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Pestana C, de Sousa AA, Todorov OS, Beaudet A, Benoit J. Evolutionary history of hominin brain size and phylogenetic comparative methods. PROGRESS IN BRAIN RESEARCH 2023; 275:217-232. [PMID: 36841569 DOI: 10.1016/bs.pbr.2022.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
An absolutely and relatively large brain has traditionally been viewed as a distinctive characteristic of the Homo genus, with anatomically modern humans presented at the apex of a long line of progressive increases in encephalization. Many studies continue to focus attention on increasing brain size in the Homo genus, while excluding measures of absolute and relative brain size of more geologically recent, smaller brained, hominins such as Homo floresiensis, and Homo naledi and smaller brained Homo erectus specimens. This review discusses the benefits of using phylogenetic comparative methods to trace the diverse changes in hominin brain evolution and the drawbacks of not doing so.
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Affiliation(s)
- Christopher Pestana
- Evolutionary Studies Institute, School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Orlin S Todorov
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
| | - Amélie Beaudet
- Department of Archaeology, University of Cambridge, Cambridge, United Kingdom; School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa; Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Julien Benoit
- Evolutionary Studies Institute, School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa
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Cook RW, Vazzana A, Sorrentino R, Benazzi S, Smith AL, Strait DS, Ledogar JA. The cranial biomechanics and feeding performance of Homo floresiensis. Interface Focus 2021; 11:20200083. [PMID: 34938433 PMCID: PMC8361579 DOI: 10.1098/rsfs.2020.0083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2021] [Indexed: 11/12/2022] Open
Abstract
Homo floresiensis is a small-bodied hominin from Flores, Indonesia, that exhibits plesiomorphic dentognathic features, including large premolars and a robust mandible, aspects of which have been considered australopith-like. However, relative to australopith species, H. floresiensis exhibits reduced molar size and a cranium with diminutive midfacial dimensions similar to those of later Homo, suggesting a reduction in the frequency of forceful biting behaviours. Our study uses finite-element analysis to examine the feeding biomechanics of the H. floresiensis cranium. We simulate premolar (P3) and molar (M2) biting in a finite-element model (FEM) of the H. floresiensis holotype cranium (LB1) and compare the mechanical results with FEMs of chimpanzees, modern humans and a sample of australopiths (MH1, Sts 5, OH5). With few exceptions, strain magnitudes in LB1 resemble elevated levels observed in modern Homo. Our analysis of LB1 suggests that H. floresiensis could produce bite forces with high mechanical efficiency, but was subject to tensile jaw joint reaction forces during molar biting, which perhaps constrained maximum postcanine bite force production. The inferred feeding biomechanics of H. floresiensis closely resemble modern humans, suggesting that this pattern may have been present in the last common ancestor of Homo sapiens and H. floresiensis.
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Affiliation(s)
- Rebecca W Cook
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Antonino Vazzana
- Department of Cultural Heritage, University of Bologna, Bologna, Italy
| | - Rita Sorrentino
- Department of Cultural Heritage, University of Bologna, Bologna, Italy.,Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Bologna, Italy.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Amanda L Smith
- Department of Anatomy, Pacific Northwest University of Health Sciences, Yakima, WA, USA
| | - David S Strait
- Department of Anthropology, Washington University in St Louis, St Louis, MO, USA
| | - Justin A Ledogar
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
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Viciano J, D'Anastasio R. Hemifacial microsomia (oculo-auriculo-vertebral spectrum) in an individual from the Teramo Sant'Anna archaeological site (7th-12th centuries of the Common Era, Italy). Arch Oral Biol 2018; 91:23-34. [PMID: 29653314 DOI: 10.1016/j.archoralbio.2018.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 03/09/2018] [Accepted: 04/05/2018] [Indexed: 02/05/2023]
Abstract
BACKGROUND This study is based in an analysis of the skeletal remains of an adult male from the Teramo Sant'Anna archaeological site (7th-12th centuries of the Common Era, Teramo, Italy). RESULTS AND DISCUSSION The individual shows distinct abnormalities that principally involve asymmetric hypoplasia and dysmorphogenesis of the facial skeleton. The combination of these findings and the absence of abnormalities of the spine strongly suggest diagnosis of the congenital malformation known as hemifacial microsomia. This very heterogeneous syndrome affects primarily aural, ocular, oral and mandibular development. Despite the lack of clinical information and the absence of soft tissue, it was possible to perform a differential diagnosis for this palaeopathological case. Mastication was probably altered considering that the mandible is extremely asymmetric and lacks true condyles. The temporomandibular joints are present, but the right one is hypoplastic and abnormal in shape. There is evidence of bilateral dislocation, and the facial muscles are hypertrophic. CONCLUSIONS This case represents an important contribution to the palaeopathological literature because this is an uncommon condition that has not been widely documented in ancient skeletal remains.
