Climate velocities and species tracking in global mountain regions.

Mountain ranges contain high concentrations of endemic species and are indispensable refugia for lowland species that are facing anthropogenic climate change1,2. Forecasting biodiversity redistribution hinges on assessing whether species can track shifting isotherms as the climate warms3,4. However, a global analysis of the velocities of isotherm shifts along elevation gradients is hindered by the scarcity of weather stations in mountainous regions5. Here we address this issue by mapping the lapse rate of temperature (LRT) across mountain regions globally, both by using satellite data (SLRT) and by using the laws of thermodynamics to account for water vapour6 (that is, the moist adiabatic lapse rate (MALRT)). By dividing the rate of surface warming from 1971 to 2020 by either the SLRT or the MALRT, we provide maps of vertical isotherm shift velocities. We identify 17 mountain regions with exceptionally high vertical isotherm shift velocities (greater than 11.67 m per year for the SLRT; greater than 8.25 m per year for the MALRT), predominantly in dry areas but also in wet regions with shallow lapse rates; for example, northern Sumatra, the Brazilian highlands and southern Africa. By linking these velocities to the velocities of species range shifts, we report instances of close tracking in mountains with lower climate velocities. However, many species lag behind, suggesting that range shift dynamics would persist even if we managed to curb climate-change trajectories. Our findings are key for devising global conservation strategies, particularly in the 17 high-velocity mountain regions that we have identified.

Ostrich eggshell beads reveal 50,000-year-old social network in Africa.

Humans evolved in a patchwork of semi-connected populations across Africa1,2; understanding when and how these groups connected is critical to interpreting our present-day biological and cultural diversity. Genetic analyses reveal that eastern and southern African lineages diverged sometime in the Pleistocene epoch, approximately 350-70 thousand years ago (ka)3,4; however, little is known about the exact timing of these interactions, the cultural context of these exchanges or the mechanisms that drove their separation. Here we compare ostrich eggshell bead variations between eastern and southern Africa to explore population dynamics over the past 50,000 years. We found that ostrich eggshell bead technology probably originated in eastern Africa and spread southward approximately 50-33 ka via a regional network. This connection breaks down approximately 33 ka, with populations remaining isolated until herders entered southern Africa after 2 ka. The timing of this disconnection broadly corresponds with the southward shift of the Intertropical Convergence Zone, which caused periodic flooding of the Zambezi River catchment (an area that connects eastern and southern Africa). This suggests that climate exerted some influence in shaping human social contact. Our study implies a later regional divergence than predicted by genetic analyses, identifies an approximately 3,000-kilometre stylistic connection and offers important new insights into the social dimension of ancient interactions.

Innovative Homo sapiens behaviours 105,000 years ago in a wetter Kalahari.

The archaeological record of Africa provides the earliest evidence for the emergence of the complex symbolic and technological behaviours that characterize Homo sapiens1-7. The coastal setting of many archaeological sites of the Late Pleistocene epoch, and the abundant shellfish remains recovered from them, has led to a dominant narrative in which modern human origins in southern Africa are intrinsically tied to the coast and marine resources8-12, and behavioural innovations in the interior lag behind. However, stratified Late Pleistocene sites with good preservation and robust chronologies are rare in the interior of southern Africa, and the coastal hypothesis therefore remains untested. Here we show that early human innovations that are similar to those dated to around 105 thousand years ago (ka) in coastal southern Africa existed at around the same time among humans who lived over 600 km inland. We report evidence for the intentional collection of non-utilitarian objects (calcite crystals) and ostrich eggshell from excavations of a stratified rockshelter deposit in the southern Kalahari Basin, which we date by optically stimulated luminescence to around 105 ka. Uranium-thorium dating of relict tufa deposits indicates sporadic periods of substantial volumes of fresh, flowing water; the oldest of these episodes is dated to between 110 and 100 ka and is coeval with the archaeological deposit. Our results suggest that behavioural innovations among humans in the interior of southern Africa did not lag behind those of populations near the coast, and that these innovations may have developed within a wet savannah environment. Models that tie the emergence of behavioural innovations to the exploitation of coastal resources by our species may therefore require revision.

