Rebecca M. Stumpf
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Rebecca M. Stumpf has a total of 224 co-authors. Here are the top co-authors by number of shared publications:
- Steven R. Leigh
Department of Anthropology, University of Colorado, Boulder, CO, 80309, USA
7 shared publications - Brenda A. Wilson
Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
4 shared publications - Ana Carolina Torregroza-Espinosa
Department of Natural and Exact Sciences, Corporación Universidad de la Costa, Barranquilla 080002, Colombia
3 shared publications - Bryan A. White
The Institute for Genomic Biology, University of Illinois, Urbana, Illinois, United States of America
3 shared publications - Rob Knight
Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
3 shared publications - Suleyman Yildirim
Department of Medical Microbiology, Istanbul Medipol University International School of Medicine
3 shared publications
Latest Publications
- Open Access
Socioecological Relationships in Strategic Wetlands of the Colombian Caribbean: Community Perceptions, Ecosystem Services, and Environmental Governance
Strategic wetlands in the Colombian Caribbean underpin local livelihoods through vital ecosystem services, yet they face severe degradation from hydrological alterations, urbanization, and anthropogenic pressures. To address the lack of integrated socioecological evaluations, this study examines community–wetland relationships, ecosystem reliance, environmental perceptions, and governance arrangements. We used a multi-scale approach, combining a regional baseline assessment of 25 strategic wetlands with localized empirical fieldwork across three contrasting study sites: Sinú-Cispatá, Magdalena River estuary, and Tasajera–Ciénaga Grande de Santa Marta. We collected data through 150 structured household surveys, semi-structured interviews, and participatory social cartography. Findings reveal a strong, structural dependence on wetland resources, dominated by artisanal fisheries, navigation, and mangrove-based livelihoods. Communities consistently link ecosystem decline to hydrological disruptions, fisheries collapse, and deteriorating water quality, with marked spatial variations driven by urban–industrial stress in Atlántico versus hydrological fragmentation in Magdalena. Results also highlight significant governance gaps, including institutional distance and multi-agency fragmentation between regional environmental authorities and fisheries bodies. Ultimately, this research underscores the necessity of establishing participatory, territorially grounded governance frameworks that integrate local ecological knowledge, community-based monitoring, and adaptive management to foster long-term socioecological resilience in Caribbean wetlands.
Open AccessSocioecological Relationships in Strategic Wetlands of the Colombian Caribbean: Community Perceptions, Ecosystem Services, and Environmental Governance
Strategic wetlands in the Colombian Caribbean underpin local livelihoods through vital ecosystem services, yet they face severe degradation from hydrological alterations, urbanization, and anthropogenic pressures. To address the lack of integrated socioecological evaluations, this study examines community–wetland relationships, ecosystem reliance, environmental perceptions, and governance arrangements. We used a multi-scale approach, combining a regional baseline assessment of 25 strategic wetlands with localized empirical fieldwork across three contrasting study sites: Sinú-Cispatá, Magdalena River estuary, and Tasajera–Ciénaga Grande de Santa Marta. We collected data through 150 structured household surveys, semi-structured interviews, and participatory social cartography. Findings reveal a strong, structural dependence on wetland resources, dominated by artisanal fisheries, navigation, and mangrove-based livelihoods. Communities consistently link ecosystem decline to hydrological disruptions, fisheries collapse, and deteriorating water quality, with marked spatial variations driven by urban–industrial stress in Atlántico versus hydrological fragmentation in Magdalena. Results also highlight significant governance gaps, including institutional distance and multi-agency fragmentation between regional environmental authorities and fisheries bodies. Ultimately, this research underscores the necessity of establishing participatory, territorially grounded governance frameworks that integrate local ecological knowledge, community-based monitoring, and adaptive management to foster long-term socioecological resilience in Caribbean wetlands.
