Lars Fehren-Schmitz

Native Americans experienced a strong population bottleneck coincident with European contact

The genetic and demographic impact of European contact with Native Americans has remained unclear despite recent interest. Whereas archeological and historical records indicate that European contact resulted in widespread mortality from various sources, genetic studies have found little evidence of a recent contraction in Native American population size. In this study we use a large dataset including both ancient and contemporary mitochondrial DNA to construct a high-resolution portrait of the Holocene and late Pleistocene population size of indigenous Americans. Our reconstruction suggests that Native Americans suffered a significant, although transient, contraction in population size some 500 y before the present, during which female effective size was reduced by ∼50%. These results support analyses of historical records indicating that European colonization induced widespread mortality among indigenous Americans.

Emerging genetic patterns of the european neolithic: Perspectives from a late neolithic bell beaker burial site in Germany

The transition from hunting and gathering to agriculture in Europe is associated with demographic changes that may have shifted the human gene pool of the region as a result of an influx of Neolithic farmers from the Near East. However, the genetic composition of populations after the earliest Neolithic, when a diverse mosaic of societies that had been fully engaged in agriculture for some time appeared in central Europe, is poorly known. At this period during the Late Neolithic (ca. 2,800-2,000 BC), regionally distinctive burial patterns associated with two different cultural groups emerge, Bell Beaker and Corded Ware, and may reflect differences in how these societies were organized. Ancient DNA analyses of human remains from the Late Neolithic Bell Beaker site of Kromsdorf, Germany showed distinct mitochondrial haplotypes for six individuals, which were classified under the haplogroups I1, K1, T1, U2, U5, and W5, and two males were identified as belonging to the Y haplogroup R1b. In contrast to other Late Neolithic societies in Europe emphasizing maintenance of biological relatedness in mortuary contexts, the diversity of maternal haplotypes evident at Kromsdorf suggests that burial practices of Bell Beaker communities operated outside of social norms based on shared maternal lineages. Furthermore, our data, along with those from previous studies, indicate that modern U5-lineages may have received little, if any, contribution from the Mesolithic or Neolithic mitochondrial gene pool.

Pre-Columbian population dynamics in coastal southern Peru: A diachronic investigation of mtDNA patterns in the Palpa region by ancient DNA analysis.

Alternative models have been proposed to explain the formation and decline of the south Peruvian Nasca culture, ranging from migration or invasion to autochthonous development and ecological crisis. To reveal to what extent population dynamic processes accounted for cultural development in the Nasca mainland, or were influenced by them, we analyzed ancient mitochondrial DNA of 218 individuals, originating from chronologically successive archaeological sites in the Palpa region, the Paracas Peninsula, and the Andean highlands in southern Peru. The sampling strategy allowed a diachronic analysis in a time frame from approximately 800 BC to 800 AD. Mitochondrial coding region polymorphisms were successfully analyzed and replicated for 130 individuals and control region sequences (np 16021-16408) for 104 individuals to determine Native American mitochondrial DNA haplogroups and haplotypes. The results were compared with ancient and contemporary Peruvian populations to reveal genetic relations of the archaeological samples. Frequency data and statistics show clear proximity of the Nasca populations to the populations of the preceding Paracas culture from Palpa and the Peninsula, and suggest, along with archaeological data, that the Nasca culture developed autochthonously in the Rio Grande drainage. Furthermore, the influence of changes in socioeconomic complexity in the Palpa area on the genetic diversity of the local population could be observed. In all, a strong genetic affinity between pre-Columbian coastal populations from southern Peru could be determined, together with a significant differentiation from ancient highland and all present-day Peruvian reference populations, best shown in the differential distribution of mitochondrial haplogroups.

Diachronic Investigations of Mitochondrial and Y‐Chromosomal Genetic Markers in Pre‐Columbian Andean Highlanders from South Peru

This study examines the reciprocal effects of cultural evolution, and population dynamics in pre‐Columbian southern Peru by the analysis of DNA from pre‐Columbian populations that lived in the fringe area between the Andean highlands and the Pacific coast. The main objective is to reveal whether the transition from the Middle Horizon (MH: 650–1000 AD) to the Late Intermediate Period (LIP: 1000–1400 AD) was accompanied or influenced by population dynamic processes. Tooth samples from 90 individuals from several archaeological sites, dating to the MH and LIP, in the research area were collected to analyse mitochodrial, and Y‐chromosomal genetic markers. Coding region polymorphisms were successfully analysed and replicated for 72 individuals, as were control region sequences for 65 individuals and Y‐chromosomal single nucleotide polymorphisms (SNPs) for 19 individuals, and these were compared to a large set of ancient and modern indigenous South American populations. The diachronic comparison of the upper valley samples from both time periods reveals no genetic discontinuities accompanying the cultural dynamic processes. A high genetic affinity for other ancient and modern highland populations can be observed, suggesting genetic continuity in the Andean highlands at the latest from the MH. A significant matrilineal differentiation to ancient Peruvian coastal populations can be observed suggesting a differential population history.

