African Diasporan Genetic, Haplogroups, Ancestry, etc Thread

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Historical DNA Study Connects Living People to Enslaved and Free African Americans at Early Ironworks

Genetic analysis offers new way to reveal relationships, help restore ancestral histories

hms.harvard.edu

*Summary

Historical DNA Study Connects Living People to Enslaved and Free African Americans at Early Ironworks​

Genetic analysis offers new way to reveal relationships, help restore ancestral histories​

By STEPHANIE DUTCHEN August 3, 2023

Site of Catoctin Furnace in Cunningham Falls State Park, Maryland. Image: Aneta Kaluzna


At a glance:

• DNA analysis of African Americans buried at an early U.S. iron forge reveals locations of their African and European ancestors and finds more than 40,000 living U.S. relatives.
• The study — led by Harvard University, the Smithsonian Institution, and 23andMe — is the first to link up ancient DNA technology with a personal ancestry testing database and use a new method for determining genetic relationships.
• The work, which followed rigorous ethical guidelines, was inspired by groups seeking to restore ancestry knowledge to African American communities

 

[The Wall Is Undefeated!]

Historical DNA Study Connects Living People to Enslaved and Free African Americans at Early Ironworks

Genetic analysis offers new way to reveal relationships, help restore ancestral histories

hms.harvard.edu

*Summary

Historical DNA Study Connects Living People to Enslaved and Free African Americans at Early Ironworks​

Genetic analysis offers new way to reveal relationships, help restore ancestral histories​

By STEPHANIE DUTCHEN August 3, 2023

Site of Catoctin Furnace in Cunningham Falls State Park, Maryland. Image: Aneta Kaluzna


At a glance:

• DNA analysis of African Americans buried at an early U.S. iron forge reveals locations of their African and European ancestors and finds more than 40,000 living U.S. relatives.
• The study — led by Harvard University, the Smithsonian Institution, and 23andMe — is the first to link up ancient DNA technology with a personal ancestry testing database and use a new method for determining genetic relationships.
• The work, which followed rigorous ethical guidelines, was inspired by groups seeking to restore ancestry knowledge to African American communities

Awesome.

 

[get these nets]

​

 

[The Wall Is Undefeated!]

Shout out to the Malagasy (Blasians)

Genomic landscape of human diversity across Madagascar

Significance
The origins of the Malagasy raise questions about ancient connections between continents; moreover, because ancestors are fundamental to Malagasy society, Malagasy origins is also a heated topic around the country, with numerous proposed hypotheses. This study provides a comprehensive view of genomic diversity (including maternal lineages, paternal lineages, and genome-wide data) based on a sampling of 257 villages across Madagascar. The observed spatial patterns lead to a scenario of a recent and sex-biased admixture between Bantu and Austronesian ancestors across the island. Moreover, we find geographical influences creating subtle signals of genetic structure that are independent of the Bantu/Austronesian admixture, suggesting that recent history has a role in the genomic diversity of the Malagasy.

Abstract
Although situated ∼400 km from the east coast of Africa, Madagascar exhibits cultural, linguistic, and genetic traits from both Southeast Asia and Eastern Africa. The settlement history remains contentious; we therefore used a grid-based approach to sample at high resolution the genomic diversity (including maternal lineages, paternal lineages, and genome-wide data) across 257 villages and 2,704 Malagasy individuals. We find a common Bantu and Austronesian descent for all Malagasy individuals with a limited paternal contribution from Europe and the Middle East. Admixture and demographic growth happened recently, suggesting a rapid settlement of Madagascar during the last millennium. However, the distribution of African and Asian ancestry across the island reveals that the admixture was sex biased and happened heterogeneously across Madagascar, suggesting independent colonization of Madagascar from Africa and Asia rather than settlement by an already admixed population. In addition, there are geographic influences on the present genomic diversity, independent of the admixture, showing that a few centuries is sufficient to produce detectable genetic structure in human populations.

Pie chart A shows Maternal Ancestry (Mt-DNA). Pie chart B shows Paternal Ancestry (Y-DNA)

TAs expected... for the most part:

Overall, Y chromosome lineages of African origin are much more frequent in Madagascar than are lineages of East Asian origin (70.7 vs. 20.7%), in contrast to the mtDNA lineages (42.4 African origin vs. 50.1% East Asian origin) (Fig. 2B and Fig. S1). Other Y chromosome lineages with uncertain origins are also present; some of these (R1a, J2, T1, G2) are also present in the Middle East and may reflect the Muslim influence on Madagascar and the Comoros (23, 24). Haplogroup R1b, characteristic of western Europeans, is present in low frequency (0.9%), suggesting a limited paternal contribution from western Europeans.

