Human Paleontology and Prehistory

Nowhere in the entire fossil record of life do we find more dramatically accelerated accumulation of evolutionary novelty than we do in the genus Homo. Quite simply, and by whatever criteria you measure it, our species Homo sapiens is more different from its own precursors of two million years ago than is any other species living in the world today. What might account for this unusually rapid rate of evolution? A major influence was almost certainly material culture, though not in the gene-culture co-evolutionary context envisaged by the evolutionary psychologists. Rather, material culture enhances the ability of hominid populations to disperse at times when conditions are favorable for expansion, while incompletely insulating the resulting enlarged populations from environmental stress when circumstances deteriorate. In other words, by facilitating expansion beyond normal physiological limits in good times, culture makes populations more vulnerable to fragmentation in bad ones. Over the course of the Pleistocene, short-term but large-scale local environmental changes became increasingly frequent over large tracts of the Old World, further amplifying the stress-and-response cycle. Since the fixation probabilities of evolutionary novelties of all kinds (as well as of local extinctions) are promoted by population fragmentation and consequent small effective population sizes, we see in the synergy between environmental effects and material culture a sort of ratchet effect which would have acted to leverage rates of accumulating change. This interaction explains the extraordinarily fast tempo of evolution within the genus Homo by invoking perfectly routine evolutionary processes; and it eliminates any need for special pleading in the hominid case, at least in terms of mechanism. Apparent recent diminution in human brain size may result from greater algorithmic efficiency.

Darwin argued that man, including his mental faculties, developed from his sub-human ancestors by natural selection, sexual selection, and the use and disuse of organs (in the Lamarckian mode). He rejected any non-natural involvement in this process, and described a large number of behavioral and mental properties, including language, which can be found in rudimentary form in some animals. However, he assumed this, prior of the discovery of the crucial differences between the instinctive and specific calls of animals, and the symbolic language of humans. His major conclusion was that although the gap in the mental properties between humans and their closest relatives is enormous, it is quantitative rather than qualitative. With regard to the different human races, Darwin suggested that they differ in their inherited mental properties, but belong to a single species. In contrast to Darwin, Wallace did not regard modern human “primitives” as candidates that could fill the gap between humans and apes. He envisioned two steps in human evolution: first, the development of upright posture and freeing of the hands, brought about by natural selection, and then a second step that involved mainly the evolution of the brain and the mind. Wallace subsequently argued that some of the higher human mental abilities (mathematics, art, or the use of abstract concepts) were not the result of natural selection, since they are beyond utility. He claimed that these properties developed as a result of the action of a “higher intelligence”, which guides human intelligence and morality, and the whole evolutionary process, purposefully. There is some disagreement as to whether Wallace’s belief in the action of a “higher intelligence”, and his descent from Darwin on this issue, were the result of his support of spiritualism or was based on purely scientific arguments. Darwin, on his part, forcefully rejected Wallace’s support of the involvement of non-natural causes in evolution of human mental faculties and provided arguments that they were the result of the same mechanisms that acted in the formation of the body, and generally in species evolution. Later, S.J. Gould pointed out that the rapid rate of the development of several mental functions, which Wallace had regarded as an indication of a lack of role in the struggle of life are actually the result of cultural evolution. Both Darwin and Wallace did not pay sufficient attention to the large diversity in human mentality, and the rare and unique existence of individuals with outstanding achievements (“geniuses”). The latter’s unusual and unique creativity in various artistic, philosophical and related activities apparently developed intrinsically, from some “inner resources”, unrelated to the Darwinian “struggle for life”.

Most evolutionary biologists, after Lamarck and Darwin, were concerned with evolutionary processes in the natural world with no special mention of Man – taking him as just another animal. Some dealt with the human species only, and were concerned with human descent from the apes – or, like Wallace and Dobzhansky, with the unique abilities of humans to protect themselves from nature. Still others, like Galton and the Eugenicists, were interested in controlling or improving the future qualities of the human population. That human activities, as a dominant species, affect the natural environment was already noted by Lyell in the early 19^th century, but the effect of mankind on the rest of the biological world became of public concern only recently. The implications of human activities for the future evolution – and fate – of our entire planet, seems to be of only limited academic concern, and Man [=mankind, the “international community”] is either uninterested or unable to do anything positive about it.