The driving force behind tool-stone selection in the African Middle Stone Age.

In the Stone Age, the collection of specific rocks was the first step in tool making. Very little is known about the choices made during tool-stone acquisition. Were choices governed by the knowledge of, and need for, specific properties of stones? Or were the collected raw materials a mere by-product of the way people moved through the landscape? We investigate these questions in the Middle Stone Age (MSA) of southern Africa, analyzing the mechanical properties of tool-stones used at the site Diepkloof Rock Shelter. To understand knapping quality, we measure flaking predictability and introduce a physical model that allows calculating the relative force necessary to produce flakes from different rocks. To evaluate their quality as finished tools, we investigate their resistance during repeated use activities (scraping or cutting) and their strength during projectile impacts. Our findings explain tool-stone selection in two emblematic periods of the MSA, the Still Bay and Howiesons Poort, as being the result of a deep understanding of these mechanical properties. In both cases, people chose those rocks, among many others, that allowed the most advantageous trade-off between anticipated properties of finished tools and the ease of acquiring rocks and producing tools. The implications are an understanding of African MSA toolmakers as engineers who carefully weighed their choices taking into account workability and the quality of the tools they made.

Genetic heritage of the Baphuthi highlights an over-ethnicized notion of "Bushman" in the Maloti-Drakensberg, southern Africa.

Using contemporary people as proxies for ancient communities is a contentious but necessary practice in anthropology. In southern Africa, the distinction between the Cape KhoeSan and eastern KhoeSan remains unclear, as ethnicity labels have been changed through time and most communities were decimated if not extirpated. The eastern KhoeSan may have had genetic distinctions from neighboring communities who speak Bantu languages and KhoeSan further away; alternatively, the identity may not have been tied to any notion of biology, instead denoting communities with a nomadic "lifeway" distinct from African agro-pastoralism. The Baphuthi of the 1800s in the Maloti-Drakensberg, southern Africa had a substantial KhoeSan constituency and a lifeway of nomadism, cattle raiding, and horticulture. Baphuthi heritage could provide insights into the history of the eastern KhoeSan. We examine genetic affinities of 23 Baphuthi to discern whether the narrative of KhoeSan descent reflects distinct genetic ancestry. Genome-wide SNP data (Illumina GSA) were merged with 52 global populations, for 160,000 SNPs. Genetic analyses show no support for a unique eastern KhoeSan ancestry distinct from other KhoeSan or southern Bantu speakers. The Baphuthi have strong affinities with early-arriving southern Bantu-speaking (Nguni) communities, as the later-arriving non-Nguni show strong evidence of recent African admixture possibly related to late-Iron Age migrations. The references to communities as "San" and "Bushman" in historic literature has often been misconstrued as notions of ethnic/biological distinctions. The terms may have reflected ambiguous references to non-sedentary polities instead, as seems to be the case for the eastern "Bushman" heritage of the Baphuthi.

Genetic structure correlates with ethnolinguistic diversity in eastern and southern Africa.

African populations are the most diverse in the world yet are sorely underrepresented in medical genetics research. Here, we examine the structure of African populations using genetic and comprehensive multi-generational ethnolinguistic data from the Neuropsychiatric Genetics of African Populations-Psychosis study (NeuroGAP-Psychosis) consisting of 900 individuals from Ethiopia, Kenya, South Africa, and Uganda. We find that self-reported language classifications meaningfully tag underlying genetic variation that would be missed with consideration of geography alone, highlighting the importance of culture in shaping genetic diversity. Leveraging our uniquely rich multi-generational ethnolinguistic metadata, we track language transmission through the pedigree, observing the disappearance of several languages in our cohort as well as notable shifts in frequency over three generations. We find suggestive evidence for the rate of language transmission in matrilineal groups having been higher than that for patrilineal ones. We highlight both the diversity of variation within Africa as well as how within-Africa variation can be informative for broader variant interpretation; many variants that are rare elsewhere are common in parts of Africa. The work presented here improves the understanding of the spectrum of genetic variation in African populations and highlights the enormous and complex genetic and ethnolinguistic diversity across Africa.

