The authors investigate the relationship between linguistic diversity and various environmental and spatial variables associated with biodiversity. Most of these variables predict linguistic diversity variably across different continents, and more so within Africa and extended Asia (Asia, the Pacific, and Australia) than within Europe and the Americas. This divide is theorized to be a result of differences in demography and impact of colonialism between the two global regions. However, two environmental factors, landscape roughness and density of river systems, are found to be significant predictors across all global regions. The authors suggest that, as in processes of speciation, rough terrain and watercourses both create physical barriers between which languages can develop in isolation while, in the case of river junctions, also providing transportation routes whereby hybrid languages can occasionally manifest.

Inter-group variation is greater in humans than in any other animal, and scholars continue to debate the cause of this diversity. Two competing explanatory models of human variation emphasize either (1) ecological differences and "evoked" culture or (2) population-level effects of cultural transmission. The former emphasizes mechanisms that operate within a single generation, while the latter emphasizes cumulative cultural history operating over many generations. To test these competing models, the authors measured the relative power of ecological variables as compared to culture history to predict behavioral variation in 172 western North American tribes. Culture history is subdivided into culture phylogeny (based on language phylogeny) and spatial distance.

Inter-group variation is greater in humans than in any other animal, and scholars continue to debate the cause of this diversity. Two competing explanatory models of human variation emphasize either (1) ecological differences and "evoked" culture or (2) population-level effects of cultural transmission. The former emphasizes mechanisms that operate within a single generation, while the latter emphasizes cumulative cultural history operating over many generations. To test these competing models, the authors measured the relative power of ecological variables as compared to culture history to predict behavioral variation in 172 western North American tribes. Culture history is subdivided into culture phylogeny (based on language phylogeny) and spatial distance.

Inter-group variation is greater in humans than in any other animal, and scholars continue to debate the cause of this diversity. Two competing explanatory models of human variation emphasize either (1) ecological differences and "evoked" culture or (2) population-level effects of cultural transmission. The former emphasizes mechanisms that operate within a single generation, while the latter emphasizes cumulative cultural history operating over many generations. To test these competing models, the authors measured the relative power of ecological variables as compared to culture history to predict behavioral variation in 172 western North American tribes. Culture history is subdivided into culture phylogeny (based on language phylogeny) and spatial distance.

Finger millet, pearl millet, and sorghum are important drought-tolerant crops used as primary staple crops in drylands. Despite their long history, they have received less attention in recent years and their production has decreased. New models show that annual precipitation is not the only factor affecting their agriculture, but other variables like growing cycle duration, soil water-holding capacity, and soil nutrient availability also play a crucial role, as evidenced by ethnographic data. The traditional cultivation practices of these crops can be a sustainable response to the increasing aridity levels worldwide and can contribute to the resilience of dryland agriculture.

Finger millet, pearl millet, and sorghum are important drought-tolerant crops used as primary staple crops in drylands. Despite their long history, they have received less attention in recent years and their production has decreased. New models show that annual precipitation is not the only factor affecting their agriculture, but other variables like growing cycle duration, soil water-holding capacity, and soil nutrient availability also play a crucial role, as evidenced by ethnographic data. The traditional cultivation practices of these crops can be a sustainable response to the increasing aridity levels worldwide and can contribute to the resilience of dryland agriculture.

Finger millet, pearl millet, and sorghum are important drought-tolerant crops used as primary staple crops in drylands. Despite their long history, they have received less attention in recent years and their production has decreased. New models show that annual precipitation is not the only factor affecting their agriculture, but other variables like growing cycle duration, soil water-holding capacity, and soil nutrient availability also play a crucial role, as evidenced by ethnographic data. The traditional cultivation practices of these crops can be a sustainable response to the increasing aridity levels worldwide and can contribute to the resilience of dryland agriculture.

Finger millet, pearl millet, and sorghum are important drought-tolerant crops used as primary staple crops in drylands. Despite their long history, they have received less attention in recent years and their production has decreased. New models show that annual precipitation is not the only factor affecting their agriculture, but other variables like growing cycle duration, soil water-holding capacity, and soil nutrient availability also play a crucial role, as evidenced by ethnographic data. The traditional cultivation practices of these crops can be a sustainable response to the increasing aridity levels worldwide and can contribute to the resilience of dryland agriculture.

The second and third parts of this book classify the economic systems of foraging and agricultural societies in the SCCS based on correlations between their institutions of property an distribution. These economic types are then examined for relationships with other social, political, demographic, and environmental factors in order to draw tentative conclusions regarding the origins of the Agricultural and Industrial Revolutions. The fourth part of the book uses cross-national data to examine similar associations in industrial/service economies, and is not included here.

Inter-group variation is greater in humans than in any other animal, and scholars continue to debate the cause of this diversity. Two competing explanatory models of human variation emphasize either (1) ecological differences and "evoked" culture or (2) population-level effects of cultural transmission. The former emphasizes mechanisms that operate within a single generation, while the latter emphasizes cumulative cultural history operating over many generations. To test these competing models, the authors measured the relative power of ecological variables as compared to culture history to predict behavioral variation in 172 western North American tribes. Culture history is subdivided into culture phylogeny (based on language phylogeny) and spatial distance.