Probably the most famous Brazil American is Gisele Bündchen, erstwhile supermodel and ex-wife of Tom Brady. Bündchen is a German Brazilian, and all the media I see say she is purely German. She grew up in a predominantly German town in the southern state of Rio Grande do Sul, which is often contrasted with the black-dominated areas of northeastern Brazil. About 80% of people in Rio Grande do Sul identify as white, about 10% mixed-race, 5% black and the remaining 5% indigenous, Asian, etc.
These sorts of facts are often used to recapitulate American racial dynamics in Brazil, except here you have a black majority and a white majority, though the latter are still socially, culturally and economically dominant. This is in contrast to the model that Brazilians themselves promoted on the 20th century of being am multiracial and mixed-race society, albeit defined by a fair amount of naked anti-black bias.
The main problem with the first narrative is it is just a plain fact that most Brazilians are mixed-race in the American context. Bündchen is the exception, not the rule. This has been hard to ascertain because of the lack of high density SNP array surveys in the early years of this blog, but I decided to go back and check now that these chips are very cheap, and a paper with 6,500 Brazilians typed on 370,000 SNPs exists to illustrate the ancestry distributions within: A minimum set of ancestry informative markers for determining admixture proportions in a mixed American population: the Brazilian set.
The admixture plot shows that under “11,” sampled in the far southern Brazilian city of Pelotas, only a few individuals on the right portion of the distribution show trace amounts of non-European ancestry. The prevalence of low but widespread Amerindian ancestry is not surprising in Brazil, where the early European settlers seem to have absorbed the natives. Second, under “12” you see samples from the city of Salvador, where 80% of people identify as mixed-race or black. Here you see lots of African ancestry, but only the individuals at the far left of the distribution are as African as the average African American (the rightmost panel is from a central Brazilian city).
This pattern is even more clear on PCA:
What’s the takeway? By American standards most Brazilians are black, because they have African ancestry. This includes a majority of self-identified “white” Brazilians.
A new paper, Language trees with sampled ancestors support a hybrid model for the origin of Indo-European languages, has made a splash by inferring a far older date of diversification of these languages than has been assumed by other linguists, archaeologists and geneticists. As you can see above, the splits start a bit earlier than 5000 BC in this model, 1,500-2,000 years before the “classic” Pontic-steppe hypothesis. There are divergences in the typology from what some have assumed, for example, the deep split of Indo-Iranian from other groups. Nemets in Proto-Indo-European Urheimat Debate has given some skeptical thoughts, while Iosif Lazaridis of the “Southern Arc” fame has also offered his two cents. Others on social media have pointed out what seem to be important errors in the paper:
1- Heggarty et al. 2023 claims that no southward migration of Steppe_MLBA pastoralists is attested by aDNA from BMAC sites in 2300-1700 BCE by citing Narasimhan et al. 2019.
2- Narasimhan et al. 2019 concludes that Steppe_MLBA pastoralists migrated southward during 2100-1700 BCE pic.twitter.com/DY6f91uTgC
I can’t speak to the linguistics. I will say that I was taught about Bayesian phylogenetic inference in graduate school, so I know some of the models and parameters they’re using, and I’ve even used BEAST 2 myself. It’s not my specialty at all, so I have weak intuition, but these are serious methods that allow for understanding the past and reconstruction of evolutionary relationships. But I will pass on Asya Pereltsvaig’s criticism in The Indo-European Controversy: Facts and Fallacies in Historical Linguistics that the reliance on lexicon as input data might be a major problem in these inferences; misleading data in, misleading result out. But I’ll comment a few issues that jumped out at me informed by ancient DNA.
