The ‘red complex’ is an aggregate of three oral bacteria ( Tannerella forsythia , Porphyromonas gingivalis and Treponema denticola ) responsible for severe clinical manifestation of periodontal disease. Here, we report the first direct evidence of ancient T. forsythia DNA in dentin and dental calculus samples from archaeological skeletal remains that span from the Pre-Hispanic to the Colonial period in Mexico. We recovered twelve partial ancient T. forsythia genomes and observed a distinct phylogenetic placement of samples, suggesting that the strains present in Pre-Hispanic individuals likely arrived with the first human migrations to the Americas and that new strains were introduced with the arrival of European and African populations in the sixteenth century. We also identified instances of the differential presence of genes between periods in the T. forsythia ancient genomes, with certain genes present in Pre-Hispanic individuals and absent in Colonial individuals, and vice versa . This study highlights the potential for studying ancient T. forsythia genomes to unveil past social interactions through analysis of disease transmission. Our results illustrate the long-standing relationship between this oral pathogen and its human host, while also unveiling key evidence to understand its evolutionary history in Pre-Hispanic and Colonial Mexico. This article is part of the theme issue ‘Insights into health and disease from ancient biomolecules'.

After the European colonization of the Americas there was a dramatic population collapse of the Indigenous inhabitants caused in part by the introduction of new pathogens. Although there is much speculation on the etiology of the Colonial epidemics, direct evidence for the presence of specific viruses during the Colonial era is lacking. To uncover the diversity of viral pathogens during this period, we designed an enrichment assay targeting ancient DNA (aDNA) from viruses of clinical importance and applied it to DNA extracts from individuals found in a Colonial hospital and a Colonial chapel (16th c. - 18th c.) where records suggest victims of epidemics were buried during important outbreaks in Mexico City. This allowed us to reconstruct three ancient human parvovirus B19 genomes, and one ancient human hepatitis B virus genome from distinct individuals. The viral genomes are similar to African strains, consistent with the inferred morphological and genetic African ancestry of the hosts as well as with the isotopic analysis of the human remains, suggesting an origin on the African continent. This study provides direct molecular evidence of ancient viruses being transported to the Americas during the transatlantic slave trade and their subsequent introduction to New Spain. Altogether, our observations enrich the discussion about the etiology of infectious diseases during the Colonial period in Mexico.

Recent investigations at the site of Xuenkal on the plains north of Chichén Itzá provide evidence of the changing regional political environment during the Terminal Classic Period (A.D. 900–1000). This paper examines a collection of spindle whorls recovered during the 2005, 2006, and 2007 field seasons of the Proyecto Arqueológico Xuenkal (PAX) as evidence for intensification of craft production. Through this analysis and comparison with spindle whorl collections from other Lowland Maya sites, we suggest the inhabitants of Xuenkal rapidly adapted to changing economic demands by increasing the amount of cloth produced in their residential settings, perhaps in response to increased tribute demands that emanated from the dominant political power of the region. Spinning and weaving is associated with the female gender during the Classic Period in Mesoamerica. Thus, intensification of this gendered activity not only produced excess materials for the state, but also reinforced its gender ideology. Analysis of these artifacts adds to the knowledge of Maya cloth production and addresses the nature of Chichén Itzá's influence on regional sites during the height of its influence in the Terminal Classic period.

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