Your article is fascinating. Thank you for reading my post. If you scroll down the page to the update from March 14th, 2019, I mention that I think it’s a mistake to take these estimates from ADMIXTURE too literally for several reasons, which I addressed there in more detail. There are caveats to most “prepackaged” statistical software in population genetics which, I think, are important to consider when trying to interpret admixture results.
In my view, it’s difficult (if not impossible in some cases) to use autosomal DNA to clearly differentiate between present-day groups which already share a significant degree of ancient genetic proximity. Furthermore, in this case, an adequate dataset should ideally include ancient Canarian samples that are representative of all the Canarian Islands and not just North African samples to be used as proxies for Guanche DNA. This is because meaningful genetic variations between ancient Canarian samples & present-day North Africans were observed in a recent paper from Serrano et al (2023). It’s called “The genomic history of the indigenous people of the Canary Islands.” In the paper, the authors analyzed ancient Canarian samples from individuals that are estimated to have lived from the 3rd to the 16th century. See this link: https://www.nature.com/articles/s41467-023-40198-w
This is why I think this topic as it relates to genetics should be further investigated and corroborated with more diversified analyses before reaching a definitive conclusion.
"Furthermore, in this case, an adequate dataset should ideally include ancient Canarian samples that are representative of all the Canarian Islands and not just North African samples to be used as proxies for Guanche DNA."
I agree. As more and more ancient DNA is being published every year, I'm hopeful that we'll get better (and more reliable) results in the coming years.
Hi there. This was very interesting but I have some caveats re. your historical approach. Why? Because, some years ago, an acquaintance of mine, Thierno (with my help but it was mostly his work) made a mini-study on actual genetic ancestry of Puerto Ricans and the actual results, which you can read here: https://forwhattheywereweare.blogspot.com/2018/10/the-major-guanche-genetic-influence-in.html (my old blog), show that every single Puerto Rican has some Guanche (Berber, the proxies were Moroccans and Sahrawis, the latter being probably more representative) ancestry, what is only logical if you consider that people do admix every generation. The average Guanche ancestry is in the ballpark of 40-50%.
Comparing your estimates and Thierno's, I think I can give a rough estimate of the likely Guanche ancestry in the Caribbean countries you considered (Central America should have also been affected):
Puerto Rico: 45%
Cuba: 53%
Dominican Rep.: 22%
Venezuela: 40%
Colombia: 8% ?
Mexico: 5% ?
Another caveat I have is about the "colonialist" (benevolent) narrative you spouse for this major migration: the anticolonialist narrative, which is, as usual hidden under the rug, talks of "Tributo de Sangre" (Blood Tax) and forced displacement of poorer (and typically more aboriginal) Canarians to the Caribbean and not by choice. The exact method varied through the centuries but it was very persistent.
I just finished reading the post by Thierno, and I must say it's excellent.
"The average Guanche ancestry is in the ballpark of 40-50%." => That seems too high. I don't dispute his results, but the only way I could conceive of such a high Guanche component is if:
A.- Canary Islander ancestry is higher than I estimated (see footnote 30). It would have to be rather close to a 100% of West Eurasian ancestry (I'm including Northern Africa in West Eurasia in this case).
B.- Guanche ancestry of Canarians was much higher during the historical period when most of the migration to the Americas took place (17th century, 18th century). It's currently around 20%, but if it was closer to 40% or 50% three centuries ago, then Thierno's results make perfect sense.
Maybe not necessarily A, but definitely B. This is a fast moving field, so maybe someone will publish old Canarian genomes soon and we'll know for certain how Guanche ancestry shifted in time.
"talks of "Tributo de Sangre" (Blood Tax) and forced displacement of poorer (and typically more aboriginal) Canarians to the Caribbean and not by choice." => I'm certain a lot of them were more or less forced by Canarian authorities who saw the Tributo de Sangre as a way to get rid of "undesirables". In fact the population structure that you imply ("and typically more aboriginal") seems like a plausible explanation (maybe better one) for the high Guanche component that I'm tentatively attributing to point B above.
The intent of the "Tributo de Sangre" was rather to settle Castilian ("Spanish") colonies that were uninteresting to the relatively few settlers the Kingdom could muster. Generally speaking there was limited interest among Castilians to migrate to the American colonies and they did get to choose where to settle, so they went to the more profittable areas of that very vast empire (places like Mexico of the Andes, where silver was extracted, economic-military centers like Cuba or would-be Colombia, etc.). Less interesting areas like Puerto Rico and Hispaniola (now Dominican Republic but also Haiti, where the few Spanish settlers were easily driven out by the French) were still strategical and needed some attention by the colonial administration, Canarians were an easy target because they were a colonial population without the rights that Castellanos had. Anyhow, there's abundant info on this issue (in Spanish language mostly) and I'm not an expert historian specialized in Canarian affairs, so feel free to research the matter on your own and reach your own conclusions.
