Marine viruses are critical drivers of ocean biogeochemistry and their abundances vary spatiotemporally in the global oceans, with upper estimates exceeding 10 8 per ml. Over many years, a consensus has emerged that virus abundances are typically 10-fold higher than prokaryote abundances. The use of a fixed-ratio suggests that the relationship between virus and prokaryote abundances is both predictable and linear. However, the true explanatory power of a linear relationship and its robustness across diverse ocean environments is unclear. Here, we compile 5671 prokaryote and virus abundance estimates from 25 distinct marine surveys to characterize the relationship between virus and prokaryote abundances. We find that the median virus-to-prokaryote ratio (VPR) is 10:1 and 16:1 in the near-and sub-surface oceans, respectively. Nonetheless, we observe substantial variation in the VPR and find either no or limited explanatory power using fixed-ratio models. Instead, virus abundances are better described as nonlinear, power-law functions of prokaryote abundances -particularly when considering relationships within distinct marine surveys. Estimated power-laws have scaling exponents that are typically less than 1, signifying that the VPR decreases with prokaryote density, rather than remaining fixed. The emergence of power-law scaling presents a challenge for mechanistic models seeking to understand the ecological causes and consequences of marine virusmicrobe interactions. Such power-law scaling also implies that efforts to average viral effects on microbial mortality and biogeochemical cycles using "representative" abundances or abundanceratios need to be refined if they are to be utilized to make quantitative predictions at regional or global ocean scales.

The human dimension of the Columbian Exchange entailed substantial genetic admixture between ancestral source populations from Africa, the Americas and Europe, which had evolved separately for many thousands of years. We sought to address the implications of the creation of admixed American genomes, containing novel allelic combinations, for human health and fitness via analysis of an admixed Colombian population from Medellin. Colombian genomes from Medellin show a wide range of three-way admixture contributions from ancestral source populations. The primary ancestry component for the population is European (average = 74.6%, range = 45.0%–96.7%), followed by Native American (average = 18.1%, range = 2.1%–33.3%) and African (average = 7.3%, range = 0.2%–38.6%). Locus-specific patterns of ancestry were evaluated to search for genomic regions that are enriched across the population for particular ancestry contributions. Adaptive and innate immune system related genes and pathways are particularly over-represented among ancestry-enriched segments, including genes (HLA-B and MAPK10) that are involved in defense against endemic pathogens such as malaria. Genes that encode functions related to skin pigmentation (SCL4A5) and cutaneous glands (EDAR) are also found in regions with anomalous ancestry patterns. These results suggest the possibility that ancestry-specific loci were differentially retained in the modern admixed Colombian population based on their utility in the New World environment.

abundances were related in a predictable way it would be possible to infer the rate of contact, and potentially the relative importance of virus-induced cell lysis, from estimates of microbial abundance alone.Virus ecology underwent a transformation in the late 1980s with the recognition that virus abundances, as estimated using culture-independent methods, were orders of magnitude higher than estimates via culture-based methods [4]. Soon thereafter, researchers began to report the "virus to bacterium ratio" (VBR) as a statistical proxy for the strength of the relationship between viruses and their potential hosts in both freshwater and marine systems [31]. This ratio is more appropriately termed the "virus-to-prokaryote ratio" (VPR) -a convention which Typeset by REVT E X

The original publication of this Article included analysis of virus and microbial cell abundances and virus-to-microbial cell ratios. Data in the Article came from 25 studies intended to be exclusively from marine sites. However, 3 of the studies included in the original unified dataset were erroneously classified as marine sites during compilation. The records with mis-recorded longitude and latitude values were, in fact, taken from inland, freshwater sources. The three inland, freshwater datasets are ELA, TROUT and SWAT. The data from these three studies represent 163 of the 5,671 records in the original publication. In the updated version of the Article, all analyses have been recalculated using the same statistical analysis pipeline released via GitHub as part of the original publication. Removal of the three studies reduces the unified dataset to 5,508 records. Analyses involving all grouped datasets have been updated with changes noted in each figure. All key results remain qualitatively unchanged. All data and scripts used in this correction have been made available as a new, updated GitHub release to reflect the updated dataset and figures.