A 44-y perspective on the influence of cash on Ju/'hoansi Bushman networks of sharing and gifting.

Money has been portrayed by major theorists as an agent of individualism, an instrument of freedom, a currency that removes personal values attached to things, and a generator of avarice. Regardless, the impact of money varies greatly with the cultural turf of the recipient societies. For traditional subsistence economies based on gifting and sharing, surplus perishable resources foraged from the environment carry low costs to the giver compared with the benefits to the receiver. With cash, costs to the giver are usually the same as benefits to the receiver, making sharing expensive and introducing new choices. Using quantitative data on possessions and expenditures collected over a 44-y period from 1974 to 2018 among the Ju/'hoansi (!Kung) in southern Africa, former hunter-gatherers, we look at how individuals spend monetary income, how a partial monetary economy alters traditional norms and institutions (egalitarianism, gifting, and sharing), and how institutions from the past steer change. Results show that gifting declines as cash is spent to increase the well-being of individual families and that gifting and sharing decrease and networks narrow. The sharing of meals and casual gifting hold fast. Substantial material inequalities develop, even between neighbors, but social, gender, and political equalities persist. A strong tradition for individual autonomy combined with monetary income allows individuals to spend their money as they choose, adapt to modern conditions, and pursue new options. However, new challenges are emerging to develop greater community cooperation and build substantial and sustainable economies in the face of such centrifugal forces.

Yeast-insect interactions in southern Africa: Tapping the diversity of yeasts for modern bioprocessing.

Yeast-insect interactions are one of the most interesting long-standing relationships whose research has contributed to our understanding of yeast biodiversity and their industrial applications. Although insect-derived yeast strains are exploited for industrial fermentations, only a limited number of such applications has been documented. The search for novel yeasts from insects is attractive to augment the currently domesticated and commercialized production strains. More specifically, there is potential in tapping the insects native to southern Africa. Southern Africa is home to a disproportionately high fraction of global biodiversity with a cluster of biomes and a broad climate range. This review presents arguments on the roles of the mutualistic relationship between yeasts and insects, the presence of diverse pristine environments and a long history of spontaneous food and beverage fermentations as the potential source of novelty. The review further discusses the recent advances in novelty of industrial strains of insect origin, as well as various ancient and modern-day industries that could be improved by use yeasts from insect origin. The major focus of the review is on the relationship between insects and yeasts in southern African ecosystems as a potential source of novel industrial yeast strains for modern bioprocesses.

Revisiting an ecophysiological oddity: Hydathode-mediated foliar water uptake in Crassula species from southern Africa.

Hydathodes are usually associated with water exudation in plants. However, foliar water uptake (FWU) through the hydathodes has long been suspected in the leaf-succulent genus Crassula (Crassulaceae), a highly diverse group in southern Africa, and, to our knowledge, no empirical observations exist in the literature that unequivocally link FWU to hydathodes in this genus. FWU is expected to be particularly beneficial on the arid western side of southern Africa, where up to 50% of Crassula species occur and where periodically high air humidity leads to fog and/or dew formation. To investigate if hydathode-mediated FWU is operational in different Crassula species, we used the apoplastic fluorescent tracer Lucifer Yellow in combination with different imaging techniques. Our images of dye-treated leaves confirm that hydathode-mediated FWU does indeed occur in Crassula and that it might be widespread across the genus. Hydathodes in Crassula serve as moisture-harvesting structures, besides their more common purpose of guttation, an adaptation that has likely played an important role in the evolutionary history of the genus. Our observations suggest that ability for FWU is independent of geographical distribution and not restricted to arid environments under fog influence, as FWU is also operational in Crassula species from the rather humid eastern side of southern Africa. Our observations point towards no apparent link between FWU ability and overall leaf surface wettability in Crassula. Instead, the hierarchically sculptured leaf surfaces of several Crassula species may facilitate FWU due to hydrophilic leaf surface microdomains, even in seemingly hydrophobic species. Overall, these results confirm the ecophysiological relevance of hydathode-mediated FWU in Crassula and reassert the importance of atmospheric humidity for some arid-adapted plant groups.

