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Introduction
Current institution
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January 2007 - present
Education
September 1999 - May 2005
Publications
Publications (93)
The sacral hiatus is typically positioned at the penultimate (S4) vertebral level in most humans and is influenced by genetic factors responsible for vertebral arch formation. However, the functional role of the hiatus has not been investigated. Also absent is a systematic comparative analysis of a diverse, global sample of humans and non-human ape...
The morphology of the primate forelimb reflects its use in positional behaviors and can be used to reconstruct locomotor behavior in fossils. Although the human forelimb is largely freed from a locomotor role, some fossil hominins seem to have engaged in climbing and suspensory behaviors. Here we test whether the radius may be a reliable indicator...
Recording of AABA 2023 Conference talk
Since its discovery two decades ago, claims for Sahelanthropus tchadensis representing a basal hominin have been met with skepticism. Its curious provenience is not often discussed, as the bones were not found in situ. Recently, two partial ulnae and a femoral shaft were published and suggested to represent postcrania associated with the TM 266 cra...
Supplementary Online Material (SOM): Knuckle-walking in Sahelanthropus?
Because the ulna supports and transmits forces during movement, its morphology can signal aspects of functional adaptation. To test whether, like extant apes, some hominins habitually recruit the forelimb in locomotion, we separate the ulna shaft and ulna proximal complex for independent shape analyses via elliptical Fourier methods to identify fun...
In their recent article, "The atlas of StW 573 and the late emergence of human-like head mobility and brain metabolism" Beaudet and colleagues (Scientific Reports, March 2020) contend that StW 573 had lower metabolic costs for cerebral tissues and that blood perfusion of these tissues increased recently over the course of hominin evolution. This co...
Objectives
In humans and known fossil hominins, lumbar lordosis is produced by vertebral body wedging and other bony and soft tissue features such as the shape of the intervertebral discs. Current techniques for quantifying the wedging of vertebral bodies are limited in utility, especially when analyzing incomplete fossil material. Here, we introdu...
Variation in ulna morphology is known to differentiate specialized locomotor groups. Using elliptical Fourier analysis, we evaluate the ulnar shaft and proximal complex in 13 hominin fossils from Sahelanthropus, Ardipithecus, Australopithecus, Paranthropus, and early Homo. Principal components of shape contours were evaluated against locomotor patt...
The ulna of extant apes is distinct from other anthropoids, with knuckle-walking engendering an especially unique robusticity and curvature in the African apes. Here we use Fourier shape descriptors to compare ulna contours in a sample of 418 extant primates from 88 species against fifteen hominin fossil ulnae from Sahelanthropus, Ardipithecus, Aus...
Despite exhibiting a range of specializations in locomotion most primates have a relatively generalized postcranial skeleton, enabling extensive locomotor flexibility. However, a small number of forelimb traits, including in the morphology of the ulna, exhibit strong functional signals that may provide a link between skeletal morphology and locomot...
Lumbar lordosis is a key adaptation to bipedal locomotion in the human lineage. Dorsoventral spinal curvatures enable the body's center of mass to be positioned above the hip, knee, and ankle joints, and minimize the muscular effort required for postural control and locomotion. Previous studies have suggested that Neandertals had less lordotic (ven...
Archaeological excavations at the Dali site complex located in southeastern Kazakhstan
provide a rich picture of Bronze Age life spanning from the early third to late second
millennia B.C. Nearly ten years of research at the site have produced an abundant
assemblage of architectural remains, ritual and burial contexts, human and animal
ancient DNA,...
Adaptations of the lower back to bipedalism are frequently discussed but infrequently demonstrated in early fossil hominins. Newly discovered lumbar vertebrae contribute to a near-complete lower back of Malapa Hominin 2 (MH2), offering additional insights into posture and locomotion in Australopithecus sediba . We show that MH2 possessed a lower ba...
