Percorrer por autor "Manthi, Fredrick Kyalo"
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- Ancient DNA and deep population structure in sub-Saharan African foragersPublication . Lipson, Mark; Sawchuk, Elizabeth A.; Thompson, Jessica C.; Oppenheimer, Jonas; Tryon, Christian A.; Ranhorn, Kathryn L.; de Luna, Kathryn M.; Sirak, Kendra A.; Olalde, Iñigo; Ambrose, Stanley H.; Arthur, John W.; Arthur, Kathryn J. W.; Ayodo, George; Bertacchi, Alex; Cerezo-Román, Jessica I.; Culleton, Brendan J.; Curtis, Matthew C.; Davis, Jacob; Gidna, Agness O.; Hanson, Annalys; Kaliba, Potiphar; Katongo, Maggie; Kwekason, Amandus; Laird, Myra F.; Lewis, Jason; Mabulla, Audax Z. P.; Mapemba, Fredrick; Morris, Alan; Mudenda, George; Mwafulirwa, Raphael; Mwangomba, Daudi; Ndiema, Emmanuel; Ogola, Christine; Schilt, Flora; Willoughby, Pamela R.; Wright, David K.; Zipkin, Andrew; Pinhasi, Ron; Kennett, Douglas J.; Manthi, Fredrick Kyalo; Rohland, Nadin; Patterson, Nick; Reich, David; Prendergast, Mary E.Multiple lines of genetic and archaeological evidence suggest that there were major demographic changes in the terminal Late Pleistocene epoch and early Holocene epoch of sub-Saharan Africa(1-4). Inferences about this period are challenging to make because demographic shifts in the past 5,000 years have obscured the structures of more ancient populations(3,5). Here we present genome-wide ancient DNA data for six individuals from eastern and south-central Africa spanning the past approximately 18,000 years (doubling the time depth of sub-Saharan African ancient DNA), increase the data quality for 15 previously published ancient individuals and analyse these alongside data from 13 other published ancient individuals. The ancestry of the individuals in our study area can be modelled as a geographically structured mixture of three highly divergent source populations, probably reflecting Pleistocene interactions around 80-20 thousand years ago, including deeply diverged eastern and southern African lineages, plus a previously unappreciated ubiquitous distribution of ancestry that occurs in highest proportion today in central African rainforest hunter-gatherers. Once established, this structure remained highly stable, with limited long-range gene flow. These results provide a new line of genetic evidence in support of hypotheses that have emerged from archaeological analyses but remain contested, suggesting increasing regionalization at the end of the Pleistocene epoch. DNA analysis of 6 individuals from eastern and south-central Africa spanning the past approximately 18,000 years, and of 28 previously published ancient individuals, provides genetic evidence supporting hypotheses of increasing regionalization at the end of the Pleistocene.
- The late pliocene to early pleistocene lomekwi faunas, west Turkana, Kenya: systematics, paleoecology, and biochronologyPublication . Geraads, Denis; Bobe, René; Ward, Carol V.; Plavcan, J. Michael; Manthi, Fredrick KyaloWe describe here the vertebrate fauna collected by the West Turkana Paleo Project at Lomekwi, a site best known for yielding the holotype of Kenyanthropus platyops and Lomekwian stone tools, and consisting of several collecting areas providing fossil samples ranging in age from about 3.6 to 2.2 Ma. Analysis of the newly recovered material, alongside a thorough revision of earlier collections, has led to the identification of 85 vertebrate taxa, which provide biochronological indications that help refine the site's chronology and shed light on the paleoenvironmental conditions prevailing during a critical period of early hominin diversification. The newly described fauna illustrates that during the time of Kenyanthropus, hominins shared their landscapes with a rich assemblage of vertebrates, including abundant megaherbivores, some 28 species of artiodactyls, diverse large and medium-size carnivores, and giant crocodiles as apex predators in the lakes and rivers of the Turkana region in the Pliocene. Among primates, the recurring association of Theropithecus with hominins is found at Lomekwi as it is elsewhere. Paleoenvironmental proxies from the Turkana region emphasize the complex and dynamic nature of the habitats that supported this rich biodiversity.
- The ecology of Australopithecus anamensis in the early Pliocene of Kanapoi, KenyaPublication . Bobe, Rene; Manthi, Fredrick Kyalo; Ward, Carol, V; Plavcan, J. Michael; Carvalho, SusanaAustralopithecus anamensis is a pivotal species in human evolution. It is likely to be the direct ancestor of Australopithecus afarensis and the species that may have given rise to the Homo and Paranthropus lineages. It had a suite of adaptations for habitual bipedalism and a diet that differed from that of earlier hominin species. Under what environmental and ecological conditions did this suite of adaptations arise? The early Pliocene site of Kanapoi in the Lake Turkana Basin of Kenya has the largest sample of A. anamensis in eastern Africa and a rich record of fossil vertebrates. Most Kanapoi fossils are chronologically well constrained by radiometrically dated tephras between the ages of 4.2 and 4.1 million years ago. Sedimentological, isotopic, and faunal data indicate that the environments of Kanapoi during the early Pliocene had a complex range of vegetation types that included closed woodlands, shrubs, and grasslands near a river (for most of the sequence) or lake. These were dynamic landscapes that could shift rapidly from fluvial to lacustrine conditions, and then back. Australopithecus anamensis shared its environments with at least 10 species of very large herbivores, which undoubtedly played a major role in modifying the landscape by opening wooded areas and providing pathways for bipedal hominins. Hominins may have competed for terrestrial resources with abundant suids (Nyanzachoerus and Notochoerus) and for arboreal resources with monkeys (Parapapio being the most common cercopithecid). Kanapoi had a formidable group of predators that included a very abundant species of hyena (Parahyaena howelli), two sabre-tooth felids (Dinofelis and Homotherium), a giant otter (Enhydriodon cf. dikikae), and three species of crocodiles. Various measures of abundance indicate that A. anamensis was an important component of the Kanapoi early Pliocene ecosystems, and that its key adaptations allowed this species to thrive in complex and dynamic landscapes. (C) 2019 Elsevier Ltd. All rights reserved.