First, the position of Tocharian is not surprising…it often comes out as diverging early from the other languages. Tocharian languages were found in the northern and northeast regions of the Tarim basin. Historically, the southern rim of the basin was dominated by Iranian languages. It seems the most likely candidate for the people that gave rise to the Tocharian languages is the Afanasievo culture. The Afanasievo we now know were basically an eastern branch of the Yamnaya that show up in the Altai 3300 BC. This is 5,300 years BP. In the paper, the Tocharian split from other Indo-Europeans 5,400 to 8,600 years BP over a 95% confidence interval. The only way this makes sense to me is if there was deep linguistic structure within the Yamnaya despite overall genetic homogeneity maintained through mate exchange. In the text the authors seem to imply that the Tocharians are an early eastward migration, perhaps from the south Caucasus region. This does not align very well with the ancient DNA. The Afanasievo early on are replica copies of Yamnaya. Were the Tocharians already there? Did the Afanasievo just adopt their language?
The second issue I have broadly is with the Indo-Iranians. The authors propose that the Indic and Iranian branches separated in 3,500 BC. While earlier work indicates that the Indo-Iranian languages descend from the Sintashta language and the cultures of the Andronovo horizon, these authors emphasize the role of populations from the south Caucasus traversing Iran south of the Caspian Sea.
Below is a map that gets to the crux of my confusion about this ancient date and longstanding indigeneity of Indo-Iranians on the Iranian plateau:
We have some histories of the Middle Eastern Bronze Age. We know that the area of southwest Iran was dominated by the non-Indo-European Elamites as early as 3000 BC, and these people persisted down into the Common Era. Modern Armenia was dominated by non-Indo-European speaking Urartians after 1000 BC. This language is related to Hurrian, documented 4,000 years ago. Before the Indo-European Hittites ruled Hatti, the Hattians ruled Hatti. And the Hattians were not Indo-European. Judging by the obscure Eteocretan language that persisted into antiquity the Minoans were almost certainly not Indo-European speaking. Around 1500 BC it is true the ruling elite of the Hurrians, the Mittani, seem to have had an Indo-Aryan connection, but they were also likely intrusive, and their emergence as mobile warriors suspiciously post-dates the development of the light war chariot and the domestic horse thousands of miles to the north several centuries earlier by the Sintashta. The Assyrian royal annals date the arrival of Persians to the 9th century BC, but the results in the paper imply that the Iranians were already present in the Zagros for thousands of years before this (the south Caucasus being the Indo-European ur-heimat ultimately, the Indo-Iranians moving south and east very early on from that region).
I’m focusing on the Middle East because there is a rich history of textual evidence starting in the third millennium BC. These results imply that Indo-European languages are in fact native to the northern Middle East, in the southern Caucasus. And yet assorted obscure languages like Gutian, Kassite and Kaska, are found where you might expect a stray Indo-European here and there. To me this is curious and weird. Further to the west, these results seem to imply that Greek was brought with Caucasus ancestry, but Minoan was likely not Indo-European. There are all these non-Indo-European languages attested in the textual record…and only a few Indo-European ones (Hittite being the first).
One of the major points of this paper that contradicts some theories in historical linguistics is a rejection of the tentative connection between Balto-Slavic and Indo-Iranian. Genetically, the curious aspect of the two language families is that Y chromosomal haplogroup R1a is very frequent in both, but differentiated into two lineages that seem to have diverged 5,500-6,000 years ago. But there is more than just Y chromosomes here; over the past decade autosomal genome analyses show that many South Asians, in particular those in the northwest and upper caste populations are enriched for a minority ancestral component that resembles Eastern Europeans. We now know what happened due to ancient DNA: Genetic ancestry changes in Stone to Bronze Age transition in the East European plain. A branch of the Corded Ware Culture (CWC) migrated eastward, becoming the Fatyanovo Culture, then the Balanovo Culture, then the Abeshevo Culture, and finally the Sintashta Culture. The Sintashta seem to have given rise a group of societies known as Andronovo that are hypothesized to evolved into Iranians and Indo-Aryans.