Evidence from the Pliocene hominin site of Laetoli in northern Tanzania demonstrates that there was a taxonomic turnover of the mammalian fauna between the Upper Laetolil Beds (3.6–3.85 Ma) and the Upper Ndolanya Beds (2.66 Ma). Paranthropus aethiopicus was one of the novel species that appeared locally as part of the restructured fauna. This turnover coincides with a major climatic shift at ~2.8–2.5 Ma, which had an important impact on the local environment and the composition of the faunal community. Investigation of the paleoecology of the Upper Ndolanya Beds provides critical evidence about how the vegetation and fauna at Laetoli, including the hominins, responded to these environmental changes. The preponderance of alcelaphin bovids and the reduced frequency of browsing ungulates, in conjunction with evidence from ecomorphology, mesowear and stable isotopes, indicate that the Upper Ndolanya Beds sample drier habitats with a greater proportion of grasslands compared with the earlier Upper Laetolil Beds. However, paleoecological inferences based on ostrich eggshells, rodents, and terrestrial gastropods present a more complicated picture, indicating instead that Upper Ndolanya habitats were more mesic and dominated by dense woodlands. Such confounding results can be reconciled as a consequence of the differential impact of climatic and environmental change on a global, regional and local scale.

While paleoneurology has undergone major changes relevant to hominid evolution, largely through newer computer-driven segmentation techniques using CT, laser, MRI, and other imaging technologies, so-called state-of-the-art techniques still require expert understanding of underlying endocranial morphology. The australopithecine endocranial remains, whether from natural endocasts such as Taung, Sts60, SK1585, or those made from rubber, silicone-based reagents, such as AL 444-2, or CT scans (MH1), still occasion major differences of interpretation and thus controversy, and the controversy initiated by Dart in 1925 for the Taung specimen is still alive and well. The newer non-invasive techniques have much to offer human paleontologists regarding the evolution of the brain as long as basic anatomical realities are appreciated.

Most explanations for the origin of hominin bipedality cannot be comparatively tested, because there are no other striding bipeds among mammals. However, there are other mammals that stand bipedally for long periods of time. One such is the gerenuk (Litocranius walleri), an African gazelle that browses while standing bipedally, with extended hips and knees and a marked lumbar lordosis. Despite these behavioral resemblances to humans, Richter’s (1970) extensive comparative study of gerenuk anatomy found only one skeletal apomorphy specifically related to bipedality – namely, a reduction in the lumbar spinous processes, which permits that lumbar lordosis. Our data show that gerenuks lack two other features – an expanded cranial sector of the acetabular semilunar surface, and “wedging” of the lumbar vertebral bodies – that we had expected from their bipedal positional behavior. We infer that even prolonged and extensive postural bipedality results in little or no postcranial remodeling, unless selection favoring the maintenance of efficient quadrupedal locomotion is relaxed. This conclusion undercuts theories, such as Hunt’s (1994) “postural feeding hypothesis,” that portray early hominin postcranial apomorphies as having originated as adaptations to bipedal feeding postures rather than to bipedal locomotion.

Until recently, there has been little consensus as to the functional benefits of having vertically-shortened canines in the earliest humans. In an effort to resolve this problem, Hylander (2013) tested the hypothesis that canine height dimensions in catarrhines are linked to modifications in the amount of jaw gape. The data demonstrate that most adult male catarrhines have relatively larger canine overlap dimensions and relatively larger gapes than do conspecific females. Humans and hylobatids are the exceptions in that canine overlap is nearly the same between sexes, and so is relative gape, although humans have relatively small gape and hylobatids have relatively large gape. A correlation analysis demonstrated that a large portion of relative gape (maximum gape/projected jaw length) is predicted by relative canine overlap (canine overlap/jaw length). Relative gape is mainly a function of jaw muscle position and/or jaw muscle-fiber length. All things equal, more caudally positioned jaw muscles and/or longer muscle fibers increase the amount of gape. The net benefit for increasing gape in catarrhines is related to within species interactions as well as predation patterns. The cost, however, is to decrease bite force. In order to compensate for a decrease in bite force, jaw muscle mass must be increased so as to assure that the original bite force is maintained. On the other hand, and all things equal, more rostrally positioned jaw muscles and/or shorter muscle fibers decrease gape. The net benefit to decreasing gape is to increase bite force without a corresponding increase in muscle mass. Alternatively, the original bite force can be maintained whereas the costs of original muscle size can be reduced. Overall, the data support the hypothesis that canine reduction in early hominins is functionally linked to increased mechanical efficiency of the jaws. The purpose of this chapter is to review certain aspects of the original paper by Hylander (2013), as well as discussing additional implications of this study not previously considered. These include, but are not restricted to: (1) a review of recent developments about muscle mass and fiber lengths in a highly dimorphic model catarrhine primate, Macaca fascicularis; (2) a discussion of the fact that relative canine overlap in male catarrhines do not mirror those in female catarrhines; and (3) based on the catarrhine data, interpretations are advanced as to relevance of the functional significance of the high mandibular condyle position in certain catarrhines, with a particular emphasis on the high condyle of robust australopithecines.