Adaptations of the lower back to bipedalism are frequently discussed but infrequently demonstrated in early fossil hominins. Newly discovered lumbar vertebrae contribute to a near-complete lower back of Malapa Hominin 2 (MH2), offering additional insights into posture and locomotion in Australopithecus sediba. We show that MH2 demonstrates a lower...
Discoveries of ulnae for early hominins such as the TM 266-01-050 Sahelanthropus tchadensis and the StW 573 (“Little Foot”) Australopithecus are welcome additions to the early hominin fossil record. Significant curvature of the ulna is a normal anatomic feature among extant apes and many early hominins that has been linked to locomotor behaviors in...
Previous work suggests the significant curvature of the StW 573 (‘Little Foot’) ulna shaft represents pathological traumatic bowing from a childhood fall. Here we test this hypothesis via elliptical Fourier shape analysis in a sample of apes, modern humans, including clinical humans with this pathology. Fossil hominins also compared here include: S...
Highlights: Previous work suggests curvature of the ‘Little Foot’ ulna represents pathological bowing from a childhood fall.
Shape analysis in apes, hominins and modern humans, including clinical humans rejects the traumatic bowing hypothesis.
Instead, the ‘Little Foot’ ulna reflects a natural degree of curvature observed in apes and many early...
Abstract: The Samuel George Morton Cranial Collection housed at the University of Pennsylvania Museum of Archaeology and Anthropology is the result of the activities of its namesake (1799–1851), a 19th century physician and physical anthropologist. Morton obtained skulls from scientists and army surgeons from around the world, although in some case...
Danuvius guggenmosi is a species of Miocene hominoid from the
11.62-million-year-old site of Hammerschmiede. On the basis of interpretations of its vertebrae and limbs, Böhme and colleagues infer that Danuvius exhibited ‘joint positions and loading patterns of both
hominin bipedalism that emphasize hindlimb extension and spinal
curvatures, and exta...
Sexual dimorphism is an important feature of adult thorax morphology, but when and how sex-related differences in the ribcage arise during ontogeny is poorly known. Previous research proposed that sex-related size differences in the nasal region arise during puberty. Therefore, we explore whether ribcage sexual dimorphism also arises at that time a...
Recent discoveries from A. anamensis at Assa Issie (4.2 Ma) and A. afarensis from Woranso Mille (3.6 Ma) in Ethiopia, along with later fossils of A. sediba from Malapa and P. robustus from Drimolen in South Africa preserve rare aspects of vertebral anatomy from opposite poles of the postcranial axial skeleton (C1-C3; S5). Here we use 2D geometric m...
In this chapter, we summarize vertebral remains from early Pleistocene Homo, including H. erectus, as well as H. naledi and H. floresiensis fossils from the Middle and Late Pleistocene, respectively. Two partial immature H. erectus skeletons where vertebrae are well represented are KNM-WT 15000 (“Turkana boy”) and the D2700 individual from Dmanisi....
The early hominin (Ardipithecus and Australopithecus) fossil record contains over 100 preserved vertebral elements (n = 107; approximately half of which are well-preserved), ~65% of which have not been described since the turn of the millennium. Many are fragments, some for which detailed descriptions are pending (e.g., those of Australopithecus an...
Australopitheus anamensis fossils demonstrate that craniodentally and postcranially the taxon was more primitive than its evolutionary successor Australopithecus afarensis. Postcranial evidence suggests habitual bipedality combined with primitive upper limbs and an inferred significant arboreal adaptation. Here we report on A. anamensis fossils fro...
The lower back is adapted to mobility and stability across mammals and reflects posture and locomotion in the framework of a species’ evolutionary history. Upright bipedalism is one such positional behavior, and due to limited fossil evidence, disagreements exist as to when, how, and in what evolutionary context bipedalism evolved. Here, we describ...
