Pre-Clovis occupation of the Americas identified by human fecal biomarkers in coprolites from Paisley Caves, Oregon

Fecal biomarkers and micromorphological indicators of sheep penning and flooring at La Fortaleza pre-Hispanic site (Gran Canaria, Canary Islands)

This study explores the lipid content and micromorphological features of sediment samples from two dwelling structures at the pre-Hispanic site of La Fortaleza in Santa Lucía de Tirajana (Gran Canaria, Spain). Previous field identification of possible sedimentary excrements inside the dwellings motivated chromatographic fecal biomarker analysis and micromorphology. The micromorphological samples reveal a complex dung-rich stratified sequence involving different layers of mixed composition, including reworked dung, clay, wood ash, and domestic refuse. The results of the lipid analysis corroborate the fecal nature of the sample and indicate the source animal: sheep. Coupled with the field evidence, the data suggest that the deposit is anthropogenic and represents a sequence of floor foundations, dung floors, and domestic and architectural refuse. This study provides valuable taxonomic and site use data for the understanding of the aboriginal societies of the Canary Islands and shows the efficacy of combining field observations with high-resolution geoarchaeological methods.

Circadian rhythm and host genetics

This chapter aims to explore the usefulness of the latest advances in genetic studies in the field of the circadian system in the future development of individualised strategies for health improvement based on lifestyle intervention. Due to the multifactorial and complex nature of the circadian system, we focus on the highly prevalent phenotypes in the population that are key to understanding its biology from an evolutionary perspective and that can be modulated by lifestyle. Therefore, we leave in the background those phenotypes that constitute infrequent pathologies or in which the current level of scientific evidence does not favour the implementation of practical approaches of this type. Therefore, from an evolutionary paradigm, this chapter addresses phenotypes such as morning chronotypes, evening chronotypes, extreme chronotypes, and other key concepts such as circadian rhythm amplitude, resilience to changes in circadian rhythm, and their relationships with pathologies associated with circadian rhythm imbalances.

Undiscovered bird extinctions obscure the true magnitude of human-driven extinction waves

Birds are among the best-studied animal groups, but their prehistoric diversity is poorly known due to low fossilization potential. Hence, while many human-driven bird extinctions (i.e., extinctions caused directly by human activities such as hunting, as well as indirectly through human-associated impacts such as land use change, fire, and the introduction of invasive species) have been recorded, the true number is likely much larger. Here, by combining recorded extinctions with model estimates based on the completeness of the fossil record, we suggest that at least ~1300-1500 bird species (~12% of the total) have gone extinct since the Late Pleistocene, with 55% of these extinctions undiscovered (not yet discovered or left no trace). We estimate that the Pacific accounts for 61% of total bird extinctions. Bird extinction rate varied through time with an intense episode ~1300 CE, which likely represents the largest human-driven vertebrate extinction wave ever, and a rate 80 (60-95) times the background extinction rate. Thus, humans have already driven more than one in nine bird species to extinction, with likely severe, and potentially irreversible, ecological and evolutionary consequences.

Analysis of microbiome diversity in coprolites from Caral, Peru

We analyzed human coprolites from the Sacred City of Caral, the oldest civilization in America (3000- and 1800-years BC). Our objective was to know the microbial diversity of the Caral Civilization through the use of a mobile ancient laboratory. DNA extraction conducted in a mobile laboratory placed near the collection site to reduce exposure of samples to contaminants and favor a rapid molecular processing. Using 16S rRNA and ITS 1 amplicon sequencing, we have elaborated the first list of the microbiomes of Caral, based on the bacterial and fungal community fingerprints detected in the coprolites recovered in six sectors of that ancient urban center. Among the most abundant sequences were those associated with Firmicutes for bacteria, Ascomycota and Basidiomycota for fungi. Bacillus was the most abundant bacterial genera in all samples analyzed, compromising up to 24.81% of the total bacterial abundance; while Aspergillus (11.43%) was the most abundant genera among fungal communities.

Intestinal parasites in the Neolithic population who built Stonehenge (Durrington Walls, 2500 BCE)

Durrington Walls was a large Neolithic settlement in Britain dating around 2500 BCE, located very close to Stonehenge and likely to be the campsite where its builders lived during its main stage of construction. Nineteen coprolites recovered from a midden and associated pits at Durrington Walls were analysed for intestinal parasite eggs using digital light microscopy. Five (26%) contained helminth eggs, 1 with those of fish tapeworm (likely Dibothriocephalus dendriticus) and 4 with those of capillariid nematodes. Analyses of bile acid and sterol from these 5 coprolites show 1 to be of likely human origin and the other 4 to likely derive from dogs. The presence of fish tapeworm reveals that the Neolithic people who gathered to feast at Durrington Walls were at risk of infection from eating raw or undercooked freshwater fish. When the eggs of capillariids are found in the feces of humans or dogs it normally indicates that the internal organs (liver, lung or intestines) of animals with capillariasis have been eaten, and eggs passed through the gut without causing disease. Their presence in multiple coprolites provides new evidence that internal organs of animals were consumed. These novel findings improve our understanding of both parasitic infection and dietary habits associated with this key Neolithic ceremonial site.

Geographically diverse canid sampling provides novel insights into pre-industrial microbiomes

Canine microbiome studies are often limited in the geographic and temporal scope of samples studied. This results in a paucity of data on the canine microbiome around the world, especially in contexts where dogs may not be pets or human associated. Here, we present the shotgun sequences of fecal microbiomes of pet dogs from South Africa, shelter and stray dogs from India, and stray village dogs in Laos. We additionally performed a dietary experiment with dogs housed in a veterinary medical school, attempting to replicate the diet of the sampled dogs from Laos. We analyse the taxonomic diversity in these populations and identify the underlying functional redundancy of these microbiomes. Our results show that diet alone is not sufficient to recapitulate the higher diversity seen in the microbiome of dogs from Laos. Comparisons to previous studies and ancient dog fecal microbiomes highlight the need for greater population diversity in studies of canine microbiomes, as modern analogues can provide better comparisons to ancient microbiomes. We identify trends in microbial diversity and industrialization in dogs that mirror results of human studies, suggesting future research can make use of these companion animals as substitutes for humans in studying the effects of industrialization on the microbiome.