John Rowan

University at Albany, The State University of New York | UAlbany · Department of Anthropology

The Kibish Formation of southern Ethiopia has yielded the earliest fossils of Homo sapiens, ca. 196 ka, and has thus figured prominently in discussions of the origins of modern humans. Here we describe the fossil Bovidae from the Kibish Formation, a record that spans the late Middle Pleistocene to the early to mid-Holocene, and reconstruct aspects...

The giraffid fossils recovered from ~ 2.8–2.6 million year old (Ma) sediments from Lee Adoyta, Ledi-Geraru, Ethiopia, are described here. Sivatherium maurusium and Giraffa cf. G. gracilis are the two identified taxa, with the former being more abundant than the latter. We interpret this skew of relative abundance to be of paleoenvironmental signifi...

Ecological research often assumes that species are adapted to their current climatic environments. However, climate fluctuations over geologic timescales have influenced species dispersal and extinction, which in turn may affect community structure. Modern community structure is likely to be the product of both palaeoclimate and modern climate, wit...

Megaherbivore extinctions in Africa Human ancestors have been proposed as drivers of extinctions of Africa's diverse large mammal communities. Faith et al. challenge this view with an analysis of eastern African herbivore communities spanning the past ∼7 million years (see the Perspective by Bobe and Carvalho). Megaherbivores (for example, elephant...

Significance Testing ecological hypotheses of human evolution requires an understanding of the ancient plant and animal communities within which our ancestors lived. Though present-day ecosystems provide the baseline for reconstructing the ecological context of human evolution, the extent to which modern ecosystems are representative of past ones i...

NOW ( New and Old Worlds ) is a global database of fossil mammal occurrences, currently containing around 68,000 locality-species entries. The database spans the last 66 million years, with its primary focus on the last 23 million years. Whereas the database contains records from all continents, the main focus and coverage of the database historica...

Food webs influence ecosystem diversity and functioning. Contemporary defaunation has reduced food web complexity, but simplification caused by past defaunation is difficult to reconstruct given the sparse paleorecord of predator-prey interactions. We identified changes to terrestrial mammal food webs globally over the past ~130,000 years using ext...

Humans evolved in the dynamic landscapes of Africa under conditions of pronounced climatic, geological and environmental change during the past 7 million years. This book brings together detailed records of the paleontological and archaeological sites in Africa that provide the basic evidence for understanding the environments in which we evolved....

Significance 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...

The Early Pleistocene was a critical time period in the evolution of eastern African mammal faunas, but fossil assemblages sampling this interval are poorly known from Ethiopia’s Afar Depression. Field work by the Hadar Research Project in the Busidima Formation exposures (~2.7–0.8 Ma) of Hadar in the lower Awash Valley, resulted in the recovery of...

Primate palaeontologist and passionate advocate for diversity in human origins research.

Research suggests that climatic variables influence the distribution of primate species. However, few studies have investigated the impact of community structure and interspecific competition on primate distributions. In this study, we examine how non-primate mammalian frugivores affect the distribution of frugivorous primates in the Neotropics, As...

Significance Many quintessential human traits (e.g., larger brains) first appear in Homo erectus . The evolution of these traits is commonly linked to a major dietary shift involving increased consumption of animal tissues. Early archaeological sites preserving evidence of carnivory predate the appearance of H. erectus , but larger, well-preserved...

The Shungura Formation (Lower Omo Valley, Ethiopia) constitutes one of the most complete stratigraphic and paleontological records for the Plio-Pleistocene of eastern Africa and has yielded a large collection of fossil bovids, in which the most abundant tribe is Reduncini (waterbucks, kobs, and relatives). We used a multi-proxy approach to precisel...

Analysis of enamel stable carbon isotopes (δ13Cenamel) of fossil herbivores is an important tool for making inferences about Plio-Pleistocene vegetation structure in Africa and the environmental context of hominin evolution. Many palaeoecological studies implicitly or explicitly assume that individual variation in C3–C4 plant consumption among foss...