The result here does away with all this. Rather than Indo-Aryan speech being brought by steppe pastoralists between 3,500 and 4,000 years ago, as genetics would imply, the Indo-Aryan speech was likely present during the Indus Valley Civilization. These results imply that Indo-Aryan arrived in India thousands of years before the intrusion of steppe pastoralists, and it was carried eastward by farmers from the Caucasus. The Vedas and Sanskrit then come down from the IVC. And yet strangely the Vedas do not depict a very complex society like the IVC, but a more simple agro-pastoralist one. And, the sacred language of the IVC people presumably, Sanskrit, was maintained in particular by a Brahmin priestly caste that is notable for having a very high fraction of steppe ancestry, that much arrived later.
A massive issue of this paper is that it makes a hash of a major phenomenon that we know between 3500 and 2500 BC, and that’s the spread of steppe-people in all directions, especially out of the Corded Ware complex. The CWC are notable for having a major admixture of Globular Amphora Culture (GAC) Neolithic ancestry, about 25-35% of their genetics, and then spreading into all directions. As noted by the authors and other observers, ancient DNA suggests that Anatolian, Armenian, and perhaps Greek and Illyrian (Albanian), are exceptions to this, deriving directly from Yamnaya or pre-Yamnaya (in the case of Hittites) Indo-European people (remember, CWC is a mix of Yamnaya and GAC). The genetics is very clear that a major wave of post-CWC people went into Asia, and south into the Indian subcontinent and Iran. The Y chromosomes imply this was male mediated, and post-CWC Y chromosomes are found in appreciable quantities as far south as Sri Lanka. But these data place this demographic migration far too late to have been the origin of Sanskrit, which is associated with Arya culture.
As Lazaridis points out on social media, the divergence of European language groups like Germanic, Celtic, Italic and Balto-Slavic also predates the CWC expansion westward. For example, Italic language split off in 3500 BC, 500 years earlier than the expansion of CWC into Eastern Europe, with a 95% lower-bound of 2200 BC, about when steppe ancestry shows up in the Italian peninsula according to ancient DNA. If the dates are true then it seems that the various Indo-European language groups were differentiated already very early on in the Yamnaya, and not later on through their expansion across Europe. In other words, this is a model of “ancient linguistic substructure.”
To be entirely candid, it’s very hard for me to reconcile the ancient DNA with this typology and time-depth in a parsimonious manner that holds together in my head. This doesn’t mean the other models don’t have holes, the “Southern Arc” theory is pretty complicated too, and everything would have been “easier” if the Hittites had steppe ancestry, and they do not seem to. But there are too many things that are hard for me to understand with this new model. For example, the vast numbers of steppe Iranian people seem to be mostly descended from the CWC societies that gave rise to Europeans, but their languages diverged extremely early from their western neighbors, almost 2,000 years before the diversification of the CWC as an archaeological, demographic and genetic unit.
The evolutionarily recent dispersal of anatomically modern humans (AMH) out of Africa (OoA) and across Eurasia provides a unique opportunity to examine the impacts of genetic selection as humans adapted to multiple new environments. Analysis of ancient Eurasian genomic datasets (~1,000 to 45,000 y old) reveals signatures of strong selection, including at least 57 hard sweeps after the initial AMH movement OoA, which have been obscured in modern populations by extensive admixture during the Holocene. The spatiotemporal patterns of these hard sweeps provide a means to reconstruct early AMH population dispersals OoA. We identify a previously unsuspected extended period of genetic adaptation lasting ~30,000 y, potentially in the Arabian Peninsula area, prior to a major Neandertal genetic introgression and subsequent rapid dispersal across Eurasia as far as Australia. Consistent functional targets of selection initiated during this period, which we term the Arabian Standstill, include loci involved in the regulation of fat storage, neural development, skin physiology, and cilia function. Similar adaptive signatures are also evident in introgressed archaic hominin loci and modern Arctic human groups, and we suggest that this signal represents selection for cold adaptation. Surprisingly, many of the candidate selected loci across these groups appear to directly interact and coordinately regulate biological processes, with a number associated with major modern diseases including the ciliopathies, metabolic syndrome, and neurodegenerative disorders. This expands the potential for ancestral human adaptation to directly impact modern diseases, providing a platform for evolutionary medicine.
