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Norwood AL, Wang B, Kingston JD. Linking African herbivore community enamel isotopes and environments: challenges, opportunities, and paleoecological implications. Oecologia 2024; 204:467-489. [PMID: 38517529 DOI: 10.1007/s00442-024-05532-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 02/18/2024] [Indexed: 03/24/2024]
Abstract
Paleoenvironmental reconstructions of fossil sites based on isotopic analyses of enamel typically rely on data from multiple herbivore taxa, with the assumption that this dietary spectrum represents the community's isotopic range and provides insights into local or regional vegetation patterns. However, it remains unclear how representative the sampled taxa are of the broader herbivore community and how well these data correspond to specific ecosystems. Verifying these underlying assumptions is essential to refining the utility of enamel isotopic values for paleoenvironmental reconstructions. This study explores potential links between modern herbivore community carbon isotopic enamel spectra, biome types, and climate in sub-Saharan Africa. This region is one of the most comprehensively isotopically sampled areas globally and is of particular relevance to hominin evolution. Our extensive data compilation reveals that published enamel isotopic data from sub-Saharan Africa typically sample only a small percentage of the taxa documented at most localities and that some biome types (e.g., subtropical savannas) are dramatically overrepresented relative to others (e.g., forests) in these modern data sets. Multiple statistical analyses, including linear models and cluster analyses, revealed weak relationships of associated mammalian herbivore enamel isotopic values, biome type, and climate parameters. These results confound any simple assumptions about how community isotopic profiles map onto specific environments, highlighting the need for more precise strategic approaches in extending isotopic frameworks into the past for paleoecological reconstructions. Developing more refined modern analogs will ultimately allow us to more accurately characterize the isotopic spectra of paleo-communities and link isotopic dietary signatures to specific ecosystems.
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Affiliation(s)
| | - Bian Wang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - John D Kingston
- Department of Anthropology, University of Michigan, Ann Arbor, USA
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Lauer DA, Lawing AM, Short RA, Manthi FK, Müller J, Head JJ, McGuire JL. Disruption of trait-environment relationships in African megafauna occurred in the middle Pleistocene. Nat Commun 2023; 14:4016. [PMID: 37463920 DOI: 10.1038/s41467-023-39480-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 06/15/2023] [Indexed: 07/20/2023] Open
Abstract
Mammalian megafauna have been critical to the functioning of Earth's biosphere for millions of years. However, since the Plio-Pleistocene, their biodiversity has declined concurrently with dramatic environmental change and hominin evolution. While these biodiversity declines are well-documented, their implications for the ecological function of megafaunal communities remain uncertain. Here, we adapt ecometric methods to evaluate whether the functional link between communities of herbivorous, eastern African megafauna and their environments (i.e., functional trait-environment relationships) was disrupted as biodiversity losses occurred over the past 7.4 Ma. Herbivore taxonomic and functional diversity began to decline during the Pliocene as open grassland habitats emerged, persisted, and expanded. In the mid-Pleistocene, grassland expansion intensified, and climates became more variable and arid. It was then that phylogenetic diversity declined, and the trait-environment relationships of herbivore communities shifted significantly. Our results divulge the varying implications of different losses in megafaunal biodiversity. Only the losses that occurred since the mid-Pleistocene were coincident with a disturbance to community ecological function. Prior diversity losses, conversely, occurred as the megafaunal species and trait pool narrowed towards those adapted to grassland environments.