Ancient DNA reveals selection acting on genes associated with hypoxia response in pre-Columbian Peruvian Highlanders in the last 8500 years

Archaeological evidence shows that humans began living in the high altitude Andes approximately 12,000 years ago. Andean highlanders are known to have developed the most complex societies of pre-Columbian South America despite challenges to their health and reproductive success resulting from chronic exposure to hypoxia. While the physiological adaptations to this environmental stressor are well studied in contemporary Andean highlanders, the molecular evolutionary processes associated with such adaptations remain unclear. We aim to better understand how humans managed to demographically establish in this harsh environment by addressing a central question: did exposure to hypoxia drive adaptation via natural selection within Andean populations or did an existing phenotype –characterized by reduced susceptibility to hypoxic stress–enable human settlement of the Andes? We genotyped three variable loci within the NOS3 and EGLN1 genes previously associated with adaptation to high altitude in 150 ancient human DNA samples from Peruvian high altitude and coastal low altitude sites in a time frame between ~8500–560 BP. We compare the data of 109 successful samples to forward simulations of genetic drift with natural selection and find that selection, rather than drift, explains the gradual frequency changes observed in the highland populations for two of the three SNPs.

Molecular characterization of ABO blood group frequencies in pre-Columbian Peruvian highlanders

The majority of Native Americans nearly exclusively belong to group O of the ABO blood group system. Several hypotheses have been formulated to explain this observation, primarily differing by the presumption that the observed patterns of ABO diversity are due to the processes of the initial peopling of the Americas or due to subsequent events, especially the demographic consequences in the wake of European contact. A promising strategy to reveal possible diachronic ABO frequency changes is the molecular genetic analysis of relevant genetic markers in precontact populations. A previous study by Halverson and Bolnick [Am J Phys Anthropol 137 (2008) 342-347] already accomplished this for indigenous North American populations. Here we present the first study to analyze ABO blood types from pre-Columbian individuals from South America using molecular genetic methods and comparing them to several extant South American, North American, and Siberian populations. We tried to determine ABO blood types for 59 individuals from the southern Peruvian highlands dating to ~650 to 1250 AD using a newly developed multiplex PCR/SBE assay coamplifying the fragments relevant for blood type determination and three highly discriminating autosomal STRs. Analysis was successful for 31 individuals and revealed that all are exclusively in the O group, predominantly carrying the O02 (01v) allele. No significant difference could be observed between the ancient and modern Native American populations, while all significantly differed from the extant Siberian populations, supporting the suggestion that low ABO diversity results from founder effects during the initial peopling of the Americas.

Who Were the Nasca? Population Dynamics in Pre-Columbian Southern Peru Revealed by Ancient DNA Analyses

Through the analysis of ancient DNA from human mortal remains it is possible to gain access to a biohistoric archive containing relevant information about the structure of prehistoric populations. The data obtained help to answer questions related to migration processes and population relationships that could not be answered by the methods of cultural science alone. The aim of this study was to show to what extent the cultural evolution of the southern Peruvian Palpa area was accompanied by processes of population exchange. Bone and tooth samples of over 200 individuals from prehistoric burial grounds from southern Peru were collected and examined with the methods of ancient DNA analysis. The study focuses on the matrilineal population dynamics by the analysis of mitochondrial genetic markers. Mitochondrial haplogroups and types could be successfully determined for over 100 individuals from different archaeological periods. The obtained data were compared with mitochondrial data from recent Native American populations. The results allow us to describe to what extent cultural changes were influenced by allochthonous contributions to the gene pool and how changes in the socioecological complexity of the cultures affected the genetic composition of the Palpa valley population. Also, a significant differentiation of ancient coastal and highland populations in southern Peru is detectable as are changes in the mitochondrial haplogroup distribution patterns as a result of the emergence of the extensive highland empires in later South American prehistory.

Brief communication: Evidence of Bartonella quintana infections in skeletons of a historical mass grave in Kassel, Germany

In 2008, a mass grave was found on the grounds of the University of Kassel, Germany. Historians hypothesized that the individuals died in a typhoid fever epidemic in winter 1813/14. To test this hypothesis, the bones were investigated on the presence of specific DNA of pathogens linked to the historical diagnosis oftyphoid fever. It was possible to prove the specific DNA of Bartonella quintana in three individuals, suggesting that their cause of death is linked to an epidemic background.

Population dynamics, cultural evolution and climate change in pre-Columbian western South America

This paper reports on an archaeogenetic study that was embedded in a transdiciplinary research project with the principal aim of understanding the cultural development in pre-Columbian Southern Peru. Ancient DNA analyses were conducted on over 300 pre-Columbian individuals from various archaeological sites in coastal Southern Peru and the Andean highlands, from periods ranging from the middle Formative Period (approx. 1000 BC) to the end of the Late Intermediate Period (approx. AD 1400). The data obtained were compared against a large set of data on contemporary and ancient South American populations to reveal biological affinities across the southern Andes and, more broadly, on the continental level, and contextualized with the archaeological and palaeoecological record. The results, albeit preliminary, shed light on populationdynamic processes accompanying cultural transformations in several archaeological periods. Changes in socioeconomic complexity and ecological alterations seem to have influenced migrational behaviour and the genetic diversity of the prehistoric central Andean populations. On the continental scale the results point to a discrete initial peopling of the western South American coast and the Andean highlands.