Adaptation to specialized diets often requires modifications at both genomic and microbiome levels. We applied a hologenomic approach to the common vampire bat (Desmodus rotundus), one of the only three obligate blood-feeding (sanguivorous) mammals, to study the evolution of its complex dietary adaptation. Specifically, we assembled its high-quality reference genome (scaffold N50 = 26.9 Mb, contig N50 = 36.6 kb) and gut metagenome, and compared them against those of insectivorous, frugivorous and carnivorous bats. Our analyses showed a particular common vampire bat genomic landscape regarding integrated viral elements, a dietary and phylogenetic influence on gut microbiome taxonomic and functional profiles, and that both genetic elements harbour key traits related to the nutritional (for example, vitamin and lipid shortage) and non-nutritional (for example, nitrogen waste and osmotic homeostasis) challenges of sanguivory. These findings highlight the value of a holistic study of both the host and its microbiota when attempting to decipher adaptations underlying radical dietary lifestyles.

While environmental DNA (eDNA) is becoming increasingly established in biodiversity monitoring of freshwater ecosystems, the use of eDNA surveys in the marine environment is still in its infancy. Here, we use two approaches: targeted quantitative PCR (qPCR) and whole‐genome enrichment capture followed by shotgun sequencing in an effort to amplify killer whale DNA from seawater samples. Samples were collected in close proximity to killer whales in inshore and offshore waters, in varying sea conditions and from the surface and subsurface but none returned strongly positive detections of killer whale eDNA. We validated our laboratory methodologies by successfully amplifying a dilution series of a positive control of killer whale DNA. Furthermore, DNA of Atlantic mackerel, which was present at all sites during sampling, was successfully amplified from the same seawater samples, with positive detections found in ten of the eighteen eDNA extracts. We discuss the various eDNA collection and amplification methodologies used and the abiotic and biotic factors that influence eDNA detection. We discuss possible explanations for the lack of positive killer whale detections, potential pitfalls, and the apparent limitations of eDNA for genetic research on cetaceans, particularly in offshore regions.

The domestic dog has inhabited the anthropogenic niche for at least 15 000 years, but despite their impact on human strategies, the lives of dogs and their interactions with humans have only recently become a subject of interest to archaeologists. In the Arctic, dogs rely exclusively on humans for food during the winter, and while stable isotope analyses have revealed dietary similarities at some sites, deciphering the details of provisioning strategies have been challenging. In this study, we apply zooarchaeology by mass spectrometry (ZooMS) and liquid chromatography tandem mass spectrometry to dog palaeofaeces to investigate protein preservation in this highly degradable material and obtain information about the diet of domestic dogs at the Nunalleq site, Alaska. We identify a suite of digestive and metabolic proteins from the host species, demonstrating the utility of this material as a novel and viable substrate for the recovery of gastrointestinal proteomes. The recovered proteins revealed that the Nunalleq dogs consumed a range of Pacific salmon species (coho, chum, chinook and sockeye) and that the consumed tissues derived from muscle and bone tissues as well as roe and guts. Overall, the study demonstrated the viability of permafrost-preserved palaeofaeces as a unique source of host and dietary proteomes.

Zoonoses are among the greatest threats to human health, with many zoonotic pathogens believed to have emerged following the Neolithic transition. Palaeomicrobiological investigations of the zooarchaeological record hold potential to uncover the reservoirs, host ranges, and host adaptations of zoonotic pathogens in the past, but face challenges in identifying promising specimens and pathogen DNA preservation. We perform palaeopathological and genetic examinations of 346 skeletal elements from domesticated and wild animals collected from 34 Eurasian sites dating across the last six millennia. We identify 116 signatures of 29 ancient (opportunistic) pathogens and find support that palaeopathological lesions provide guidance for specimen selection. For two pathogen species, Erysipelothrix rhusiopathiae and Streptococcus lutetiensis , we confirm their ancient authenticity using phylogenetics, showcasing an approach to explore the relationship between ancient low-coverage genomes and their modern-day relatives. Our work presents a pathway to understanding prehistoric zoonotic diseases by integrating zooarchaeological, palaeopathological, and genetic data.

Zoonoses are among the greatest threats to human health, with many zoonotic pathogens believed to have emerged during prehistory. Palaeomicrobiological investigations of the zooarchaeological record hold potential to uncover the reservoirs, host ranges, and host adaptations of zoonotic pathogens but face challenges in identifying promising specimens and pathogen DNA preservation. We performed palaeopathological and genetic examinations of 346 skeletal elements from domesticated and wild animals collected from 34 Eurasian sites dating across the last six millennia. We identified 68 signatures of ancient (opportunistic) pathogens, including the important zoonotic pathogen Salmonella enterica , and found support that palaeopathological lesions provide guidance for specimen selection. For two pathogen species, Erysipelothrix rhusiopathiae and Streptococcus lutetiensis , we confirmed their ancient authenticity using phylogenetics, showcasing an approach to explore the relationship between ancient low-coverage genomes and their modern-day relatives. Our work presents a pathway to understanding prehistoric zoonotic diseases by integrating zooarchaeological, palaeopathological, and genetic data.