Substack cometh, and lo it is good. (Pricing)

Open Thread: Ash and Elm…

I’m rereading Children of Ash and Elm: A History of the Vikings, along with some other books on the Vikings and Scandinavians. Also revisiting papers like Population genomics of Mesolithic Scandinavia: Investigating early postglacial migration routes and high-latitude adaptation, which I believe reports the first individual that almost certainly had light hair and eyes in the ancient DNA record (look at “Sbj”). You can probably guess why I’m doing this, why I’m reading these papers and books. At the same time I also have started listening to “Viking music,” which is its own genre. It’s a nice juxtaposition.

I do not have much time for this blog right now, between the Substack and my primary focus, GenRAIT, which we introduced to the world at PAG 30 (we’re still rai$ing, so if you an angel you know to reach me).

But I’ll keep posting here now and then as usual. This blog has been going for more than 20 years now (since the spring of 2002).

10 thoughts on “Open Thread: Ash and Elm…

  1. Not too sure about this but seems GNXP relevant – https://www.nature.com/articles/s42003-023-04510-0

    “Prehistoric human migration between Sundaland and South Asia was driven by sea-level rise”

    “Rapid sea-level rise between the Last Glacial Maximum (LGM) and the mid-Holocene transformed the Southeast Asian coastal landscape, but the impact on human demography remains unclear. Here, we create a paleogeographic map, focusing on sea-level changes during the period spanning the LGM to the present-day and infer the human population history in Southeast and South Asia using 763 high-coverage whole-genome sequencing datasets from 59 ethnic groups. We show that sea-level rise, in particular meltwater pulses 1 A (MWP1A, ~14,500–14,000 years ago) and 1B (MWP1B, ~11,500–11,000 years ago), reduced land area by over 50% since the LGM, resulting in segregation of local human populations. Following periods of rapid sea-level rises, population pressure drove the migration of Malaysian Negritos into South Asia. Integrated paleogeographic and population genomic analysis demonstrates the earliest documented instance of forced human migration driven by sea-level rise.” …

    “A comparison of the admixture analysis on the X chromosomes with that on the autosomes shows that the genetic contributions of male and female Malaysian Negritos to the South Asian Austroasiatic groups are different (Supplementary Fig. 3). The proportion of Malaysian Negrito ancestry in the X chromosomes (1.3% ± 2.8) is less than that in the autosomes (7.4% ± 2.9), suggesting a male bias in the potential migration of Malaysian Negritos to South Asia (Supplementary Fig. 3).”

    A theory of Austroasiatic languages into MSEA?

  2. https://medicalxpress.com/news/2023-02-rare-genetic-disease-ashkenazi-jews.html“Rare genetic disease may protect Ashkenazi Jews against TB”

    Think Greg Cochran thought Gaucher in AJs was due to selection for intelligence; this study seems to think it’s for resistance to TB.

    “However, when Ramakrishnan and colleagues modeled a lysosomal storage disease known as Gaucher disease, they found something unexpected: TB resistance rather than susceptibility.

    Gaucher disease is a rare disease, affecting around one in 40,000 to 60,000 births in the general population, but rates are significantly higher among Ashkenazi Jews—around one in 800 births. In most cases, the disease can be relatively mild—with symptoms including enlarged spleen and liver, and anemia—and around two-thirds of people carrying two copies of the most common genetic variant are unaware they are carriers.

    When the researchers genetically engineered zebrafish with genetic variants causing Gaucher disease that are common among Ashkenazi Jews, as anticipated their macrophages became enlarged and unable to break down the toxic materials, in this case an unusual type of fat (called sphingolipids) rather than protein. But when the team exposed the fish to TB, they discovered unexpectedly that the fish were resistant to infection, not susceptible.

    The reason for this resistance to infection was because of the fatty chemical that accumulates within the macrophages in Gaucher disease, called glucosylsphingosine. Glucosylsphingosine was found to act as a detergent-like microbicide that kills TB mycobacteria within minutes by disrupting their cell walls.

    Professor Ramakrishnan added, “We’d unknowingly landed in a debate that’s been going on in human genetics for decades: are Ashkenazi Jews—who we know are at a much greater risk of Gaucher disease—somehow less likely to get TB infection? The answer appears to be yes.”

    The Ashkenazi Jewish diaspora has experienced centuries of persecution, often forced to live in ghettos and migrate from country to country. They would almost certainly have been exposed to TB, which spreads more widely among poorer living conditions and densely-populated urban areas.

    Although this genetic mutation is associated with Gaucher disease, the fact that it makes people more resistant to TB would likely have outweighed the potential fitness cost of Gaucher disease. This would have increased the likelihood of affected individuals passing on their genes to future generations and therefore spread the mutation within the population. A similar phenomenon is seen among some individuals who carry genetic variants that protect them from malaria but, when more than one copy is present, cause harmful anemia or even sickle cell disease. “

    It would be interesting to check out the sphingolipid associated AJ genetic diseases and see what happens there under the same experimental models, if possible; possibly the founder population for AJ got whacked with TB and that explains a bunch of the mutations.