Access article with this link: https://authors.elsevier.com/a/1dF8iAlZXMPP6

A central goal of paleoanthropology is understanding the role of ecological change in hominin evolution. Over the past several decades researchers have expanded the hominin fossil record and assembled detailed late Cenozoic paleoclimatic, paleoenvironmental, and paleoecological archives. However, effective use of these data is precluded by the limi...

Grevy's zebra (Equus grevyi) has been reported from fossil sites spanning the past 2.3 Myr and covering a wide geographic range. However, no currently published reports dating to >200 ka can be confidently attributed to E. grevyi, with most specimens better allocated to another taxon or lacking diagnostic characteristics aligning them with E. grevy...

Aim Reinstating large, native herbivores is an essential component of ecological restoration efforts, as these taxa can be important drivers of ecological processes. However, many herbivore species have gone globally or regionally extinct during the last 50,000 years, leaving simplified herbivore assemblages and trophically downgraded ecosystems. H...

Prehistoric and recent extinctions of large-bodied terrestrial herbivores had significant and lasting impacts on Earth’s ecosystems due to the loss of their distinct trait combinations. The world’s surviving large-bodied avian and mammalian herbivores remain among the most threatened taxa. As such, a greater understanding of the ecological impacts...

We report on the Late Pleistocene (36-12 ka) mammals from Kibogo in the Nyanza Rift of western Kenya, providing (1) a systematic description of the mammal remains, (2) an assessment of their paleoenvironmental implications, and (3) an analysis of the biogeographic implications of non-analog species associations. Kibogo has yielded one of the larges...

A growing body of literature proposes that our ancestors contributed to large mammal extinctions in Africa long before the appearance of Homo sapiens, with some arguing that premodern hominins (e.g., Homo erectus) triggered the demise of Afri-ca's largest herbivores and the loss of carnivoran diversity. Though such arguments have been around for de...

Significance Humans have caused extinctions of large-bodied mammalian herbivores over the past ∼100,000 y, leading to cascading changes in ecosystems. Conversely, introductions of herbivores have, in part, numerically compensated for extinction losses. However, the net outcome of the twin anthropogenic forces of extinction and introduction on herbi...

Large-bodied mammalian herbivores can influence processes that exacerbate or mitigate climate change. Herbivore impacts are, in turn, influenced by predators that place top-down forcing on prey species within a given body size range. Here, we explore how the functional composition of terrestrial large-herbivore and -carnivore guilds varies between...

Significance Research in ecology and biogeography often assumes that ecological communities are shaped primarily by recent drivers, such as current climate and human activity. Here we analyze a comprehensive dataset of 515 large mammal communities across the Earth’s tropics and subtropics and show that present-day diversity patterns are codetermine...

Reliable estimates of when hominin taxa originated and went extinct are central to addressing many paleoanthropological questions, including those relating to macroevolutionary patterns. The timing of hominin temporal ranges can be used to test chronological predictions generated from phylogenetic hypotheses. For example, hypotheses of phyletic anc...

As recently as ~50,000 years ago, a great diversity of large-bodied mammalian herbivores (species >44 kg) occupied nearly all of Earth’s terrestrial realms. Outside of sub-Saharan Africa, the vast majority of these species had disappeared by the Pleistocene-Holocene boundary ~11,700 years ago, either from human impacts, climate change, or some comb...

Ecometric analysis involves the examination of quantifiable functional traits across the taxa in a biotic community. Well-documented relationships between certain functional traits and environmental gradients in the present provide the empirical framework for a large body of research that uses ecometrics to reconstruct environments in the fossil re...

Analyses of stable carbon isotopes (δ13C) from herbivore dental enamel and paleosol carbonates are important tools for Plio-Pleistocene paleovegetation reconstructions. A single herbivore tooth documents an isotopic record of vegetation on the order of 10–1–1 years and in proportion to that individual's foraging range. Paleosol carbonates, converse...