Seven A. anamensis vertebral fossils from the Assa Isse locality in Ethiopia's Middle Awash area dated to ~4.2 Ma constitute the oldest known australopith axial remains. Because the spine is the interface between major body segments, these fossils can be informative on the behavior and evolution of the first australopiths. Two C1 vertebrae are simi...
Australopithecus sediba is known from two partial skeletons, Malapa Hominins 1 and 2 (MH1 and MH2), a juvenile male and an adult female, respectively. Forty-eight elements of the axial skeleton, including vertebrae, ribs, a sternum, and a sacrum, are known from MH1 and MH2. Here, we describe these ~2.0 Ma fossils and provide raw data and plots of s...
Mammals: An increase in body size requires an isometric increase in lung capacity/thorax size.
Great Apes: We hypothesize that wide lower thoraces accommodate body size increases, while narrow upper thoraces maintain efficient forearm locomotion.
Hominins: We hypothesize that wide upper thoraces accommodate body size increases and maximize the ac...
Objectives: Uncinate processes are protuberances on the cranial surface of subaxial cervical vertebrae that assist in stabilizing and guiding spinal motion. Shallow uncinate processes reduce cervical stability but confer an increased range of motion in clinical studies. Here we assess uncinate processes among extant primates and model cervical kine...
Postcranial measurements.
DOI:
http://dx.doi.org/10.7554/eLife.24232.047
Canonical variates analysis of carpal morphology.
DOI:
http://dx.doi.org/10.7554/eLife.24232.048
Traits of the LES1 cranium in comparison to H. naledi and other hominin species.
DOI:
http://dx.doi.org/10.7554/eLife.24232.045
Cranial and mandibular measurements.
DOI:
http://dx.doi.org/10.7554/eLife.24232.046
Taphonomic observations by specimen from the Lesedi Chamber.
DOI:
http://dx.doi.org/10.7554/eLife.24232.049
ELife digest
Species of ancient humans and the extinct relatives of our ancestors are typically described from a limited number of fossils. However, this was not the case with Homo naledi. More than 1500 fossils representing at least 15 individuals of this species were unearthed from the Rising Star cave system in South Africa between 2013 and 2014...
H. naledi shows a mosaic morphological pattern
with several derived (Homo-like) features of the
skull, hands and feet, and primitive (australopith-
like) features in the ribcage, shoulder, and
pelvis. This pattern reflects a morphology that
might be expected of a hominin at the evolutionary
transition between Australopithecus and
Homo. Two thoracic...
Considered individually, many aspects of early
hominin cervical anatomy appear more similar
to the African great apes than to humans,
suggesting an ape-like pattern of load transfer,
and by extension points to significant differences
with human head carriage.
However, when the australopith cervical spine
is examined as a whole, rather than as separ...
Spinal cord dimensions increased in both relative and absolute terms during the course of hominin evolution. Recent discoveries demonstrate the presence of a fully developed human-sized cervical spinal cord in Australopithecus afarensis at 3.6 million years before present (Ma) and in the cervical and thoracic regions of Homo erectus at 1.8 Ma. The...
We describe the earliest evidence for neoplastic disease in the hominin lineage. This is reported from the type specimen of the extinct hominin Australopithecus sediba from Malapa, South Africa, dated to 1.98 million years ago. The affected individual was male and developmentally equivalent to a human child of 12 to 13 years of age. A penetrating l...
In this preliminary reconstruction of Homo naledi’s gait we begin with the null hypothesis that it walked similarly to modern humans, as the overall anatomy of this extinct hominin’s lower limb, especially its foot, is mostly modern human-like. We note the following characters as modern-like: dorsally-canting metatarsophalangeal joints facilitating...
Early hominin vertebrae are extremely rare in the Pliocene fossil record. Currently known vertebral specimens are either fragmentary or isolated. Here we describe a series of 3.6 million-year-old vertebrae from the KSD-VP-1/1 (“Kadanuumuu”) postcranial skeleton, representing the oldest adult cervical column known in the hominin fossil record. Surpr...