This “stand still” out of Africa has been identified for a few decades now in the genomic data. I’m not sure people necessarily believe it…but it’s clear that non-Africans are very homogeneous and closely related to each other compared to various diverse African groups. That indicates a long period of isolation and homogeneity. The “Basal Eurasians” were part of this.
But earlier “modern” or “para-stem” populations may not have been. The Altai Neanderthal samples that date to 100,000 years ago have some “modern” ancestry. How? The best assumption right now is that these were very early migrants out of the African ur-heimat that mixed with Neanderthals in their eastern range, likely coming up through East Asia? Possibly mixed with Denisovans?
The point here is that some elements of the “weakly structured model” probably applies to Eurasia too. Africa is a big continent and good habitat for humans. Pulses out of this continent probably happened all the time. It’s just that the last Eurasian expansion about 50,000 years ago erased everything earlier (or absorbed it). Though I still think if we get ancient DNA from Laos it may turn out that 1% or something of the ancestry of Andamanese may date to a population that diverged 85,000 years ago from the main out-of-Africa group, before their isolation in the Near East (since the divergence is not that great, I don’t think the models would have good power to detect this proportion).
In northwestern Africa, lifestyle transitioned from foraging to food production around 7,400 years ago but what sparked that change remains unclear. Archaeological data support conflicting views: (1) that migrant European Neolithic farmers brought the new way of life to North Africa1,2,3 or (2) that local hunter-gatherers adopted technological innovations4,5. The latter view is also supported by archaeogenetic data6. Here we fill key chronological and archaeogenetic gaps for the Maghreb, from Epipalaeolithic to Middle Neolithic, by sequencing the genomes of nine individuals (to between 45.8- and 0.2-fold genome coverage). Notably, we trace 8,000 years of population continuity and isolation from the Upper Palaeolithic, via the Epipaleolithic, to some Maghrebi Neolithic farming groups. However, remains from the earliest Neolithic contexts showed mostly European Neolithic ancestry. We suggest that farming was introduced by European migrants and was then rapidly adopted by local groups. During the Middle Neolithic a new ancestry from the Levant appears in the Maghreb, coinciding with the arrival of pastoralism in the region, and all three ancestries blend together during the Late Neolithic. Our results show ancestry shifts in the Neolithization of northwestern Africa that probably mirrored a heterogeneous economic and cultural landscape, in a more multifaceted process than observed in other regions.
Basically, the ancestors of the Berbers seem to be a mix of indigenous people whose ancestors were Eurasians who arrived during the Last Glacial Maximum, Early European Farmers (Anatolian) and Levantine farmers/pastoralists, in that order of timing, but reverse order of contribution. To me it is interesting that there is no Sub-Saharan African ancestry in the earliest populations, indicating that the Sahara was really not habitable for humans for much of the Ice Age.
A few weeks ago I wrote on my Substack about a new model of African H. sapiens genesis that assumes recurrent gene flow between deeply divergent populations within the continent. In contrast, the out-of-Africa movement was defined by a rapid expansion from a small ancestral founding group that diversified over the last 50,000 years. But there is a twist to this: the out-of-Africa event was presaged by many earlier expansions outward.. The Neandersovans were one clear example, about 600,000 years ago. But there were others. We know this because Neanderthal Y and mtDNA seems to be more closely related to modern humans than the whole genome, and the Altai Neanderthal shows clear evidence of modern human admixture as early as 100,000 years ago, far earlier than the primary out-of-Africa event 50,000 years ago.
Archaeologists have uncovered two new bone fragments in a cave in northern Laos, suggesting that Homo sapiens wandered southeast Asia up to 86,000 years ago. The findings, published this week in Nature Communications1, indicate that humans migrated through the area earlier than previously thought.
Over more than a decade, excavations in the Tam Pà Ling cave have uncovered seven bone fragments sandwiched between layers of clay. Laura Shackelford, an anthropologist at the University of Illinois Urbana–Champaign, and her colleagues have regularly had to hike through sticky tropical heat to reach the mountain-top cave.
