The Hospital Real de San Jose de los Naturales, and the evidence in its graves
A royal hospital in Mexico City founded to treat the indigenous population - the first in Mexico dedicated to it - whose cemetery has been excavated. Over 600 people lie in mass burials laid down in haste, the shape of an epidemic. Ancient DNA from the teeth has identified African-born people buried there and reconstructed the viruses they carried, including one that passed to an indigenous man in the same city. The institution and its cost are in the same ground.
Why this wins its question: A royal hospital built for indigenous patients in the capital of New Spain is the kind of fact this domain usually asserts and never evidences. Here the institution is approached through its cemetery, where the evidence cuts in every direction at once and all of it is peer-reviewed: over 600 people in mass graves dug in haste, autopsy descriptions of the 1576 cocoliztli made in the same building, three African-born people identified by mitochondrial haplogroup and by enamel strontium of 0.71098 to 0.71109 against bone values from the Valley of Mexico, a hepatitis B sub-genotype never otherwise seen in the Americas, and an indigenous man infected with a West African virus. Set beside the Campeche churchyard - 129 burials, ten genomes, no admixture among them, everyone in the same consecrated ground - it gives the reader something no polemic on either side supplies: the institution, its patients, the people the colony imported in chains, and the exact evidence for each.
Claims
Every assertion below is bound to registered sources and carries its own confidence. Weight them; do not treat the page as uniformly authoritative.
The institution is described by the study used here as the first hospital in Mexico dedicated specifically to treating the indigenous population. That source gives no foundation date and none is asserted here; what it establishes is the hospital's purpose and that it was still receiving the sick during the great epidemics of the sixteenth century.
Its burial ground is unusually large and unusually informative. The skeletal remains of over 600 individuals were recovered from mass burials associated with the hospital's architectural remnants, many from contexts suggestive of an urgent and simultaneous disposal of the bodies, as in the case of an epidemic.
The hospital is also where part of the clinical record of the 1576 cocoliztli epidemic was made. Autopsies of victims treated there describe an enlarged hard liver and jaundice, and a black spleen, with lungs and heart carrying yellow liquid and black blood. The medical observation and the mass graves come from the same institution and the same disaster.
The genomic study sampled 21 teeth from hospital individuals who showed dental modifications or morphological indicators typical of African ancestry, together with five samples from the chapel of La Concepcion in Coyoacan, a pre-Hispanic indigenous neighbourhood ten kilometres to the south and one of the first Catholic conversion centres of New Spain.
Three of the people buried at the hospital were born in Africa, and three independent lines of evidence say so. All three fall within African genetic variation in principal component analysis and carry mitochondrial haplogroup L; strontium ratios in their tooth enamel, 0.71098 to 0.71109, match West African geology against a West African average of 0.71044, while their bone values of 0.70672 to 0.70755 record later residence in Mexico City; radiocarbon places two of them at 1442-1608 and 1472-1625, the early decades of the colony.
Their infections crossed with them. Three parvovirus B19 genomes of genotype 3 - the genotype most prevalent in West Africa and rare in the Americas - were reconstructed at 92.4 to 99.1 per cent coverage, and one hepatitis B genome of sub-genotype A4, at 89.9 per cent coverage, a sub-genotype never found in the Americas and previously recovered only from African individuals in Belgium. This is direct molecular evidence of viruses carried to the Americas in the transatlantic slave trade.
One of the infected was not African. The individual COYC4, of wholly indigenous ancestry and clustering with present-day Mexicans and Peruvians, carried an African B19 strain - the first genotype 3 genome obtained from a non-African individual - which shows transmission between African and Native American people in colonial Mexico City rather than two sealed populations.
The authors state the attribution themselves and it is quoted rather than paraphrased: the introduction of these and other pathogens from Africa to the Americas should be attributed to the brutal and harsh conditions of the Middle Passage that enslaved Africans were subjected to by traders and colonizers, and not to the African peoples themselves.
A second colonial cemetery, at San Francisco de Campeche in Yucatan, gives the same kind of evidence for a whole town rather than a hospital. The settlement was founded by Francisco de Montejo the younger by the end of 1540 on the site of the Maya town of Ah Kin Pech; its early churchyard, excavated in 2000, held 129 interments and was in use for about 140 years, from the mid sixteenth century until the present cathedral replaced it in 1680, serving Spaniards, mestizos, mulattos, blacks, Indian naborios and seven other Indian groups.
Ten of those individuals were analysed genomically. Eight carried purely Maya ancestry with mitochondrial haplogroups A2 or B2; one young woman was of West African origin, haplogroup L3, whose childhood diet of C3 plants such as rice and whose strontium value, among the highest in the graveyard, show she was not born in Yucatan; one adult man was of unmixed western Mediterranean ancestry, most likely southwestern Spain on lead isotopes, and had lived long in Campeche. Among the ten there was no evidence of mixing across the groups.
The Campeche ground holds a contradiction worth stating in full. Individuals from populations segregated in most other aspects of life - Spanish records describe neighbourhoods divided by ethnicity - were nonetheless buried in the same Catholic cemetery. The burial practice was shared and the living arrangements were not, and neither fact cancels the other.
The cost is measurable there too. Earlier isotopic work identified about a dozen individuals of West African origin in the Campeche series, and most first-generation African immigrants in that series died in their early twenties; one burial shows venereal treponematosis with dense sclerotic bone and a long sequence of repeated active episodes.
This is why the graves matter as a source at all. The Campeche authors note that the voices of Natives and Africans, and of children and women, tend to be harshly underrepresented in colonial historical accounts, which is what makes bioarchaeological and genetic evidence necessary for understanding that society rather than merely decorative.