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Fillion EN, Harrison T. Hominin turnover at Laetoli is associated with vegetation change: Multiproxy evidence from the large herbivore community. J Hum Evol 2024; 191:103546. [PMID: 38795630 DOI: 10.1016/j.jhevol.2024.103546] [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: 10/31/2023] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/28/2024]
Abstract
Vegetation change in eastern Africa during the Pliocene would have had an important impact on hominin adaptation and ecology, and it may have been a key driver of hominin macroevolution, including the extinction of Australopithecus and the emergence of Paranthropus and Homo. The Pliocene paleoanthropological site of Laetoli in Tanzania provides an opportunity to investigate the relationship between vegetation change and hominin turnover because it encompasses the time period when grass cover was spreading across eastern Africa and because hominin species turnover occurred locally at Laetoli, with Paranthropus aethiopicus in the Upper Ndolanya Beds (UNB) replacing Australopithecus afarensis in the Upper Laetolil Beds (ULB). However, it remains unresolved how the vegetation of the UNB and the ULB differed from each other. To examine differences between the two stratigraphic units, multiple proxies-hypsodonty, mesowear, and stable carbon isotopes of tooth enamel (δ13Cenamel)-are used to infer the diets of large herbivores and compare the dietary guild structure of the large herbivore communities. All three proxies indicate an increase in the abrasiveness and C4-content in the diets of the large herbivores in the UNB relative to those in the ULB. After inferring the diets of species based on all three proxies, the large herbivore community of the UNB had a greater proportion of grazers and a smaller proportion of mixed feeders than in the ULB but maintained a similar proportion of browsers and frugivores. The ULB community has few modern-day analogs, whereas the UNB community is most closely analogous to those in modern African grasslands. Thus, hominin turnover at Laetoli is associated with an increase in grass cover within a woodland-grassland mosaic and is part of a broader transformation of the herbivore community structure.
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Affiliation(s)
- Elizabeth N Fillion
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA.
| | - Terry Harrison
- Center for the Study of Human Origins, Department of Anthropology, New York University, 25 Waverly Pl., New York, NY, 10003, USA; New York Consortium in Evolutionary Primatology, New York, NY, 10024, USA
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2
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Karp AT, Koerner SE, Hempson GP, Abraham JO, Anderson TM, Bond WJ, Burkepile DE, Fillion EN, Goheen JR, Guyton JA, Kartzinel TR, Kimuyu DM, Mohanbabu N, Palmer TM, Porensky LM, Pringle RM, Ritchie ME, Smith MD, Thompson DI, Young TP, Staver AC. Grazing herbivores reduce herbaceous biomass and fire activity across African savannas. Ecol Lett 2024; 27:e14450. [PMID: 38857323 DOI: 10.1111/ele.14450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 04/29/2024] [Accepted: 04/29/2024] [Indexed: 06/12/2024]
Abstract
Fire and herbivory interact to alter ecosystems and carbon cycling. In savannas, herbivores can reduce fire activity by removing grass biomass, but the size of these effects and what regulates them remain uncertain. To examine grazing effects on fuels and fire regimes across African savannas, we combined data from herbivore exclosure experiments with remotely sensed data on fire activity and herbivore density. We show that, broadly across African savannas, grazing herbivores substantially reduce both herbaceous biomass and fire activity. The size of these effects was strongly associated with grazing herbivore densities, and surprisingly, was mostly consistent across different environments. A one-zebra increase in herbivore biomass density (~100 kg/km2 of metabolic biomass) resulted in a ~53 kg/ha reduction in standing herbaceous biomass and a ~0.43 percentage point reduction in burned area. Our results indicate that fire models can be improved by incorporating grazing effects on grass biomass.
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Affiliation(s)
- Allison Tyler Karp
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
- Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, Rhode Island, USA
| | - Sally E Koerner
- Department of Biology, University of North Carolina Greensboro, Greensboro, North Carolina, USA
| | - Gareth P Hempson
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Joel O Abraham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - T Michael Anderson
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, USA
| | - William J Bond
- Biological Sciences, University of Cape Town, Cape Town, South Africa
| | - Deron E Burkepile
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California, USA
- South African Environmental Observation Network, Ndlovu Node, Scientific Services, Kruger National Park, Phalaborwa, South Africa
| | - Elizabeth N Fillion
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
| | - Jacob R Goheen
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
- Mpala Research Centre, Nanyuki, Kenya
| | - Jennifer A Guyton
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Tyler R Kartzinel
- Institute at Brown for Environment and Society, Brown University, Providence, Rhode Island, USA
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, Rhode Island, USA
| | - Duncan M Kimuyu
- Mpala Research Centre, Nanyuki, Kenya
- Department of Natural Resources, Karatina University, Karatina, Kenya
| | - Neha Mohanbabu
- Department of Biology, Syracuse University, Syracuse, New York, USA
- University of Minnesota, Twin Cities, Minnesota, USA
| | - Todd M Palmer
- Biological Sciences, University of Cape Town, Cape Town, South Africa
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | - Lauren M Porensky
- Rangeland Resources and Systems Research Unit, USDA Agricultural Research Service, Fort Collins, Colorado, USA
| | - Robert M Pringle
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Mark E Ritchie
- Department of Wildland Resources, Utah State University, Logan, Utah, USA
| | - Melinda D Smith
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Dave I Thompson
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
- South African Environmental Observation Network, Ndlovu Node, Scientific Services, Kruger National Park, Phalaborwa, South Africa
| | - Truman P Young
- Mpala Research Centre, Nanyuki, Kenya
- Department of Plant Sciences, University of California Davis, Davis, California, USA
| | - A Carla Staver
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
- Yale Institute for Biospheric Studies, Yale University, New Haven, Connecticut, USA
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3
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Cooper RB, Flannery-Sutherland JT, Silvestro D. DeepDive: estimating global biodiversity patterns through time using deep learning. Nat Commun 2024; 15:4199. [PMID: 38760390 PMCID: PMC11101433 DOI: 10.1038/s41467-024-48434-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 04/30/2024] [Indexed: 05/19/2024] Open
Abstract
Understanding how biodiversity has changed through time is a central goal of evolutionary biology. However, estimates of past biodiversity are challenged by the inherent incompleteness of the fossil record, even when state-of-the-art statistical methods are applied to adjust estimates while correcting for sampling biases. Here we develop an approach based on stochastic simulations of biodiversity and a deep learning model to infer richness at global or regional scales through time while incorporating spatial, temporal and taxonomic sampling variation. Our method outperforms alternative approaches across simulated datasets, especially at large spatial scales, providing robust palaeodiversity estimates under a wide range of preservation scenarios. We apply our method on two empirical datasets of different taxonomic and temporal scope: the Permian-Triassic record of marine animals and the Cenozoic evolution of proboscideans. Our estimates provide a revised quantitative assessment of two mass extinctions in the marine record and reveal rapid diversification of proboscideans following their expansion out of Africa and a >70% diversity drop in the Pleistocene.
