Biology subjects

Malmström, H.

Publications and source records attributed to Malmström, H..

4 recordsLinked to original sources

bioRxiv2025

Ancestry, admixture, and pathogens in contemporaneous Neolithic farmers and foragers on the Island of Gotland

Two archaeological cultural complexes coexisted on Gotland for over 500 years, between [~]3300 and 2800 calBCE, i.e. the Neolithic Funnelbeaker culture (FBC), and the Pitted ware culture (PWC). The ancestry of the FBC farmers and PWC marine foragers largely aligns with European Neolithic Farmers and European Mesolithic foragers, respectively, but the direct interactions between the groups on Gotland is not understood. We present a Middle Neolithic (MN) high-coverage genome and a Late Neolithic (LN) low-coverage genome from the Ansarve FBC dolmen. We investigate ancestry, admixture, and pathogens among these MN farmers (n =6), foragers (n=19), and a LN individual. We find that recent gene-flow between farmers and foragers could have taken place, although most gene-flow happened prior to their coexistence on the island. We also find evidence of different Yersinia pestis strains in the three cultural groups, showing that the pestis was widespread among groups with different subsistence strategies.

genomics↗

bioRxiv2024

READv2: Advanced and user-friendly detection of biological relatedness in archaeogenomics

The possibility to obtain genome-wide ancient DNA data from multiple individuals has facilitated an unprecedented perspective into prehistoric societies. Studying biological relatedness in these groups requires tailored approaches for analyzing ancient DNA due to its low coverage, post-mortem damage, and potential ascertainment bias. Here we present READv2 (Relatedness Estimation from Ancient DNA version 2), an improved Python 3 re-implementation of the most widely used tool for this purpose. While providing increased portability and making the software future-proof, we are also able to show that READv2 (a) is orders of magnitude faster than its predecessor; (b) has increased power to detect pairs of relatives using optimized default parameters; and, when the number of overlapping SNPs is sufficient, (c) can differentiate between full-siblings and parent-offspring, and (d) can classify pairs of third-degree relatedness. We further use READv2 to analyze a large empirical dataset that has previously needed two separate tools to reconstruct complex pedigrees. We show that READv2 yields results and precision similar to the combined approach but is faster and simpler to run. READv2 will become a valuable part of the archaeogenomic toolkit in providing an efficient and user-friendly classification of biological relatedness from pseudohaploid ancient DNA data.

bioinformatics↗

bioRxiv2017

Genomics of Mesolithic Scandinavia reveal colonization routes and high-latitude adaptation

Scandinavia was one of the last geographic areas in Europe to become habitable for humans after the last glaciation. However, the origin(s) of the first colonizers and their migration routes remain unclear. We sequenced the genomes, up to 57x coverage, of seven hunter-gatherers excavated across Scandinavia and dated to 9,500-6,000 years before present. Surprisingly, among the Scandinavian Mesolithic individuals, the genetic data display an east-west genetic gradient that opposes the pattern seen in other parts of Mesolithic Europe. This result suggests that Scandinavia was initially colonized following two different routes: one from the south, the other from the northeast. The latter followed the ice-free Norwegian north Atlantic coast, along which novel and advanced pressure-blade stone-tool techniques may have spread. These two groups met and mixed in Scandinavia, creating a genetically diverse population, which shows patterns of genetic adaptation to high latitude environments. These adaptations include high frequencies of low pigmentation variants and a gene-region associated with physical performance, which shows strong continuity into modern-day northern Europeans.

genomics↗

bioRxiv2017

Ancient genomes from southern Africa pushes modern human divergence beyond 260,000 years ago

Southern Africa is consistently placed as one of the potential regions for the evolution of Homo sapiens. To examine the regions human prehistory prior to the arrival of migrants from East and West Africa or Eurasia in the last 1,700 years, we generated and analyzed genome sequence data from seven ancient individuals from KwaZulu-Natal, South Africa. Three Stone Age hunter-gatherers date to ~2,000 years ago, and we show that they were related to current-day southern San groups such as the Karretjie People. Four Iron Age farmers (300-500 years old) have genetic signatures similar to present day Bantu-speakers. The genome sequence (13x coverage) of a juvenile boy from Ballito Bay, who lived ~2,000 years ago, demonstrates that southern African Stone Age hunter-gatherers were not impacted by recent admixture; however, we estimate that all modern-day Khoekhoe and San groups have been influenced by 9-22% genetic admixture from East African/Eurasian pastoralist groups arriving >1,000 years ago, including the Ju| hoansi San, previously thought to have very low levels of admixture. Using traditional and new approaches, we estimate the population divergence time between the Ballito Bay boy and other groups to beyond 260,000 years ago. These estimates dramatically increases the deepest divergence amongst modern humans, coincide with the onset of the Middle Stone Age in sub-Saharan Africa, and coincide with anatomical developments of archaic humans into modern humans as represented in the local fossil record. Cumulatively, cross-disciplinary records increasingly point to southern Africa as a potential (not necessarily exclusive) hot spot for the evolution of our species.

evolutionary biology↗