Journal Of Human Evolution Research Articles

Moving beyond the adaptationist paradigm for human evolution, and why it matters

The Journal of Human Evolution (JHE) was founded 50 years ago when much of the foundation for how we think about human evolution was in place or being put in place, providing the main framework for how we consider our origins today. Here, we will explore historical developments, including early JHE outputs, as they relate to our understanding of the relationship between phenotypic variation and evolutionary process, and use that as a springboard for considering our current understanding of these links as applied to human evolution. We will focus specifically on how the study of variation itself has shifted us away from taxonomic and adaptationist perspectives toward a richer understanding of the processes shaping human evolutionary history, using literature searches and specific test cases to highlight this. We argue that natural selection, gene exchange, genetic drift, and mutation should not be considered individually when considering the production of hominin diversity. In this context, we offer suggestions for future research directions and reflect on this more complex understanding of human evolution and its broader relevance to society. Finally, we end by considering authorship demographics and practices in the last 50 years within JHE and how a shift in these demographics has the potential to reshape the science of human evolution going forward.

The game of models: Dietary reconstruction in human evolution

Despite substantial additions to the paleontological record and unanticipated improvements in analytical techniques since the Journal of Human Evolution was first published, consensus on the diet of early hominin species remains elusive. For instance, the notable advances in the analyses of hominin dental microwear and stable isotopes have provided a plethora of data that have in some instances clouded what was once ostensibly a clear picture of dietary differentiation between and within hominin taxa. In the present study, we explore the reasons why the retrodiction of diet in human evolution has proven vexing over the last half century from the perspective of both ecological and functional-mechanical models. Such models continue to be indispensable for paleobiological reconstructions, but they often contain rigid or unstated assumptions about how primary paleontological data, such as fossils and their geological and taphonomic contexts, allow unambiguous insight into the evolutionary processes that produced them. In theoretical discussions of paleobiology, it has long been recognized that a mapping function of morphology to adaptation is not one-to-one, in the sense that a particular trait cannot necessarily be attributed to a specific selective pressure and/or behavior. This article explores how the intrinsic variability within biological systems has often been underappreciated in paleoanthropological research. For instance, to claim that derived anatomical traits represent adaptations related to stereotypical behaviors largely ignores the importance of biological roles (i.e., how anatomical traits function in the environment), a concept that depends on behavioral flexibility for its potency. Similarly, in the paleoecological context, the underrepresentation of variability within the ‘edible landscapes’ our hominin ancestors occupied has inhibited an adequate appreciation of early hominin dietary flexibility. Incorporating the reality of variation at organismal and ecological scales makes the practice of paleobiological reconstruction more challenging, but in return, allows for a better appreciation of the evolutionary possibilities that were open to early hominins.

3D models related to the publication: New record of Neosaimiri (Cebidae, Platyrrhini) from the late Middle Miocene of Peruvian Amazonia

This contribution contains the 3D models of the fossil teeth of a small-bodied platyrrhine primate, Neosaimiri cf. fieldsi (Cebinae, Cebidae, Platyrrhini) discovered from Laventan deposits (late Middle Miocene) of Peruvian Amazonia, San Martin Department (TAR-31: Tarapoto/Juan Guerra vertebrate fossil-bearing locus n°31). These fossils were described and figured in the following publication: Marivaux et al. (2020), New record of Neosaimiri (Cebidae, Platyrrhini) from the late Middle Miocene of Peruvian Amazonia. Journal of Human Evolution. https://doi.org/10.1016/j.jhevol.2020.102835