  3. The thesis of Luka Papac (the author who gave us the very detailed Czech Early Corded Ware transect and more) has been uploaded by Planck:

    https://pure.mpg.de/pubman/faces/ViewItemOverviewPage.jsp?itemId=item_3489057“Tracking population history, social structure and intergroup exchange in Neolithic to Bronze Age Europe using ancient human and virus genomes”

    phd thesis for free download – https://www.db-thueringen.de/receive/dbt_mods_00053720

    “Abstract: Archaeogenetics has revealed two major migrations that shaped European prehistory; one starting in the 7th millennium BCE and associated with the transition to agriculture, and another with the appearence of the Corded Ware cultural complex in the early 3rd millennium BCE. However, most findings have come from studies employing a continent-wide and/or low regional density sampling approach, leaving many temporal and geographic gaps in the current European archaeogenetic record. In order to build upon previous studies, this thesis employed a high-density sampling approach to study the population structure of Neolithic to Bronze Age central Europe in finer detail.

    In total, genome-wide ancient DNA was analysed from 283 newly reported individuals from present-day Bohemia, Czech Republic. In doing so, new insights into population structure, genetic turnovers, and social processes were discovered and discussed. These include a genetic turnover between the Jordanow and Funnelbeaker cultural groups, a genetic turnover between Early and Late Corded Ware groups, and a genetic turnover between Bell Beaker and Únětice groups. Insights into social structure and processes revealed the likely contacts between early farming communities with hunter-gatherer groups of Eastern Europe, that the integration of pre-Corded Ware people into Corded Ware society was likely a sex-biased process, and the emergence of a strict patrilineal social system in Late Corded Ware and Bell Beaker cultural groups which broke down with the appearance of early Únětice cultural groups.

    Insights from a detailed investigation into an Early Bronze Age cemetery from Mikulovice revealed a genetically homogeneous group with evidence of patrilocality and families spanning up to four generations. This thesis shows the potential of more detailed, higher-resolution studies to reveal previously unknown genetic structure and social processes.”

    May be some more detail than we saw in the shorter paper.

  4. The thesis of Luciana Simoes, Uppsala Uni – https://tinyurl.com/39atcwku

    “Uncovering the Past through ancient DNA: The Fate and Legacy of the last hunter-gatherers in Western Europe and Northwestern Africa”

    “The genetic analysis of ancient human remains has revolutionized the study of human history, opening a direct window onto the demographic and evolutionary events that shaped our species’ past. I use state-of-the-art ancient DNA methodologies, from sample collection and DNA extraction to data analysis, to study the ancient past of the western Mediterranean region, where climate does not favour DNA preservation. After the Last Glacial Maximum, amenable climatic conditions enabled the development of agriculture in the Levant, initiating the Neolithic period. In Europe, the transition from foraging to farming was driven by the migration of people from Anatolia, but in North Africa, evidence indicates a cultural diffusion, instead of population replacement.

    In this thesis, I show that this transition was in fact ignited by the migration of early farmers from Iberia. Moreover, a different migration wave, originating in the Levant and expanding within Africa, was associated with pastoralism in that region during the Neolithic.

    While the Neolithic transition is one of the most studied periods of pre-history, earlier periods are comparatively under-studied.

    Using whole genome sequencing data for 36 hunter-gatherers from Iberia and France, I observed that genetic lineages rooted in the Palaeolithic, survived throught the Mesolithic. Mesolithic hunter-gatherer populations formed social units that were not based on familial bonds; exchanges between groups avoided consanguinity. Coexistence with the first farming communities resulted in unidirectional admixture patterns, as we do not find gene flow from farmers to the last hunter-gatherers. Finally, using a multidisciplinary approach to study an exceptional individual of African descent buried in a Mesolithic shell midden, we find that the burial of this man during the transatlantic slave trade period could be an example of the maintenance of African cultural practices by African people displaced to Europe. My thesis highlights the power of ancient DNA analysis to uncover events and patterns of the human evolutionary history, but also that integrative approaches, where different lines of evidence are combined, can lead to exciting findings.”

    (No preferential consangunity is not exactly a surprise; only times we find this are pre-Greeks (and to some extent Greeks too) https://www.nature.com/articles/s41559-022-01952-3, allyu system in the Andes https://pubmed.ncbi.nlm.nih.gov/32898493/, and then contemporary societies in the sphere of Islam. Cousin marriage seems all about farmers and pastoralists sharing resources within the family, in countries that are rugged or insular?)

  5. Some thoughts on the Chinese monologue: The part where you talk about prehistoric art: Gravettians aren’t responsible for lion man or much art for that matter. The Lionman is possibly Aurignacian (not totally sure because I can’t find commentary on the material culture, only the time, and time =/= culture especially when it could also possibly be a pre-Aurignacian based on the dates), and Altamira is Aurignacian-Solutrean-Magdalenian.

    Also what did you mean by Mesolithic hunter gatherers being recent migrants out of West Asia? I was under the impression that the Basal Eurasian ancestry in West Asians going back to 30,000 years ago precludes WHG from being West Asians. Do you have news on the topic that changes this picture?

    The Tianyuan stuff is sort of complicated. Oase to the best of my knowledge was an early European, who might have been pre-Aurignacian (not associated with Aurignacian material culture) who as correctly implied isn’t relevant to later populations, but then there is Kostenki from 37,000 years ago who is about as similar to modern Europeans as Tianyuan man is to modern East Asians if not slightly more so, and Kostenki is quite different from modern Europeans for that matter. Tianyuan is phylogenetically closest to modern East Asians but the LGM bottleneck made East Asians grow very distant in terms of raw genetic distance to the point where coastal Asians like Onge are closer to Tianyuan in terms of raw genetic distance. Lastly an explanation for Goyet-Tianyuan/East Asian affinity is common Bacho Kiro ancestry found in both.

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