Honey, Hadza, hunter-gatherers, and human evolution

Ecology and Management of African Honey Bees (Apis mellifera L.)

In Africa, humans evolved as honey hunters of honey bee subspecies adapted to diverse geographical regions. Beekeeping today is practiced much as it was when Africans moved from honey hunting to beekeeping nearly 5,000 years ago, with beekeepers relying on seasonally available wild bees. Research suggests that populations are resilient, able to resist diseases and novel parasites. Distinct biomes, as well as environmental pressures, shaped the behavior and biology of these bees and in turn influenced how indigenous beekeeping developed. It appears that passive beekeeping practices that enabled free-living populations contributed to the overall resilience and health of the bee. There is clearly a need for research aimed at a deeper understanding of bee biology and the ecosystems from which they benefit and on which humans depend, as well as a growing realization that the management of these bees requires an indigenous approach that reflects a broader knowledge base and the economics of local communities and markets.

Culturally determined interspecies communication between humans and honeyguides

Species interactions that vary across environments can create geographical mosaics of genetic coevolution. However, traits mediating species interactions are sometimes culturally inherited. Here we show that traditions of interspecies communication between people and wild birds vary in a culturally determined geographical mosaic. Honey hunters in different parts of Africa use different calls to communicate with greater honeyguides (Indicator indicator) that lead them to bees' nests. We show experimentally that honeyguides in Tanzania and Mozambique discriminate among honey hunters' calls, responding more readily to local than to foreign calls. This was not explained by variation in sound transmission and instead suggests that honeyguides learn local human signals. We discuss the forces stabilizing and diversifying interspecies communication traditions, and the potential for cultural coevolution between species.

Comparing measured dietary variation within and between tropical hunter-gatherer groups to the Paleo Diet

BACKGROUND

Although human diets varied considerably before the spread of agriculture, public perceptions of preagricultural diets have been strongly influenced by the Paleo Diet, which prescribes percentage calorie ranges of 19-35% protein, 22-40% carbohydrate, and 28-47% fat, and prohibits foods with added sugar, dairy, grains, most starchy tubers, and legumes. However, the empirical basis for Paleolithic nutrition remains unclear, with some of its assumptions challenged by the archaeological record and theoretical first principles.

OBJECTIVES

We assessed the variation in diets among tropical hunter-gatherers, including the effect of collection methods on implied macronutrient percentages.

METHODS

We analyzed data on animal food, plant food, and honey consumption by weight and kcal from 15 high-quality published ethnographic studies representing 11 recent tropical hunter-gatherer groups. We used Bayesian analyses to perform inference and included data collection methods and environmental variables as predictors in our models.

RESULTS

Our analyses reveal high levels of variation in animal versus plant foods consumed and in corresponding percentages of protein, fat, and carbohydrates. In addition, studies that weighed food items consumed in and out of camp and across seasons and years reported higher consumption of animal foods, which varied with annual mean temperature.

CONCLUSIONS

The ethnographic evidence from tropical foragers refutes the concept of circumscribed macronutrient ranges modeling preagricultural diets.

Ultra-deep sequencing of Hadza hunter-gatherers recovers vanishing gut microbes

The gut microbiome modulates immune and metabolic health. Human microbiome data are biased toward industrialized populations, limiting our understanding of non-industrialized microbiomes. Here, we performed ultra-deep metagenomic sequencing on 351 fecal samples from the Hadza hunter-gatherers of Tanzania and comparative populations in Nepal and California. We recovered 91,662 genomes of bacteria, archaea, bacteriophages, and eukaryotes, 44% of which are absent from existing unified datasets. We identified 124 gut-resident species vanishing in industrialized populations and highlighted distinct aspects of the Hadza gut microbiome related to in situ replication rates, signatures of selection, and strain sharing. Industrialized gut microbes were found to be enriched in genes associated with oxidative stress, possibly a result of microbiome adaptation to inflammatory processes. This unparalleled view of the Hadza gut microbiome provides a valuable resource, expands our understanding of microbes capable of colonizing the human gut, and clarifies the extensive perturbation induced by the industrialized lifestyle.

Comparative physiological anthropogeny: exploring molecular underpinnings of distinctly human phenotypes

Anthropogeny is a classic term encompassing transdisciplinary investigations of the origins of the human species. Comparative anthropogeny is a systematic comparison of humans and other living nonhuman hominids (so-called "great apes"), aiming to identify distinctly human features in health and disease, with the overall goal of explaining human origins. We begin with a historical perspective, briefly describing how the field progressed from the earliest evolutionary insights to the current emphasis on in-depth molecular and genomic investigations of "human-specific" biology and an increased appreciation for cultural impacts on human biology. While many such genetic differences between humans and other hominids have been revealed over the last two decades, this information remains insufficient to explain the most distinctive phenotypic traits distinguishing humans from other living hominids. Here we undertake a complementary approach of "comparative physiological anthropogeny," along the lines of the preclinical medical curriculum, i.e., beginning with anatomy and considering each physiological system and in each case considering genetic and molecular components that are relevant. What is ultimately needed is a systematic comparative approach at all levels from molecular to physiological to sociocultural, building networks of related information, drawing inferences, and generating testable hypotheses. The concluding section will touch on distinctive considerations in the study of human evolution, including the importance of gene-culture interactions.

The Ideal Diet for Humans to Sustainably Feed the Growing Population - Review, Meta-Analyses, and Policies for Change

INTRODUCTION

As of now, no study has combined research from different sciences to determine the most suitable diet for humans. This issue is urgent due to the predicted population growth, the effect of this on the environment, and the deterioration of human health and associated costs.

METHODS

A literature review determined whether an optimal diet for humans exists and what such a diet is, followed by six meta-analyses. The standard criteria for conducting meta-analyses of observational studies were followed. A review of literature reporting Hazard Ratios with a 95% confidence interval for red meat intake, dairy intake, plant-based diet, fiber intake, and serum IGF-1 levels were extracted to calculate effect sizes.