As for the genetic data, it is objective, well done, autosomal genetic analysis. I supervised it personally and there should be no question about it unless someone independently does a similar analysis and (somehow, would be very shocking to me) gets different results. Of course there's a small chance that the publicly available PUR sample could be somehow biased but I have no reason to think so.
I'd go with your option B anyhow: the conquest of the Canary Islands was indeed brutal but it didn't devastate the aboriginal population, much better protected against Ero-Afro-Asian epidemics than the natives of America (who were ravaged by them). Castile actually got Papal support for their conquest (Portugal was a rival) largely thanks to their less brutal attitude, especially re. the convert natives, which were at least nominally spared from outright slavery (this practice, as you surely know, was also applied in theory to the American colonies, although in practice there were huge contradictions and illegal abuses that were particularly devastating in the Caribbean islands).
I don't know enough but I think that the European settling of Canarias was a relatively gradual process, with the two main cities (La Palma and Santa Cruz) being the main destinations originally, largely in intimate relation to the colonization of and trade with America. That should mean that otherwise the rest of the archipelago was only gradually settled, with lots of admixture with the native Guanches. Canarias was less of a plantation colony and much more of a trade and military (naval) hub, accidentally perfect for the Castilian colonial goals in the Americas (originally it was meant as base looking to Africa rather but then Tordesillas Treaty happened).
Separate academic analyses (probably linked to in that article, can't recall, maybe it was in the comments section?) also show that, while the 20% of aboriginal Guanche ancestry is correct for the (known samples of) the two major Canarian islands (Gran Canaria and Tenerife), the figure is at least double for Gomera (where Guanche traditions have been particularly well preserved) and doubts exist for some of the other islands and even less capitaline locations within the large islands.
The higher Guanche component in La Gomera does point to some heterogeneity in the colonization of the Canaries and in the mixing between Guanches and Iberians (lots of Portuguese also).
Indeed but please notice that we're observing the end point of five centuries of colonialism (both in Canarias as in America), so in the 16th, 17th, 18th and even 19th centuries this settlement should have been weaker. Remember that most of the "whitening" of the Americas happened in the 19th and even the early 20th centuries, previously mass migration was not so easy (sail vs steam) and the causes of it (industrialization, displacement of rapidly growing rural populations) were not present yet. I don't know for sure but I presume that some of that also applied to Canarias. Cheers.
Your article is fascinating. Thank you for reading my post. If you scroll down the page to the update from March 14th, 2019, I mention that I think it’s a mistake to take these estimates from ADMIXTURE too literally for several reasons, which I addressed there in more detail. There are caveats to most “prepackaged” statistical software in population genetics which, I think, are important to consider when trying to interpret admixture results.
In my view, it’s difficult (if not impossible in some cases) to use autosomal DNA to clearly differentiate between present-day groups which already share a significant degree of ancient genetic proximity. Furthermore, in this case, an adequate dataset should ideally include ancient Canarian samples that are representative of all the Canarian Islands and not just North African samples to be used as proxies for Guanche DNA. This is because meaningful genetic variations between ancient Canarian samples & present-day North Africans were observed in a recent paper from Serrano et al (2023). It’s called “The genomic history of the indigenous people of the Canary Islands.” In the paper, the authors analyzed ancient Canarian samples from individuals that are estimated to have lived from the 3rd to the 16th century. See this link: https://www.nature.com/articles/s41467-023-40198-w
This is why I think this topic as it relates to genetics should be further investigated and corroborated with more diversified analyses before reaching a definitive conclusion.
"Furthermore, in this case, an adequate dataset should ideally include ancient Canarian samples that are representative of all the Canarian Islands and not just North African samples to be used as proxies for Guanche DNA."
I agree. As more and more ancient DNA is being published every year, I'm hopeful that we'll get better (and more reliable) results in the coming years.
Hi there. This was very interesting but I have some caveats re. your historical approach. Why? Because, some years ago, an acquaintance of mine, Thierno (with my help but it was mostly his work) made a mini-study on actual genetic ancestry of Puerto Ricans and the actual results, which you can read here: https://forwhattheywereweare.blogspot.com/2018/10/the-major-guanche-genetic-influence-in.html (my old blog), show that every single Puerto Rican has some Guanche (Berber, the proxies were Moroccans and Sahrawis, the latter being probably more representative) ancestry, what is only logical if you consider that people do admix every generation. The average Guanche ancestry is in the ballpark of 40-50%.
Comparing your estimates and Thierno's, I think I can give a rough estimate of the likely Guanche ancestry in the Caribbean countries you considered (Central America should have also been affected):
Puerto Rico: 45%
Cuba: 53%
Dominican Rep.: 22%
Venezuela: 40%
Colombia: 8% ?
Mexico: 5% ?
