Ancient genomes reveal a deep history of treponemal disease in the Americas.

Human treponemal infections are caused by a family of closely related Treponema pallidum that give rise to the diseases yaws, bejel, pinta and, most famously, syphilis. Debates on both a common origin for these pathogens and the history of syphilis itself has weighed evidence for the "Columbian hypothesis", which argues for an American origin, against that for the "pre-Columbian hypothesis", which argues for presence of the disease in Eurasia in the Medieval period and possibly earlier. While molecular data has provided a genetic basis for distinction of the typed subspecies, deep evolution of the complex has remained unresolved due to limitations in the conclusions that can be drawn from the sparse paleogenomic data currently available.

Late Pleistocene to early Holocene high-quality quartz crystal procurement from the Valiente quarry workshop site (32°S, Chile, South America).

The procurement of high-quality lithic resources is amongst the most indicative processes of decision-making in the archaeology of early human groups peopling the Americas. Directly dated deposits from quarry workshops have been absent of the late Pleistocene record of South America. We present the results of the excavations of a high-quality translucent quartz crystal workshop that yielded radiocarbon-dated coherently layered stratigraphic deposits that shed light into the behavior of the initial stages of lithic procurement.

mtDNA microevolution in Southern Chile's archipelagos.

The genetic variability of four predominantly Indian populations of southern Chile's archipelagos was examined by determining the frequencies of four mitochondrial DNA haplogroups that characterize the American Indian populations. Over 90% of the individuals analyzed presented Native American mtDNA haplogroups. By means of an unweighted group pair method with arithmetic mean (UPGMA) dendrogram, a principal component analysis (PCA) derived from a distance matrix of mtDNA, and the exact test of population differentiation, we are able to prove the existence of a North-South cline.