RESULTS

Results calculated using NCSS software show that high meat consumption increases mortality probability by 18% on average and increases diabetes risk by 50%. Plant-based and high-fiber diets decrease mortality by 15% and 20% respectively ( p < .001). Plant-based diets decreased diabetes risk by 27%, and dairy consumption (measured by increased IGF-1 levels) increased cancer probability by 48% ( p < 0.01). A vegetarian or Mediterranean diet was not found to decrease the probability of heart disease. A vegetarian diet can be healthy or not, depending on the foods consumed. A Mediterranean diet with high quantities of meat and dairy products will not produce the health effects desired. The main limitations of the study were that observational studies were heterogeneous and limited by potential confounders.

DISCUSSION

The literature and meta-analyses point to an optimal diet for humans that has followed our species from the beginnings of humankind. The optimal diet is a whole food, high fiber, low-fat, 90+% plant-based diet. This diet allowed humans to become the most developed species on Earth. To ensure people's nutritional needs are met healthily and sustainably, governmental dietary interventions are necessary.

Insight into the Recent Application of Chemometrics in Quality Analysis and Characterization of Bee Honey during Processing and Storage

The application of chemometrics, a widely used science in food studies (and not only food studies) has begun to increase in importance with chemometrics being a very powerful tool in analyzing large numbers of results. In the case of honey, chemometrics is usually used for assessing honey authenticity and quality control, combined with well-established analytical methods. Research related to investigation of the quality changes in honey due to modifications after processing and storage is rare, with a visibly increasing tendency in the last decade (and concentrated on investigating novel methods to preserve the honey quality, such as ultrasound or high-pressure treatment). This review presents the evolution in the last few years in using chemometrics in analyzing honey quality during processing and storage. The advantages of using chemometrics in assessing honey quality during storage and processing are presented, together with the main characteristics of some well-known chemometric methods. Chemometrics prove to be a successful tool to differentiate honey samples based on changes of characteristics during storage and processing.

Relationship between proximity and physiological stress levels in hunter-gatherers: The Hadza

In recent years there has been a great deal of documentation on how social relationships are related to various aspects of human wellbeing. However, until recently most studies investigating the effects of social relationships on wellbeing have applied social network measures to reported social contacts. Recent advances in the application of bio-loggers in biological studies have now made it possible to quantify social relationships based on in-person, rather than self-reported, social interactions. We used GPS-derived in-camp and out-of-camp proximity data to analyse how in-person proximity is related to Hair Cortisol Concentration (HCC) among Hadza hunter-gatherers. Time spent in close proximity to other camp members was associated with higher HCC, especially in women. In contrast, individuals who spent more time in close out-of-camp proximity to their best friend experienced lower HCC. Our study suggests that physiological costs related to group living might be mitigated by in-person interactions with close friends. We also find that the location (i.e., in-camp vs out-of-camp) of proximity to others and self-perceived friends is associated with HCC among the Hadza.

Genetic and functional odorant receptor variation in the Homo lineage

Humans, Neanderthals, and Denisovans independently adapted to a wide range of geographic environments and their associated food odors. Using ancient DNA sequences, we explored the in vitro function of thirty odorant receptor genes in the genus Homo. Our extinct relatives had highly conserved olfactory receptor sequence, but humans did not. Variations in odorant receptor protein sequence and structure may have produced variation in odor detection and perception. Variants led to minimal changes in specificity but had more influence on functional sensitivity. The few Neanderthal variants disturbed function, whereas Denisovan variants increased sensitivity to sweet and sulfur odors. Geographic adaptations may have produced greater functional variation in our lineage, increasing our olfactory repertoire and expanding our adaptive capacity. Our survey of olfactory genes and odorant receptors suggests that our genus has a shared repertoire with possible local ecological adaptations.

Olapegba P, Sawamiya Y, Suzuki T, Yamamiya Y, Wagner MJ, Drysch M, Lehnhardt M, Behr B. Interethnic Influencing Factors Regarding Buttocks Body Image in Women from Nigeria, Germany, USA and Japan

BACKGROUND

Body image research deals a lot with awareness of the body as an entity. Studies that consider individual anatomical aspects and place them in an intercultural context are rarely present.

METHODS

For this purpose, general data, body perception and judgment of body images from 2163 (48% female and 52% male) participants from Germany, Nigeria, the USA and Japan were evaluated as part of a survey.

RESULTS

There were clear differences in the personal body image of the participants' own buttocks, the buttocks as a beauty ideal and the way in which dissatisfaction was dealt with in different countries. In addition to sexual well-being (importance score: 0.405 a.u.), the country of origin (0.353), media consumption (0.042) and one's own weight (0.069) were also identified as influencing factors for satisfaction with one's own buttocks. A clear evolution could be derived regarding a WHR (waist-to-hip ratio) of well below 0.7, which was consistently favored by the participants but also propagated by influencers through images (p < 0.001). In this context, participants who indicated celebrities as role models for the buttocks showed a correspondingly high level of dissatisfaction with their own buttocks (R = -0.207, p < 0.001, ρ = -0.218).

CONCLUSION

Overall, a highly significant correlation was shown between the consumption frequency of Instagram, TikTok and pornography with the negative perception of women's own buttocks.