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Affiliation(s)
- Rebecca B Cooper
- Department of Biology, University of Fribourg, 1700, Fribourg, Switzerland.
- Swiss Institute of Bioinformatics, 1700, Fribourg, Switzerland.
| | | | - Daniele Silvestro
- Department of Biology, University of Fribourg, 1700, Fribourg, Switzerland.
- Swiss Institute of Bioinformatics, 1700, Fribourg, Switzerland.
- Department of Biological and Environmental Sciences, Global Gothenburg Biodiversity Centre, University of Gothenburg, Gothenburg, 413 19, Sweden.
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4
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Ritwika VPS, Gopinathan A, Yeakel JD. Beyond the kill: The allometry of predation behaviours among large carnivores. J Anim Ecol 2024; 93:554-566. [PMID: 38459609 DOI: 10.1111/1365-2656.14070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 02/06/2024] [Indexed: 03/10/2024]
Abstract
The costs of foraging can be high while also carrying significant risks, especially for consumers feeding at the top of the food chain. To mitigate these risks, many predators supplement active hunting with scavenging and kleptoparasitic behaviours, in some cases specializing in these alternative modes of predation. The factors that drive differential utilization of these tactics from species to species are not well understood. Here, we use an energetics approach to investigate the survival advantages of hunting, scavenging and kleptoparasitism as a function of predator, prey and potential competitor body sizes for terrestrial mammalian carnivores. The results of our framework reveal that predator tactics become more diverse closer to starvation, while the deployment of scavenging and kleptoparasitism is strongly constrained by the ratio of predator to prey body size. Our model accurately predicts a behavioural transition away from hunting towards alternative modes of predation with increasing prey size for predators spanning an order of magnitude in body size, closely matching observational data across a range of species. We then show that this behavioural boundary follows an allometric power-law scaling relationship where the predator size scales with an exponent nearing 3/4 with prey size, meaning that this behavioural switch occurs at relatively larger threshold prey body size for larger carnivores. We suggest that our approach may provide a holistic framework for guiding future observational efforts exploring the diverse array of predator foraging behaviours.
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Affiliation(s)
- V P S Ritwika
- Department of Physics, UC Merced, Merced, California, USA
- Department of Communication, UCLA, Los Angeles, California, USA
- Life and Environmental Sciences, UC Merced, Merced, California, USA
| | | | - Justin D Yeakel
- Life and Environmental Sciences, UC Merced, Merced, California, USA
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5
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Figueirido B, Tucker S, Lautenschlager S. Comparing cranial biomechanics between Barbourofelis fricki and Smilodon fatalis: Is there a universal killing-bite among saber-toothed predators? Anat Rec (Hoboken) 2024. [PMID: 38613218 DOI: 10.1002/ar.25451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024]
Abstract
Saber-tooths, extinct apex predators with long and blade-like upper canines, have appeared iteratively at least five times in the evolutionary history of vertebrates. Although saber-tooths exhibit a relatively diverse range of morphologies, it is widely accepted that all killed their prey using the same predatory behavior. In this study, we CT-scanned the skull of Barbourofelis fricki and compared its cranial mechanics using finite element analysis (FEA) with that of Smilodon fatalis. Our aim was to investigate potential variations in killing behavior between two dirk-toothed sabretooths from the Miocene and Pleistocene of North America. The study revealed that B. fricki had a stoutly-built skull capable of withstanding stress in various prey-killing scenarios, while the skull of S. fatalis appeared less optimized for supporting stress, which highlights the highly derived saber-tooth morphology of the former. The results may indicate that B. fricki was more of a generalist in prey-killing compared to S. fatalis, which experiences lower stresses under stabbing loads. We hypothesize that morphological specialization in saber-tooths does not necessarily indicate ecological specialization. Our results support the notion that morphological convergence among saber-toothed cats may obscure differences in hunting strategies employed to dispatch their prey. Our findings challenge the assumption of the universally assumed canine-shear biting as the prey-killing behavior of all saber-toothed cats. However, further research involving a wider range of dirk and scimitar-toothed forms could provide additional insights into the diversity of cranial biomechanics within this fascinating group of extinct mammalian predators.
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Affiliation(s)
- Borja Figueirido
- Departamento de Ecología y Geología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Shane Tucker
- Department of Earth and Planetary Sciences, University of Nebraska State Museum, Lincoln, Nebraska, USA
| | - Stephan Lautenschlager
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
- The Lapworth Museum of Geology, Birmingham, UK
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6
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Piwczyński M, Granjon L, Trzeciak P, Carlos Brito J, Oana Popa M, Daba Dinka M, Johnston NP, Boratyński Z. Unraveling phylogenetic relationships and species boundaries in the arid adapted Gerbillus rodents (Muridae: Gerbillinae) by RAD-seq data. Mol Phylogenet Evol 2023; 189:107913. [PMID: 37659480 DOI: 10.1016/j.ympev.2023.107913] [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: 02/20/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/04/2023]
Abstract
Gerbillus is one of the most speciose genera among rodents, with ca. 51 recognized species. Previous attempts to reconstruct the evolutionary history of Gerbillus mainly relied on the mitochondrial cyt-b marker as a source of phylogenetic information. In this study, we utilize RAD-seq genomic data from 37 specimens representing 11 species to reconstruct the phylogenetic tree for Gerbillus, applying concatenation and coalescence methods. We identified four highly supported clades corresponding to the traditionally recognized subgenera: Dipodillus, Gerbillus, Hendecapleura and Monodia. Only two uncertain branches were detected in the resulting trees, with one leading to diversification of the main lineages in the genus, recognized by quartet sampling analysis as uncertain due to possible introgression. We also examined species boundaries for four pairs of sister taxa, including potentially new species from Morocco, using SNAPP. The results strongly supported a speciation model in which all taxa are treated as separate species. The dating analyses confirmed the Plio-Pleistocene diversification of the genus, with the uncertain branch coinciding with the beginning of aridification of the Sahara at the the Plio-Pleistocene boundary. This study aligns well with the earlier analyses based on the cyt-b marker, reaffirming its suitability as an adequate marker for estimating genetic diversity in Gerbillus.