After digging 7 metres down, excavations have finally hit bedrock, and the team has been able to reconstruct a complete chronology of the cave, says Shackelford. Sediment and bones unearthed in the cave show that modern humans have inhabited the mountainous region for at least 68,000 years, and passed through even earlier.
These archaeological findings seem to solidify the idea of modern (African) humans in Southeast Asia. They don’t seem to have left an imprint, but that’s OK, the first modern Europeans didn’t either.
Background The Sahelian Fulani are the largest nomadic pastoral ethnic group. Their origins are still largely unknown and their Eurasian genetic component is usually explained by recent admixture events with northern African groups. However, it has also been proposed that Fulani may be the descendants of ancient groups settled in the Sahara during its last Green phase (12000-5000 BP), as also suggested by Y chromosome results. Results We produced 23 high-coverage (30 X) whole genomes from Fulani individuals from 8 Sahelian countries, plus 17 samples from other African groups and 3 Europeans as controls, for a total of 43 new whole genome sequences. These data have been compared with 814 published modern whole genomes and analyzed together with relevant published ancient individuals (for a total of > 1800 samples). These analyses showed that the non-sub-Saharan genetic ancestry component of Fulani cannot be only explained by recent admixture events, but it could be shaped at least in part by older events by events more ancient than previously reported, possibly tracing its origin to the last Green Sahara. Conclusions According to our results, Fulani may be the descendants of Saharan cattle herders settled in that area during the last Green Sahara. The exact ancestry composition of such ghost Saharan population(s) cannot be completely unveiled from modern genomes only, but the joint analysis with the available African ancient samples suggested a similarity between ancient Saharans and Late Neolithic Moroccans.
Two points
– Lots of suspicion about this before. Basically, a West Eurasian-related population (admixed) was extant in the Sahara for the first half of the Holocene.
– I don’t think they’ve totally figured out Afro-Asiatic, and these results make me more open to the idea that Afro-Asiatic came from the Sahara, not less
Query: write a razib khan style essay on the genetic history of india
Title: The Genetic Kaleidoscope: A Razib Khan Style Essay on the Genetic History of India
Introduction
India, a land of diversity and ancient civilizations, has long been a genetic melting pot that has captured the interest of researchers and historians alike. Drawing from a Razib Khan style perspective, this essay aims to delve into the intricate genetic history of India, unraveling the complex tapestry of its people and their origins.
Section 1: The Arrival of Ancestral South Indians (ASI) and Ancestral North Indians (ANI)
The genetic story of India begins with two ancestral groups: the Ancestral South Indians (ASI) and the Ancestral North Indians (ANI). The ASI descended from hunter-gatherers who inhabited the subcontinent around 50,000 years ago, while the ANI arrived later, around 15,000 to 12,000 years ago, as a result of human migrations from Central Asia and the Middle East.
Section 2: Dravidian and Indo-Aryan Interactions
The linguistic and cultural differences between the ASI and ANI led to the formation of the Dravidian and Indo-Aryan language families, respectively. Genetic studies have shown a gradual mixing of these populations, resulting in the diverse gene pool of modern-day Indians. The Harappan civilization, which thrived between 2600 and 1900 BCE, likely played a critical role in facilitating this genetic exchange.
Section 3: The Aryan Migration Theory and the Steppe Hypothesis
One of the most debated topics in Indian genetic history is the Aryan migration theory. The Steppe Hypothesis posits that the Indo-European language family, which includes Sanskrit and modern Indo-Aryan languages, originated from the Pontic-Caspian steppe. Around 1500 BCE, Indo-European-speaking pastoralists migrated into the Indian subcontinent, where they
Query: write a razib khan style essay on the heritability of IQ
Title: The Inheritance of Intelligence: A Razib Khan Style Essay on the Heritability of IQ
Introduction
The heritability of intelligence has been a topic of debate and fascination for decades, with implications for education, social policy, and personal identity. Drawing inspiration from Razib Khan’s analytical style, this essay delves into the complex relationship between genetics and intelligence, highlighting the heritability of IQ and its implications on our understanding of human potential.