New Chronology and Stratigraphy for Kathu Pan 6, South Africa

Kathu Pan 6 (Northern Cape Province) is an open-air site exposed by sinkhole activity that includes a Middle Stone Age Howiesons Poort (HP) component in a stratigraphic sequence that also includes Later Stone Age, early Middle Stone Age, and Earlier Stone Age (Fauresmith) assemblages. Here, we present the dating of the Kathu Pan 6 sequence using multiple luminescence signals: optically stimulated luminescence (blue OSL) and thermally transferred OSL (TT-OSL) on quartz; and the infrared stimulated luminescence (IRSL) post IR-IR290 signal on potassium feldspar. The results obtained from analyses of different minerals and signals for the archaeological deposits do not always conform but the quartz OSL provides the most accurate set of ages for the HP at KP6 (between 100 ± 6 and 74 ± 5 ka). This age range places the KP6 HP earlier than any of the scenarios considered plausible by Jacobs and Roberts (Journal of Human Evolution, 107, 1–13 2017) but fits well with the extended duration for the HP at Diepkloof proposed by Tribolo et al. (Journal of Archaeological Science, 36(3) 730–39 2009) and promoted by Feathers (Journal of Archaeological Science, 63, 164–174 2017). Two OSL ages bracket the Later Stone Age Wilton industry at KP6, placing it between 5.7 ± 0.3 ka and 2.3 ± 0.1 ka. These fit with known ages for the Wilton and place the KP6 occupation contemporary with Strata 4c–3b at Wonderwerk Cave.

Debrief: Digital minimalism and the Deep End.

Mark Zuckerberg was just 8 years old when anthropologist Robert Dunbar hypothesised, in the Journal of Human Evolution in 1992, that there was a maximum number of individuals with whom it was possible to maintain a genuine social relationship.1 It’s a hard limitation estimated on the basis of the size of our neocortex. He calculated that the ‘Dunbar Number’ for Homo sapiens is 150 when Facebook was still a twinkle in Zuckerberg’s eye. How many Facebook friends do you have? The media report daily on the dangers of social media. There are clear benefits in technology but there are emerging harms related to psychological health. Many of these are associations and it would be reckless to draw causal inferences without care. Yet, there are plausible biological mechanisms, temporal relationships, and suggestions of a dose–response effect. It’s also bound up in a hysterical tone. The future …

3D model related to the publication: A platyrrhine talus from the early Miocene of Peru (Amazonian Madre de Dios Sub-Andean Zone)

This contribution contains the 3D model of the fossil talus of a small-bodied anthropoid primate (Platyrrhini, Cebidae, Cebinae) discovered from lower Miocene deposits of Peruvian Amazonia (MD-61 locality, Upper Madre de Dios Basin). This fossil was described and figured in the following publication: Marivaux et al. (2012), A platyrrhine talus from the early Miocene of Peru (Amazonian Madre de Dios Sub-Andean Zone). Journal of Human Evolution.

3D models related to the publication: Neotropics provide insights into the emergence of New World monkeys: new dental evidence from the late Oligocene of Peruvian Amazonia

This contribution contains the 3D models of the isolated teeth of Canaanimico amazonensis, a new stem platyrrhine primate, described and figured in the following publication: Marivaux et al. (2016), Neotropics provide insights into the emergence of New World monkeys: new dental evidence from the late Oligocene of Peruvian Amazonia. Journal of Human Evolution. http://dx.doi.org/10.1016/j.jhevol.2016.05.011

Contrast reversal of the eyes impairs infants’ face processing: A near-infrared spectroscopic study

Human can easily detect other’s eyes and gaze from early in life. Such sensitivity is supported by the contrast polarity of human eyes, which have a white sclera contrasting with the darker colored iris (Kobayashi & Kohshima, (1997). Nature, 387, 767–768; Kobayashi & Kohshima, (2001). Journal of Human Evolution, 40, 419–435). Recent studies suggest that the contrast polarity around the eyes plays an important role in infants’ face processing. Newborns preferred upright face images to inverted ones in contrast-preserved faces, but not in contrast-reversed faces (Farroni et al., (2005). Proceedings of National Academy of Sciences of the United States of America, 102, p. 17245–17250). Seven- to 8-month-old infants failed to discriminate between faces when the contrast polarity of eyes was reversed (Otsuka et al., (2013). Journal of Experimental Child Psychology, 115, 598–606). Neuroimaging study with adults revealed that full-negative faces induced less activation in the right fusiform gyrus than either full-positive faces or negative faces with contrast-preserved eyes (Gilad et al., (2009). Proceedings of National Academy of Sciences of the United States of America, 106, p. 5353–5358). In the present study, we investigated whether contrast-reversed eyes diminish infants’ brain activity related to face processing. We measured hemodynamic responses in the bilateral temporal area of 5- to 6-month-old infants. Their hemodynamic responses to faces with positive eyes and those with negative eyes were compared against the baseline activation during the presentation of object images. We found that the presentation of faces with positive eyes increased the concentration of oxy-Hb in the right temporal area and those of total-Hb in the bilateral temporal areas. No such change occurred for faces with negative eyes. Our results suggest the importance of contrast polarity of the eyes in the face-selective neural responses from early development.