- Open Access
- 27 August 2026
- Published by MDPI AG in Environments
- Vol. 13 (9) , 475
Socio-Environmental Characterization of Artisanal Fishers in the Lower Magdalena River Estuarine Zone: Implications for Water Governance and Monitoring Systems
Artisanal fisheries are fundamental to riverine socioecological systems, yet fishing communities remain underrepresented in environmental governance and decision-making. This gap constrains the incorporation of local knowledge into environmental decision-making and may reduce the effectiveness of governance strategies for addressing complex socioecological challenges. This study analyzes the socio-environmental characteristics of artisanal fisheries in the lower Magdalena River estuarine zone (Colombia) and discusses their implications for water governance and monitoring systems. Using a mixed-methods integrative design, we combined a PRISMA-guided literature review with a structured survey of 43 community members in the strategic territory of Bocas de Cenizas–Ciénaga de Mallorquín. The results reveal strong livelihood dependence on aquatic ecosystems, increasing environmental pressures, and limited institutional coordination. Respondents reported clear perceptions of environmental degradation, including declines in fish availability, vegetation cover, and water quality. Crucially, local actors possess detailed experiential knowledge of these transformations and show favorable conditions for participatory engagement. The integrative analysis indicates that artisanal fishers are not merely vulnerable populations, but key environmental observers whose knowledge can enhance adaptive and inclusive water governance. The findings identify a specific monitoring gap in the lower Magdalena estuarine zone: the environmental changes most consistently perceived by local actors—including declining fish availability, deteriorating water conditions, vegetation loss, and shoreline erosion—are directly linked to livelihood dependence but remain weakly connected to formal governance processes. These locally observed variables provide a context-specific basis for developing integrated socioecological and hydroenvironmental monitoring systems that combine conventional scientific indicators with community-based observations, thereby improving the territorial relevance of environmental information for water governance and decision-making.
- 27 August 2026
- Published by MDPI AG in Environments
- Vol. 13 (9) , 475
Open AccessSocio-Environmental Characterization of Artisanal Fishers in the Lower Magdalena River Estuarine Zone: Implications for Water Governance and Monitoring Systems
Artisanal fisheries are fundamental to riverine socioecological systems, yet fishing communities remain underrepresented in environmental governance and decision-making. This gap constrains the incorporation of local knowledge into environmental decision-making and may reduce the effectiveness of governance strategies for addressing complex socioecological challenges. This study analyzes the socio-environmental characteristics of artisanal fisheries in the lower Magdalena River estuarine zone (Colombia) and discusses their implications for water governance and monitoring systems. Using a mixed-methods integrative design, we combined a PRISMA-guided literature review with a structured survey of 43 community members in the strategic territory of Bocas de Cenizas–Ciénaga de Mallorquín. The results reveal strong livelihood dependence on aquatic ecosystems, increasing environmental pressures, and limited institutional coordination. Respondents reported clear perceptions of environmental degradation, including declines in fish availability, vegetation cover, and water quality. Crucially, local actors possess detailed experiential knowledge of these transformations and show favorable conditions for participatory engagement. The integrative analysis indicates that artisanal fishers are not merely vulnerable populations, but key environmental observers whose knowledge can enhance adaptive and inclusive water governance. The findings identify a specific monitoring gap in the lower Magdalena estuarine zone: the environmental changes most consistently perceived by local actors—including declining fish availability, deteriorating water conditions, vegetation loss, and shoreline erosion—are directly linked to livelihood dependence but remain weakly connected to formal governance processes. These locally observed variables provide a context-specific basis for developing integrated socioecological and hydroenvironmental monitoring systems that combine conventional scientific indicators with community-based observations, thereby improving the territorial relevance of environmental information for water governance and decision-making.
- Open Access
- 9 January 2026
- Published by Elsevier in The Lancet Microbe
- Vol. 7 (4) , 101319
Integrating microbiomes into One Health: insights from the 2025 One Health World Microbiome Partnership Summit
- 9 January 2026
- Published by Elsevier in The Lancet Microbe
- Vol. 7 (4) , 101319
Open AccessIntegrating microbiomes into One Health: insights from the 2025 One Health World Microbiome Partnership Summit
- Open Access
Ancestral Knowledge and River Systems: Pathways to Sustainability, Peace, and Community Resilience
This study offers a unique perspective on the role of ancestral knowledge in sustainable river management and community resilience. Specifically, this study draws on (1) a systematic literature review using the PRISMA methodology and (2) a qualitative analysis of community surveys conducted with 39 women in Zambrano, Colombia, to examine the impact of ancestral knowledge on sustainability, peace promotion, and community development. The findings highlight that women’s traditional water management practices significantly contribute to environmental sustainability, conflict resolution, and social cohesion. Women play a central role in transmitting and applying ancestral water knowledge, yet they remain marginalized in decision-making processes, often facing barriers to participation in governance structures. Finally, these findings proposed strategies for integrating ancestral knowledge into sustainable resource management policies. This study underscores the urgent need for legal recognition, intercultural dialogue, gender-inclusive governance, and educational programs to ensure the transmission and adaptation of these practices in contemporary contexts. Integrating ancestral knowledge into water management policies is essential for strengthening gender equity, community resilience, and fostering governance models that harmoniously combine traditional and scientific approaches.