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Affiliation(s)
- Marcin Piwczyński
- Department of Ecology and Biogeography, Nicolaus Copernicus University in Toruń, Lwowska 1, PL-87-100 Toruń, Poland.
| | - Laurent Granjon
- CBGP, IRD, CIRAD, INRAE, Institut Agro, Université de Montpellier, Montpellier, France
| | - Paulina Trzeciak
- Department of Ecology and Biogeography, Nicolaus Copernicus University in Toruń, Lwowska 1, PL-87-100 Toruń, Poland
| | - José Carlos Brito
- CIBIO-InBio, Research Center in Biodiversity and Genetic Resources, University of Porto, Campus de Vairão, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal; BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal; Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
| | - Madalina Oana Popa
- Department of Ecology and Biogeography, Nicolaus Copernicus University in Toruń, Lwowska 1, PL-87-100 Toruń, Poland; "Stejarul" Research Centre for Biological Sciences, National Institute of Research and Development for Biological Sciences, Alexandru cel Bun 6, RO-610004, Piatra Neamţ, Romania
| | - Mergi Daba Dinka
- Department of Ecology and Biogeography, Nicolaus Copernicus University in Toruń, Lwowska 1, PL-87-100 Toruń, Poland
| | - Nikolas P Johnston
- School of Life Sciences, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia; Centre for Sustainable Ecosystem Solutions, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Ave, Wollongong, NSW 2500, Australia
| | - Zbyszek Boratyński
- CIBIO-InBio, Research Center in Biodiversity and Genetic Resources, University of Porto, Campus de Vairão, Rua Padre Armando Quintas 7, 4485-661 Vairão, Portugal; BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, Vairão, Portugal
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7
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Voysey MD, de Bruyn PJN, Davies AB. Are hippos Africa's most influential megaherbivore? A review of ecosystem engineering by the semi-aquatic common hippopotamus. Biol Rev Camb Philos Soc 2023; 98:1509-1529. [PMID: 37095627 DOI: 10.1111/brv.12960] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 03/30/2023] [Accepted: 04/03/2023] [Indexed: 04/26/2023]
Abstract
Megaherbivores perform vital ecosystem engineering roles, and have their last remaining stronghold in Africa. Of Africa's remaining megaherbivores, the common hippopotamus (Hippopotamus amphibius) has received the least scientific and conservation attention, despite how influential their ecosystem engineering activities appear to be. Given the potentially crucial ecosystem engineering influence of hippos, as well as mounting conservation concerns threatening their long-term persistence, a review of the evidence for hippos being ecosystem engineers, and the effects of their engineering, is both timely and necessary. In this review, we assess, (i) aspects of hippo biology that underlie their unique ecosystem engineering potential; (ii) evaluate hippo ecological impacts in terrestrial and aquatic environments; (iii) compare the ecosystem engineering influence of hippos to other extant African megaherbivores; (iv) evaluate factors most critical to hippo conservation and ecosystem engineering; and (v) highlight future research directions and challenges that may yield new insights into the ecological role of hippos, and of megaherbivores more broadly. We find that a variety of key life-history traits determine the hippo's unique influence, including their semi-aquatic lifestyle, large body size, specialised gut anatomy, muzzle structure, small and partially webbed feet, and highly gregarious nature. On land, hippos create grazing lawns that contain distinct plant communities and alter fire spatial extent, which shapes woody plant demographics and might assist in maintaining fire-sensitive riverine vegetation. In water, hippos deposit nutrient-rich dung, stimulating aquatic food chains and altering water chemistry and quality, impacting a host of different organisms. Hippo trampling and wallowing alters geomorphological processes, widening riverbanks, creating new river channels, and forming gullies along well-utilised hippo paths. Taken together, we propose that these myriad impacts combine to make hippos Africa's most influential megaherbivore, specifically because of the high diversity and intensity of their ecological impacts compared with other megaherbivores, and because of their unique capacity to transfer nutrients across ecosystem boundaries, enriching both terrestrial and aquatic ecosystems. Nonetheless, water pollution and extraction for agriculture and industry, erratic rainfall patterns and human-hippo conflict, threaten hippo ecosystem engineering and persistence. Therefore, we encourage greater consideration of the unique role of hippos as ecosystem engineers when considering the functional importance of megafauna in African ecosystems, and increased attention to declining hippo habitat and populations, which if unchecked could change the way in which many African ecosystems function.
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Affiliation(s)
- Michael D Voysey
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA, 02138, USA
| | - P J Nico de Bruyn
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Andrew B Davies
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA, 02138, USA
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8
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Saarinen J, Lister AM. Fluctuating climate and dietary innovation drove ratcheted evolution of proboscidean dental traits. Nat Ecol Evol 2023; 7:1490-1502. [PMID: 37580434 PMCID: PMC10482678 DOI: 10.1038/s41559-023-02151-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 07/05/2023] [Indexed: 08/16/2023]
Abstract
Identification of the selective forces that shaped adaptive phenotypes generally relies on current habitat and function, but these may differ from the context in which adaptations arose. Moreover, the fixation of adaptive change in a fluctuating environment and the mechanisms of long-term trends are still poorly understood, as is the role of behaviour in triggering these processes. Time series of fossils can provide evidence on these questions, but examples of individual lineages with adequate fossil and proxy data over extended periods are rare. Here, we present new data on proboscidean dental evolution in East Africa over the past 26 million years, tracking temporal patterns of morphological change in relation to proxy evidence of diet, vegetation and climate (aridity). We show that behavioural experimentation in diet is correlated with environmental context, and that major adaptive change in dental traits followed the changes in diet and environment but only after acquisition of functional innovations in the masticatory system. We partition traits by selective agent, showing that the acquisition of high, multiridged molars was primarily a response to an increase in open, arid environments with high dust accumulation, whereas enamel folding was more associated with the amount of grass in the diet. We further show that long-term trends in these features proceeded in a ratchet-like mode, alternating between directional change at times of high selective pressure and stasis when the selective regime reversed. This provides an explanation for morphology adapted to more extreme conditions than current usage (Liem's Paradox). Our study illustrates how, in fossil series with adequate stratigraphic control and proxy data, environmental and behavioural factors can be mapped on to time series of morphological change, illuminating the mode of acquisition of an adaptive complex.