More on the Liang Bua finds and modern human cretins

Brown (2012: LB1 and LB6 Homo floresiensis are not modern human (Homo sapiens) cretins, Journal of Human Evolution) makes errors of fact, omission and interpretation. Brown's comments refer, among others, to (1) delayed growth and development indicated by unfused epiphyses, (2) postcranial limb proportions: limbs to trunk, between limbs, and within limbs, (3) postcranial bone torsions and angles, (4) postcranial robusticity, real and apparent, (5) skull features, and (6) cretinism on Flores. In each of these areas, much information about cretins is incorrect and much information (Oxnard et al., 2010) comparing the Liang Bua remains with cretins is ignored.

Thermoregulation and endurance running in extinct hominins: Wheeler’s models revisited

Thermoregulation is often cited as a potentially important influence on the evolution of hominins, thanks to a highly influential series of papers in the Journal of Human Evolution in the 1980s and 1990s by Peter Wheeler. These papers developed quantitative modeling of heat balance between different potential hominins and their environment. Here, we return to these models, update them in line with new developments and measurements in animal thermal biology, and modify them to represent a running hominin rather than the stationary form considered previously. In particular, we use our modified Wheeler model to investigate thermoregulatory aspects of the evolution of endurance running ability. Our model suggests that for endurance running to be possible, a hominin would need locomotive efficiency, sweating rates, and areas of hairless skin similar to modern humans. We argue that these restrictions suggest that endurance running may have been possible (from a thermoregulatory viewpoint) for Homo erectus, but is unlikely for any earlier hominins.

Currents and trends in the archaeological sciences

Here I use ISI Web of Knowledge to build on a recent paper by Butzer (2009) and track current trends in the archaeological sciences. I researched eight thematic keywords replete in the title, abstract, keywords and main body of archaeological science literature for the period 1970–2008. For all keywords investigated a steady rise in archaeological science research is evidenced after 1980, with pronounced growth occurring after 2000. I attribute this pattern to the standardisation of research production and academic evaluation, in addition to the democratisation of new information technologies, notably the Internet. The evolution of 10 leading archaeological science journals was also tracked. Since the 1970s, the bibliometric data show that nine of the ten journals have successfully expanded on an annual basis. I found that the biggest growers (the Journal of Archaeological Science [JAS], the Journal of Human Evolution and the Journal of Anthropological Archaeology) are all published by Elsevier. In 2008, the JAS was ranked first for five of the eight thematic keywords by ISI, underlining the popularity and interdisciplinary scope of the journal. According to the 2008 Journal Citation Reports, the JAS ranks second for total citations (4219) in archaeological science and third for its overall impact factor (1.779).

Reappraisal of Macaca speciosa subfossilis from the Late Pleistocene of Northern Vietnam Based on the Analysis of Cranial Anatomy