Feeding Our Microbiota: Stimulation of the Immune/Semiochemical System and the Potential Amelioration of Non-Communicable Diseases

Non-communicable diseases are those conditions to which causative infectious agents cannot readily be assigned. It is increasingly likely that at least some of these conditions are due to the breakdown of the previously mutualistic intestinal microbiota under the influence of a polluted, biocide-rich, environment. Following the mid-20th century African studies of Denis Burkitt, the environmental cause of conditions such as obesity has been ascribed to the absence of sufficient fibre in the modern diet, however in itself that is insufficient to explain the parallel rise of problems with both the immune system and of mental health. Conversely, Burkitt himself noted that the Maasai, a cattle herding people, remained healthy even with their relatively low intake of dietary fibre. Interestingly, however, Burkitt also emphasised that levels of non-communicable disease within a population rose as faecal weight decreased significantly, to about one third of the levels found in healthy populations. Accordingly, a more cogent explanation for all the available facts is that the fully functioning, adequately diverse microbiome, communicating through what has been termed the microbiota-gut-brain axis, helps to control the passage of food through the digestive tract to provide itself with the nutrition it needs. The method of communication is via the production of semiochemicals, interkingdom signalling molecules, potentially including dopamine. In turn, the microbiome aids the immune system of both adult and, most importantly, the neonate. In this article we consider the role of probiotics and prebiotics, including fermented foods and dietary fibre, in the stimulation of the immune system and of semiochemical production in the gut lumen. Finally, we reprise our suggestion of an ingestible sensor, calibrated to the detection of such semiochemicals, to assess both the effectiveness of individual microbiomes and methods of amelioration of the associated non-communicable diseases.

Safeguarding human-wildlife cooperation

Human-wildlife cooperation occurs when humans and free-living wild animals actively coordinate their behavior to achieve a mutually beneficial outcome. These interactions provide important benefits to both the human and wildlife communities involved, have wider impacts on the local ecosystem, and represent a unique intersection of human and animal cultures. The remaining active forms are human-honeyguide and human-dolphin cooperation, but these are at risk of joining several inactive forms (including human-wolf and human-orca cooperation). Human-wildlife cooperation faces a unique set of conservation challenges, as it requires multiple components-a motivated human and wildlife partner, a suitable environment, and compatible interspecies knowledge-which face threats from ecological and cultural changes. To safeguard human-wildlife cooperation, we recommend: (i) establishing ethically sound conservation strategies together with the participating human communities; (ii) conserving opportunities for human and wildlife participation; (iii) protecting suitable environments; (iv) facilitating cultural transmission of traditional knowledge; (v) accessibly archiving Indigenous and scientific knowledge; and (vi) conducting long-term empirical studies to better understand these interactions and identify threats. Tailored safeguarding plans are therefore necessary to protect these diverse and irreplaceable interactions. Broadly, our review highlights that efforts to conserve biological and cultural diversity should carefully consider interactions between human and animal cultures. Please see AfricanHoneyguides.com/abstract-translations for Kiswahili and Portuguese translations of the abstract.

Ultra-deep Sequencing of Hadza Hunter-Gatherers Recovers Vanishing Microbes.. [PMID: 36238714 PMCID: PMC9558438 DOI: 10.1101/2022.03.30.486478]

The gut microbiome is a key modulator of immune and metabolic health. Human microbiome data is biased towards industrialized populations, providing limited understanding of the distinct and diverse non-industrialized microbiomes. Here, we performed ultra-deep metagenomic sequencing and strain cultivation on 351 fecal samples from the Hadza, hunter-gatherers in Tanzania, and comparative populations in Nepal and California. We recover 94,971 total genomes of bacteria, archaea, bacteriophages, and eukaryotes, 43% of which are absent from existing unified datasets. Analysis of in situ growth rates, genetic pN/pS signatures, high-resolution strain tracking, and 124 gut-resident species vanishing in industrialized populations reveals differentiating dynamics of the Hadza gut microbiome. Industrialized gut microbes are enriched in genes associated with oxidative stress, possibly a result of microbiome adaptation to inflammatory processes. This unparalleled view of the Hadza gut microbiome provides a valuable resource that expands our understanding of microbes capable of colonizing the human gut and clarifies the extensive perturbation brought on by the industrialized lifestyle.

Dietary Transitions and Health Outcomes in Four Populations - Systematic Review

IMPORTANCE

Non-communicable chronic diseases (NCDs) such as obesity, type 2 diabetes, heart disease, and cancer were rare among non-western populations with traditional diets and lifestyles. As populations transitioned toward industrialized diets and lifestyles, NCDs developed.

OBJECTIVE

We performed a systematic literature review to examine the effects of diet and lifestyle transitions on NCDs.

EVIDENCE REVIEW

We identified 22 populations that underwent a nutrition transition, eleven of which had sufficient data. Of these, we chose four populations with diverse geographies, diets and lifestyles who underwent a dietary and lifestyle transition and explored the relationship between dietary changes and health outcomes. We excluded populations with features overlapping with selected populations or with complicating factors such as inadequate data, subgroups, and different study methodologies over different periods. The selected populations were Yemenite Jews, Tokelauans, Tanushimaru Japanese, and Maasai. We also review transition data from seven excluded populations (Pima, Navajo, Aboriginal Australians, South African Natal Indians and Zulu speakers, Inuit, and Hadza) to assess for bias.

FINDINGS

The three groups that replaced saturated fats (SFA) from animal (Yemenite Jews, Maasai) or plants (Tokelau) with refined carbohydrates had negative health outcomes (e.g., increased obesity, diabetes, heart disease). Yemenites reduced SFA consumption by >40% post-transition but men's BMI increased 19% and diabetes increased ~40-fold. Tokelauans reduced fat, dramatically reduced SFA, and increased sugar intake: obesity and diabetes rose. The Tanushimaruans transitioned to more fats and less carbohydrates and used more anti-hypertensive medications; stroke and breast cancer declined while heart disease was stable. The Maasai transitioned to lower fat, SFA and higher carbohydrates and had increased BMI and diabetes. Similar patterns were observed in the seven other populations.

CONCLUSION

The nutrient category most strongly associated with negative health outcomes - especially obesity and diabetes - was sugar (increased 600-650% in Yemenite Jews and Tokelauans) and refined carbohydrates (among Maasai, total carbohydrates increased 39% in men and 362% in women), while increased calories was less strongly associated with these disorders. Across 11 populations, NCDs were associated with increased refined carbohydrates more than increased calories, reduced activity or other factors, but cannot be attributed to SFA or total fat consumption.