Out of the desert: Paleoclimatic changes drove the diversification of arid-adapted Ocymyrmex ants in southern Africa.

A highly endemic ant fauna is found in the arid regions of southern Africa, including species in the genus Ocymyrmex. This genus of ants has higher species richness in the western arid regions of southern Africa compared to tropical and subtropical parts of the continent. The processes that have produced these patterns of diversity and distribution of arid adapted ants in southern Africa have never been investigated. The diversification of many other taxa in the region has been associated with past climate fluctuations that occurred during the Miocene epoch. In this study, the nature and timing of historical processes that may have led to the diversification within Ocymyrmex were assessed. We hypothesized that past climate oscillations, characterized by long periods of aridification, have driven the current distribution of Ocymyrmex species that resulted in the highest species richness of the genus in the Deserts & xeric shrublands biome in southern Africa. Ninety-four Ocymyrmex worker specimens from Botswana, Kenya, Namibia, South Africa, Tanzania and Zimbabwe, representing 21 currently described species and six morphospecies, were included in a phylogenomic analysis. Phylogenies for the genus, based on next generation sequencing data from ultraconserved elements, were inferred using Maximum Likelihood, and a dating analysis was performed using secondary age estimates as calibration points. A distribution database of Ocymyrmex records was used to assign species ranges, which were then coded according to major biomes in southern Africa and used as input for biogeographical analysis. We explored the phylogenomic relationships of Ocymyrmex and analysed these within a biogeographical and paleoclimatic framework to disentangle the potential processes responsible for diversification in this group. Dating analyses estimated that the crown age of Ocymyrmex dates to the Oligocene, around 32 Ma. Diversification within this group occurred between the mid-Miocene (∼12.5 Ma) and Pleistocene (∼2 Ma). Our biogeographic analyses suggest that Ocymyrmex species originated in the south-western region of southern Africa, which is now part of the Deserts & xeric shrublands biome and diversified into eastern subtropical areas during the Pliocene. Paleoclimatic changes resulting in increased aridity during the Miocene likely drove the diversification of the genus Ocymyrmex. It is most likely that the diversification of grasslands, because of historical climate change, facilitated the diversification of these ants to the eastern parts of southern Africa when open grasslands replaced forests during the early Miocene.

Substrate specialisation drives an unexpectedly diverse radiation in barking geckos (Ptenopus: Gekkonidae).

Barking geckos (genus Ptenopus) are terrestrial, burrowing lizards endemic to southern Africa, currently with three recognised species. Two species are range-restricted (P. kochi and P. carpi) and display clear differences in substrate preference (soft sand vs. hard gravel). The third and most widespread species, P. garrulus, occurs on a variety of substrates of differing hardness, across potential geographic barriers, and over a steep climatic gradient. Variations in morphology and advertisement calls indicates that P. garrulus may be a species complex. Two subspecies of P. garrulus are currently recognised: P. g. maculatus and P. g. garrulus. To investigate species boundaries, we produced the first comprehensive phylogeny for the genus. We used a novel application of multiple regression on matrices models to assess multiple environmental drivers of diversification, as contrasted to isolation by distance. We show that P. kochi, P. carpi, and P. g. garrulus are valid species, but that P. g. maculatus is a paraphyletic complex of five previously unrecognised taxa. Specialisation onto different substrates was likely the main driver of divergence, with parapatric occurrence of two to four clades occurring at each of the three substrate transition zones identified a priori. The region encompasses diverse bioclimatic regions and potential geographic barriers, and these likely played a role in some divergence events.