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Affiliation(s)
- Juha Saarinen
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland.
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9
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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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10
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Bibi F, Cantalapiedra JL. Plio-Pleistocene African megaherbivore losses associated with community biomass restructuring. Science 2023; 380:1076-1080. [PMID: 37289876 DOI: 10.1126/science.add8366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 05/10/2023] [Indexed: 06/10/2023]
Abstract
Fossil abundance data can reveal ecological dynamics underpinning taxonomic declines. Using fossil dental metrics, we reconstructed body mass and mass-abundance distributions in Late Miocene to recent African large mammal communities. Despite collection biases, fossil and extant mass-abundance distributions are highly similar, with unimodal distributions likely reflecting savanna environments. Above 45 kilograms, abundance decreases exponentially with mass, with slopes close to -0.75, as predicted by metabolic scaling. Furthermore, communities before ~4 million years ago had considerably more large-sized individuals, with a greater proportion of total biomass allocated in larger size categories, than did later communities. Over time, individuals and biomass were redistributed into smaller size categories, reflecting a gradual loss of large-sized individuals from the fossil record paralleling the long-term decline of Plio-Pleistocene large mammal diversity.
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Affiliation(s)
- Faysal Bibi
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, 10115 Berlin, Germany
| | - Juan L Cantalapiedra
- GloCEE-Global Change Ecology and Evolution Research Group, Department of Life Sciences, Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain
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11
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Szilágyi A, Kovács VP, Czárán T, Szathmáry E. Evolutionary ecology of language origins through confrontational scavenging. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210411. [PMID: 36688391 PMCID: PMC9869442 DOI: 10.1098/rstb.2021.0411] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
A dynamic model and an agent-based simulation model implementing the assumptions of the confrontational scavenging hypothesis on early protolanguage as an adaptive response of Homo erectus to gradual change in their habitat has been developed and studied. The core assumptions of the hypothesis and the model scenario are the pre-adaptation of our ancestors to occupy the ecological niche that they constructed for themselves by having evolved displaced communication and a rudimentary tool manufacture, two features allowing them to use a new, concentrated and abundant resource-megafauna carrion-on the savannahs replacing arboreal habitats owing to the drying climate of East Africa at about 2 Ma. The shift in diet required coordinated cooperation by the hominin scavengers confronted with concurrent predators. Power scavenging compelled displaced symbolic communication featuring a limited semantic range; syntax was not yet required. We show that phenotypic evolution on the accuracy of information transfer between cooperating hominins is a necessary and sufficient condition for the population of agents to survive the diet shift. Both the individual and the group fitness of the hominin horde increased with the accuracy of their protolanguage, with decreasing time allocated to foraging and thus more time left for culture. This article is part of the theme issue 'Human socio-cultural evolution in light of evolutionary transitions'.
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Affiliation(s)
- András Szilágyi
- Institute of Evolution, Centre for Ecological Research, Konkoly-Thege Miklós út 29-33. 1121, Budapest, Hungary,MTA–ELTE Theoretical Biology and Evolutionary Ecology Research Group, Eötvös Loránd University, Pázmány P. s. 1C 1117 Budapest, Hungary,Center for Conceptual Foundation of Science, Parmenides Foundation, Hindenburgstrasse 15, 82343 Pöcking, Germany
| | - Viktor P. Kovács
- Institute of Evolution, Centre for Ecological Research, Konkoly-Thege Miklós út 29-33. 1121, Budapest, Hungary
| | - Tamás Czárán
- Institute of Evolution, Centre for Ecological Research, Konkoly-Thege Miklós út 29-33. 1121, Budapest, Hungary,MTA–ELTE Theoretical Biology and Evolutionary Ecology Research Group, Eötvös Loránd University, Pázmány P. s. 1C 1117 Budapest, Hungary
| | - Eörs Szathmáry
- Institute of Evolution, Centre for Ecological Research, Konkoly-Thege Miklós út 29-33. 1121, Budapest, Hungary,MTA–ELTE Theoretical Biology and Evolutionary Ecology Research Group, Eötvös Loránd University, Pázmány P. s. 1C 1117 Budapest, Hungary,Center for Conceptual Foundation of Science, Parmenides Foundation, Hindenburgstrasse 15, 82343 Pöcking, Germany
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12
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Quinn RL, Lepre CJ. C 4 plant food loss probably influenced Paranthropus boisei's extinction: A reply to Patterson et al.'s commentary on Quinn and Lepre (2021). J Hum Evol 2022; 173:103269. [PMID: 36270813 DOI: 10.1016/j.jhevol.2022.103269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Rhonda L Quinn
- School of Earth, Environment and Society, Bowling Green State University, Bowling Green, OH, 43402, USA.