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'.

United States Dietary Trends Since 1800: Lack of Association Between Saturated Fatty Acid Consumption and Non-communicable Diseases

We reviewed data on the American diet from 1800 to 2019. Methods: We examined food availability and estimated consumption data from 1800 to 2019 using historical sources from the federal government and additional public data sources. Results: Processed and ultra-processed foods increased from <5 to >60% of foods. Large increases occurred for sugar, white and whole wheat flour, rice, poultry, eggs, vegetable oils, dairy products, and fresh vegetables. Saturated fats from animal sources declined while polyunsaturated fats from vegetable oils rose. Non-communicable diseases (NCDs) rose over the twentieth century in parallel with increased consumption of processed foods, including sugar, refined flour and rice, and vegetable oils. Saturated fats from animal sources were inversely correlated with the prevalence of NCDs. Conclusions: As observed from the food availability data, processed and ultra-processed foods dramatically increased over the past two centuries, especially sugar, white flour, white rice, vegetable oils, and ready-to-eat meals. These changes paralleled the rising incidence of NCDs, while animal fat consumption was inversely correlated.

Awer Honey-Hunting Culture With Greater Honeyguides in Coastal Kenya

The remarkable mutualism between humans and greater honeyguides (Indicator indicator) is known still to thrive in only a few places in Africa. Here, we report on the honey-hunting culture of the marginalised Awer people in Kenya, historically a hunter-gatherer culture who today practise a mixed economy including significant amounts of foraging for wild foods. As part of a larger effort to document cross-cultural honey-hunting traditions in Africa, we interviewed six Awer honey-hunters to document their cultural practices. The interviewees reported that they depend on wild honey as a source of income, and that they readily seek the cooperation of honeyguides. Honey-hunting skills and the calls/whistles used to communicate with honeyguides are learnt from their fathers and other elders in village. The best time to honey-hunt is in the months following the big rains (August–December), when interviewees go out honey-hunting once a week on average. Honeyguides are not actively rewarded with wax, as it is believed that once a bird is fed it will not cooperate again for some time, and therefore after the honey harvest is complete, all remaining wax comb is buried. Honey-hunting practices are declining in this region, which interviewees attributed to drought and a lack of interest by the youth. These findings expand our understanding of how human-honeyguide mutualism persists across a range of human cultural variation.

The Cost of Gathering Among the Baka Forager-Horticulturalists From Southeastern Cameroon

What present-day foragers do for their living and what they eat have long been privileged areas for exploring human behavior, global health, and human evolution. While many studies have focused on hunting and meat acquisition, less attention has been given to gathering and plant foods. Despite evidence of variation in both nutritional quality and energetic costs of gathering different plants, the overall effort spent on gathering in relation to other subsistence tasks is still under explored. In the current context of economic, climate, and social changes, many forager societies also rely on other subsistence strategies, including agriculture and wage labor. In this study, we aim to explore the place of gathering in the livelihood of a mixed economy society, the Baka forager-horticulturalists of southeastern Cameroon, by comparing the involvement and the costs of activities related to food acquisition. From a pool of 153 adult participants (97 women and 56 men), we collected 246 daily records using a GPS (Global Positioning System) tracker combined with heart rate monitor and time allocation recalls. We compared the duration, distance traveled, and the intensity of work, measured by calculating the metabolic equivalent of task (MET), of subsistence activities related to food acquisition. Results from this work show that gathering activities, performed by both women and men, are energetically costly, with higher MET values than hunting and fishing activities. Furthermore, the MET values vary depending on the targeted plant foods. We discuss these insights in the overall framework of subsistence patterns, merging them with the socio-cultural and environmental factors that might explain Baka livelihood and subsistence strategy.

Global hunter-gatherer population densities constrained by influence of seasonality on diet composition

The dependence of hunter-gatherers on local net primary production (NPP) to provide food played a major role in shaping long-term human population dynamics. Observations of contemporary hunter-gatherers have shown an overall correlation between population density and annual NPP but with a 1,000-fold variation in population density per unit NPP that remains unexplained. Here, we build a process-based hunter-gatherer population model embedded within a global terrestrial biosphere model, which explicitly addresses the extraction of NPP through dynamically allocated hunting and gathering activities. The emergent results reveal a strong, previously unrecognized effect of seasonality on population density via diet composition, whereby hunter-gatherers consume high fractions of meat in regions where growing seasons are short, leading to greatly reduced population density due to trophic inefficiency. This seasonal carnivory bottleneck largely explains the wide variation in population density per unit NPP and questions the prevailing usage of annual NPP as the proxy of carrying capacity for ancient humans. Our process-based approach has the potential to greatly refine our understanding of dynamical responses of ancient human populations to past environmental changes.

Bee products in the prehistoric southern levant: evidence from the lipid organic record

Beehive products have a rich global history. In the wider Levantine region, bees had a significant role in Egypt and Mesopotamia, and intensive beekeeping was noted in Israel during the Biblical period when apiaries were first identified. This study investigates the origins of this extensive beekeeping through organic residue analysis of pottery from prehistoric sites in the southern Levant. The results suggest that beehive products from likely wild bees were used during the Chalcolithic period as a vessel surface treatment and/or as part of the diet. These functions are reinforced by comparison to the wider archaeological record. While the true frequency of beeswax use may be debated, alternatives to beehive products were seemingly preferred as wild resources contrasted with the socio-economic system centred on domesticated resources, controlled production and standardization. Bee products only became an important part of the economic canon in the southern Levant several millennia later.