Admixture analyses (25) of the genome-wide data, based on various datasets (Dataset S1), confirm Southeast Asian and East African Bantu groups as the major contributors and exclude any major influence from other parts of the world (Fig. 3). Admixture results at k = 3 from the high-density panel produced a clear distinction between African, East Asian, and West Eurasian populations, permitting us to estimate the frequency of each ancestry component across Madagascar (Fig. S2). On average, the African component is 59.4 ± 0.4%, and the Asian component is 36.6 ± 0.4%, whereas the West-Eurasian component is only 3.9 ± 0.1%. All studied individuals present a similar pattern associating African and East Asian components, but with considerable variation (with African ancestry ranging from 26.1 to 92.6%).

@get these nets , @DrBanneker , @Soldier , @Waldo Geraldo Faldo , @Ty Daniels , @nullnullnullnull

 

[DrBanneker]

Shout out to the Malagasy (Blasians)

Genomic landscape of human diversity across Madagascar

Pie chart A shows Maternal Ancestry (Mt-DNA). Pie chart B shows Paternal Ancestry (Y-DNA)

TAs expected... for the most part:




@get these nets , @DrBanneker , @Soldier , @Waldo Geraldo Faldo , @Ty Daniels , @nullnullnullnull

Interesting. I had read an older article claiming sex contribution from Africans and Asians was relatively unbiased. Maybe the new data is better?

 

[The Wall Is Undefeated!]

Ancient DNA Studies and African Population History

In the last three decades, genetics played an increasingly important role in the inference of human history. Genetic studies provided conclusive information that helped to answer challenging questions, such as the “Out of Africa” migration of modern humans. Moreover, genetics helped to establish Africa as the birthplace of anatomically modern humans. The history of human populations in Africa is complex and includes various demographic events that influenced patterns of genetic variation across the continent. Several studies based on mitochondrial DNA, Y-chromosomes, autosomal markers, whole genomes and ancient DNA, contributed to unraveling the genetic sub-structure of African populations. Through these genetic studies of modern-day, and most recently, ancient African genetic variation, it became evident the deepest population split among modern humans was between southern African Khoe-San populations and other African groups, while the central African rainforest hunter-gatherer groups diverged subsequently from the common human lineage. Furthermore, it was shown that agriculture had a large influence on the distribution of current-day Africans and that West African agriculturist populations populated the whole of sub-Saharan Africa, replacing and/or assimilating former groups. Other farming groups from Northeast Africa, speaking Nilo-Saharan and Afro-Asiatic languages, admixed with Eurasian groups and also expanded southwards. They settled in East Africa and migrated as far as southern Africa where they admixed with San hunter-gatherer ancestors to form the Khoekhoe herding groups. These later population movements disrupted pre-existing population distributions and complicate inferences regarding deep human history. With the increased availability of full genomic data from diverse modern-day African populations and prehistoric Africans, we will have more power to infer human demography. The first successful ancient DNA studies in Africa and the promise of many more African ancient DNA studies to come, will enable direct temporal comparisons – which will further contribute to unraveling deep human history on the African continent. With improvements in laboratory techniques and the strengthening of bioinformatics analysis, we are constantly increasing our ability to analyze ancient DNA more effectively and the next few years will be exciting for investigating human history on the African continent.

Due to the difficulty of extracting DNA from samples from warm climates and the initial focus on European aDNA studies, genome-wide aDNA studies in Africa presently number only few (Gallego Llorente et al., 2015, Skoglund et al., 2017, Prendergast et al., 2019, Lipson et al., 2020, Schlebusch et al., 2017, van de Loosdrecht et al., 2018, Fregel et al., 2018, Schuenemann et al., 2017, Rodriguez-Varela et al., 2017). However, with the development of new and improved molecular genetic methods and bioinformatic tools, it is becoming easier to not only extract DNA from samples found in warm climates, but more ancient samples too. At the time of writing this review, only nine studies in total have published ancient genome-wide results from Africa, four studies for North African aDNA and five for sub-Saharan African aDNA. We analyzed the results of aDNA studies from continental Africa, published to date, in context of modern day African genetic variation.

Basically, it is a round-up of some aDNA (Ancient DNA that was extracted from skeletons) studies and papers.

Modern-day and ancient genetic structure in Africa.

I remember reading about the aDNA study about Malawi HGs. I thought that the Malawi HGs were just a mix of East African and Khoisan but it turns out they are an ancient, complex mix of East African, Central African rainforest hunter-gatherers and Southern African San hunter-gatherers.
I personally think the scientists' conclusions about not finding any of Malawi HG blood/ancestry in Malawi Bantus and no similar modern-day genetic populations are wrong. Plus they haven't tested surrounding Bantu and HG populations in other countries (Mozambique, Zambia and Zimbabwe). I have a feeling that Malawi HGs exist in some shape or form. I also believe that they (or a similar genetic population) made it to the island of Madagascar before the Austronesians.


@get these nets , @DrBanneker , @Soldier , @Waldo Geraldo Faldo , @Ty Daniels , @nullnullnullnull