In 1960 John Robinson suggested that the newly defined species Zinjanthropus boisei should be transferred to the genus Paranthropus Paranthropus (Broom 1938) as Paranthropus boisei (Leakey 1959). Since then fossil evidence of two hyper-megadont early hominin taxa has come to light. One of these taxa, Paraustralopithecus aethiopicus (Arambourg and Coppens 1968), has been added to the Paranthropus genus, whereas the second taxon, Australopithecus garhi (Asfaw et al. 1999), has been included in a different taxon, Australopithecus. This contribution will tease out why different alpha-taxonomic decisions were made about the generic affinities of Paraustralopithecus aethiopicus and Australopithecus garhi. It will also review the types of data that are now available for generating and testing hypotheses about the relationships of megadont and hyper-megadont hominins. On the basis of this review, in this paper we will suggest a hypothesis, or hypotheses, that are most consistent with the current fossil and contextual data from East and southern Africa.

The craniofacial morphology of Paranthropus boisei is highly derived, representing the evolutionary culmination of one robust australopith lineage. Following its discovery, OH 5 was popularly described as “Nutcracker Man,” and this image of the East African robust australopiths as hard-object feeders has persisted for the last half-century. Emerging lines of evidence, however, suggest that the diet of this species was not primarily comprised of hard foods. An alternative view is that P. boisei consumed a relatively tough diet of grasses and sedges. As the covariation of diet and/or feeding behavior with mandibular morphology has been the focus of a voluminous literature, this paper evaluates whether the jaws of P. boisei – interpreted within a framework of masticatory mechanics in particular and bone biology in general – can be interpreted as functionally coherent with a herbivorous diet that lacked a significant component of durophagy. In terms of proportion and geometry, australopith mandibles have no parallel among living primates and P. boisei represents the extreme expression of this morphotype. From the perspective of primate masticatory biomechanics, the inference of loading regimes experienced in this fossil species is speculative, and subsequent inference of diet from corpus geometry should be regarded with skepticism. However, in terms of overall mandibular architecture, and from what is known about the biomechanical influences governing bone hypertrophy, competing hypotheses of dietary specialization are equally plausible on morphological criteria. Mandibular hypertrophy is an expected outcome of a fibrous diet requiring extensive and prolonged mastication, especially in a taxon in which occlusal morphology is suboptimal for the breakdown of fibrous foods.

Human and ape mandibles differ in the proportion of adult size attained at equivalent dental emergence stages; for most dimensions human mandibles are more advanced. These dissimilarities in pattern of growth underlie the vastly different adult mandibular morphologies of these taxa. Australopithecus mandibles represent a third distinctive mandibular morphology, but the pattern of its mandibular growth remains underexplored. The Australopithecus afarensis sample from the Hadar site, Ethiopia, ca. 3.4–3.0 Ma, is represented by three infant (pre-M₁ emergence) and two juvenile (pre-M₃ emergence) mandibles. A recently recovered mandible, A.L. 1920-1, though edentulous, appears to capture an A. afarensis individual during M₂ emergence, thus bridging these developmental stages. In this chapter, we (1) describe three new infant/juvenile A. afarensis mandibles and confirm that the suite of features used to distinguish A. afarensis from other taxa is present early in ontogeny, and (2) investigate how the A. afarensis mandible changes in size and shape throughout growth in comparison to humans and chimpanzees. Our results indicate that A. afarensis resembles humans more than chimpanzees in its percentage of adult corpus breadth attained at successive stages of dental emergence. A. afarensis is also more similar to humans in corpus cross-sectional shape changes throughout ontogeny. We suggest that canine reduction may have had an important influence on the growth trajectory of the A. afarensis mandibular corpus such that, as in humans, it achieved adult values relatively early. Our results underscore the importance of considering the influence of the developing dentition on both juvenile and adult mandibular morphology.