Seasonality and Oldowan behavioral variability in East Africa

The extent, nature, and temporality of early hominin food procurement strategies have been subject to extensive debate. In this article, we examine evidence for the seasonal scheduling of resource procurement and technological investment in the Oldowan, starting with an evaluation of the seasonal signature of underground storage organs, freshwater resources, and terrestrial animal resources in extant primates and modern human hunter-gatherer populations. Subsequently, we use the mortality profiles, taxonomic composition, and taphonomy of the bovid assemblages at Kanjera South (Homa Peninsula, Kenya) and FLK-Zinj (Olduvai Gorge, Tanzania) to illustrate the behavioral flexibility of Oldowan hominins, who were targeting different seasonally vulnerable demographics. In terms of the lithic assemblages, the specific opportunities and constraints afforded by dry season subsistence at FLK-Zinj may have disincentivized lithic investment, resulting in a more expedient toolkit for fast and effective carcass processing. This may have been reinforced by raw material site provisioning during a relatively prolonged seasonal occupation, reducing pressures on the reduction and curation of lithic implements. In contrast, wet season plant abundance would have offered a predictable set of high-quality resources associated with low levels of competition and reduced search times, in the context of perhaps greater seasonal mobility and consequently shorter occupations. These factors appear to have fostered technological investment to reduce resource handling costs at Kanjera South, facilitated by more consistent net returns and enhanced planning of lithic deployment throughout the landscape. We subsequently discuss the seasonality of freshwater resources in Oldowan procurement strategies, focusing on FwJj20 (Koobi Fora, Kenya). Although more analytical studies with representative sample sizes are needed, we argue that interassemblage differences evidence the ability of Oldowan hominins to adapt to seasonal constraints and opportunities in resource exploitation.

Effects of Evolution, Ecology, and Economy on Human Diet: Insights from Hunter-Gatherers and Other Small-Scale Societies

We review the evolutionary origins of the human diet and the effects of ecology economy on the dietary proportion of plants and animals. Humans eat more meat than other apes, a consequence of hunting and gathering, which arose ∼2.5 Mya with the genus Homo. Paleolithic diets likely included a balance of plant and animal foods and would have been remarkably variable across time and space. A plant/animal food balance of 40-60% prevails among contemporary warm-climate hunter-gatherers, but these proportions vary widely. Societies in cold climates, and those that depend more on fishing or pastoralism, tend to eat more meat. Warm-climate foragers, and groups that engage in some farming, tend to eat more plants. We present a case study of the wild food diet of the Hadza, a community of hunter-gatherers in northern Tanzania, whose diet is high in fiber, adequate in protein, and remarkably variable over monthly timescales. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Harm Avoidance and Mobility During Middle Childhood and Adolescence among Hadza Foragers

Cross-cultural sex differences in mobility and harm avoidance have been widely reported, often emphasizing fitness benefits of long-distance travel for males and high costs for females. Data emerging from adults in small-scale societies, however, are challenging the assumption that female mobility is restricted during reproduction. Such findings warrant further exploration of the ontogeny of mobility. Here, using a combination of machine-learning, mixed-effects linear regression, and GIS mapping, we analyze range size, daily distance traveled, and harm avoidance among Hadza foragers during middle childhood and adolescence. Distance traveled increased with age and, while male adolescents had the longest daily ranges, average daily distance traveled by each sex was similar. We found few age- or sex-related patterns in harm-avoidant responses and a high degree of individual variation. When queried on the same issues, children and their parents were often in alignment as to expectations pertaining to harm avoidance, and siblings tended to behave in similar ways. To the extent that sex differences in mobility did emerge, they were associated with ecological differences in physical threats associated with sex-specific foraging behaviors. Further, we found no strong association between harm avoidance and mobility. Young Hadza foragers of both sexes are highly mobile, regardless of how harm avoidant they are. Taken together, our findings indicate that the causal arrows between harm avoidance and mobility must be evaluated in ecologically specific frameworks where cultural expectations of juvenile mobility can be contextualized.

Honey-collecting in prehistoric West Africa from 3500 years ago

Honey and other bee products were likely a sought-after foodstuff for much of human history, with direct chemical evidence for beeswax identified in prehistoric ceramic vessels from Europe, the Near East and Mediterranean North Africa, from the 7^th millennium BC. Historical and ethnographic literature from across Africa suggests bee products, honey and larvae, had considerable importance both as a food source and in the making of honey-based drinks. Here, to investigate this, we carry out lipid residue analysis of 458 prehistoric pottery vessels from the Nok culture, Nigeria, West Africa, an area where early farmers and foragers co-existed. We report complex lipid distributions, comprising n-alkanes, n-alkanoic acids and fatty acyl wax esters, which provide direct chemical evidence of bee product exploitation and processing, likely including honey-collecting, in over one third of lipid-yielding Nok ceramic vessels. These findings highlight the probable importance of honey collecting in an early farming context, around 3500 years ago, in West Africa.

Though there is a long archaeological record of the use of honey, beeswax and other bee products, there are few known records from Africa. Here Dunne et al. analyse lipid residues from pottery from the Nok culture, Nigeria, dating to ~3500 years ago and find evidence of the collection and processing of bee products, likely honey.

What Does the Taste System Tell Us About the Nutritional Composition and Toxicity of Foods?

One of the distinctive features of the human taste system is that it categorizes food into a few taste qualities - e.g., sweet, salty, sour, bitter, and umami. Here, I examined the functional significance of these taste qualities by asking what they tell us about the nutritional composition and toxicity of foods. I collected published data on the composition of raw and unprocessed foods - i.e., fruits, endosperm tissues, starchy foods, mushrooms, and meats. Sweet taste is thought to help identify foods with a high caloric or micronutrient density. However, the sweetest foods (fruits) had a relatively modest caloric density and low micronutrient density, whereas the blandest foods (endosperm tissues and meats) had a relatively high caloric and high micronutrient density. Salty taste is thought to be a proxy for foods high in sodium. Sodium levels were higher in meats than in most plant materials, but raw meats lack a salient salty taste. Sour taste (a measure of acidity) is thought to signify dangerous or spoiled foods. While this may be the case, it is notable that most ripe fruits are acidic. Umami taste is thought to reflect the protein content of food. I found that free L-glutamate (the prototypical umami tastant) concentration varies independently of protein content in foods. Bitter taste is thought to help identify poisonous foods, but many nutritious plant materials taste bitter. Fat taste is thought to help identify triglyceride-rich foods, but the role of taste versus mouthfeel in the attraction to fatty foods is unresolved. These findings indicate that the taste system provides incomplete or, in some cases, misleading information about the nutritional content and toxicity of foods. This may explain why inputs from the taste system are merged with inputs from the other cephalic senses and intestinal nutrient-sensing systems. By doing so, we create a more complete sensory representation and nutritional evaluation of foods.