Open AccessAncestral Knowledge and River Systems: Pathways to Sustainability, Peace, and Community Resilience
This study offers a unique perspective on the role of ancestral knowledge in sustainable river management and community resilience. Specifically, this study draws on (1) a systematic literature review using the PRISMA methodology and (2) a qualitative analysis of community surveys conducted with 39 women in Zambrano, Colombia, to examine the impact of ancestral knowledge on sustainability, peace promotion, and community development. The findings highlight that women’s traditional water management practices significantly contribute to environmental sustainability, conflict resolution, and social cohesion. Women play a central role in transmitting and applying ancestral water knowledge, yet they remain marginalized in decision-making processes, often facing barriers to participation in governance structures. Finally, these findings proposed strategies for integrating ancestral knowledge into sustainable resource management policies. This study underscores the urgent need for legal recognition, intercultural dialogue, gender-inclusive governance, and educational programs to ensure the transmission and adaptation of these practices in contemporary contexts. Integrating ancestral knowledge into water management policies is essential for strengthening gender equity, community resilience, and fostering governance models that harmoniously combine traditional and scientific approaches.
- Open Access
- 29 June 2022
- Published by American Society for Microbiology in Microbiology Spectrum
- Vol. 10 (3) , e0164321
Large Comparative Analyses of Primate Body Site Microbiomes Indicate that the Oral Microbiome Is Unique among All Body Sites and Conserved among Nonhuman Primates
The microbiome is critical to host health and disease, but much remains unknown about the determinants, levels, and evolution of host-microbial diversity. The relationship between hosts and their associated microbes is complex.
- 29 June 2022
- Published by American Society for Microbiology in Microbiology Spectrum
- Vol. 10 (3) , e0164321
Open AccessLarge Comparative Analyses of Primate Body Site Microbiomes Indicate that the Oral Microbiome Is Unique among All Body Sites and Conserved among Nonhuman Primates
The microbiome is critical to host health and disease, but much remains unknown about the determinants, levels, and evolution of host-microbial diversity. The relationship between hosts and their associated microbes is complex.
- Open Access
- 8 October 2019
- Published by Springer Nature in Genome Biology
- Vol. 20 (1) , 1-12
Convergence of human and Old World monkey gut microbiomes demonstrates the importance of human ecology over phylogeny
Background: Comparative data from non-human primates provide insight into the processes that shaped the evolution of the human gut microbiome and highlight microbiome traits that differentiate humans from other primates. Here, in an effort to improve our understanding of the human microbiome, we compare gut microbiome composition and functional potential in 14 populations of humans from ten nations and 18 species of wild, non-human primates.Results: Contrary to expectations from host phylogenetics, we find that human gut microbiome composition and functional potential are more similar to those of cercopithecines, a subfamily of Old World monkey, particularly baboons, than to those of African apes. Additionally, our data reveal more inter-individual variation in gut microbiome functional potential within the human species than across other primate species, suggesting that the human gut microbiome may exhibit more plasticity in response to environmental variation compared to that of other primates.Conclusions: Given similarities of ancestral human habitats and dietary strategies to those of baboons, these findings suggest that convergent ecologies shaped the gut microbiomes of both humans and cercopithecines, perhaps through environmental exposure to microbes, diet, and/or associated physiological adaptations. Increased inter-individual variation in the human microbiome may be associated with human dietary diversity or the ability of humans to inhabit novel environments. Overall, these findings show that diet, ecology, and physiological adaptations are more important than host-microbe co-diversification in shaping the human microbiome, providing a key foundation for comparative analyses of the role of the microbiome in human biology and health.
