SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Jakobsson Mattias) ;pers:(Lombard Marlize)"

Sökning: WFRF:(Jakobsson Mattias) > Lombard Marlize

  • Resultat 1-9 av 9
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Breton, Gwenna, et al. (författare)
  • Lactase Persistence Alleles Reveal Partial East African Ancestry of Southern African Khoe Pastoralists
  • 2014
  • Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 24:8, s. 852-858
  • Tidskriftsartikel (refereegranskat)abstract
    • The ability to digest milk into adulthood, lactase persistence (LP), as well as specific genetic variants associated with LP, is heterogeneously distributed in global populations [1-4]. These variants were most likely targets of selection when some populations converted from hunter-gatherer to pastoralist or farming lifestyles [5-7]. Specific LP polymorphisms are associated with particular geographic regions and populations [1-4, 8-10]; however, they have not been extensively studied in southern Africa. We investigate the LP-regulatory region in 267 individuals from 13 southern African populations (including descendants of hunter-gatherers, pastoralists, and agropastoralists), providing the first comprehensive study of the LP-regulatory region in a large group of southern Africans. The "East African" LP single-nucleotide polymorphism (SNP) (14010G>C) was found at high frequency (>20%) in a strict pastoralist Khoe population, the Nama of Namibia, suggesting a connection to East Africa, whereas the "European" LP SNP (13910C>T) was found in populations of mixed ancestry. Using genome-wide data from various African populations, we identify admixture (13%) in the Nama, from an Afro-Asiatic group dating to >1,300 years ago, with the remaining fraction of their genomes being from San hunter-gatherers. We also find evidence of selection around the LCT gene among Khoe-speaking groups, and the substantial frequency of the 14010C variant among the Nama is best explained by adaptation to digesting milk. These genome-local and genome-wide results support a model in which an East African group brought pastoralist practices to southern Africa and admixed with local hunter-gatherers to form the ancestors of Khoe people.
  •  
2.
  • Coutinho, Alexandra, et al. (författare)
  • Later Stone Age human hair from Vaalkrans Shelter, Cape Floristic Region of South Africa, reveals genetic affinity to Khoe groups
  • 2021
  • Ingår i: American Journal of Physical Anthropology. - : John Wiley & Sons. - 0002-9483 .- 1096-8644. ; 174:4, s. 701-713
  • Tidskriftsartikel (refereegranskat)abstract
    • Previous studies show that the indigenous people of the southern Cape of South Africa were dramatically impacted by the arrival of European colonists starting ~400 years ago and their descendants are today mixed with Europeans and Asians. To gain insight on the occupants of the Vaalkrans Shelter located at the southernmost tip of Africa, we investigated the genetic make-up of an individual who lived there about 200 years ago. We further contextualize the genetic ancestry of this individual among prehistoric and current groups. From a hair sample excavated at the shelter, which was indirectly dated to about 200 years old, we sequenced the genome (1.01 times coverage) of a Later Stone Age individual. We analyzed the Vaalkrans genome together with genetic data from 10 ancient (pre-colonial) individuals from southern Africa spanning the last 2000 years. We show that the individual from Vaalkrans was a man who traced ~80% of his ancestry to local southern San hunter–gatherers and ~20% to a mixed East African-Eurasian source. This genetic make-up is similar to modern-day Khoekhoe individuals from the Northern Cape Province (South Africa) and Namibia, but in the southern Cape, the Vaalkrans man's descendants have likely been assimilated into mixed-ancestry “Coloured” groups. The Vaalkrans man's genome reveals that Khoekhoe pastoralist groups/individuals lived in the southern Cape as late as 200 years ago, without mixing with non-African colonists or Bantu-speaking farmers. Our findings are also consistent with the model of a Holocene pastoralist migration, originating in Eastern Africa, shaping the genomic landscape of historic and current southern African populations.
  •  
3.
  •  
4.
  • Lombard, Marlize, et al. (författare)
  • Genetic data and radiocarbon dating question Plovers Lake as a Middle Stone Age hominin-bearing site
  • 2019
  • Ingår i: Journal of Human Evolution. - : Elsevier. - 0047-2484 .- 1095-8606. ; 131, s. 203-209
  • Tidskriftsartikel (refereegranskat)abstract
    • We have sampled five out of the eleven previously identified human specimens and some faunal remains from the Plovers Lake site in the Cradle of Humankind, South Africa, for ancient DNA. We were successful in obtaining positive results for three of the human individuals and three 'buffalo' teeth. Based on ages obtained for flowstone and one bovid tooth, the site was interpreted previously as a hominin-bearing Middle Stone Age site of more than 60 000 years old. Our work, however, revealed that not all the material accumulated during the Pleistocene. Instead, the sampled humans and bovids most likely represent a Bantu-speaking Iron Age population (mtDNA haplogroup L3d) and their Nguni cattle. Newly obtained radiocarbon dates confirmed that these remains are probably no older than the last 500 years bp. This study demonstrates the usefulness of inter-disciplinary investigation into the human past, and the depositional and stratigraphic complexities that researchers in the Cradle of Humankind need to contend with before interpreting their assemblages.
  •  
5.
  •  
6.
  • Rifkin, Riaan F. F., et al. (författare)
  • Rickettsia felis DNA recovered from a child who lived in southern Africa 2000 years ago