A fossilized human cranium was discovered by miners quarrying at Broken Hill (now Kabwe) in 1921. Broken Hill is one of the best preserved hominins ever recovered from a later Middle Pleistocene locality. Remarkably, no comprehensive descriptive or comparative account has been published since 1928. Overall, Broken Hill resembles Homo erectus. The frontal is flattened with midline keeling, the vault is low, and the massive face is “hafted” to the braincase in such a way as to accentuate facial projection. At the same time, there are apomorphic features shared with later humans. Brain size is 1280 cm³, the temporal squama is arch-shaped, and the upper scale of the occipital is expanded relative to its lower nuchal portion. Specialized characters of the temporomandibular joint region include a raised articular tubercle and a sphenoid spine. Reorientation of the nasal aperture and placement of the incisive canal suggest that the face may be more nearly vertical than in H. erectus. It is apparent that Broken Hill is similar to other African crania from Bodo, Ndutu, and Elandsfontein as well as European fossils including Arago and Petralona. However, the systematic position of these hominins remains controversial. The material has been grouped into a series of grades within a broad H. sapiens category. A very different reading of the record recognizes multiple, distinct taxa and suggests that speciation must have occurred repeatedly throughout the Pleistocene. Still another perspective holds that differences among the African and European specimens are minor and can be attributed to geography and intragroup variation. It is argued that many of the fossils belong together in one widely dispersed taxon. If the Mauer mandible is included within this hypodigm, then the appropriate name is H. heidelbergensis. Treated in a broad sense, H. heidelbergensis is ancestral to both H. neanderthalensis and H. sapiens. This study will provide a detailed account of the morphology of Broken Hill and its similarities to other Middle Pleistocene hominins from Africa. Comparisons will include Arago, Petralona, and assemblages such as Sima de los Huesos. My approach will address the taxonomic utility of characters of the vault, cranial base and face, species-level systematics, and evolutionary relationships.

Thermoregulation is widely believed to have influenced body size and shape in the two best-known extinct members of genus Homo, Homo erectus and Homo neanderthalensis, and to have done so in contrasting ways. H. erectus is thought to have been warm adapted, while H. neanderthalensis is widely held to have been cold adapted. However, the methods that have been used to arrive at these conclusions ignore differences among body segments in a number of thermoregulation-related variables. We carried out a study designed to determine whether the current consensus regarding the thermoregulatory implications of the size and shape of the bodies of H. erectus and H. neanderthalensis is supported when body segment differences in surface area, skin temperature, and rate of movement are taken into account.

The study involved estimating heat loss for a number of Holocene modern human skeletal samples and several fossil hominin specimens, including five Pleistocene H. sapiens, the well-known H. erectus partial skeleton KNM-WT 15000, a H. erectus specimen from Dmanisi, Georgia, and three Neanderthals. The resulting heat loss estimates were then used in two sets of comparative analyses. In the first, we focused on whole-body heat loss and tested predictions concerning heat loss in KNM-WT 15000 and European Neanderthals relative to modern humans, and within H. erectus and H. neanderthalensis. In the second set of analyses we again tested predictions concerning heat loss in H. erectus and H. neanderthalensis relative to modern humans, and within H. erectus and H. neanderthalensis, but this time we focused on the contribution of their limbs to heat loss.

The results of the study do not fully support the current consensus regarding the thermoregulatory adaptations of Homo erectus and Homo neanderthalensis. The whole-body heat loss estimates were consistent with the idea that KNM-WT 15000 was warm adapted and that European Neanderthals were cold adapted, and with the notion that there are thermoregulation-related differences in body size and shape within H erectus and H. neanderthalensis. The whole-limb estimates told a similar story. In contrast, the results of our analysis of limb segment-specific heat loss were not consistent with the current consensus regarding the thermoregulatory significance of distal limb length in H. erectus and H. neanderthalensis. Contrary to expectation, differences between the proximal and distal limb segments did not follow any particular trend.

The obvious implication of these results is that, while we can be more confident about the basic idea that thermoregulation influenced the evolution of body size and shape in H. erectus and H. neanderthalensis, we need to be more cautious in attributing differences in limb segment size to thermoregulation. Based on our results, it is possible that other factors influenced limb segment size in these species more than thermoregulation. Identifying these factors will require further research.

The differences and similarities between Near Eastern Neanderthals and the early modern humans from Skhul and Qafzeh in Israel have long been a point of study and debate. Conclusions about the magnitude and especially the implications of the differences have served as evidence to support or refute competing hypotheses about their cultural and biological differences. Here we revisit the controversy by assessing the midshaft shapes and robusticity of the femur, tibial, humerus, and radius of these Middle Paleolithic samples in comparison to European Neanderthals, Gravettian modern humans, several modern individuals from other late Pleistocene cultures in Europe and Israel, and a diverse set of Holocene humans from around the globe. The results show that the Near Eastern Neanderthals resemble European Neanderthals as well as a diverse array of modern agriculturalists and intensive foragers. In contrast, the people from Skhul and Qafzeh are much more distinct from recent samples but bear a degree of resemblance to Khoesan and Zulu males and females, Amud 1, and Ohalo 2. Additional insights emerge when the upper and lower limb are considered separately, but the result remains that the early moderns rather than Neanderthals seem to have faced an unusual, or at least uncommon, set of mechanical demands in comparison to most of the more recent groups.

Misliya Cave, Mount Carmel, Israel was occupied between 250 and 160 ka. During this time the site was inhabited by bearers of the Acheulo-Yabrudian and Early Middle Paleolithic (Mousterian) techno-complexes. The Acheulo-Yabrudian industry is characterized by production of thick and wide flakes and shows no evidence of laminar or Levallois methods. The varied assemblage encompasses true bifaces, artifacts fully worked on one face and only partially on the other, unifaces and scrapers. All these morphological groups were produced using the same flaking and retouching modes. The emergence of the Early Middle Paleolithic is manifested by a technological break, marked by the disappearance of bifaces and thick-flake production technology and the introduction of blade manufacture using laminar and Levallois production methods, and Levallois points and triangular flakes. The mean TL ages of the Acheulo-Yabrudian assemblage indicate production of this cultural complex 257 ± 28 ka – 247 ± 24 ka. The mean TL ages of the Early Middle Paleolithic industries range from 212 ± 27 to 166 ± 23 ka. The pronounced differences in lithic technology together with TL chronology indicate that the transition from the Lower to the Middle Paleolithic in the Levant was rapid and may imply the arrival of a new population around 250 ka.

The Tabun cave is among the most important paleoanthropological sites in the Near East. It has yielded a long sequence of archeological record, as well as important fossil human remains, notably the Tabun C1 partial skeleton and the Tabun C2 mandible. The chronology of these specimens, as well as their respective provenience, has been intensely debated. Most recent estimates place the C1 skeleton at oxygen isotope stage 5 or 6, while the C2 mandible is thought to be significantly older. The affinities of the C2 remains are unresolved. While general consensus sees the Tabun C1 skeleton as a lightly built Neanderthal, the Tabun C2 mandible has variably been attributed to early modern humans and to Neanderthals based on both metric and non-metric traits. We conducted a comparative analysis of the three-dimensional shape of the C2 mandible using the methods of geometric morphometrics, with the goal of helping to resolve its taxonomic affinities. Results show that Tabun C2 cannot be easily accommodated either within the early modern human or the Neanderthal sample. This finding is consistent with the proposed great geological age of the specimen.

African and Western Asian contemporaries of Neanderthals, generally considered to be the earliest Homo sapiens, are not particularly ‘modern’ looking in their cranial anatomy. Here we test whether the dental morphological signal agrees with this assessment. We used a Bayesian statistical approach to classifying individuals into ‘modern’ and ‘non-modern’ groups based on dental non-metric traits. The classification was based on dental trait frequencies for two ‘known’ samples of 109 Upper Paleolithic H. sapiens and 129 Neanderthal individuals. A cross-validation test of these individuals correctly classified them 95% of the time. Our early H. sapiens sample included 41 individuals from Southern Africa, Northern Africa and Western Asia. We treated our early H. sapiens individuals as ‘unknown’ and calculated the probability that each belonged to either the Upper Paleolithic or Neanderthal sample. We hypothesized that if the earliest H. sapiens were already dentally modern, then they would be assigned to the Upper Paleolithic H. sapiens group. We also hypothesized that if there had been significant admixture in Western Asia during the initial dispersal out of Africa, these samples would have the largest proportion of individuals classified as Neanderthal. Our results indicated that the latter was not the case. The smallest proportion of misclassified individuals came from Western Asia (7%) and the highest proportion of misclassified individuals came from Northern Africa (38%). In most cases it appears to be the predominance of primitive features, rather than derived Neanderthal traits that drove the classification. We conclude (1) by the time the earliest H. sapiens dispersed from Africa they had already attained a more-or-less modern dental pattern; (2) in the past, as is the case today, Late Pleistocene Africans were not a homogeneous group, some retained primitive dental traits in higher proportions than others. Furthermore, we acknowledge that while our method is an excellent tool for discriminating between Upper Paleolithic H. sapiens and Neanderthals, it may not be appropriate for testing Neanderthal – H. sapiens admixture because all traits (primitive and derived) are weighed equally. Moreover, to best assess admixture it is likely necessary to incorporate a model for how the traits track population history and/or gene flow.

Yoel Rak and others published the first known Neanderthal hyoid bone in 1989. Contrary to expectations, the ~60 ka Kebara hyoid was completely within modern human variation and led them to conclude, “the assumed speech limitations of Neanderthals… would seem to require revision.” Subsequently two more fragmentary hyoid bones from Sima de los Huesos (Atapuerca), dating to over 400,000 years ago were determined to be not different from anatomically modern morphology. Most recently, the hyoid of the Dikika child (Au. afarensis), dated much earlier at ~3.3 Ma, was found to clearly resemble that of an ape. The time span represented by these three sites shows that at least part of the anatomy surrounding the vocal tract was of a modern morphology in Neanderthals and their likely ancestors, but not in the much earlier Australopithecus. It was the Kebara hyoid which marks the beginning of a modern understanding of Neanderthal speech capability. This paper reviews the controversy surrounding the interpretation of the Kebara hyoid and other evidence from fossil anatomy, archaeology and paleogenetic data accumulated since 1989, which convincingly shows that Neanderthals possessed the ability to speak like us.

Spinal posture has vast biomechanical, locomotor and pathological implications in hominins. Assessing the curvatures of the spine of fossil hominins can provide important information towards the understanding of their paleobiology. Unfortunately, complete hominin spines are very rarely preserved in the fossil record. The Neanderthal partial skeleton, Kebara 2 from Israel, constitutes a remarkable exception, representing an almost complete spine and pelvis. The aim of this study is, therefore, to create a new 3D virtual reconstruction of the spine of Kebara 2. To build the model, we used the CT scans of the sacrum, lumbar and thoracic vertebrae of Kebara 2, captured its 3D morphology, and, using visualization software (Amira 5.2©), aligned the 3D reconstruction of the original bones into the spinal curvature. First we aligned the sacrum and then we added one vertebra at a time, until the complete spine (T1-S5) was intact. The amount of spinal curvature (lordosis and kyphosis), the sacral orientation, and the coronal plane deviation was determined based on the current literature or measured and calculated specifically for this study based on published methods. This reconstruction provides, for the first time, a complete 3D virtual reconstruction of the spine of an extinct hominin. The spinal posture and spinopelvic alignment of Kebara 2 show a unique configuration compared with that of modern humans, suggesting locomotor and weight-bearing differences between the two. The spinal posture of Kebara 2 also shows slight asymmetry in the coronal plane. Stature estimation of Kebara 2 based on spinal length confirms that the height of Kebara 2 was around 170 cm. This reconstruction can now serve as the basis for a more complete reconstruction of the Kebara 2 specimen, which will include other parts of this remarkable fossil, such as the pelvis, the rib cage and the cervical spine.

Few have provided insights and thoughtful explanations for Neanderthals that equal what have been a central theme in Yoel Rak’s publications. One of his deep understandings is that Neanderthals are another way of being human: not inferior, not superior, but different. Looking at what we now understand, Rak has been fundamentally correct in this insight, and where new discoveries have been unexpected, they serve to expand its scope and meaning. Unexpected new information about Neanderthal body form, demography, and even breeding behavior support and flesh out Rak’s essential insight about the place of Neanderthals in human evolution. In this paper some of the new discoveries and interpretations of Neanderthals and their evolution are discussed in this context. We examine three aspects of how Neanderthals are another way of being human: body shape (as revealed in the pelvis), population structure (as revealed in their paleodemography), and breeding behavior (as revealed by paleogenetics, in the pattern of ancient gene flow). In these ways Neanderthals are like their ancestors, or more broadly are the plesiomorphic condition.