Traditional Human Populations and Nonhuman Primates Show Parallel Gut Microbiome Adaptations to Analogous Ecological Conditions

The results of this study highlight parallel gut microbiome traits in human and nonhuman primates, depending on subsistence strategy. Although these similarities have been reported before, the functional and ecological bases of this convergence are not fully understood.

Compared with urban-industrial populations, small-scale human communities worldwide share a significant number of gut microbiome traits with nonhuman primates. This overlap is thought to be driven by analogous dietary triggers; however, the ecological and functional bases of this similarity are not fully understood. To start addressing this issue, fecal metagenomes of BaAka hunter-gatherers and traditional Bantu agriculturalists from the Central African Republic were profiled and compared with those of a sympatric western lowland gorilla group (Gorillagorilla gorilla) across two seasons of variable dietary intake. Results show that gorilla gut microbiomes shared similar functional traits with each human group, depending on seasonal dietary behavior. Specifically, parallel microbiome traits were observed between hunter-gatherers and gorillas when the latter consumed more structural polysaccharides during dry seasons, while small-scale agriculturalist and gorilla microbiomes showed significant functional overlap when gorillas consumed more seasonal ripe fruit during wet seasons. Notably, dominance of microbial transporters, transduction systems, and gut xenobiotic metabolism was observed in association with traditional agriculture and energy-dense diets in gorillas at the expense of a functional microbiome repertoire capable of metabolizing more complex polysaccharides. Differential abundance of bacterial taxa that typically distinguish traditional from industrialized human populations (e.g., Prevotella spp.) was also recapitulated in the human and gorilla groups studied, possibly reflecting the degree of polysaccharide complexity included in each group’s dietary niche. These results show conserved functional gut microbiome adaptations to analogous diets in small-scale human populations and nonhuman primates, highlighting the role of plant dietary polysaccharides and diverse environmental exposures in this convergence.

IMPORTANCE The results of this study highlight parallel gut microbiome traits in human and nonhuman primates, depending on subsistence strategy. Although these similarities have been reported before, the functional and ecological bases of this convergence are not fully understood. Here, we show that this parallelism is, in part, likely modulated by the complexity of plant carbohydrates consumed and by exposures to diverse xenobiotics of natural and artificial origin. Furthermore, we discuss how divergence from these parallel microbiome traits is typically associated with adverse health outcomes in human populations living under culturally westernized subsistence patterns. This is important information as we trace the specific dietary and environmental triggers associated with the loss and gain of microbial functions as humans adapt to various dietary niches.

Perspective: Measuring Sweetness in Foods, Beverages, and Diets: Toward Understanding the Role of Sweetness in Health

Various global public health agencies recommend minimizing exposure to sweet-tasting foods or beverages. The underlying rationale is that reducing exposure to the perception of sweet tastes, without regard to the source of sweetness, may reduce preferences for sweetness, added sugar intake, caloric intake, and body weight. However, the veracity of this sequence of outcomes has yet to be documented, as revealed by findings from recent systematic reviews on the topic. Efforts to examine and document the effects of sweetness exposure are needed to support evidence-based recommendations. They require a generally agreed-upon methodology for measuring sweetness in foods, beverages, and the overall diet. Although well-established sensory evaluation techniques exist for individual foods in laboratory settings, they are expensive and time-consuming, and agreement on the optimal approach for measuring the sweetness of the total diet is lacking. If such a measure could be developed, it would permit researchers to combine data from different studies and populations and facilitate the design and conduct of new studies to address unresolved research questions about dietary sweetness. This narrative review includes an overview of available sensory techniques, their strengths and limitations, recent efforts to measure the sweetness of foods and diets across countries and cultures, and a proposed future direction for improving methods for measuring sweetness toward developing the data required to support evidence-based recommendations around dietary sweetness.

Falsehoods and facts about dietary sugars: a call for evidence-based policy

Sugar, tobacco, and alcohol have been demonized since the seventeenth century. Yet unlike tobacco and alcohol, there is indisputable scientific evidence that dietary sugars were essential for human evolution and are essential for human health and development. Therefore, the purpose of this analytic review and commentary is to demonstrate that anti-sugar rhetoric is divorced from established scientific facts and has led to politically expedient but ill-informed policies reminiscent of those enacted about alcohol a century ago in the United States. Herein, we present a large body of interdisciplinary research to illuminate several misconceptions, falsehoods, and facts about dietary sugars. We argue that anti-sugar policies and recommendations are not merely unscientific but are regressive and unjust because they harm the most vulnerable members of our society while providing no personal or public health benefits.

THE EXPOSOME IN HUMAN EVOLUTION: FROM DUST TO DIESEL

Global exposures to air pollution and cigarette smoke are novel in human evolutionary history and are associated with about 16 million premature deaths per year. We investigate the history of the human exposome for relationships between novel environmental toxins and genetic changes during human evolution in six phases. Phase I: With increased walking on savannas, early human ancestors inhaled crustal dust, fecal aerosols, and spores; carrion scavenging introduced new infectious pathogens. Phase II: Domestic fire exposed early Homo to novel toxins from smoke and cooking. Phases III and IV: Neolithic to preindustrial Homo sapiens incurred infectious pathogens from domestic animals and dense communities with limited sanitation. Phase V: Industrialization introduced novel toxins from fossil fuels, industrial chemicals, and tobacco at the same time infectious pathogens were diminishing. Thereby, pathogen-driven causes of mortality were replaced by chronic diseases driven by sterile inflammogens, exogenous and endogenous. Phase VI: Considers future health during global warming with increased air pollution and infections. We hypothesize that adaptation to some ancient toxins persists in genetic variations associated with inflammation and longevity.