Section 1: Understanding Heritability and Intelligence
To effectively discuss the heritability of IQ, it is crucial to understand the concept of heritability itself. Heritability is the proportion of phenotypic variance that can be attributed to genetic variance within a population. This means that heritability is not an absolute measure of the genetic contribution to a trait but rather a reflection of the relationship between genetic and environmental factors.
Intelligence is a multifaceted construct that has been widely studied and measured through IQ tests. While IQ is not a perfect representation of intelligence, it serves as a useful proxy for the cognitive abilities that contribute to problem-solving, reasoning, and learning.
Section 2: Twin Studies and the Heritability of IQ
Twin studies have been instrumental in estimating the heritability of IQ. By comparing the IQ similarity of monozygotic (identical) and dizygotic (fraternal) twins, researchers have been able to ascertain the extent to which genetic factors contribute to intelligence. Meta-analyses of twin studies have suggested that the heritability of IQ ranges from 50% to 80%, with the remaining variance attributed to environmental factors.
Section 3: The Complex Interplay of Genes and Environment
The heritability of IQ underscores the importance of genetic factors in shaping cognitive abilities. However, it is essential to recognize that intelligence is a product of the intricate interplay between genes and environment. For instance, environmental factors such as nutrition, education, and early life experiences can significantly impact cognitive development.
Moreover, gene-environment correlations and interactions further complicate the relationship between genetics and intelligence. These phenomena occur when genetic factors influence the likelihood of encountering specific environmental conditions, or when environmental factors modify the expression of genetic traits.
Section 4: Implications for Society and Education
Understanding the heritability of IQ has profound implications for society and education. Recognizing the role of genetics in shaping cognitive abilities can inform personalized educational approaches and interventions. However, the potential for genetic information to be misused or lead to discrimination must be carefully considered.
Moreover, acknowledging the importance of environmental factors in intelligence highlights the need for equitable access to resources and opportunities that foster cognitive development. This awareness can inform policies and initiatives that aim to reduce disparities in educational outcomes.
Conclusion
The heritability of IQ sheds light on the complex interplay of genetic and environmental factors that shape intelligence. While genetics play a significant role in determining cognitive abilities, environmental factors and their interaction with genes are equally important. Recognizing the multifaceted nature of intelligence can inform more effective and equitable approaches to education and social policy, promoting a deeper understanding of human potential.
One of the major weak points of The Horse the Wheel and Language is that there isn’t good evidence for horsemanship during the period of Yamnaya expansion. More recently, the genetic evidence seems pretty clear that modern horses descend from Sintashta populations after 2000 BC. Nevertheless, it’s pretty weird how fast the pastoralist Yamnaya moved. I suspect that a more primitive form of horse utilization was the norm for the Yamnaya. They didn’t have cavalry, but they may have ridden ponies to get to a location or escape the scene of a raid.
The origins of horseback riding remain elusive. Scientific studies show that horses were kept for their milk ~3500 to 3000 BCE, widely accepted as indicating domestication. However, this does not confirm them to be ridden. Equipment used by early riders is rarely preserved, and the reliability of equine dental and mandibular pathologies remains contested. However, horsemanship has two interacting components: the horse as mount and the human as rider. Alterations associated with riding in human skeletons therefore possibly provide the best source of information. Here, we report five Yamnaya individuals well-dated to 3021 to 2501 calibrated BCE from kurgans in Romania, Bulgaria, and Hungary, displaying changes in bone morphology and distinct pathologies associated with horseback riding. These are the oldest humans identified as riders so far.
Probably the most famous Brazil American is Gisele Bündchen, erstwhile supermodel and ex-wife of Tom Brady. Bündchen is a German Brazilian, and all the media I see say she is purely German. She grew up in a predominantly German town in the southern state of Rio Grande do Sul, which is often contrasted with the black-dominated areas of northeastern Brazil. About 80% of people in Rio Grande do Sul identify as white, about 10% mixed-race, 5% black and the remaining 5% indigenous, Asian, etc.
