que é o seu destino final.  Diante do exposto, a presente revisão tem como objetivo esclarecer como a palha na superfície do solo pode influenciar o controle químico das plantas daninhas e o comportamento dos herbicidas em áreas cultivadas com cana-de-açúcar.

Association among race/color, gender, and intrinsic capacity: results from the ELSI-Brazil study

OBJECTIVE: To investigate associations among race/color, gender, and intrinsic capacity (IC) (total and by domains) in middle-aged and older adults from a Brazilian cohort. As a secondary objective, we investigate these associations across Brazilian regions. METHODS: This is a cross-sectional study conducted with baseline data from the 2015–2016 Brazilian Longitudinal Study of Aging (ELSI-Brazil). IC was investigated via cognitive (verbal fluency), physical (gait velocity/handgrip), and psychosocial (Center for Epidemiological Studies Depression) domains. Moreover, IC sensory domain was evaluated via self-reported sensory disease diagnoses (vision and/or hearing impairment) and race/color was identified via self-reported criteria. RESULTS: We evaluated a total of 9,070 participants (aged ≥ 50 years). Black and Brown participants were 80% and 41% more likely to show a worse IC cognitive domain than white controls, respectively (OR = 1.80, 95%CI: 1.42–2.28, p < 0.001 and OR = 1.41, 95%CI: 1.21–1.65, p < 0.001). Moreover, Black and Brown women had almost a threefold greater chance of showing a worse IC than white men (OR = 2.91, 95%CI: 1.89–4.47, p < 0.001 and OR = 2.51, 95%CI: 2.09 - 3.02, p < 0.001) and a 62% (OR = 1.62, 95%CI: 1.02–2.57) and 32% (OR = 1.32, 95%CI: 1.10–1.57) greater risk of falling below our IC score cutoff point than white women. We found the greatest differences in the Brazilian South, whereas its North showed the lowest associations among race/color, gender, and IC. CONCLUSION: IC racial and gender disparities reinforce the need for public health policies to guarantee equality during aging. Promoting greater access to good health care requires understanding how racism and sexism can contribute to health inequities and their consequences in different Brazilian regions