Charting a landmark-driven path forward for population genetics and ancient DNA research in Africa.

Population history-focused DNA and ancient DNA (aDNA) research in Africa has dramatically increased in the past decade, enabling increasingly fine-scale investigations into the continent's past. However, while international interest in human genomics research in Africa grows, major structural barriers limit the ability of African scholars to lead and engage in such research and impede local communities from partnering with researchers and benefitting from research outcomes. Because conversations about research on African people and their past are often held outside Africa and exclude African voices, an important step for African DNA and aDNA research is moving these conversations to the continent. In May 2023 we held the DNAirobi workshop in Nairobi, Kenya and here we synthesize what emerged most prominently in our discussions. We propose an ideal vision for population history-focused DNA and aDNA research in Africa in ten years' time and acknowledge that to realize this future, we need to chart a path connecting a series of "landmarks" that represent points of consensus in our discussions. These include effective communication across multiple audiences, reframed relationships and capacity building, and action toward structural changes that support science and beyond. We concluded there is no single path to creating an equitable and self-sustaining research ecosystem, but rather many possible routes linking these landmarks. Here we share our diverse perspectives as geneticists, anthropologists, archaeologists, museum curators, and educators to articulate challenges and opportunities for African DNA and aDNA research and share an initial map toward a more inclusive and equitable future.

Water Insecurity, Water Borrowing, and Psychosocial Stress Among Daasanach Pastoralists in Northern Kenya.

This article quantifies Daasanach water insecurity experiences in Northern Kenya, examines how water insecurity is associated with water borrowing and psychosocial stress, and evaluates if water borrowing mitigates the stress from water insecurity. Of 133 households interviewed in 7 communities, 94% were water insecure and 74.4% borrowed water three or more times in the prior month. Regression analyses demonstrate water borrowing frequency moderates the relationship between water insecurity and psychosocial stress. Only those who rarely or never borrowed water reported greater stress with higher water insecurity. The coping mechanism of water borrowing may help blunt water insecurity-related stress.

The co-occurrence of water insecurity and food insecurity among Daasanach pastoralists in northern Kenya.

OBJECTIVE: Water plays a critical role in the production of food and preparation of nutritious meals, yet few studies have examined the relationship between water and food insecurity. The primary objective of this study, therefore, was to examine how experiences of household water insecurity (HWI) relate to experiences of household food insecurity (HFI) among a pastoralist population living in an arid, water-stressed region of northern Kenya. DESIGN: We implemented the twelve-item Household Water Insecurity Experiences (HWISE, range 0-36) Scale and the nine-item Household Food Insecurity Access Scale (HFIAS, range 0-27) in a cross-sectional survey to measure HWI and HFI, respectively. Data on socio-demographic characteristics and intake of meat and dairy in the prior week were collected as covariates of interest. SETTING: Northern Kenya, June-July 2019. PARTICIPANTS: Daasanach pastoralist households (n 136) from seven communities. RESULTS: In the prior 4 weeks, 93·4 % and 98·5 % of households had experienced moderate-to-severe HWI and HFI, respectively. Multiple linear regression analyses indicated a strong association between HWI and HFI. Each point higher HWISE score was associated with a 0·44-point (95 % CI: 0·22, 0·66, P = 0·003) higher HFIAS score adjusting for socio-economic status and other covariates. CONCLUSIONS: These findings demonstrate high prevalence and co-occurrence of HWI and HFI among Daasanach pastoralists in northern Kenya. This study highlights the need to address HWI and HFI simultaneously when developing policies and interventions to improve the nutritional well-being of populations whose subsistence is closely tied to water availability and access.

Mobility ideation due to water problems during historic 2022 drought associated with livestock wealth, water and food insecurity, and fingernail cortisol concentration in northern Kenya.

Climate change is triggering environmental mobility through chronic water problems and punctuated events. Thinking about moving locations, or "mobility ideation", is the precursor to migration intentionality and actual migration. Drawing on the embodiment construct, this study examines how the worst drought in recent history in the Horn of Africa affected water-related mobility ideation and, in turn, fingernail cortisol concentration (FCC), a chronic stress biomarker, among Daasanach semi-nomadic pastoralists in northern Kenya. To address these questions, we primarily draw on survey, anthropometric, water quality, and biomarker data among 175 adults living in seven communities in 2022. We used mixed-effects ordered logistic regression to test how livestock wealth, water insecurity, food insecurity, and anxiety/depression symptom scores were associated with household mobility ideation. We then used generalized linear models to test the association between mobility ideation on FCC. Thinking about moving at least once due to water problems increased from pre-drought in 2019 (55%) to during the drought in 2022 (92%), while actual mobility declined. Livestock wealth, while associated with actual mobility in the prior year, was protective against increased mobility ideation, while water insecurity, food insecurity, and anxiety/depression symptoms were associated with greater odds of thinking of leaving in 2022. Compared to adults who did not consider moving, those who considered moving rarely, sometimes, and often had FCC levels 18.1% higher (95% CI, 1.01-1.38; p = 0.039), 19.4% higher (1.01-1.41; p = 0.040), and 32.3% higher (1.01-1.73; p = 0.039), respectively, with results consistent in sensitivity analyses. Extreme climatic events in water scarce regions may increase mobility ideation through worsened experiential indicators of well-being and resource insecurity. Mobility ideation may capture measures of adversity suffered by pastoralists and signify climate distress. This research broadens understanding of how droughts get under the skin by leading to resource insecurity and triggering thoughts of moving, which increases chronic stress.

New hominin remains and revised context from the earliest Homo erectus locality in East Turkana, Kenya.

The KNM-ER 2598 occipital is among the oldest fossils attributed to Homo erectus but questions have been raised about whether it may derive from a younger horizon. Here we report on efforts to relocate the KNM-ER 2598 locality and investigate its paleontological and geological context. Although located in a different East Turkana collection area (Area 13) than initially reported, the locality is stratigraphically positioned below the KBS Tuff and the outcrops show no evidence of deflation of a younger unit, supporting an age of >1.855 Ma. Newly recovered faunal material consists primarily of C4 grazers, further confirmed by enamel isotope data. A hominin proximal 3rd metatarsal and partial ilium were discovered <50 m from the reconstructed location where KNM-ER 2598 was originally found but these cannot be associated directly with the occipital. The postcrania are consistent with fossil Homo and may represent the earliest postcrania attributable to Homo erectus.

Ancient DNA reveals a multistep spread of the first herders into sub-Saharan Africa.

How food production first entered eastern Africa ~5000 years ago and the extent to which people moved with livestock is unclear. We present genome-wide data from 41 individuals associated with Later Stone Age, Pastoral Neolithic (PN), and Iron Age contexts in what are now Kenya and Tanzania to examine the genetic impacts of the spreads of herding and farming. Our results support a multiphase model in which admixture between northeastern African-related peoples and eastern African foragers formed multiple pastoralist groups, including a genetically homogeneous PN cluster. Additional admixture with northeastern and western African-related groups occurred by the Iron Age. These findings support several movements of food producers while rejecting models of minimal admixture with foragers and of genetic differentiation between makers of distinct PN artifacts.