Carbohydrate Monotony as Protection and Treatment for Inflammatory Bowel Disease

The nutritional developmental origins of inflammatory bowel disease[s] (IBDs: Crohn's disease or Crohn disease [CD] and ulcerative colitis [UC]) and their diet-based treatments continue to receive increasing attention. There is growing evidence for the success of nutrition-based treatments, such as exclusive enteral nutrition [EEN] and the specific carbohydrate diet [SCD], in both paediatric and adult patients. Beyond these two dietary interventions, symptomatic benefit in IBD has also been shown from a gluten-free diet [GFD] and paleolithic diet [PALEO], among others. These nutritional therapies may point to critical factors in not only the pathology, but also the pathogenesis of the disease group. It is difficult, however, to discern a common element within the large number of diet-based causation theories [e.g. emulsifiers, processed foods, refrigeration, increased total fat intake, low fibre intake, carbohydrate dominant food, etc.] and the varied dietary treatments of IBD. This Viewpoint article highlights that carbohydrate variation links diet-based causation theories, and that carbohydrate monotony or persistence is the commonly shared characteristic of diet-based IBD therapy. Further research directed towards carbohydrate monotony may critically advance the prevention and treatment of these highly morbid conditions.

Tools, trails and time: Debating Acheulian group size at Attirampakkam, India

Estimating Acheulian group sizes based on a fragmentary archaeological record is fraught with difficulties, more so in regions like India, where lithics form the primary source of information. Here, we review current approaches towards modeling group size in Indian archaeology. We then examine to what extent one may address issues related to seasonality, fission-fusion strategies and group size in the context of Acheulian sites, drawing on our research along the southeastern coast of India. We move between multiple scales of analysis: from the regional Acheulian archaeological record to specific studies at the site of Attirampakkam (ATM). We consider aspects of site distribution, sizes, artefact densities and Acheulian lithic reduction strategies, factoring in issues related to geomorphology, taphonomy and chronology. Acheulian hominins occupied the study region over the early to middle Pleistocene, and the fragmented lithic reduction sequence noted on landscape scales suggests diverse site functions structured by ease of access to quartzite raw material for large flake production in addition to other resources. In contrast to most sites, the absence of raw material at ATM necessitated groups to anticipate this, and organize their behavior on landscape scales, and on-site, to resolve this issue. We show how successive groups were attracted to the site over the early Pleistocene, potentially aiming at exploiting seasonally predictable biological resources in a riparian environment, knowledge of which was transmitted across generations. Considerations of the spatial and temporal variability in artefact densities across a vast site area, along with aspects of the lithic reduction sequences suggests a short-duration occupation by a potentially large group, possibly resulting from aggregation of several small groups as noted in some ethnographic examples of hunter-gatherer fission-fusion strategies. We show drastic changes in behavioral organization in the succeeding Middle Palaeolithic phases at the site and in the region.

Microbes: possible link between modern lifestyle transition and the rise of metabolic syndrome

The rapid decrease in infectious diseases globally has coincided with an increase in the prevalence of obesity and other components of metabolic syndrome. Insulin resistance is a common feature of metabolic syndrome and can be influenced by genetic and non-genetic/environmental factors. The emergence of metabolic syndrome epidemics over only a few decades suggests a more prominent role of the latter. Changes in our environment and lifestyle have indeed paralleled the rise in metabolic syndrome. Gastrointestinal tract microbiota, the composition of which plays a significant role in host physiology, including metabolism and energy homeostasis, are distinctly different within the context of metabolic syndrome. Among humans, recent lifestyle-related changes could be linked to changes in diversity and composition of 'ancient' microbiota. Given the co-adaptation and co-evolution of microbiota with the immune system over a long period of time, it is plausible that such lifestyle-related microbiota changes could trigger aberrant immune responses, thereby predisposing an individual to a variety of diseases. Here, we review current evidence supporting a role for gut microbiota in the ongoing rise of metabolic syndrome. We conclude that population-level shifts in microbiota can play a mediatory role between lifestyle factors and pathogenesis of insulin resistance and metabolic syndrome.

Hunter-gatherers as models in public health

Hunter-gatherer populations are remarkable for their excellent metabolic and cardiovascular health and thus are often used as models in public health, in an effort to understand the root, evolutionary causes of non-communicable diseases. Here, we review recent work on health, activity, energetics and diet among hunter-gatherers and other small-scale societies (e.g. subsistence farmers, horticulturalists and pastoralists), as well as recent fossil and archaeological discoveries, to provide a more comprehensive perspective on lifestyle and health in these populations. We supplement these analyses with new data from the Hadza, a hunter-gatherer population in northern Tanzania. Longevity among small-scale populations approaches that of industrialized populations, and metabolic and cardiovascular disease are rare. Obesity prevalence is very low (<5%), and mean body fat percentage is modest (women: 24-28%, men: 9-18%). Activity levels are high, exceeding 100 min d^-1 of moderate and vigorous physical activity, but daily energy expenditures are similar to industrialized populations. Diets in hunter-gatherer and other small-scale societies tend to be less energy dense and richer in fibre and micronutrients than modern diets but are not invariably low carbohydrate as sometimes argued. A more integrative understanding of hunter-gatherer health and lifestyle, including elements beyond diet and activity, will improve public health efforts in industrialized populations.