The fossiliferous late Pliocene deposits of the Lee Adoyta sub-basin, lower Awash Valley (LAV), Ethiopia, sample a poorly-known time interval in this region (~2.82 to <2.5 Ma). Recent fieldwork in Lee Adoyta by the Ledi-Geraru Research Project has produced a rich mammalian fauna, including the earliest specimen of the genus Homo. Here, we describe...

Camels are exceptionally rare in the Plio-Pleistocene fossil record of Africa, hindering attempts to understand the evolution of this family on the continent. Here we describe recently collected camel specimens from the Shungura Formation, Lower Omo Valley, Ethiopia, and attribute these remains to Camelus grattardi. The new specimens date to the la...

Fossil bovids are described from the late Pliocene site of Ledi-Geraru, mainly from the Gurumaha and Lee Adoyta sedimentary packages (2.8–2.6 Ma). Finds include taxa already known from the slightly older Hadar Formation, such as the buffalo Ugandax coryndonae, the bongo-like Tragelaphus rastafari-nakuae lineage, an alcelaphin resembling Parmularius...

It has long been hypothesized that the transition from Australopithecus to Homo in eastern Africa was linked to the spread of open and arid environments near the Plio−Pleistocene boundary, but data for the latest Pliocene are scarce. Here we present new stable carbon isotope data from the late Pliocene mammalian fauna from Ledi-Geraru, in the lower...

Establishing the relationship between craniodental morphology and dietary ecology in extant species permits inferences to be made about the ecology and biology of fossil species and the habitats they inhabited. Previous work linking diet and craniodental morphology has historically relied upon categorical classifications of diet and has not conside...

Ecological research often assumes that species are adapted to their current climatic environments. However, climate fluctuations over geologic timescales have influenced species dispersal and extinction, which in turn may affect community structure. Modern community structure is likely to be the product of both palaeoclimate and modern climate, wit...

East Africa has produced the earliest record of Homo sapiens ~200ka and a punctuated record of Middle Stone Age and Later Stone Age behaviors. We lack, however, a detailed late Quaternary paleoenvironmental record for the region, particularly during humid periods. Without a regional record, hypotheses about the evolution and ecology of early Homo s...

Evidence for C 4-dominated savanna environments, which have often been linked to the origins of the genus Homo, is not documented in eastern Africa until ~2 Ma based on evidence from the Omo-Turkana Basin. The critical period for understanding the origins of Homo, the latest Pliocene (~3.0-2.6 Ma), however, has been poorly represented in the fossil...

Ecological research often assumes that species are adapted to their current climatic environments. However, climate fluctuations over geologic time scales have influenced species dispersal and extinction, which in turn may affect community structure. Modern community structure is likely to be the product of both palaeoclimate and modern climate, wi...

The paleoenvironmental conditions surrounding the origins of pastoralism and the movement of herders from eastern to southern Africa sometime between ~4000 and 2000 ybp have been much debated. We lack, however, detailed paleoenvironmental data from sites sampling the hunter-to-herder transition in southeastern Africa, the likely corridor from easte...

New evidence from relatively recent methodological advances into hominin autecology presents interesting and often contradictory data. This article presents a broad overview of various paleoecological methods and summarizes what is known about the paleoecology of late Miocene hominins, through the hominin genera that begin to appear in the early Pl...

The Lee Adoyta region of the Ledi-Geraru Research Project Area, Mille District, Afar Regional State, Ethiopia, has 2.8 Ma sediments that fill a significant temporal gap in our understanding of Pliocene mammalian evolution in eastern Africa. Giraffid fossils from Lee Adoyta are identified as Sivatherium maurusium and Giraffa gracilis, the latter of...

The evolutionary history of ungulates in Africa is marked by the appearance and diversification of a suite of craniodental adaptations presumably related to diet. These morphological traits, in addition to stable carbon isotope (δ13C) data, have been widely used to infer the diet of extinct species, although the relationship between these proxies r...