  • 2023
  • Ingår i: Communications Biology. - : Springer Nature. - 2399-3642. ; 6
  • Tidskriftsartikel (refereegranskat)abstract
    • The Stone Age record of South Africa provides some of the earliest evidence for the biological and cultural origins of Homo sapiens. While there is extensive genomic evidence for the selection of polymorphisms in response to pathogen-pressure in sub-Saharan Africa, e.g., the sickle cell trait which provides protection against malaria, there is inadequate direct human genomic evidence for ancient human-pathogen infection in the region. Here, we analysed shotgun metagenome libraries derived from the sequencing of a Later Stone Age hunter-gatherer child who lived near Ballito Bay, South Africa, c. 2000 years ago. This resulted in the identification of ancient DNA sequence reads homologous to Rickettsia felis, the causative agent of typhus-like flea-borne rickettsioses, and the reconstruction of an ancient R. felis genome.
  •  
7.
  • Schlebusch, Carina, 1977-, et al. (författare)
  • Khoe-San Genomes Reveal Unique Variation and Confirm the Deepest Population Divergence in Homo sapiens
  • 2020
  • Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 37:10, s. 2944-2954
  • Tidskriftsartikel (refereegranskat)abstract
    • The southern African indigenous Khoe-San populations harbor the most divergent lineages of all living peoples. Exploring their genomes is key to understanding deep human history. We sequenced 25 full genomes from five Khoe-San populations, revealing many novel variants, that 25% of variants are unique to the Khoe-San, and that the Khoe-San group harbors the greatest level of diversity across the globe. In line with previous studies, we found several gene regions with extreme values in genome-wide scans for selection, potentially caused by natural selection in the lineage leading to Homo sapiens and more recent in time. These gene regions included immunity-, sperm-, brain-, diet-, and muscle-related genes. When accounting for recent admixture, all Khoe-San groups display genetic diversity approaching the levels in other African groups and a reduction in effective population size starting around 100,000 years ago. Hence, all human groups show a reduction in effective population size commencing around the time of the Out-of-Africa migrations, which coincides with changes in the paleoclimate records, changes that potentially impacted all humans at the time.
  •  
8.
  • Schlebusch, Carina M., et al. (författare)
  • The disappearing San of southeastern Africa and their genetic affinities
  • 2016
  • Ingår i: Human Genetics. - : Springer Science and Business Media LLC. - 0340-6717 .- 1432-1203. ; 135:12, s. 1365-1373
  • Tidskriftsartikel (refereegranskat)abstract
    • Southern Africa was likely exclusively inhabited by San hunter-gatherers before similar to 2000 years ago. Around that time, East African groups assimilated with local San groups and gave rise to the Khoekhoe herders. Subsequently, Bantu-speaking farmers, arriving from the north (similar to 1800 years ago), assimilated and displaced San and Khoekhoe groups, a process that intensified with the arrival of European colonists similar to 350 years ago. In contrast to the western parts of southern Africa, where several Khoe-San groups still live today, the eastern parts are largely populated by Bantu speakers and individuals of non-African descent. Only a few scattered groups with oral traditions of Khoe-San ancestry remain. Advances in genetic research open up new ways to understand the population history of southeastern Africa. We investigate the genomic variation of the remaining individuals from two South African groups with oral histories connecting them to eastern San groups, i.e., the San from Lake Chrissie and the Duma San of the uKhahlamba-Drakensberg. Using similar to 2.2 million genetic markers, combined with comparative published data sets, we show that the Lake Chrissie San have genetic ancestry from both Khoe-San (likely the parallel to Xegwi San) and Bantu speakers. Specifically, we found that the Lake Chrissie San are closely related to the current southern San groups (i.e., the Karretjie people). Duma San individuals, on the other hand, were genetically similar to southeastern Bantu speakers from South Africa. This study illustrates how genetic tools can be used to assess hypotheses about the ancestry of people who seemingly lost their historic roots, only recalling a vague oral tradition of their origin.
  •  
9.
  • Schlebusch, Carina, 1977-, et al. (författare)
  • Southern African ancient genomes estimate modern human divergence to 350,000 to 260,000 years ago
  • 2017
  • Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 358:6363, s. 652-655
  • Tidskriftsartikel (refereegranskat)abstract
    • Southern Africa is consistently placed as a potential region for the evolution of Homo sapiens We present genome sequences, up to 13x coverage, from seven ancient individuals from KwaZulu-Natal, South Africa. The remains of three Stone Age hunter-gatherers (about 2000 years old) were genetically similar to current-day southern San groups, and those of four Iron Age farmers (300 to 500 years old) were genetically similar to present-day Bantu-language speakers. We estimate that all modern-day Khoe-San groups have been influenced by 9 to 30% genetic admixture from East Africans/Eurasians. Using traditional and new approaches, we estimate the first modern human population divergence time to between 350,000 and 260,000 years ago. This estimate increases the deepest divergence among modern humans, coinciding with anatomical developments of archaic humans into modern humans, as represented in the local fossil record.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-9 av 9

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy