A5030613783- Evolution and Paleontology Studies
- Pleistocene-Era Hominins and Archaeology
- Wildlife Ecology and Conservation
- Geology and Paleoclimatology Research
- Primate Behavior and Ecology
- Ecology and Vegetation Dynamics Studies
- Species Distribution and Climate Change
- Archaeology and ancient environmental studies
- Animal Ecology and Behavior Studies
- Isotope Analysis in Ecology
- Forensic Anthropology and Bioarchaeology Studies
- Morphological variations and asymmetry
- Pacific and Southeast Asian Studies
- Historical and Cultural Archaeology Studies
- Student Assessment and Feedback
- Human-Animal Interaction Studies
- Innovative Teaching Methods
- Marine Biology and Ecology Research
- Geographies of human-animal interactions
- Genetics, Aging, and Longevity in Model Organisms
- Zoonotic diseases and public health
- Experimental Learning in Engineering
- Plant and animal studies
- Sex and Gender in Healthcare
- Aeolian processes and effects
Colorado State University
2019-2024
Illinois State Museum
2022
George Washington University
2014-2019
University of Chicago
2018-2019
National Museum of Natural History
2014-2018
Smithsonian Institution
2018
Rutgers, The State University of New Jersey
2009-2017
University of California, San Diego
2017
Significance Testing ecological hypotheses of human evolution requires an understanding the ancient plant and animal communities within which our ancestors lived. Though present-day ecosystems provide baseline for reconstructing context evolution, extent to modern are representative past ones is unknown. Through analyses a fossil dataset spanning last 7 Myr, we show that eastern African large-bodied mammalian herbivores differed markedly from those today until ∼700,000 y ago. Because large...
Africa's fossil record of late Cenozoic mammals documents considerable ecological and evolutionary changes through time. Here, we synthesize those in the context mechanisms proposed to account for them, including bottom-up (e.g., climate change) top-down hominin impacts) processes. In doing so, (a) examine how incompleteness varied spatiotemporal scales evidence complicate efforts establish cause-effect relationships; (b) evaluate hypothesized drivers long-term change, highlighting key...
Environmental conditions, dispersal lags, and interactions among species are major factors structuring communities through time across space. Ecologists have emphasized the importance of biotic in determining local patterns association. In contrast, abiotic limits, limitation, historical commonly been invoked to explain community structure at larger spatiotemporal scales, such as appearance late Pleistocene no‐analog or latitudinal gradients richness both modern fossil assemblages....
Abstract Reconstructing hominin paleoecology is critical for understanding our ancestors’ diets, social organizations and interactions with other animals. Most paleoecological models lack fine-scale resolution due to fossil scarcity the time-averaged accumulation of faunal assemblages. Here we present data from 481 tracks northwestern Kenya, including 97 footprints attributed Homo erectus . These are found in multiple sedimentary layers spanning approximately 20 thousand years. Taphonomic...
It has long been proposed that pre-modern hominin impacts drove extinctions and shaped the evolutionary history of Africa's exceptionally diverse large mammal communities, but this hypothesis yet to be rigorously tested. We analyzed eastern African herbivore communities spanning past 7 million years-encompassing entirety history-to test top-down tool-bearing, meat-eating hominins contributed demise megaherbivores prior emergence Homo sapiens document a steady, long-term decline beginning...
Large mammals are at high risk of extinction globally. To understand the consequences their demise for community assembly, we tracked structure through end-Pleistocene megafaunal in North America. We decomposed effects biotic and abiotic factors by analyzing co-occurrence within mutual ranges species pairs. Although shifting climate drove an increase niche overlap, decreased, signaling shifts interactions. Furthermore, effect on remained constant over time while decreased. Biotic apparently...
A large brain is a defining feature of modern humans, yet there no consensus regarding the patterns, rates and processes involved in hominin size evolution. We use reliable proxy for fossils, endocranial volume (ECV), to better understand how evolved at both clade- lineage-level scales. For clade overall, dominant signal consistent with gradual increase size. This trend appears have been generated primarily by operating within hypothesized lineages—64% or 88% depending on whether one uses...
Significance Many quintessential human traits (e.g., larger brains) first appear in Homo erectus . The evolution of these is commonly linked to a major dietary shift involving increased consumption animal tissues. Early archaeological sites preserving evidence carnivory predate the appearance H. , but larger, well-preserved only after arrival This qualitative pattern key tenet “meat made us human” viewpoint, data from across eastern Africa have not been quantitatively synthesized test this...
Comparisons between modern death assemblages and their source communities have demonstrated fidelity to species diversity across a variety of environments taxonomic groups. However, differential preservation collection (including body-size bias) in both fossil may still skew the representation other important ecological characteristics. Here, we move beyond live-dead focus on recovery functional ecology (how interact with ecosystem) at community level for diverse non-volant mammal (87...
Abstract Biotic homogenization—increasing similarity of species composition among ecological communities—has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization North American mammalian assemblages during late Pleistocene through Holocene (~30,000 ybp recent), a timespan encompassing increased evidence landscape (~20,000–14,000 ybp). From ~10,000...
Dietary variation within species has important ecological and evolutionary implications. While theoreticians have debated the consequences of trait variance (including dietary specialization), empirical studies yet to examine intraspecific variability across globe through time. Here, we use new published serial sampled δ 13 C enamel values herbivorous mammals from Miocene present (318 individuals summarized, 4134 samples) how strategy (i.e. browser, mixed-feeder, grazer) affects individual...
Significance We have developed an Africa-wide synthesis of paleoenvironmental variability over the Plio-Pleistocene. show that there is strong evidence for orbital forcing during this time superimposed on a longer trend increasing environmental variability, supporting combination both low- and high-latitude drivers variability. combine these results with robust estimates mammalian speciation extinction rates find not significantly correlated rates. These findings do currently support link...
Abstract A growing body of literature proposes that our ancestors contributed to large mammal extinctions in Africa long before the appearance Homo sapiens , with some arguing premodern hominins (e.g., erectus ) triggered demise Africa's largest herbivores and loss carnivoran diversity. Though such arguments have been around for decades, they are now increasingly accepted by those concerned biodiversity decline present-day, despite near complete absence critical discussion or debate. To...