| | - Christopher J Lepre
- School of Earth, Environment and Society, Bowling Green State University, Bowling Green, OH, 43402, USA
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13
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Plio-Pleistocene environmental variability in Africa and its implications for mammalian evolution. Proc Natl Acad Sci U S A 2022; 119:e2107393119. [PMID: 35412903 PMCID: PMC9169865 DOI: 10.1073/pnas.2107393119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
We have developed an Africa-wide synthesis of paleoenvironmental variability over the Plio-Pleistocene. We show that there is strong evidence for orbital forcing of variability during this time that is superimposed on a longer trend of increasing environmental variability, supporting a combination of both low- and high-latitude drivers of variability. We combine these results with robust estimates of mammalian speciation and extinction rates and find that variability is not significantly correlated with these rates. These findings do not currently support a link between environmental variability and turnover and thus fail to corroborate predictions derived from the variability selection hypothesis. Understanding the climatic drivers of environmental variability (EV) during the Plio-Pleistocene and EV’s influence on mammalian macroevolution are two outstanding foci of research in African paleoclimatology and evolutionary biology. The potential effects of EV are especially relevant for testing the variability selection hypothesis, which predicts a positive relationship between EV and speciation and extinction rates in fossil mammals. Addressing these questions is stymied, however, by 1) a lack of multiple comparable EV records of sufficient temporal resolution and duration, and 2) the incompleteness of the mammalian fossil record. Here, we first compile a composite history of Pan-African EV spanning the Plio-Pleistocene, which allows us to explore which climatic variables influenced EV. We find that EV exhibits 1) a long-term trend of increasing variability since ∼3.7 Ma, coincident with rising variability in global ice volume and sea surface temperatures around Africa, and 2) a 400-ky frequency correlated with seasonal insolation variability. We then estimate speciation and extinction rates for fossil mammals from eastern Africa using a method that accounts for sampling variation. We find no statistically significant relationship between EV and estimated speciation or extinction rates across multiple spatial scales. These findings are inconsistent with the variability selection hypothesis as applied to macroevolutionary processes.
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14
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A nonanalog Pliocene ungulate community at Laetoli with implications for the paleoecology of Australopithecus afarensis. J Hum Evol 2022; 167:103182. [DOI: 10.1016/j.jhevol.2022.103182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 11/17/2022]
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15
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Kraft TS, Venkataraman VV, Wallace IJ, Crittenden AN, Holowka NB, Stieglitz J, Harris J, Raichlen DA, Wood B, Gurven M, Pontzer H. The energetics of uniquely human subsistence strategies. Science 2021; 374:eabf0130. [PMID: 34941390 DOI: 10.1126/science.abf0130] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Thomas S Kraft
- Department of Anthropology, University of California, Santa Barbara, CA, USA.,Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Department of Anthropology, University of Utah, Salt Lake City, UT, USA
| | - Vivek V Venkataraman
- Institute for Advanced Study in Toulouse, Toulouse, France.,Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Ian J Wallace
- Department of Anthropology, University of New Mexico, Albuquerque, NM, USA
| | | | | | | | - Jacob Harris
- Department of Anthropology, University of California, Los Angeles, CA, USA.,Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA
| | - David A Raichlen
- Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Brian Wood
- Department of Human Behavior, Ecology, and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Department of Anthropology, University of California, Los Angeles, CA, USA
| | - Michael Gurven
- Department of Anthropology, University of California, Santa Barbara, CA, USA
| | - Herman Pontzer
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA.,Duke Global Health Institute, Duke University, Durham, NC, USA
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16
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The rise and fall of proboscidean ecological diversity. Nat Ecol Evol 2021; 5:1266-1272. [PMID: 34211141 DOI: 10.1038/s41559-021-01498-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/28/2021] [Indexed: 02/06/2023]
Abstract
Proboscideans were keystone Cenozoic megaherbivores and present a highly relevant case study to frame the timing and magnitude of recent megafauna extinctions against long-term macroevolutionary patterns. By surveying the entire proboscidean fossil history using model-based approaches, we show that the dramatic Miocene explosion of proboscidean functional diversity was triggered by their biogeographical expansion beyond Africa. Ecomorphological innovations drove niche differentiation; communities that accommodated several disparate proboscidean species in sympatry became commonplace. The first burst of extinctions took place in the late Miocene, approximately 7 million years ago (Ma). Importantly, this and subsequent extinction trends showed high ecomorphological selectivity and went hand in hand with palaeoclimate dynamics. The global extirpation of proboscideans began escalating from 3 Ma with further extinctions in Eurasia and then a dramatic increase in African extinctions at 2.4 Ma. Overhunting by humans may have served as a final double jeopardy in the late Pleistocene after climate-triggered extinction trends that began long before hominins evolved suitable hunting capabilities.
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17
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Abstract
Ecotourism can fuel an important source of financial income for African countries and can therefore help biodiversity policies in the continent. Translocations can be a powerful tool to spread economic benefits among countries and communities; yet, to be positive for biodiversity conservation, they require a basic knowledge of conservation units through appropriate taxonomic research. This is not always the case, as taxonomy was considered an outdated discipline for almost a century, and some plurality in taxonomic approaches is incorrectly considered as a disadvantage for conservation work. As an example, diversity of the genus Giraffa and its recent taxonomic history illustrate the importance of such knowledge for a sound conservation policy that includes translocations. We argue that a fine-grained conservation perspective that prioritizes all remaining populations along the Nile Basin is needed. Translocations are important tools for giraffe diversity conservation, but more discussion is needed, especially for moving new giraffes to regions where the autochthonous taxa/populations are no longer existent. As the current discussion about the giraffe taxonomy is too focused on the number of giraffe species, we argue that the plurality of taxonomic and conservation approaches might be beneficial, i.e., for defining the number of units requiring separate management using a (majority) consensus across different concepts (e.g., MU—management unit, ESU—evolutionary significant unit, and ECU—elemental conservation unit). The taxonomically sensitive translocation policy/strategy would be important for the preservation of current diversity, while also supporting the ecological restoration of some regions within rewilding. A summary table of the main translocation operations of African mammals that have underlying problems is included. Therefore, we call for increased attention toward the taxonomy of African mammals not only as the basis for sound conservation but also as a further opportunity to enlarge the geographic scope of ecotourism in Africa.