A series of six partial cervical vertebrae were recovered in association with the KSD-VP-1/1 Australopithecus afarensis postcranial remains dated to 3.6 million years before present (Meyer 2016). The series preserves elements from the C2 axis to the C7 vertebral level and represents the oldest adult cervical column known in the hominin fossil recor...
We describe the axial skeletal material recovered from the Dinaledi chamber of Rising Star cave that, together with some pelvis and shoulder remains, document the complicated nature of trunk evolution. The axial material includes two near-complete lower thoracic vertebrae found in articulation with an 11th rib, the proximal portion of a 12th rib, a...
A series of six partial cervical vertebrae were recovered in association with the KSD-VP-1/1 postcranial remains from the C2 axis to the C7 vertebral level, representing the oldest adult cervical column known in the hominin fossil record. The vertebrae of this large male australopith are more derived than those of its smaller female counterparts, a...
A series of six partial cervical vertebrae were recovered in association with the KSD-VP-1/1 postcranial remains from the C2 axis
to the C7
vertebral level, representing the oldest adult cervical column
known in the hominin fossil record. The vertebrae of this large male australopith are more derived than those of its smaller female counterparts, a...
KSD-VP-1/1 is a 3.6 million years old (Ma) partial skeleton of Australopithecus
afarensis
recently discovered from the Woranso-Mille
study area in the Afar
region of Ethiopia. The recovered elements of this specimen, which include cervical vertebrae, a complete scapula, clavicle, numerous ribs, pelvis, and elements of the fore- and hindlimbs, great...
Traits of H. naledi and comparative species.
DOI:
http://dx.doi.org/10.7554/eLife.09560.029
Holotype and paratype specimens and referred materials.
DOI:
http://dx.doi.org/10.7554/eLife.09560.028
Homo naledi is a previously-unknown species of extinct hominin discovered within the
Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is
characterized by body mass and stature similar to small-bodied human populations but a small
endocranial volume similar to australopiths. Cranial morphology of H. na...
Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. na...
In the description of postcranial material associated with the A.L.288-1 partial skeleton popularly known as Lucy, Johanson et al. (1982:432) noted that the A.L.288-1am thoracic neural arch fragment stood out from the other fossils because it was " polished or even 'water-worn' and is the only specimen from A.L.288 with these characters. " This obs...
Spinal canal dimensions in the Nariokotome boy KNM-WT 15000, the best preserved skeleton of Homo erectus, are strikingly narrow except for the caudalmost lumbar vertebrae when compared to modern humans (MacLarnon 1993). They thus resemble those of chimpanzees and australopithecines. The hypothesis of Latimer and Ohman (2001) that Nariokotome’s narr...
Pearce and Dunbar (2011) suggest there has been independent selection for larger orbits in lower light conditions, as they find larger orbits in humans in progressively higher latitudes (N=55). As large eyes necessitate relatively larger visual cortices, Pearce et al. (2013) posit Neandertal brains skewed proportionately more towards vision, and we...
Several features of the human thoracic vertebrae confer greater flexibility, load bearing, and neurological capacity than is seen in australopithecines and apes. The Dmanisi and Nariokotome fossil vertebrae provide a window into the evolution of these features in early genus Homo. The thoracic articular complex in early Homo differs somewhat from m...
[This corrects the article on p. e1001071 in vol. 9.].
Additional historical background.
(DOC)
Morton's raw cranial capacity data from his three major publications, Crania Americana [8], Crania Aegyptiaca [9], and Catalogue of Skulls [10], in Microsoft Excel format.
(XLS)
The raw cranial capacity data of the present study, in Microsoft Excel format.
(XLS)
The analytical spreadsheets showing the calculations described, in Microsoft Excel format.