Accurately identifying the habitat preferences of extinct taxa is important for understanding how ecological and evolutionary mechanisms functioned in the past. Previous studies have inferred habitat preference from proxies such as functional morphology, stable isotopes, dental wear, and/or habitat preferences of extant relatives. These measures, h...

The Late Pleistocene of Africa was characterized by climatic changes that led to major redistributions of terrestrial vegetation biomes during the transition from glacial to interglacial conditions over the last ~ 26 ka. Most notable are the particularly cold and arid Last Glacial Maximum (LGM) ~ 26-20 ka, and the warm and wet African Humid Period...

Recent studies have observed that taxonomic turnover (across space or through time) is higher than its functional counterpart with the latter reflecting ecosystem processes and stability. However, it is well known that ecological patterns and processes change across spatial and temporal scales. Given the current biodiversity crisis, one might be mo...

Here we describe the first known skull and associated postcrania of the small bothriodontine anthracotheriid Sivameryx africanus, which fills an important gap in the current knowledge of morphological diversity within the Anthracotheriidae of Africa. The skull was recovered from the latest early Miocene sediments of the Kalodirr Member in the Turka...

Hawks et al. argue that our analysis of Australopithecus sediba mandibles is flawed and that specimen LD 350-1 cannot be distinguished from this, or any other, Australopithecus species. Our reexamination of the evidence confirms that LD 350-1 falls outside of the pattern that A. sediba shares with Australopithecus and thus is reasonably assigned to...

The Ledi-Geraru research area forms part the Lower Awash Valley (Afar, Ethiopia), a region with abundant sedimentary deposits which have yielded some of the most emblematic hominin fossil discoveries in the history of paleoanthropology. Ledi-Geraru is localized north of Hadar and Dikika, and west of Gona. A series of surveys carried out since 2002...

Previous researchers have inferred habitat associations of extinct mammals using functional morphology, stable isotopes, dental wear, and/or habitat associations of extant relatives. These measures, however, are all indirect habitat indicators and do not measure the direct association between a taxon of interest and its inhabited environment. Under...

The potential role of basinal endemism in structuring patterns of hominin biogeography remains largely unexplored. Here we attempt to bridge this gap by analyzing patterns of endemism across eastern Africa during two periods in human evolution, one in which a single lineage (Australopithecus anamensis-afarensis) is patchily distributed, and the sec...

Sedimentary basins in eastern Africa preserve a record of continental rifting and contain important fossil assemblages for interpreting hominin evolution. However, the record of hominin evolution between 3 and 2.5 million years ago (Ma) is poorly documented in surface outcrops, particularly in Afar, Ethiopia. Here we present the discovery of a 2.84...

Sedimentary basins in eastern Africa preserve a record of continental rifting and contain important fossil assemblages for interpreting hominin evolution. However, the record of hominin evolution between 3 and 2.5 million years ago (Ma) is poorly documented in surface outcrops, particularly in Afar, Ethiopia. Here we present the discovery of 2.84-2...

Our understanding of the origin of the genus Homo has been hampered by a limited fossil record in eastern Africa between 2.0 and 3.0 million years ago (Ma). Here we report the discovery of a partial hominin mandible with teeth from the Ledi-Geraru research area, Afar Regional State, Ethiopia, that establishes the presence of Homo at 2.80-2.75 Ma. T...

Bovids are frequently used as environmental indicators and in habitat reconstructions of the East African Plio-Pleistocene due to their ubiquity in fossil deposits and their tribal preferences for particular habitats. However, their commonness also lends itself to testing biogeographical hypotheses regarding endemism and dispersal in mammalian asse...

Despite representing a rare time interval in the Afar during the Plio-Pleistocene, the mammalian fauna of the Busidima Formation at Hadar in northeast Ethiopia, ca. 2.7 to 0.8 Ma, has not been intensively studied despite offering insights into the paleoenvironmental and ecological context of early toolmakers and the origin of Homo. Busidima sedimen...