- 8 October 2019
- Published by Springer Nature in Genome Biology
- Vol. 20 (1) , 1-12
Open AccessConvergence of human and Old World monkey gut microbiomes demonstrates the importance of human ecology over phylogeny
Background: Comparative data from non-human primates provide insight into the processes that shaped the evolution of the human gut microbiome and highlight microbiome traits that differentiate humans from other primates. Here, in an effort to improve our understanding of the human microbiome, we compare gut microbiome composition and functional potential in 14 populations of humans from ten nations and 18 species of wild, non-human primates.Results: Contrary to expectations from host phylogenetics, we find that human gut microbiome composition and functional potential are more similar to those of cercopithecines, a subfamily of Old World monkey, particularly baboons, than to those of African apes. Additionally, our data reveal more inter-individual variation in gut microbiome functional potential within the human species than across other primate species, suggesting that the human gut microbiome may exhibit more plasticity in response to environmental variation compared to that of other primates.Conclusions: Given similarities of ancestral human habitats and dietary strategies to those of baboons, these findings suggest that convergent ecologies shaped the gut microbiomes of both humans and cercopithecines, perhaps through environmental exposure to microbes, diet, and/or associated physiological adaptations. Increased inter-individual variation in the human microbiome may be associated with human dietary diversity or the ability of humans to inhabit novel environments. Overall, these findings show that diet, ecology, and physiological adaptations are more important than host-microbe co-diversification in shaping the human microbiome, providing a key foundation for comparative analyses of the role of the microbiome in human biology and health.
- Open Access
- 26 January 2019
- Published by Cold Spring Harbor Laboratory in bioRxiv
- p. 527796
Global phylogeography and ancient evolution of the widespread human gut virus crAssphage
Microbiomes are vast communities of microbes and viruses that populate all natural ecosystems. Viruses have been considered the most variable component of microbiomes, as supported by virome surveys and examples of high genomic mosaicism. However, recent evidence suggests that the human gut virome is remarkably stable compared to other environments. Here we investigate the origin, evolution, and epidemiology of crAssphage, a widespread human gut virus. Through a global collaboratory, we obtained DNA sequences of crAssphage from over one-third of the world's countries, and showed that its phylogeography is locally clustered within countries, cities, and individuals. We also found colinear crAssphage-like genomes in both Old-World and New-World primates, challenging genomic mosaicism and suggesting that the association of crAssphage with primates may be millions of years old. We conclude that crAssphage is a benign globetrotter virus that may have co-evolved with the human lineage and an integral part of the normal human gut virome.
- 26 January 2019
- Published by Cold Spring Harbor Laboratory in bioRxiv
- p. 527796
Open AccessGlobal phylogeography and ancient evolution of the widespread human gut virus crAssphage
Microbiomes are vast communities of microbes and viruses that populate all natural ecosystems. Viruses have been considered the most variable component of microbiomes, as supported by virome surveys and examples of high genomic mosaicism. However, recent evidence suggests that the human gut virome is remarkably stable compared to other environments. Here we investigate the origin, evolution, and epidemiology of crAssphage, a widespread human gut virus. Through a global collaboratory, we obtained DNA sequences of crAssphage from over one-third of the world's countries, and showed that its phylogeography is locally clustered within countries, cities, and individuals. We also found colinear crAssphage-like genomes in both Old-World and New-World primates, challenging genomic mosaicism and suggesting that the association of crAssphage with primates may be millions of years old. We conclude that crAssphage is a benign globetrotter virus that may have co-evolved with the human lineage and an integral part of the normal human gut virome.
- 16 March 2016
- Published by Springer Nature in Microbial Ecology
- Vol. 72 (4) , 943-954
Effect of Antibiotic Treatment on the Gastrointestinal Microbiome of Free-Ranging Western Lowland Gorillas (Gorilla g. gorilla)
The mammalian gastrointestinal (GI) microbiome, which plays indispensable roles in host nutrition and health, is affected by numerous intrinsic and extrinsic factors. Among them, antibiotic (ATB) treatment is reported to have a significant effect on GI microbiome composition in humans and other animals. However, the impact of ATBs on the GI microbiome of free-ranging or even captive great apes remains poorly characterized. Here, we investigated the effect of cephalosporin treatment (delivered by intramuscular dart injection during a serious respiratory outbreak) on the GI microbiome of a wild habituated group of western lowland gorillas (Gorilla gorilla gorilla) in the Dzanga Sangha Protected Areas, Central African Republic. We examined 36 fecal samples from eight individuals, including samples before and after ATB treatment, and characterized the GI microbiome composition using Illumina-MiSeq sequencing of the bacterial 16S rRNA gene. The GI microbial profiles of samples from the same individuals before and after ATB administration indicate that the ATB treatment impacts GI microbiome stability and the relative abundance of particular bacterial taxa within the colonic ecosystem of wild gorillas. We observed a statistically significant increase in Firmicutes and a decrease in Bacteroidetes levels after ATB treatment. We found disruption of the fibrolytic community linked with a decrease of Ruminoccocus levels as a result of ATB treatment. Nevertheless, the nature of the changes observed after ATB treatment differs among gorillas and thus is dependent on the individual host. This study has important implications for ecology, management, and conservation of wild primates.