(XLS)
![Table 1. Crania mismeasured by Morton with shot [10], using our...](profile/Jason-Lewis-4/publication/51213090/figure/fig5/AS:343505491775497@1458909499835/Crania-mismeasured-by-Morton-with-shot-10-using-our-measurements-as-the-gold_Q320.jpg)
Stephen Jay Gould, the prominent evolutionary biologist and science historian, argued that ‘‘unconscious manipulation of data may be a scientific norm’’ because ‘‘scientists are human beings rooted in cultural contexts, not automatons directed toward external truth’’, a view now popular in social studies of science. In support of his argument Gould...
In this study, we attempt to create a method for the determination of the carrying
angle (Cubitus Valgus) in unarticulated modern human humerii. We test the efficacy
of 3 different measures of the obliquity of the distal morphology of the humerus in
their correlation to the Trochlear Angle, a classically used medical measurement of
elbow angulation...
The recent discovery of several axial elements attributed to the D2700 hominid from Dmanisi offers an opportunity to compare locomotor patterns in early Homo erectus with other hominids. Cervical, thoracic and lumbar vertebral elements from D2700 were compared with those from 91 modern humans, 26 fossil hominids, 27 chimpanzees, and 22 gorillas.
C...
The external dimensions and internal
morphology of the Neandertal nose are often
considered to reflect physiological and
behavioral adaptations to the cold, dry
climate of the late Pleistocene. An extension
of this perspective argues that these putative
adaptations represent unique derived traits
(autapomorphies) distinguishing Neandertals
from mod...
Recently, a partial spinal column attributed to Homo erectus was discovered at the site of Dmanisi, Georgia (Meyer 2005). Dated to 1.78 million years before present, the Dmanisi vertebrae are the oldest known for the genus, and present an important opportunity to examine the spinal anatomy and neuroanatomical potential of early Homo . Comparative a...
Based on the singular fossil spinal column known for Homo erectus (KNM-WT-15000), it has been maintained that the spinal cord of this early human species was small and apelike, lacking a human level of innervation to respiratory muscles involved in spoken language. Thus, it has been suggested that this taxon had not evolved the capacity for spoken...
Photocopy. Thesis (Ph. D.)--University of Pennsylvania, 2005. Includes bibliographical references and index.
Neandertals have exceptionally broad nasal apertures. The Neandertal nose has been referred to as "the prime architect of the Neandertal face" (Coon 1962) - functional explanations for the size of Neandertal noses have historically considered them to be specializations for a cold, arid environment. The adaptive nature of human nasal form is suggest...
Estimates of sexual dimorphism are used in fossil studies for questions on several, interrelated topics; direct discussions of the amount of sexual dimorphism in a fossil sample and its implications, accurate sexual classification, and accurate taxonomic classification. Previous work by the authors has shown that human populations in different area...
Nasal morphology represents a classic example of skeletal variation long depicted as reflecting adaptation to regional climatic regimes in both modern and fossil humans. Temperature, and especially humidity, have been implicated in strongly affecting nasal form, with longer, narrower and more projecting noses associated with dry, cold climates, and...
Uncertainty regarding the degree and nature of sexual dimorphism in fossil hominids is a major obstacle in their accurate taxonomic classification. Modern analogs for sexual dimorphism, either generated from single populations or from geographically dispersed samples, are often used to interpret the degree of sexual dimorphism in fossil hominid sam...
It has been suggested that the size of thoracic vertebral foramina in WT-15000 reflects the degree of neurological control of the intercostal muscles, providing insight into Nariokotome’s motor capabilities for spoken language. This is due to the putative relationship between the intercostals and fine-tuned breath control utilized during speech. Ho...
Questions
Question (1)
There are many contradictions in the literature as to the origin of the omo-cervicalis (aka, atlanto-cervicalis, levator claviculae) muscle in non-human primates. Miller 1932 reports it's on the spinous process but all images (including his) appear to depict its origin on the lateral aspect of the pars interarticularis. Any informed knowledge on this from dissection or otherwise? Not from the usual literature citing Miller (ie., Aiello, Wood).