Jouffroy (Bulletin du Museum National d'Histoire Naturelle. Serie 2 31:209–216, 1959) described Macaca speciosa subfossilis on the basis of her study of the external anatomy of a nearly complete cranium (PV F1; Museum national d’Histoire naturelle, Paris) found in the Late Pleistocene cave deposits, Thung-Lang, northern Vietnam. Whereas Jouffroy (Bulletin du Museum National d'Histoire Naturelle. Serie 2 31:209–216, 1959) considered it to belong to an ancestor of Macaca arctoides or M. thibetana, Fooden (Journal of Human Evolution 19:607–686, 1990) reexamined the facial anatomy and assigned it to the extant species M. arctoides. We used computed tomography images to reevaluate the phylogenetic position of Macaca speciosa subfossilis by comparing the external and internal features of PV F1 with those of the crania of the extant macaque species. PV F1 shows a lower degree of preorbital concavity than Macaca arctoides, M. assamensis, and M. thibetana, but shares an anteriorly directed malar as seen in the crania of the two former species. The size of the molars of PV F1 falls within a range such that the cranium may be assigned to any of the five species of Macaca arctoides, M. assamensis, M. thibetana, M. mulatta, and M. nemestrina. An analysis of the internal structure of the cranium reveals that only PV F1 and the cranium of Macaca arctoides have a pear-shaped nasal cavity expanding laterally at both the anterior and posterior regions. Such a feature is probably a derived condition in the macaque lineage, suggesting a close relationship between Macaca speciosa subfossilis and M. arctoides. This finding supports the paleobiological scenario that the members of the lineage of Macaca arctoides diverged from the other members of Asian macaques and became distributed in northern Vietnam as early as the Late Pleistocene.

A cautionary tale from down under: Dating the BlackCreek Swamp megafauna site on Kangaroo Island, South Australia

The extinction of the Australian megafauna is presently one of the most hotly contested debates in Australian Quaternary sciences. [Roberts et al., 2001. U-series and ESR analyses of bones and teeth relating to the human burials from Skhul. Journal of Human Evolution. 49, 316–334.] proposed contentiously that the megafauna went extinct within a short time period somewhere in the range of 39,000–52,000 years ago. Being tucked away at the continental fringe, Kangaroo Island offers an ideal refuge for the megafauna for survival. Initial radiocarbon analyses of soil organic matter, ESR of teeth and OSL of quartz provided consistent age assessments, which strongly suggested that the site could be as young as 20,000 years. However, it turned out that the sediments contained extreme disequilibria in the U-decay chain, with 230Th/ 238U ratios in the range of 0.3 and 210Pb/ 238U ratios around 0.1. Furthermore, in situ laser ablation analysis revealed that uranium migrated into the teeth at a very late stage during the Holocene. Contrary to expectations, insoluble organic matter was considerably younger than the soluble fraction. After combining all analytical results, a complex geochemical history can be reconstructed, implying that organic matter and large amounts of uranium were injected into the megafauna-bearing layers around the Last Glacial Maximum. When combined U-series/ESR dates are calculated, they all turn out older than the proposed extinction window. This was confirmed by a subsequent OSL study. The Black Creek Swamp site is another example that the parametric early (EU) and linear U-uptake (LU) ESR age models, particularly when applied to teeth with high-U concentrations, may provide completely unreliable age results.

On the age of Border Cave 5 human mandible.

An enamel fragment from the Border Cave 5 specimen was analysed with non-destructive ESR combined with laser ablation ICP-MS for uranium profiling. We obtained an age of 74+/-5 ka which fits exactly into the chronological framework that has been previously established for Border Cave by a variety of dating techniques. The result lays at rest the view that BC5 could be of Iron Age, as was implied by (Journal of Human Evolution, 31 (1996) 499) based on nitrogen contents and infra-red splitting factors.

Erratum to “Energy transformation during erect and ‘bent-hip, bent-knee’ walking by humans with implications for the evolution of bipedalism” (Journal of Human Evolution 44 (2003), 563–579)

Erratum to “Energy transformation during erect and ‘bent-hip, bent-knee’ walking by humans with implications for the evolution of bipedalism” (Journal of Human Evolution 44 (2003), 563–579)

The mechanics of the first bite.

An analysis of the action of the incisor teeth in humans is presented in terms of the fracture of food particles. It is predicted that the resistance of foods with an essentially linear elastic response to an initial bite by the incisors will depend on the square root of the product of two food properties, Young's modulus and toughness. This quantity should be approximately equal to the product of the stress at cracking during a bite, and the square root of the length of a notch or indentation from which that crack initiates. As a test of the theory, the relationship between in vivo stresses and the depth of incisal penetration, measured during bites on seven 'snack' foods by 10 subjects, and food properties established from mechanical testing, was investigated. Theory and experiment were found to be in excellent agreement. A dimensionless index of the efficiency of incision is suggested, relating fracture performance by subjects to values from a testing machine. This appears to have a high level of inter-subject discrimination with efficiencies varying about threefold. The method appears to have potential applications in dentistry, food science and studies of human and primate evolution.