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18
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Quinn RL, Lepre CJ. Contracting eastern African C 4 grasslands during the extinction of Paranthropus boisei. Sci Rep 2021; 11:7164. [PMID: 33785831 PMCID: PMC8009881 DOI: 10.1038/s41598-021-86642-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 03/18/2021] [Indexed: 02/01/2023] Open
Abstract
The extinction of the Paranthropus boisei estimated to just before 1 Ma occurred when C4 grasslands dominated landscapes of the Eastern African Rift System (EARS). P. boisei has been characterized as an herbivorous C4 specialist, and paradoxically, its demise coincided with habitats favorable to its dietary ecology. Here we report new pedogenic carbonate stable carbon (δ13CPC) and oxygen (δ18OPC) values (nodules = 53, analyses = 95) from an under-sampled interval (1.4-0.7 Ma) in the Turkana Basin (Kenya), one of the most fossiliferous locales of P. boisei. We combined our new results with published δ13CPC values from the EARS dated to 3-0 Ma, conducted time-series analysis of woody cover (ƒWC), and compared the EARS ƒWC trends to regional and global paleo-environmental and -climatic datasets. Our results demonstrate that the long-term rise of C4 grasslands was punctuated by a transient but significant increase in C3 vegetation and warmer temperatures, coincident with the Mid-Pleistocene Transition (1.3-0.7 Ma) and implicating a short-term rise in pCO2. The contraction of C4 grasslands escalated dietary competition amongst the abundant C4-feeders, likely influencing P. boisei's demise.
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Affiliation(s)
- Rhonda L. Quinn
- grid.263379.a0000 0001 2172 0072Department of Sociology, Anthropology, Social Work and Criminal Justice, Seton Hall University, 400 South Orange Ave, South Orange, NJ 07079 USA ,grid.430387.b0000 0004 1936 8796Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 USA
| | - Christopher J. Lepre
- grid.430387.b0000 0004 1936 8796Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 USA
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19
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Ben-Dor M, Sirtoli R, Barkai R. The evolution of the human trophic level during the Pleistocene. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 175 Suppl 72:27-56. [PMID: 33675083 DOI: 10.1002/ajpa.24247] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/07/2020] [Accepted: 01/19/2021] [Indexed: 02/06/2023]
Abstract
The human trophic level (HTL) during the Pleistocene and its degree of variability serve, explicitly or tacitly, as the basis of many explanations for human evolution, behavior, and culture. Previous attempts to reconstruct the HTL have relied heavily on an analogy with recent hunter-gatherer groups' diets. In addition to technological differences, recent findings of substantial ecological differences between the Pleistocene and the Anthropocene cast doubt regarding that analogy's validity. Surprisingly little systematic evolution-guided evidence served to reconstruct HTL. Here, we reconstruct the HTL during the Pleistocene by reviewing evidence for the impact of the HTL on the biological, ecological, and behavioral systems derived from various existing studies. We adapt a paleobiological and paleoecological approach, including evidence from human physiology and genetics, archaeology, paleontology, and zoology, and identified 25 sources of evidence in total. The evidence shows that the trophic level of the Homo lineage that most probably led to modern humans evolved from a low base to a high, carnivorous position during the Pleistocene, beginning with Homo habilis and peaking in Homo erectus. A reversal of that trend appears in the Upper Paleolithic, strengthening in the Mesolithic/Epipaleolithic and Neolithic, and culminating with the advent of agriculture. We conclude that it is possible to reach a credible reconstruction of the HTL without relying on a simple analogy with recent hunter-gatherers' diets. The memory of an adaptation to a trophic level that is embedded in modern humans' biology in the form of genetics, metabolism, and morphology is a fruitful line of investigation of past HTLs, whose potential we have only started to explore.
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Affiliation(s)
- Miki Ben-Dor
- Department of Archaeology, Tel Aviv University, Tel Aviv, Israel
| | | | - Ran Barkai
- Department of Archaeology, Tel Aviv University, Tel Aviv, Israel
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20
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Braun DR, Faith JT, Douglass MJ, Davies B, Power MJ, Aldeias V, Conard NJ, Cutts R, DeSantis LRG, Dupont LM, Esteban I, Kandel AW, Levin NE, Luyt J, Parkington J, Pickering R, Quick L, Sealy J, Stynder D. Ecosystem engineering in the Quaternary of the West Coast of South Africa. Evol Anthropol 2021; 30:50-62. [PMID: 33604991 DOI: 10.1002/evan.21886] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 06/30/2020] [Accepted: 12/22/2020] [Indexed: 11/09/2022]
Abstract
Despite advances in our understanding of the geographic and temporal scope of the Paleolithic record, we know remarkably little about the evolutionary and ecological consequences of changes in human behavior. Recent inquiries suggest that human evolution reflects a long history of interconnections between the behavior of humans and their surrounding ecosystems (e.g., niche construction). Developing expectations to identify such phenomena is remarkably difficult because it requires understanding the multi-generational impacts of changes in behavior. These long-term dynamics require insights into the emergent phenomena that alter selective pressures over longer time periods which are not possible to observe, and are also not intuitive based on observations derived from ethnographic time scales. Generative models show promise for probing these potentially unexpected consequences of human-environment interaction. Changes in the uses of landscapes may have long term implications for the environments that hominins occupied. We explore other potential proxies of behavior and examine how modeling may provide expectations for a variety of phenomena.