Another caveat I have is about the "colonialist" (benevolent) narrative you spouse for this major migration: the anticolonialist narrative, which is, as usual hidden under the rug, talks of "Tributo de Sangre" (Blood Tax) and forced displacement of poorer (and typically more aboriginal) Canarians to the Caribbean and not by choice. The exact method varied through the centuries but it was very persistent.
I just finished reading the post by Thierno, and I must say it's excellent.
"The average Guanche ancestry is in the ballpark of 40-50%." => That seems too high. I don't dispute his results, but the only way I could conceive of such a high Guanche component is if:
A.- Canary Islander ancestry is higher than I estimated (see footnote 30). It would have to be rather close to a 100% of West Eurasian ancestry (I'm including Northern Africa in West Eurasia in this case).
B.- Guanche ancestry of Canarians was much higher during the historical period when most of the migration to the Americas took place (17th century, 18th century). It's currently around 20%, but if it was closer to 40% or 50% three centuries ago, then Thierno's results make perfect sense.
Maybe not necessarily A, but definitely B. This is a fast moving field, so maybe someone will publish old Canarian genomes soon and we'll know for certain how Guanche ancestry shifted in time.
"talks of "Tributo de Sangre" (Blood Tax) and forced displacement of poorer (and typically more aboriginal) Canarians to the Caribbean and not by choice." => I'm certain a lot of them were more or less forced by Canarian authorities who saw the Tributo de Sangre as a way to get rid of "undesirables". In fact the population structure that you imply ("and typically more aboriginal") seems like a plausible explanation (maybe better one) for the high Guanche component that I'm tentatively attributing to point B above.
The intent of the "Tributo de Sangre" was rather to settle Castilian ("Spanish") colonies that were uninteresting to the relatively few settlers the Kingdom could muster. Generally speaking there was limited interest among Castilians to migrate to the American colonies and they did get to choose where to settle, so they went to the more profittable areas of that very vast empire (places like Mexico of the Andes, where silver was extracted, economic-military centers like Cuba or would-be Colombia, etc.). Less interesting areas like Puerto Rico and Hispaniola (now Dominican Republic but also Haiti, where the few Spanish settlers were easily driven out by the French) were still strategical and needed some attention by the colonial administration, Canarians were an easy target because they were a colonial population without the rights that Castellanos had. Anyhow, there's abundant info on this issue (in Spanish language mostly) and I'm not an expert historian specialized in Canarian affairs, so feel free to research the matter on your own and reach your own conclusions.
As for the genetic data, it is objective, well done, autosomal genetic analysis. I supervised it personally and there should be no question about it unless someone independently does a similar analysis and (somehow, would be very shocking to me) gets different results. Of course there's a small chance that the publicly available PUR sample could be somehow biased but I have no reason to think so.
I'd go with your option B anyhow: the conquest of the Canary Islands was indeed brutal but it didn't devastate the aboriginal population, much better protected against Ero-Afro-Asian epidemics than the natives of America (who were ravaged by them). Castile actually got Papal support for their conquest (Portugal was a rival) largely thanks to their less brutal attitude, especially re. the convert natives, which were at least nominally spared from outright slavery (this practice, as you surely know, was also applied in theory to the American colonies, although in practice there were huge contradictions and illegal abuses that were particularly devastating in the Caribbean islands).
I don't know enough but I think that the European settling of Canarias was a relatively gradual process, with the two main cities (La Palma and Santa Cruz) being the main destinations originally, largely in intimate relation to the colonization of and trade with America. That should mean that otherwise the rest of the archipelago was only gradually settled, with lots of admixture with the native Guanches. Canarias was less of a plantation colony and much more of a trade and military (naval) hub, accidentally perfect for the Castilian colonial goals in the Americas (originally it was meant as base looking to Africa rather but then Tordesillas Treaty happened).
Separate academic analyses (probably linked to in that article, can't recall, maybe it was in the comments section?) also show that, while the 20% of aboriginal Guanche ancestry is correct for the (known samples of) the two major Canarian islands (Gran Canaria and Tenerife), the figure is at least double for Gomera (where Guanche traditions have been particularly well preserved) and doubts exist for some of the other islands and even less capitaline locations within the large islands.
The higher Guanche component in La Gomera does point to some heterogeneity in the colonization of the Canaries and in the mixing between Guanches and Iberians (lots of Portuguese also).
Indeed but please notice that we're observing the end point of five centuries of colonialism (both in Canarias as in America), so in the 16th, 17th, 18th and even 19th centuries this settlement should have been weaker. Remember that most of the "whitening" of the Americas happened in the 19th and even the early 20th centuries, previously mass migration was not so easy (sail vs steam) and the causes of it (industrialization, displacement of rapidly growing rural populations) were not present yet. I don't know for sure but I presume that some of that also applied to Canarias. Cheers.