- 16 March 2016
- Published by Springer Nature in Microbial Ecology
- Vol. 72 (4) , 943-954
Effect of Antibiotic Treatment on the Gastrointestinal Microbiome of Free-Ranging Western Lowland Gorillas (Gorilla g. gorilla)
The mammalian gastrointestinal (GI) microbiome, which plays indispensable roles in host nutrition and health, is affected by numerous intrinsic and extrinsic factors. Among them, antibiotic (ATB) treatment is reported to have a significant effect on GI microbiome composition in humans and other animals. However, the impact of ATBs on the GI microbiome of free-ranging or even captive great apes remains poorly characterized. Here, we investigated the effect of cephalosporin treatment (delivered by intramuscular dart injection during a serious respiratory outbreak) on the GI microbiome of a wild habituated group of western lowland gorillas (Gorilla gorilla gorilla) in the Dzanga Sangha Protected Areas, Central African Republic. We examined 36 fecal samples from eight individuals, including samples before and after ATB treatment, and characterized the GI microbiome composition using Illumina-MiSeq sequencing of the bacterial 16S rRNA gene. The GI microbial profiles of samples from the same individuals before and after ATB administration indicate that the ATB treatment impacts GI microbiome stability and the relative abundance of particular bacterial taxa within the colonic ecosystem of wild gorillas. We observed a statistically significant increase in Firmicutes and a decrease in Bacteroidetes levels after ATB treatment. We found disruption of the fibrolytic community linked with a decrease of Ruminoccocus levels as a result of ATB treatment. Nevertheless, the nature of the changes observed after ATB treatment differs among gorillas and thus is dependent on the individual host. This study has important implications for ecology, management, and conservation of wild primates.
- Open Access
- 16 November 2015
- Published by Springer Nature in Microbiome
- Vol. 3 (1) , 1-9
Variable responses of human and non-human primate gut microbiomes to a Western diet
The human gut microbiota interacts closely with human diet and physiology. To better understand the mechanisms behind this relationship, gut microbiome research relies on complementing human studies with manipulations of animal models, including non-human primates. However, due to unique aspects of human diet and physiology, it is likely that host-gut microbe interactions operate differently in humans and non-human primates. Here, we show that the human microbiome reacts differently to a high-protein, high-fat Western diet than that of a model primate, the African green monkey, or vervet (Chlorocebus aethiops sabaeus). Specifically, humans exhibit increased relative abundance of Firmicutes and reduced relative abundance of Prevotella on a Western diet while vervets show the opposite pattern. Predictive metagenomics demonstrate an increased relative abundance of genes associated with carbohydrate metabolism in the microbiome of only humans consuming a Western diet. These results suggest that the human gut microbiota has unique properties that are a result of changes in human diet and physiology across evolution or that may have contributed to the evolution of human physiology. Therefore, the role of animal models for understanding the relationship between the human gut microbiota and host metabolism must be re-focused.
- 16 November 2015
- Published by Springer Nature in Microbiome
- Vol. 3 (1) , 1-9
Open AccessVariable responses of human and non-human primate gut microbiomes to a Western diet
The human gut microbiota interacts closely with human diet and physiology. To better understand the mechanisms behind this relationship, gut microbiome research relies on complementing human studies with manipulations of animal models, including non-human primates. However, due to unique aspects of human diet and physiology, it is likely that host-gut microbe interactions operate differently in humans and non-human primates. Here, we show that the human microbiome reacts differently to a high-protein, high-fat Western diet than that of a model primate, the African green monkey, or vervet (Chlorocebus aethiops sabaeus). Specifically, humans exhibit increased relative abundance of Firmicutes and reduced relative abundance of Prevotella on a Western diet while vervets show the opposite pattern. Predictive metagenomics demonstrate an increased relative abundance of genes associated with carbohydrate metabolism in the microbiome of only humans consuming a Western diet. These results suggest that the human gut microbiota has unique properties that are a result of changes in human diet and physiology across evolution or that may have contributed to the evolution of human physiology. Therefore, the role of animal models for understanding the relationship between the human gut microbiota and host metabolism must be re-focused.