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Affiliation(s)
- David R Braun
- The George Washington University, Center for the Advanced Study of Human Paleobiology, Washington, District of Columbia, USA.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - John Tyler Faith
- Natural History Museum of Utah, University of Utah, Salt Lake City, Utah, USA.,Department of Anthropology, University of Utah, Salt Lake City, Utah, USA
| | - Matthew J Douglass
- College of Agricultural Sciences and Natural Resources, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.,Agricultural Research Division, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Benjamin Davies
- Natural History Museum of Utah, University of Utah, Salt Lake City, Utah, USA
| | - Mitchel J Power
- Natural History Museum of Utah, University of Utah, Salt Lake City, Utah, USA.,Department of Geography, Natural History Museum of Utah, University of Utah, Salt Lake City, Utah, USA
| | - Vera Aldeias
- Interdisciplinary Center for Archaeology and Evolution of Human Behaviour (ICArEHB), Universidade do Algarve, Faro, Portugal
| | - Nicholas J Conard
- Department of Early Prehistory and Quaternary Ecology, University of Tübingen, Schloss Hohentübingen, Tübingen, Germany
| | - Russell Cutts
- Emory University-Oxford College, History and Social Sciences (Anthropology), Oxford, Georgia, USA
| | - Larisa R G DeSantis
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Lydie M Dupont
- MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Irene Esteban
- Evolutionary Studies Institute, University of Witwatersrand, Johannesburg, South Africa
| | - Andrew W Kandel
- The Role of Culture in Early Expansions of Humans, Heidelberg Academy of Sciences and Humanities, Tübingen, Germany
| | - Naomi E Levin
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Julie Luyt
- Department of Archaeology, University of Cape Town, Cape Town, South Africa
| | - John Parkington
- Department of Archaeology, University of Cape Town, Cape Town, South Africa
| | - Robyn Pickering
- Department of Geological Science, University of Cape Town, Cape Town, Western Cape, South Africa.,Human Evolution Research Institute, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Lynne Quick
- African Centre for Coastal Palaeoscience, Nelson Mandela University, Port Elizabeth, South Africa
| | - Judith Sealy
- Department of Archaeology, University of Cape Town, Cape Town, South Africa
| | - Deano Stynder
- Department of Archaeology, University of Cape Town, Cape Town, South Africa
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21
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Thompson JC, Wright DK, Ivory SJ. The emergence and intensification of early hunter-gatherer niche construction. Evol Anthropol 2020; 30:17-27. [PMID: 33341104 DOI: 10.1002/evan.21877] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 03/31/2020] [Accepted: 08/30/2020] [Indexed: 01/13/2023]
Abstract
Hunter-gatherers, especially Pleistocene examples, are not well-represented in archeological studies of niche construction. However, as the role of humans in shaping environments over long time scales becomes increasingly apparent, it is critical to develop archeological proxies and testable hypotheses about early hunter-gatherer impacts. Modern foragers engage in niche constructive behaviors aimed at maintaining or increasing the productivity of their environments, and these may have had significant ecological consequences over later human evolution. In some cases, they may also represent behaviors unique to modern Homo sapiens. Archeological and paleoenvironmental data show that African hunter-gatherers were niche constructors in diverse environments, which have legacies in how ecosystems function today. These can be conceptualized as behaviorally mediated trophic cascades, and tested using archeological and paleoenvironmental proxies. Thus, large-scale niche construction behavior is possible to identify at deeper time scales, and may be key to understanding the emergence of modern humans.
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Affiliation(s)
- Jessica C Thompson
- Department of Anthropology, Yale University, New Haven, Connecticut, USA
| | - David K Wright
- Department of Archaeology, Conservation and History, University of Oslo, Oslo, Norway.,State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Sarah J Ivory
- Department of Geosciences and Earth and Environmental Sciences Institute, Pennsylvania State University, University Park, Pennsylvania, USA
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22
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Reply to Weihmann: Fifty gazelles do not equal an elephant, and other ecological misunderstandings. Proc Natl Acad Sci U S A 2020; 117:3370-3371. [PMID: 32019886 DOI: 10.1073/pnas.1920565117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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23
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Faurby S, Silvestro D, Werdelin L, Antonelli A. Brain expansion in early hominins predicts carnivore extinctions in East Africa. Ecol Lett 2020; 23:537-544. [PMID: 31943670 PMCID: PMC7079157 DOI: 10.1111/ele.13451] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/09/2019] [Accepted: 11/21/2019] [Indexed: 01/04/2023]
Abstract
While the anthropogenic impact on ecosystems today is evident, it remains unclear if the detrimental effect of hominins on co-occurring biodiversity is a recent phenomenon or has also been the pattern for earlier hominin species. We test this using the East African carnivore fossil record. We analyse the diversity of carnivores over the last four million years and investigate whether any decline is related to an increase in hominin cognitive capacity, vegetation changes or climatic changes. We find that extinction rates in large carnivores correlate with increased hominin brain size and with vegetation changes, but not with precipitation or temperature changes. While temporal analyses cannot distinguish between the effects of vegetation changes and hominins, we show through spatial analyses of contemporary carnivores in Africa that only hominin causation is plausible. Our results suggest that substantial anthropogenic influence on biodiversity started millions of years earlier than currently assumed.
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Affiliation(s)
- Søren Faurby
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE, 40530, Göteborg, Sweden.,Gothenburg Global Biodiversity Centre, Box 461, SE, 40530, Göteborg, Sweden
| | - Daniele Silvestro
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE, 40530, Göteborg, Sweden.,Gothenburg Global Biodiversity Centre, Box 461, SE, 40530, Göteborg, Sweden.,Department of Computational Biology, Biophore, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Quartier Sorge, 1015, Lausanne, Switzerland
| | - Lars Werdelin
- Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, SE, 10405, Stockholm, Sweden
| | - Alexandre Antonelli
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE, 40530, Göteborg, Sweden.,Gothenburg Global Biodiversity Centre, Box 461, SE, 40530, Göteborg, Sweden.,Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, U.K
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24
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Abstract
Reconstructing prehistoric animal communities is important for understanding the emergence of modern ecosystems and the environmental context of human evolution. A new study of African fossils spanning seven million years shows that ancient large-herbivore assemblages were functionally distinct from those that exist today.
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Affiliation(s)
- Robert M Pringle
- Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
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25
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Du A, Rowan J, Wang SC, Wood BA, Alemseged Z. Statistical estimates of hominin origination and extinction dates: A case study examining the Australopithecus anamensis–afarensis lineage. J Hum Evol 2020; 138:102688. [DOI: 10.1016/j.jhevol.2019.102688] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 10/03/2019] [Accepted: 10/09/2019] [Indexed: 11/28/2022]
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26
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Geographically divergent evolutionary and ecological legacies shape mammal biodiversity in the global tropics and subtropics. Proc Natl Acad Sci U S A 2019; 117:1559-1565. [PMID: 31843924 DOI: 10.1073/pnas.1910489116] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Studies of the factors governing global patterns of biodiversity are key to predicting community responses to ongoing and future abiotic and biotic changes. Although most research has focused on present-day climate, a growing body of evidence indicates that modern ecological communities may be significantly shaped by paleoclimatic change and past anthropogenic factors. However, the generality of this pattern is unknown, as global analyses are lacking. Here we quantify the phylogenetic and functional trait structure of 515 tropical and subtropical large mammal communities and predict their structure from past and present climatic and anthropogenic factors. We find that the effects of Quaternary paleoclimatic change are strongest in the Afrotropics, with communities in the Indomalayan realm showing mixed effects of modern climate and paleoclimate. Malagasy communities are poorly predicted by any single factor, likely due to the atypical history of the island compared with continental regions. Neotropical communities are mainly codetermined by modern climate and prehistoric and historical human impacts. Overall, our results indicate that the factors governing tropical and subtropical mammalian biodiversity are complex, with the importance of past and present factors varying based on the divergent histories of the world's biogeographic realms and their native biotas. Consideration of the evolutionary and ecological legacies of both the recent and ancient past are key to understanding the forces shaping global patterns of present-day biodiversity and its response to ongoing and future abiotic and biotic changes in the 21st century.