Erratum to ‘Early hominin limb proportions’(Journal of Human Evolution 43 (2002) 529–548)

Fig. 9. Schematic diagram of limb proportions in extant taxa (P. troglodytes, far left; H. sapiens, far right) and fossil taxa. Two schematic individuals, representing extremes in our sample, are shown for each extant taxon. Each fossil taxon (and Bouri) is represented by an individual skeleton (it remains to be determined whether or not these specimens are truly representative of their respective taxa): A. afarensis (AL 288-1), H. (A.) habilis (OH 62), Bouri (BOU-VP 12/1), and H. ergaster (KNM-WT 15000). Data on associated limbs are not currently available for A. africanus; in light of studies by McHenry and Berger (1998a, b), A. africanus is provisionally given more apelike limb proportions than those of A. afarensis. Since humerus length, relative to body mass, does not differ among African apes and humans (Jungers, 1994), the schematic representations were given equal humerus lengths. Intermembral and brachial proportions are shown relative to this standardized humerus length. African apes and humans also show little interspecific differences in crural proportions (Aiello and Dean, 1990), so all schematics were given equivalent crural indices, with the exception of H. ergaster, for which crural proportions are known. Trunks, heads, and feet are shown in grey for illustrative purposes only and are not drawn to scale. Lines representing limbs are shown in grey where little or no direct evidence is available. Journal of Human Evolution 44 (2003) 397

Tephrostratigraphy and the Acheulian to Middle Stone Age transition in the Kapthurin Formation, Kenya

Sites containing Acheulian, Sangoan, Fauresmith, and Middle Stone Age artefacts occur within and below the Bedded Tuff, a widespread volcaniclastic member of the Kapthurin Formation, Kenya. The Bedded Tuff eruptive complex consists of up to twelve tephra beds, intercalated sediments, and paleosols. Two pumiceous units, high in the Bedded Tuff sequence, have been dated by40Ar/39Ar, one to 235±2ka (Deino & McBrearty, 2002, Journal of Human Evolution, 42, 185–210, cf. Tallon, 1978, Geological Background to Fossil Man, pp. 361–373, Scottish Academic Press), the other to 284±12ka (Deino & McBrearty, 2001), the latter now providing a minimum age estimate for all underlying archaeological sites. Bedded Tuff outcrops are correlated through field stratigraphic and electron microprobe geochemical analyses of individual beds. Bedded Tuff units show increasingly evolved composition through the stratigraphic succession, indicating that the beds are the product of intermittent eruption of a single differentiating magma system, and the chemical signatures of these beds permit the chronological ordering of archaeological sites. Our results indicate that the transition to Middle Stone Age technology occurred prior to 285ka in this region of East Africa. The interstratification of sites containing Acheulian, Sangoan, Fauresmith, and Middle Stone Age artefacts suggests that these technologies were contemporary in a single depositional basin over the duration of the transition.

Lithostratigraphy and depositional history of the Late Cenozoic hominid-bearing successions in the Yuanmou Basin, southwest China

Late Cenozoic strata bearing hominids and hominoids are distributed in the Yuanmou Basin, Yunnan, southwest China. Incisors of Homo erectus discovered in these strata in 1965 reportedly show primitive features known in Africa (Hu, Acta geologica sinica 1 (1973, p. 65). However, recent paleomagnetic study has revealed that the age of the hominid correlates to the early Brunhes chron (Hyodo et al., Journal of human evolution (2001), submitted). The lithostratigraphy of the successions that yield many mammalian fossils including those of the hominid, and the record of Equus is re-examined. The successions are divided in ascending order into the Longchuan, Shagou, Gantang (newly proposed Yangliuchun and Daipojing Members) and Yuanmou (newly proposed Dainawu and Niujianbao Members) Formations, based on different lithology and sedimentary facies. The newly proposed depositional systems of the formations are in ascending order, alluvial fan, ephemeral braided river, sandy braided river, ephemeral gravelly braided river and alluvial fan systems. The change in facies and paleocurrents revealed in the successions suggest that the basin was initiated as a syncline basin at ca 3.5 Ma and was completed as an asymmetric half graben by active movement of the eastern marginal fault in the early Middle Pleistocene.