Southern Africa's Great Escarpment as an amphitheater of climate-driven diversification and a buffer against future climate change in bats.

Hosting 1460 plant and 126 vertebrate endemic species, the Great Escarpment (hereafter, Escarpment) forms a semi-circular "amphitheater" of mountains girdling southern Africa from arid west to temperate east. Since arid and temperate biota are usually studied separately, earlier studies overlooked the biogeographical importance of the Escarpment as a whole. Bats disperse more widely than other mammalian taxa, with related species and intraspecific lineages occupying both arid and temperate highlands of the Escarpment, providing an excellent model to address this knowledge gap. We investigated patterns of speciation and micro-endemism from modeled past, present, and future distributions in six clades of southern African bats from three families (Rhinolophidae, Cistugidae, and Vespertilionidae) having different crown ages (Pleistocene to Miocene) and biome affiliations (temperate to arid). We estimated mtDNA relaxed clock dates of key divergence events across the six clades in relation both to biogeographical features and patterns of phenotypic variation in crania, bacula and echolocation calls. In horseshoe bats (Rhinolophidae), both the western and eastern "arms" of the Escarpment have facilitated dispersals from the Afrotropics into southern Africa. Pleistocene and pre-Pleistocene "species pumps" and temperate refugia explained observed patterns of speciation, intraspecific divergence and, in two cases, mtDNA introgression. The Maloti-Drakensberg is a center of micro-endemism for bats, housing three newly described or undescribed species. Vicariance across biogeographic barriers gave rise to 29 micro-endemic species and intraspecific lineages whose distributions were congruent with those identified in other phytogeographic and zoogeographic studies. Although Köppen-Geiger climate models predict a widespread replacement of current temperate ecosystems in southern Africa by tropical or arid ecosystems by 2070-2100, future climate Maxent models for 13 bat species (all but one of those analyzed above) showed minimal range changes in temperate species from the eastern Escarpment by 2070, possibly due to the buffering effect of mountains to climate change.

Malaria elimination and the need for intensive inter-country cooperation. a critical evaluation of regional technical co-operation in Southern Africa.

BACKGROUND: Malaria elimination requires closely co-ordinated action between neighbouring countries. In Southern Africa several countries have reduced malaria to low levels, but the goal of elimination has eluded them thus far. The Southern Africa Development Community (SADC) Malaria Elimination Eight (E8) initiative was established in 2009 between Angola, Botswana, Eswatini, Mozambique, Namibia, South Africa, Zambia, and Zimbabwe to coordinate malaria interventions aiming to eliminate malaria by 2030. Cross-border coordination is important in malaria elimination settings as it strengthens surveillance, joint planning and implementation, knowledge exchange and optimal use of resources. This paper describes how this collaboration is realized in practice, its achievements and challenges, and its significance for malaria elimination prospects. METHODS: The ministers of health of the E8 countries oversee an intergovernmental technical committee supported by specialist working groups consisting of technical personnel from member countries and partner institutions. These technical working groups are responsible for malaria elimination initiatives in key focus areas such as surveillance, vector control, diagnosis, case management, behaviour change and applied research. The technical working groups have initiated and guided several collaborative projects which lay essential groundwork for malaria elimination. RESULTS: The E8 collaboration has yielded achievements in the following key areas. (1) Establishment and evaluation of malaria border health posts to improve malaria services in border areas and reduce malaria among resident and, mobile and migrant populations. (2) The development of a regional malaria microscopy slide bank providing materials for diagnostic training and proficiency testing. (3) A facility for regional external competency assessment and training of malaria microscopy trainers in collaboration with the World Health Organization. (4) Entomology fellowships that improved capacity in entomological surveillance; an indoor residual spraying (IRS) training of trainers' scheme to enhance the quality of this core intervention in the region. (5) Capacity development for regional malaria parasite genomic surveillance. (6) A mechanism for early detection of malaria outbreak through near real time reporting and a quarterly bulletins of malaria incidence in border districts. CONCLUSIONS: The E8 technical working groups system embodies inter-country collaboration of malaria control and elimination activities. It facilitates sustained interaction between countries through a regional approach. The groundwork for elimination has been laid, but the challenge will be to maintain funding for collaboration at this level whilst reducing reliance on international donors and to build capacities necessary to prepare for malaria elimination.