- 18 July 2014
- Published by Oxford University Press (OUP) in The ISME Journal
- Vol. 8 (12) , 2431-2444
Primate vaginal microbiomes exhibit species specificity without universal Lactobacillus dominance
Bacterial communities colonizing the reproductive tracts of primates (including humans) impact the health, survival and fitness of the host, and thereby the evolution of the host species. Despite their importance, we currently have a poor understanding of primate microbiomes. The composition and structure of microbial communities vary considerably depending on the host and environmental factors. We conducted comparative analyses of the primate vaginal microbiome using pyrosequencing of the 16S rRNA genes of a phylogenetically broad range of primates to test for factors affecting the diversity of primate vaginal ecosystems. The nine primate species included: humans (Homo sapiens), yellow baboons (Papio cynocephalus), olive baboons (Papio anubis), lemurs (Propithecus diadema), howler monkeys (Alouatta pigra), red colobus (Piliocolobus rufomitratus), vervets (Chlorocebus aethiops), mangabeys (Cercocebus atys) and chimpanzees (Pan troglodytes). Our results indicated that all primates exhibited host-specific vaginal microbiota and that humans were distinct from other primates in both microbiome composition and diversity. In contrast to the gut microbiome, the vaginal microbiome showed limited congruence with host phylogeny, and neither captivity nor diet elicited substantial effects on the vaginal microbiomes of primates. Permutational multivariate analysis of variance and Wilcoxon tests revealed correlations among vaginal microbiota and host species-specific socioecological factors, particularly related to sexuality, including: female promiscuity, baculum length, gestation time, mating group size and neonatal birth weight. The proportion of unclassified taxa observed in nonhuman primate samples increased with phylogenetic distance from humans, indicative of the existence of previously unrecognized microbial taxa. These findings contribute to our understanding of host–microbe variation and coevolution, microbial biogeography, and disease risk, and have important implications for the use of animal models in studies of human sexual and reproductive diseases.
- 18 July 2014
- Published by Oxford University Press (OUP) in The ISME Journal
- Vol. 8 (12) , 2431-2444
Primate vaginal microbiomes exhibit species specificity without universal Lactobacillus dominance
Bacterial communities colonizing the reproductive tracts of primates (including humans) impact the health, survival and fitness of the host, and thereby the evolution of the host species. Despite their importance, we currently have a poor understanding of primate microbiomes. The composition and structure of microbial communities vary considerably depending on the host and environmental factors. We conducted comparative analyses of the primate vaginal microbiome using pyrosequencing of the 16S rRNA genes of a phylogenetically broad range of primates to test for factors affecting the diversity of primate vaginal ecosystems. The nine primate species included: humans (Homo sapiens), yellow baboons (Papio cynocephalus), olive baboons (Papio anubis), lemurs (Propithecus diadema), howler monkeys (Alouatta pigra), red colobus (Piliocolobus rufomitratus), vervets (Chlorocebus aethiops), mangabeys (Cercocebus atys) and chimpanzees (Pan troglodytes). Our results indicated that all primates exhibited host-specific vaginal microbiota and that humans were distinct from other primates in both microbiome composition and diversity. In contrast to the gut microbiome, the vaginal microbiome showed limited congruence with host phylogeny, and neither captivity nor diet elicited substantial effects on the vaginal microbiomes of primates. Permutational multivariate analysis of variance and Wilcoxon tests revealed correlations among vaginal microbiota and host species-specific socioecological factors, particularly related to sexuality, including: female promiscuity, baculum length, gestation time, mating group size and neonatal birth weight. The proportion of unclassified taxa observed in nonhuman primate samples increased with phylogenetic distance from humans, indicative of the existence of previously unrecognized microbial taxa. These findings contribute to our understanding of host–microbe variation and coevolution, microbial biogeography, and disease risk, and have important implications for the use of animal models in studies of human sexual and reproductive diseases.