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Affiliation(s)
- Daniel A Lauer
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
| | - A Michelle Lawing
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, 77843, USA
| | - Rachel A Short
- Department of Natural Resource Management, South Dakota State University, Rapid City, SD, 57703, USA
| | - Fredrick K Manthi
- Department of Earth Sciences, National Museums of Kenya, Nairobi, Kenya
| | - Johannes Müller
- Leibniz Institute for Evolution and Biodiversity Science, Museum für Naturkunde Berlin, 10115, Berlin, Germany
| | - Jason J Head
- Department of Zoology and University Museum of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK
| | - Jenny L McGuire
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
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Negash EW, Barr WA. Relative abundance of grazing and browsing herbivores is not a direct reflection of vegetation structure: Implications for hominin paleoenvironmental reconstruction. J Hum Evol 2023; 177:103328. [PMID: 36857987 DOI: 10.1016/j.jhevol.2023.103328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 01/23/2023] [Accepted: 01/23/2023] [Indexed: 03/03/2023]
Abstract
The diet of fossil herbivores inferred from enamel stable carbon isotopes is often used to make paleoenvironmental reconstructions. While many studies have focused on using environmental indicator taxa to make paleoenvironmental reconstructions, community-based approaches are considered to provide a more complete picture of paleolandscapes. These studies assume that the diet and relative abundance of herbivores are related to the areal extent of different vegetation types on the landscape. Here, we quantitatively test this assumption in 16 modern ecosystems in eastern and southern Africa with a wide range of woody vegetation cover. We conducted a landscape-level spatial analysis of vegetation patterns using a published land cover data set and computed landscape metrics. We compiled data on relative abundance and diet of herbivores inferred from carbon isotope studies for all large herbivores in these ecosystems. We found that despite differences in the total areal extent of different vegetation types, numerous sizable patches of each vegetation type are available in most ecosystems. However, despite variation across the ecosystems examined, grazers are typically the most abundant herbivores even in sites that have a higher proportion of forest and shrub cover. This indicates that the diet and relative abundance of herbivores is not a simple reflection of the total areal extent of vegetation types available on the landscape. The higher proportion of grazers observed in these ecosystems is a result of multiple factors including habitat heterogeneity, differences in biomass turnover rate between grasses and woody vegetation, resource partitioning, and the advantages of group living in open environments. Comparison of diet and relative abundance of herbivores in modern ecosystems to fossil herbivore assemblages shows that very different vegetation regimes can support similar herbivore assemblages. This study has significant implications for paleolandscape reconstructions and cautions against a simplistic wooded vs. grassland paleoenvironmental interpretations based on fossil herbivore assemblages.
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Affiliation(s)
- Enquye W Negash
- Center for the Advanced Study of Human Paleobiology, George Washington University, 800 22nd Street, Northwest, Washington D.C. 20052, USA.
| | - W Andrew Barr
- Center for the Advanced Study of Human Paleobiology, George Washington University, 800 22nd Street, Northwest, Washington D.C. 20052, USA
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Patterson DB, Du A, Faith JT, Rowan J, Uno K, Behrensmeyer AK, Braun DR, Wood BA. Did vegetation change drive the extinction of Paranthropus boisei? J Hum Evol 2022; 173:103154. [PMID: 35314089 DOI: 10.1016/j.jhevol.2022.103154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 01/03/2022] [Accepted: 01/24/2022] [Indexed: 12/31/2022]
Affiliation(s)
- David B Patterson
- Department of Biology, University of North Georgia, Dahlonega, GA 30597, USA.
