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Abstract Malaria-causing protozoa of the genusPlasmodiumhave exerted one of the strongest selective pressures on the human genome, and resistance alleles provide biomolecular footprints that outline the historical reach of these species¹. Nevertheless, debate persists over when and how malaria parasites emerged as human pathogens and spread around the globe^1,2. To address these questions, we generated high-coverage ancient mitochondrial and nuclear genome-wide data fromP. falciparum,P. vivaxandP. malariaefrom 16 countries spanning around 5,500 years of human history. We identifiedP. vivaxandP. falciparumacross geographically disparate regions of Eurasia from as early as the fourth and first millenniabce, respectively; forP. vivax, this evidence pre-dates textual references by several millennia³. Genomic analysis supports distinct disease histories forP. falciparumandP. vivaxin the Americas: similarities between now-eliminated European and peri-contact South American strains indicate that European colonizers were the source of AmericanP. vivax, whereas the trans-Atlantic slave trade probably introducedP. falciparuminto the Americas. Our data underscore the role of cross-cultural contacts in the dissemination of malaria, laying the biomolecular foundation for future palaeo-epidemiological research into the impact ofPlasmodiumparasites on human history. Finally, our unexpected discovery ofP. falciparumin the high-altitude Himalayas provides a rare case study in which individual mobility can be inferred from infection status, adding to our knowledge of cross-cultural connectivity in the region nearly three millennia ago. 

Climatic, cryospheric, and biologic changes taking place in the northern Antarctic Peninsula provide examples for how ongoing systemic change may pro‐ gress through the entire Antarctic system. A large, interdisciplinary research project focused on the Larsen Ice Shelf system, synthesized here, has documented dramatic ice cover, oceanographic, and ecosystem changes in the Antarctic Peninsula during the Holocene and the present period of rapid regional warming. The responsive- ness of the region results from its position in the climate and ocean system, in which a narrow continental block extends across zonal atmospheric and ocean flow, creating high snow accumulation, strong gradients and gyres, dynamic oceanography, outlet glaciers feeding into many fjords and bays having steep topography, and a continental shelf that contains many glacially carved troughs separated by areas of glacial sedi- ment accumulation. The microcosm of the northern Antarctic Peninsula has a tendency to change rapidly—rapid relative not just to Antarctica’s mainland but compared to the rest of the planet as well—and it is generally warmer than the rest of Antarctica. Both its Holocene and modern glaciological retreats offer a picture of how larger areas of Antarctica farther south might change under future warming. 

Abstract The calving of A‐68, the 5,800‐km², 1‐trillion‐ton iceberg shed from the Larsen C Ice Shelf in July 2017, is one of over 10 significant ice‐shelf loss events in the past few decades resulting from rapid warming around the Antarctic Peninsula. The rapid thinning, retreat, and collapse of ice shelves along the Antarctic Peninsula are harbingers of warming effects around the entire continent. Ice shelves cover more than 1.5 million km²and fringe 75% of Antarctica's coastline, delineating the primary connections between the Antarctic continent, the continental ice, and the Southern Ocean. Changes in Antarctic ice shelves bring dramatic and large‐scale modifications to Southern Ocean ecosystems and continental ice movements, with global‐scale implications. The thinning and rate of future ice‐shelf demise is notoriously unpredictable, but models suggest increased shelf‐melt and calving will become more common. To date, little is known about sub‐ice‐shelf ecosystems, and our understanding of ecosystem change following collapse and calving is predominantly based on responsive science once collapses have occurred. In this review, we outline what is known about (a) ice‐shelf melt, volume loss, retreat, and calving, (b) ice‐shelf‐associated ecosystems through sub‐ice, sediment‐core, and pre‐collapse and post‐collapse studies, and (c) ecological responses in pelagic, sympagic, and benthic ecosystems. We then discuss major knowledge gaps and how science might address these gaps. This article is categorized under:Climate, Ecology, and Conservation > Modeling Species and Community Interactions