Comparative genomics of Cryptosporidium parvum reveals the emergence of an outbreak-associated population in Europe and its spread to the United States

The zoonotic parasite Cryptosporidium parvum is a global cause of gastrointestinal disease in humans and ruminants. Sequence analysis of the highly polymorphic gp60 gene enabled the classification of C. parvum isolates into multiple groups (e.g., IIa, IIc, Id) and a large number of subtypes. In Europe, subtype IIaA15G2R1 is largely predominant and has been associated with many water- and food-borne outbreaks. In this study, we generated new whole-genome sequence (WGS) data from 123 human- and ruminant-derived isolates collected in 13 European countries and included other available WGS data from Europe, Egypt, China, and the United States (n = 72) in the largest comparative genomics study to date. We applied rigorous filters to exclude mixed infections and analyzed a data set from 141 isolates from the zoonotic groups IIa (n = 119) and IId (n = 22). Based on 28,047 high-quality, biallelic genomic SNPs, we identified three distinct and strongly supported populations: Isolates from China (IId) and Egypt (IIa and IId) formed population 1; a minority of European isolates (IIa and IId) formed population 2; and the majority of European (IIa, including all IIaA15G2R1 isolates) and all isolates from the United States (IIa) clustered in population 3. Based on analyses of the population structure, population genetics, and recombination, we show that population 3 has recently emerged and expanded throughout Europe to then, possibly from the United Kingdom, reach the United States, where it also expanded. The reason(s) for the successful spread of population 3 remain elusive, although genes under selective pressure uniquely in this population were identified.

Ancient DNA confirms diverse origins of early post-Columbian cattle in the Americas

Before the arrival of Europeans, domestic cattle (Bos taurus) did not exist in the Americas, and most of our knowledge about how domestic bovines first arrived in the Western Hemisphere is based on historical documents. Sixteenth-century colonial accounts suggest that the first cattle were brought in small numbers from the southern Iberian Peninsula via the Canary archipelago to the Caribbean islands where they were bred locally and imported to other circum-Caribbean regions. Modern American heritage cattle genetics and limited ancient mtDNA data from archaeological colonial cattle suggest a more complex story of mixed ancestries from Europe and Africa. So far little information exists to understand the nature and timing of the arrival of these mixed-ancestry populations. In this study we combine ancient mitochondrial and nuclear DNA from a robust sample of some of the earliest archaeological specimens from Caribbean and Mesoamerican sites to clarify the origins and the dynamics of bovine introduction into the Americas. Our analyses support first arrival of cattle from diverse locales and potentially confirm the early arrival of African-sourced cattle in the Americas, followed by waves of later introductions from various sources over several centuries.

Low-carbon cows: From microbial metabolism to the symbiotic planet

This article focuses on two projects - one at a large chemical company and the other at a small start-up - to intervene in the relations between cows and ruminal microbes to reduce bovine methane emissions. It describes these interventions as 'symbiotic engineering': a biopolitical technique targeting holobionts and becoming effective by working on interlaced sets of living things. Based on the analysis of these cases, the article elucidates a planetary symbiopolitics (Helmreich) that connects 'molecular biopolitics' (Rose) and 'microbiopolitics' (Paxson) to 'bovine biopolitics' (Lorimer, Driessen) and the politics of climate change. We critically investigate the spatial imaginaries of symbiotic engineering practices that single out the microbial realm as an Archimedean point to address planetary problems. This technoscientific vision resonates with the notion of the 'symbiotic planet' advanced by Lynn Margulis that depicts the Earth System, or Gaia, as a vast set of relations among living things down to the tiniest microbes. Margulis' concept, as well as the 'symbiotic view of life' (Gilbert, Scott, Sapp) has been embraced in recent debates in STS as a way to think of multispecies worldings. The article contributes critically to these debates by showing what happens when the topology of the symbiotic Earth becomes the operating space for symbiotic engineering practices.

Anthropology and the Anthropocene: Criticisms, Experiments, and Collaborations

The Anthropocene, a proposed name for a geological epoch marked by human impacts on global ecosystems, has inspired anthropologists to critique, to engage in theoretical and methodological experimentation, and to develop new forms of collaboration. Critics are concerned that the term Anthropocene overemphasizes human mastery or erases differential human responsibilities, including imperialism, capitalism, and racism, and new forms of technocratic governance. Others find the term helpful in drawing attention to disastrous environmental change, inspiring a reinvigorated attention to the ontological unruliness of the world, to multiple temporal scales, and to intertwined social and natural histories. New forms of noticing can be linked to systems analytics, including capitalist world systems, structural comparisons of patchy landscapes, infrastructures and ecological models, emerging sociotechnical assemblages, and spirits. Rather than a historical epoch defined by geologists, the Anthropocene is a problem that is pulling anthropologists into new forms of noticing and analysis, and into experiments and collaborations beyond anthropology.

Climate Change Adaptation in Natural World Heritage Sites: A Triage Approach

Climate change is a certainty, but the degree and rate of change, as well as impacts of those changes are highly site-specific. Natural World Heritage sites represent a treasure to be managed and sustained for all humankind. Each World Heritage site is so designated on the basis of one or more Outstanding Universal Values. Because climate change impacts are site-specific, adaptation to sustain Universal Values also must be specific. As such, climate change adaptation is a wicked problem, with no clear action strategies available. Further, adaptation resources are limited at every site. Each site management team must decide which adaptations are appropriate investments. A triage approach guides that evaluation. Some impacts will be so large and/or uncertain that the highest probability of adaptation success comes from a series of uncertain actions that reduce investment risk. Others will be small, certain, comfortable and yet have low probable impact on the Universal Value. A triage approach guides the management team toward highest probable return on investment, involving stakeholders from the surrounding landscape, advancing engagement and communication, and increasing transparency and accountability.