| | - Andrew Du
- Department of Anthropology and Geography, Colorado State University, Fort Collins, CO 80523, USA
| | - J Tyler Faith
- Natural History Museum of Utah, University of Utah, Salt Lake City, UT 84108, USA; Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
| | - John Rowan
- Department of Anthropology, University at Albany, Albany, NY 12222, USA
| | - Kevin Uno
- Division of Biology and Paleo Environment, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - Anna K Behrensmeyer
- Department of Paleobiology, National Museum of Natural History, Washington, DC 20013, USA
| | - David R Braun
- Technological Primate Research Group, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 604103, Leipzig, Germany; Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052, USA
| | - Bernard A Wood
- Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC 20052, USA
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Mosaic habitats at Woranso-Mille (Ethiopia) during the Pliocene and implications for Australopithecus paleoecology and taxonomic diversity. J Hum Evol 2022; 163:103076. [PMID: 34998271 DOI: 10.1016/j.jhevol.2021.103076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 08/27/2021] [Accepted: 08/27/2021] [Indexed: 11/21/2022]
Abstract
Many important Pliocene hominin specimens have been recovered from Woranso-Mille, a paleontological research area in the Afar region of Ethiopia, including the complete cranium of Australopithecus anamensis, a partial skeleton of Australopithecus afarensis, mandibular and maxillary elements representing a new species, Australopithecus deyiremeda, and a partial foot of an as-yet-unnamed species. Woranso-Mille is the only site, so far, to have reported the co-existence of more than one early hominin species between 3.8 and 3.3 Ma and the temporal overlap between A. anamensis and A. afarensis. Thus, the site has important implications for our understanding of the paleoecology and taxonomic diversity of early hominins and their ecological niche. This paper explores the paleohabitats of Woranso-Mille through its faunal community ecological structure and taxonomic composition using correspondence analysis and Forbes modified similarity index. The results suggest that Pliocene Woranso-Mille was a mosaic of different habitat types, with riparian woodland and floodplain grassland along rivers draining into a lake, along with less mesic habitats such as woodland, grassland, and shrubland. The apparent high level of vegetation heterogeneity may have promoted dietary specializations and niche differentiation among the different Australopithecus species at Woranso-Mille and allowed for their co-existence at the site.
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Li W, Yang P, Li B, Liu C, Sun L, Li J. Habitat characteristics or protected area size: What is more important for the composition and diversity of mammals in nonprotected areas? Ecol Evol 2021; 11:7250-7263. [PMID: 34188810 PMCID: PMC8216947 DOI: 10.1002/ece3.7540] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/02/2021] [Accepted: 03/25/2021] [Indexed: 11/06/2022] Open
Abstract
The margins of protected areas are usually considered to have greater forest degradation, and given that most mammals live outside protected areas, researchers and conservation practitioners are increasingly recognizing that nonprotected areas must be incorporated into conservation strategy. However, the strategy used to manage these areas still involves increasing the size of protected areas, while not considering the habitat characteristics and requirements of the species. In this study, during a 3-year period, camera trap and habitat characteristic surveys were used to estimate composition, diversity, and habitat characteristics of mammals to determine habitat characteristics or increase the size of protected areas what should be considered first for mammals' conservation in a nonprotected area near the Huangshan Mountains in Anhui Province, China. From June 2017 to October 2019, 18 species of mammals were recorded, more than in any other protected area nearby. The linear model analysis results showed that habitat characteristics of mammals were different and showed a significant correlation with their relative abundance. Most species were related to vegetation characteristics, except primates (Macaca thibetana), and rodents (Leopoldamys edwardsi). Therefore, to establish conservation policies for nonprotected areas, habitat characteristics should be of prime concern, followed by increasing the size of protected areas to provide effective refuge areas for species conservation.
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Affiliation(s)
- Wenbo Li
- School of Resources and Environmental EngineeringAnhui UniversityHefeiChina
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral EcologyAnhui UniversityHefeiChina
| | - Peipei Yang
- School of Resources and Environmental EngineeringAnhui UniversityHefeiChina
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral EcologyAnhui UniversityHefeiChina
| | - Bowen Li
- School of Resources and Environmental EngineeringAnhui UniversityHefeiChina
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral EcologyAnhui UniversityHefeiChina
| | - Chao Liu
- School of Resources and Environmental EngineeringAnhui UniversityHefeiChina
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral EcologyAnhui UniversityHefeiChina
| | - Lixing Sun
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral EcologyAnhui UniversityHefeiChina
- Department of Biological SciencesCentral Washington UniversityEllensburgWAUSA
| | - Jinhua Li
- School of Resources and Environmental EngineeringAnhui UniversityHefeiChina
- International Collaborative Research Center for Huangshan Biodiversity and Tibetan Macaque Behavioral EcologyAnhui UniversityHefeiChina
- School of Life SciencesHefei Normal UniversityHefeiChina
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