Earliest evidence of caries lesion in hominids reveal sugar-rich diet for a Middle Miocene dryopithecine from Europe

The formation of dental caries is mainly caused by dietary habits and therefore, may contain information for dietary reconstructions of fossil hominids. This study investigates the caries lesion in the 12.5 Ma old type specimen of Dryopithecus carinthiacus Mottl 1957 (Primates, Hominidae) from St. Stefan (Austria). Potential food sources are identified on associated palynological data, which allow conclusions about food quality, sugar availability and the hominid metabolism during the Middle Miocene. Using micro computed tomography (μCT) and scanning electron microscopy (SEM) we provide a detailed analysis and characterization of the individuals' caries type. Its lesion is compared with a dataset of 311 wild chimpanzees, indicating morphological and etiological differences in caries formation between both species. The affected molar of D. carinthiacus reveals features known from severe dental caries in humans: (1) Cavitation with steep walls and smooth surface; (2) Reparative dentine at the roof of the pulp chamber; (3) Sclerotic dentine below the cavitation; (4) Association with dental calculus and (5) Unilateral usage of the healthy right tooth row. Its advanced primary caries, initiating on the intact enamel surface, indicates a frequent intake of highly cariogenic sugar-rich fruits, which likely exceeds the frugivory of extant chimpanzees. This finding corresponds with the associated palynological record, which infers a habitat with nearly year-round supply (9-10 months/year) of high quality foods (>carbohydrates; < fibers). Our conclusions challenge the model of a step-wise increase in dietary quality during hominid evolution and support the uricase hypothesis, which discusses the hominid autapomorphy of a fructose-based fat accumulation for periods of starvation. This model receives further validation by the identification of soft-tissue preservation, interpreted as fossilized white adipose cells, in the articulated hominid skeleton of Oreopithecus bamboli from Italy.

Links between environment, diet, and the hunter-gatherer microbiome

The study of traditional populations provides a view of human-associated microbes unperturbed by industrialization, as well as a window into the microbiota that co-evolved with humans. Here we discuss our recent work characterizing the microbiota from the Hadza hunter-gatherers of Tanzania. We found seasonal shifts in bacterial taxa, diversity, and carbohydrate utilization by the microbiota. When compared to the microbiota composition from other populations around the world, the Hadza microbiota shares bacterial families with other traditional societies that are rare or absent from microbiotas of industrialized nations. We present additional observations from the Hadza microbiota and their lifestyle and environment, including microbes detected on hands, water, and animal sources, how the microbiota varies with sex and age, and the short-term effects of introducing agricultural products into the diet. In the context of our previously published findings and of these additional observations, we discuss a path forward for future work.

Cell-Specific "Competition for Calories" Drives Asymmetric Nutrient-Energy Partitioning, Obesity, and Metabolic Diseases in Human and Non-human Animals

The mammalian body is a complex physiologic “ecosystem” in which cells compete for calories (i.e., nutrient-energy). Axiomatically, cell-types with competitive advantages acquire a greater number of consumed calories, and when possible, increase in size and/or number. Thus, it is logical and parsimonious to posit that obesity is the competitive advantages of fat-cells (adipocytes) driving a disproportionate acquisition and storage of nutrient-energy. Accordingly, we introduce two conceptual frameworks. Asymmetric Nutrient-Energy Partitioning describes the context-dependent, cell-specific competition for calories that determines the partitioning of nutrient-energy to oxidation, anabolism, and/or storage; and Effective Caloric Intake which describes the number of calories available to constrain energy-intake via the inhibition of the sensorimotor appetitive cells in the liver and brain that govern ingestive behaviors. Inherent in these frameworks is the independence and dissociation of the energetic demands of metabolism and the neuro-muscular pathways that initiate ingestive behaviors and energy intake. As we demonstrate, if the sensorimotor cells suffer relative caloric deprivation via asymmetric competition from other cell-types (e.g., skeletal muscle- or fat-cells), energy-intake is increased to compensate for both real and merely apparent deficits in energy-homeostasis (i.e., true and false signals, respectively). Thus, we posit that the chronic positive energy balance (i.e., over-nutrition) that leads to obesity and metabolic diseases is engendered by apparent deficits (i.e., false signals) driven by the asymmetric inter-cellular competition for calories and concomitant differential partitioning of nutrient-energy to storage. These frameworks, in concert with our previous theoretic work, the Maternal Resources Hypothesis, provide a parsimonious and rigorous explanation for the rapid rise in the global prevalence of increased body and fat mass, and associated metabolic dysfunctions in humans and other mammals inclusive of companion, domesticated, laboratory, and feral animals.

In Defense of Sugar: A Critique of Diet-Centrism

Sugars are foundational to biological life and played essential roles in human evolution and dietary patterns for most of recorded history. The simple sugar glucose is so central to human health that it is one of the World Health Organization's Essential Medicines. Given these facts, it defies both logic and a large body of scientific evidence to claim that sugars and other nutrients that played fundamental roles in the substantial improvements in life- and health-spans over the past century are now suddenly responsible for increments in the prevalence of obesity and chronic non-communicable diseases. Thus, the purpose of this review is to provide a rigorous, evidence-based challenge to 'diet-centrism' and the disease-mongering of dietary sugar. The term 'diet-centrism' describes the naïve tendency of both researchers and the public to attribute a wide-range of negative health outcomes exclusively to dietary factors while neglecting the essential and well-established role of individual differences in nutrient-metabolism. The explicit conflation of dietary intake with both nutritional status and health inherent in 'diet-centrism' contravenes the fact that the human body is a complex biologic system in which the effects of dietary factors are dependent on the current state of that system. Thus, macronutrients cannot have health or metabolic effects independent of the physiologic context of the consuming individual (e.g., physical activity level). Therefore, given the unscientific hyperbole surrounding dietary sugars, I take an adversarial position and present highly-replicated evidence from multiple domains to show that 'diet' is a necessary but trivial factor in metabolic health, and that anti-sugar rhetoric is simply diet-centric disease-mongering engendered by physiologic illiteracy. My position is that dietary sugars are not responsible for obesity or metabolic diseases and that the consumption of simple sugars and sugar-polymers (e.g., starches) up to 75% of total daily caloric intake is innocuous in healthy individuals.