Cannibalism and violence

International Journal of OsteoarchaeologyVolume 10, Issue 1 p. 1-3 EditorialFree Access Cannibalism and violence Simon Hillson, Simon Hillson Institute of Archaeology, University College London, London, UKSearch for more papers by this author Simon Hillson, Simon Hillson Institute of Archaeology, University College London, London, UKSearch for more papers by this author First published: 02 February 2000 https://doi.org/10.1002/(SICI)1099-1212(200001/02)10:1<1::AID-OA501>3.0.CO;2-WCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. References Arens, W. (1979) The Man-Eating Myth. Anthropology and Anthropophagy. Oxford University Press: Oxford. Lloyd Parry, R. (1999) Apocalypse now. The Independent, 25 March: Thursday, Review 1 McKie, R. (1998) The people eaters. New Scientist, 157: 43– 46. Pickering, T.R., White, T.D. and Toth, N. (1999) Stone tool cut marks on Stw 53, and early hominid from Sterkfontein, South Africa. Journal of Human Evolution, 36: A17. Preston, D. (1998) Cannibals of the canyon. The New Yorker, November 30: 76– 89. Russell, M.D. (1987a) Mortuary practices at the Krapina Neandertal site. American Journal of Physical Anthropology, 72: 381– 397. Russell, M.D. (1987b) Bone breakage in the Krapina hominid collection. American Journal of Physical Anthropology, 72: 373– 379. Trinkaus, E. (1985) Cannibalism and burial at Krapina. Journal of Human Evolution, 14: 203– 216. Turner, C.G. II and Morris, N.T. (1970) A massacre at Hopi. American Antiquity, 35: 320– 331. Turner, C.G. II and Turner, J.A. (1992) On Peter Y. Bullock's ‘A reappraisal of Anasazi cannibalism’. Kiva, 58: 189– 201. Turner, C.G. II and Turner, J.A. (1995) Cannibalism in the prehistoric American Southwest: occurrence, taphonomy, explanation, and suggestions for standardized world definition. Anthropological Science, 103: 1– 22. Turner, C.G. II and Turner, J.A. (1999) Man Corn. Cannibalism and Violence in the Prehistoric American Southwest. Salt Lake City: University of Utah Press. Turner, C.G. II (1983) Taphonomic reconstructions of human violence and cannibalism based on mass burials in the American Southwest. In: Carnivores, Human Scavengers and Predators: a Question of Bone Technology (edited by G.M. LeMaine and A.S. MacEachern). Calgary: Archaeological Association of the University of Calgary, 219– 240. Turner, C.G. II (1992) Southwestern U.S. Anasazi cannibalism. Review of Anthropology, 13: 7– 13. Turner, C.G. II (1993) Cannibalism in Chaco Canyon: the charnel pit excavated in 1926 at Small House Ruin by Frank H.H. Roberts, Jr. American Journal of Physical Anthropology, 91: 421– 439. Villa, P., Courtin, J., Helmer, D. and Shipman, P. (1987) Cannibalisme dans la grotte d Fontebregoua. 223: 40– 52. Villa, P. (1992) Cannibalism in prehistoric Europe. 1: 93– 104. White, T.D. (1986) Cutmarks on the Bodo cranium: a case of prehistoric defleshing. American Journal of Physical Anthropology, 69: 503– 509. White, T.D. (1992) Prehistoric Cannibalism at Mancos 5MTUMR-2346. Princeton: Princeton University Press. Citing Literature Volume10, Issue1Special Issue: Cannibalism and ViolenceJanuary/February 2000Pages 1-3 ReferencesRelatedInformation