An abstract drawing from the 73,000-year-old levels at Blombos Cave, South Africa.

Depictive and abstract representations produced by drawing-known from Europe, Africa and Southeast Asia after 40,000 years ago-are a prime indicator of modern cognition and behaviour1. Here we report a cross-hatched pattern drawn with an ochre crayon on a ground silcrete flake recovered from approximately 73,000-year-old Middle Stone Age levels at Blombos Cave, South Africa. Our microscopic and chemical analyses of the pattern confirm that red ochre pigment was intentionally applied to the flake with an ochre crayon. The object comes from a level associated with stone tools of the Still Bay techno-complex that has previously yielded shell beads, cross-hatched engravings on ochre pieces and a variety of innovative technologies2-5. This notable discovery pre-dates the earliest previously known abstract and figurative drawings by at least 30,000 years. This drawing demonstrates the ability of early Homo sapiens in southern Africa to produce graphic designs on various media using different techniques.

Systematic review of cash plus or bundled interventions targeting adolescents in Africa to reduce HIV risk.

BACKGROUND: HIV remains a leading cause of death for adolescents and young people aged 10-24 years. HIV prevention requires multisectoral approaches that target adolescents and young people, addressing HIV risk pathways (e.g., transactional sex, gender-based violence, and school attendance) through bundled interventions that combine economic strengthening, health capabilities, and gender equality education. However, best practices are unknown because evidence on multisectoral programming targeted to adolescents and combining these components has not been systematically reviewed. METHODS: We conducted a systematic review to summarize the evidence on bundled interventions combining health and economic strengthening components for adolescents and young people and their effects on HIV/STI incidence and risk factors. We included studies from Africa published between 2005 and 2023, combining at least one economic strengthening and one health component, directed toward adolescents and young people aged 10-24 years. Included studies measured programmatic impacts on primary outcomes: HIV and STI incidence/prevalence; and mediators as secondary outcomes: sexual behaviours, sexual and reproductive health, school attendance, health-seeking behaviours, and violence. We conducted key word searches in PubMed, EMBASE, and Web of Science, imported titles/abstracts from the initial search, and reviewed them using the inclusion criteria. Full texts of selected articles were reviewed and information was extracted for analysis. Findings from the full texts identified were summarized. RESULTS: We reviewed 58 studies, including 43 quantitative studies and 15 qualitative studies, evaluating 26 unique interventions. A majority of studies reviewed were conducted in Eastern and Southern Africa. Interventions reviewed showed a greater number of significant results in improving economic outcomes; mental health and psychosocial outcomes; sexual and reproductive health knowledge and services utilization; and HIV prevention knowledge and testing. They showed fewer significant results in improving outcomes related to HIV incidence/prevalence; sexual risk behaviours; gender-based violence; gender attitudes; education; STI incidence, prevalence and testing; and sexual debut. CONCLUSIONS: Our review demonstrated the potential for bundled, multisectoral interventions for preventing HIV and facilitating safe transitions to adulthood. Findings have implications for designing HIV sensitive programmes on a larger scale, including how interventions may need to address multiple strata of the social ecological model to achieve success in the prevention of HIV and related pathways.

Reports of Pennellidae Burmeister, 1835 (Copepoda: Siphonostomatoida) post metamorphosed females off the coast of southern Africa.