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27
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Swedell L, Plummer T. Social evolution in Plio-Pleistocene hominins: Insights from hamadryas baboons and paleoecology. J Hum Evol 2019; 137:102667. [PMID: 31629289 DOI: 10.1016/j.jhevol.2019.102667] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 08/21/2019] [Accepted: 08/23/2019] [Indexed: 11/16/2022]
Abstract
Reconstructions of hominin evolution have long benefited from comparisons with nonhuman primates, especially baboons and chimpanzees. The hamadryas baboon (Papio hamadryas) is arguably one of the best such models, as it exhibits both the male kin bonding and the cross-sex pair bonding thought to have been important in hominin evolution. Here we link processes of behavioral evolution in hamadryas baboons with those in a Plio-Pleistocene hominin, provisionally identified as Homo erectus (sensu lato) - a pivotal species in that its larger body and brain size and wider ranging patterns increased female costs of reproduction, increasing the importance of sociality. The combination of these higher costs of reproduction and shifts in diet and food acquisition have previously been argued to have been alleviated either via strengthening of male-female bonds (involving male provisioning and the evolution of monogamy) or via the assistance of older, post-reproductive females (leading to post-reproductive longevity in females, i.e., the grandmother hypothesis). We suggest that both arrangements could have been present in Plio-Pleistocene hominins if they lived in multilevel societies. Here we expand on our earlier scenario with two sets of recent data in support of it, (1) archaeological data from the 2 million year old Oldowan site of Kanjera South, Kenya and other sites that are suggestive of tool dependent foraging on nutrient dense resources (animal carcasses and plant underground storage organs), cooperation, and food sharing; and (2) a pattern of genetic variation in hamadryas baboons that suggests the operation of kin selection among both males and females at multiple levels of society. Taken together, these two sets of data strengthen our model and support the idea of a complex society linked by male-male, male-female, and female-female bonds at multiple levels of social organization in Plio-Pleistocene hominins.
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Affiliation(s)
- Larissa Swedell
- Dept of Anthropology, Queens College, City University of New York, Flushing, NY 11367-1597, USA; New York Consortium in Evolutionary Primatology, New York, NY, USA; Anthropology Program, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA; Biology and Psychology Programs, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA; Dept of Archaeology, University of Cape Town, Rondebosch 7701, Cape Town, South Africa.
| | - Thomas Plummer
- Dept of Anthropology, Queens College, City University of New York, Flushing, NY 11367-1597, USA; New York Consortium in Evolutionary Primatology, New York, NY, USA; Anthropology Program, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA.
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28
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Abstract
Present-day African ecosystems serve as referential models for conceptualizing the environmental context of early hominin evolution, but the degree to which modern ecosystems are representative of those in the past is unclear. A growing body of evidence from eastern Africa's rich and well-dated late Cenozoic fossil record documents communities of large-bodied mammalian herbivores with ecological structures differing dramatically from those of the present day, implying that modern communities may not be suitable analogs for the ancient ecosystems of hominin evolution. To determine when and why the ecological structure of eastern Africa's herbivore faunas came to resemble those of the present, here we analyze functional trait changes in a comprehensive dataset of 305 modern and fossil herbivore communities spanning the last ∼7 Myr. We show that nearly all communities prior to ∼700 ka were functionally non-analog, largely due to a greater richness of non-ruminants and megaherbivores (species >1,000 kg). The emergence of functionally modern communities precedes that of taxonomically modern communities by 100,000s of years, and can be attributed to the combined influence of Plio-Pleistocene C4 grassland expansion and pulses of aridity after ∼1 Ma. Given the disproportionate ecological impacts of large-bodied herbivores on factors such as vegetation structure, hydrology, and fire regimes, it follows that the vast majority of early hominin evolution transpired in the context of ecosystems that functioned unlike any today. Identifying how past ecosystems differed compositionally and functionally from those today is key to conceptualizing ancient African environments and testing ecological hypotheses of hominin evolution.
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Bernor RL, Cirilli O, Jukar AM, Potts R, Buskianidze M, Rook L. Evolution of Early Equus in Italy, Georgia, the Indian Subcontinent, East Africa, and the Origins of African Zebras. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00166] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Quinn RL. Isotopic equifinality and rethinking the diet of
Australopithecus anamensis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 169:403-421. [DOI: 10.1002/ajpa.23846] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 03/08/2019] [Accepted: 04/16/2019] [Indexed: 01/06/2023]
Affiliation(s)
- Rhonda L. Quinn
- Department of Sociology, Anthropology and Social WorkSeton Hall University South Orange New Jersey
- Department of Earth and Planetary SciencesRutgers University Piscataway New Jersey
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Affiliation(s)
- René Bobe
- Primate Models for Behavioural Evolution Lab, Institute of Cognitive and Evolutionary Anthropology, School of Anthropology, University of Oxford, Oxford, UK
- Gorongosa National Park, Sofala, Mozambique
- Interdisciplinary Center for Archaeology and Evolution of Human Behaviour (ICArEHB), Universidade do Algarve, Portugal
| | - Susana Carvalho
- Primate Models for Behavioural Evolution Lab, Institute of Cognitive and Evolutionary Anthropology, School of Anthropology, University of Oxford, Oxford, UK
- Gorongosa National Park, Sofala, Mozambique
- Interdisciplinary Center for Archaeology and Evolution of Human Behaviour (ICArEHB), Universidade do Algarve, Portugal
- Centre for Functional Ecology–Science for People & the Planet, Universidade de Coimbra, Portugal
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