Ancient genetic landscape of archaeological human remains from Panama, South America and Oceania described through STR genotype frequencies and mitochondrial DNA sequences
von Mélida Inés Núñez Castillo
Datum der mündl. Prüfung:2021-11-30
Erschienen:2021-12-20
Betreuer:Dr. Susanne Hummel
Gutachter:Prof. Dr. Peter M. Kappeler
Gutachter:Prof. Dr. Julia Ostner
Dateien
Name:Núñez Castillo Mélida Inés.pdf
Size:33.8Mb
Format:PDF
Description: Dissertation
Zusammenfassung
Englisch
The settlements of the Americas and Oceania are particularly fascinating topics. On the one side is the settlements of Australia and New Guinea (30,000 – 50,000 years ago) were the scenarios of one of the earliest migration events carried out by modern humans after left Africa, while Polynesia around 3,000 years ago was the stage of the last major colonization event. Regarding America, despite broad agreement that the Americas were initially populated via Bering, during the Upper Pleistocene 14,600 years ago, it is still a topic controversial, mysterious, shifting, and continuously conflictive as the Ice Age archaeology of the Americas, since, the dates and routes of the peopling of the Americas remain unresolved. Thus, ancient DNA studies on archaeological human remains from Oceania and America are useful to explore the genetic history of these human groups. Given that Near Oceania colonization was the endpoint of one of the earliest Out-of-Africa migrations about 50,000 years ago, and the islands of East Polynesia were the last region of the world to be colonized by humans approximately 1,000 years ago. Whilst, in America, one of the most contentious issues is whether the settlement occurred by means of a single migration or migration streams of migrations from Siberia. Because the gene flow is an important mechanism that contributes to genetic diversity among populations, the presence or absence of certain haplogroups changes the distribution of genetic diversity within populations. Thus, to understand the population dynamics of Oceanians and American peoples before European contact, it was necessary to describe the grade of nuclear and mitochondrial DNA genetic variation. One hundred twenty-five paleo-anthropological remains were analysed via genotyping of six short tandem repeats (STR) markers (nuclear DNA). Moreover, the genetic variation, inferences of demographic histories and clustering trends of these samples were evaluated through the hypervariable segment I (HVSI) of mitochondrial DNA (mtDNA). 35% of the archaeological remains analysed were genotyped successfully. Mitochondrial genetic diversity observed in Oceanian, South American and Panamanian samples reflected the genetic drift effects on these individuals through the founder effect, which happened during Upper Pleistocene when the modern humans reached these regions for the first time. The inferences of historical demographic patterns suggest that ancient individuals from Oceania went through population expansion about 37,972 years ago, which is consistent with the initial colonization of Melanesia. Whilst, ancient individuals from South America and Panama went through population expansions about 14,150 and 9,468 years ago, respectively, correspond to the initial settlement of America during the Upper Pleistocene. The clustering patterns showed that ancient individuals from Bismark Archipelago and Papua New Guinea, and the ancient individuals from New Zealand and Samoa exhibited greater affinity with each other. The cluster branch of America exhibited genetic affinities between ancient Panamanian and South American samples, probably resulted from a migratory event, along the Pacific North Coast, from North America to South America that took place between the Middle and the Upper Holocene.
Keywords: aDNA; Panama; South America; Oceania; migration; population genetics; DNA typing; mitochondrial lineages; genetic landscapes