Seven species belonging to Pennellidae are reported from marine teleosts caught off southern Africa. Additionally, complete re-descriptions are provided for Propeniculus stromatei and Sarcotretes scopeli. Examination of Lernaeenicus gonostomae, deposited in the Iziko South African Museum, indicated that it has the morphological features of Sarcotretes rather than Lernaeenicus and thus should be moved to Sarcotretes i.e. S. gonostomae n. comb. for which a re-description is also provided. Reports of new host records include those of Pennella instructa from Seriola lalandi; Propeniculus stromatei from Rhabdosargus holubi and Pomadasys commersonnii; Sarcotretes scopeli from Nansenia tenera, and Sarcotretes longirostris from Centrolophus niger. New geographical records include those of P. instructa, P. stromatei, S. scopeli, S. longirostris, and L. longiventris off southern Africa. Additionally, an attempt to estimate the evolutionary relationships amongst some genera is done from partial COI sequences deposited in Genbank.

Utilisation of indigenous knowledge to control gastrointestinal nematodes in Southern Africa.

Gastrointestinal nematodes (GIN) exacerbate the impact of droughts on the survival of cattle. The inadequacies of the conventional system make it increasingly important to explore indigenous knowledge (IK) to create drought-tolerant and GIN resilient herds. The objective of the study was to assess the indigenous strategies for controlling GIN during droughts. Face-to-face interviews with experts on IK were conducted to give insight into the importance, methods and ranking of GIN control. The experts identified 86 cattle that were used to test their assertions. The control methods used were identifying cattle that were susceptible to high GIN loads using predisposing factors, diagnosis of GIN burdens using faecal appearance, and treatment using phytotherapy. Experts ranked predisposing factors as the most critical control strategy and identified body condition, class, sex, coat colour, pregnancy status and lactation status as predisposing factors to high GIN burdens. Thin, older, dark-coloured cattle, as well as pregnant and lactating cows, were considered susceptible to GIN. However, pregnancy status, coat colour and sex were significantly associated with high GIN burdens. Cows were 2.6 times more likely to have high GIN burdens than bulls. Dark-coloured cattle were 3.5 times more likely to have high GIN burdens than light-coloured ones, and the likelihood of pregnant cows was 4.9 times higher than non-pregnant cows. A dark-coloured pregnant cow was extremely susceptible to high GIN burdens. In conclusion, knowledge of predisposing factors informs selection decisions when purchasing foundation stock. Cattle that are susceptible to high GIN loads are prioritised during droughts or culled where resources are scarce.

The future of HIV testing in eastern and southern Africa: Broader scope, targeted services.

In this Policy Forum, Anna Grimsrud and colleagues discuss the future of HIV testing in eastern and southern Africa, using insights gleaned from a 2021 expert consultation.

Bantu-speaker migration and admixture in southern Africa.

The presence of Early and Middle Stone Age human remains and associated archeological artifacts from various sites scattered across southern Africa, suggests this geographic region to be one of the first abodes of anatomically modern humans. Although the presence of hunter-gatherer cultures in this region dates back to deep times, the peopling of southern Africa has largely been reshaped by three major sets of migrations over the last 2000 years. These migrations have led to a confluence of four distinct ancestries (San hunter-gatherer, East-African pastoralist, Bantu-speaker farmer and Eurasian) in populations from this region. In this review, we have summarized the recent insights into the refinement of timelines and routes of the migration of Bantu-speaking populations to southern Africa and their admixture with resident southern African Khoe-San populations. We highlight two recent studies providing evidence for the emergence of fine-scale population structure within some South-Eastern Bantu-speaker groups. We also accentuate whole genome sequencing studies (current and ancient) that have both enhanced our understanding of the peopling of southern Africa and demonstrated a huge potential for novel variant discovery in populations from this region. Finally, we identify some of the major gaps and inconsistencies in our understanding and emphasize the importance of more systematic studies of southern African populations from diverse ethnolinguistic groups and geographic locations.