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Affiliation(s)
- Joan Viciano
- Operative Unit of Anthropology, Department of Medicine and Aging Sciences, 'G. d'Annunzio' University of Chieti-Pescara, Piazza Trento e Trieste 1, 66100 Chieti, Italy.
| | - Ruggero D'Anastasio
- Operative Unit of Anthropology, Department of Medicine and Aging Sciences, 'G. d'Annunzio' University of Chieti-Pescara, Piazza Trento e Trieste 1, 66100 Chieti, Italy
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Martinón-Torres M, Wu X, Bermúdez de Castro JM, Xing S, Liu W. Homo sapiens in the Eastern Asian Late Pleistocene. CURRENT ANTHROPOLOGY 2017. [DOI: 10.1086/694449] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Stilkerich J, Smrecak TA, De Baets K. 3D-Analysis of a non-planispiral ammonoid from the Hunsrück Slate: natural or pathological variation? PeerJ 2017; 5:e3526. [PMID: 28674668 PMCID: PMC5494166 DOI: 10.7717/peerj.3526] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/10/2017] [Indexed: 11/20/2022] Open
Abstract
We herein examine the only known non-planispirally coiled early Devonian ammonoid, the holotype specimen of Ivoites opitzi, to investigate if the host was encrusted in vivo and if these sclerobionts were responsible for the trochospiral coiling observed in this unique specimen. To test if the presence of runner-like sclerobionts infested the historically collected specimen of Ivoites opitzi during its life, we used microCT to produce a three-dimensional model of the surface of the specimen. Our results indicate that sclerobionts grew across the outer rim (venter) on both sides of the ammonoid conch at exactly the location where the deviation from the planispiral was recognized, and where subsequent ammonoid growth would likely preclude encrustation. This indicates in vivo encrustation of the I. opitzi specimen, and represents the earliest documentation of the phenomenon. Further, this suggests that non-planispiral coiling in I. opitzi was likely pathologically induced and does not represent natural morphological variation in the species. Despite the observed anomalies in coiling, the specimen reached adulthood and retains important identifying morphological features, suggesting the ammonoid was minimally impacted by encrustation in life. As such, appointing a new type specimen—as suggested by some authors—for the species is not necessary. In addition, we identify the sclerobionts responsible for modifying the coiling of this specimen as hederelloids, a peculiar group of sclerobionts likely related to phoronids. Hederelloids in the Devonian are commonly found encrusting on fossils collected in moderately deep environments within the photic zone and are rarely documented in dysphotic and aphotic samples. This indicates that when the ammonoid was encrusted it lived within the euphotic zone and supports the latest interpretations of the Hunsrück Slate depositional environment in the Bundenbach-Gemünden area.
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Affiliation(s)
- Julia Stilkerich
- Geozentrum Nordbayern, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Trisha A Smrecak
- Department of Geology, Grand Valley State University, Allendale, United States of America
| | - Kenneth De Baets
- Geozentrum Nordbayern, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
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Baab KL, Brown P, Falk D, Richtsmeier JT, Hildebolt CF, Smith K, Jungers W. A Critical Evaluation of the Down Syndrome Diagnosis for LB1, Type Specimen of Homo floresiensis. PLoS One 2016; 11:e0155731. [PMID: 27275928 PMCID: PMC4898715 DOI: 10.1371/journal.pone.0155731] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 05/03/2016] [Indexed: 11/21/2022] Open
Abstract
The Liang Bua hominins from Flores, Indonesia, have been the subject of intense scrutiny and debate since their initial description and classification in 2004. These remains have been assigned to a new species, Homo floresiensis, with the partial skeleton LB1 as the type specimen. The Liang Bua hominins are notable for their short stature, small endocranial volume, and many features that appear phylogenetically primitive relative to modern humans, despite their late Pleistocene age. Recently, some workers suggested that the remains represent members of a small-bodied island population of modern Austro-Melanesian humans, with LB1 exhibiting clinical signs of Down syndrome. Many classic Down syndrome signs are soft tissue features that could not be assessed in skeletal remains. Moreover, a definitive diagnosis of Down syndrome can only be made by genetic analysis as the phenotypes associated with Down syndrome are variable. Most features that contribute to the Down syndrome phenotype are not restricted to Down syndrome but are seen in other chromosomal disorders and in the general population. Nevertheless, we re-evaluated the presence of those phenotypic features used to support this classification by comparing LB1 to samples of modern humans diagnosed with Down syndrome and euploid modern humans using comparative morphometric analyses. We present new data regarding neurocranial, brain, and symphyseal shape in Down syndrome, additional estimates of stature for LB1, and analyses of inter- and intralimb proportions. The presence of cranial sinuses is addressed using CT images of LB1. We found minimal congruence between the LB1 phenotype and clinical descriptions of Down syndrome. We present important differences between the phenotypes of LB1 and individuals with Down syndrome, and quantitative data that characterize LB1 as an outlier compared with Down syndrome and non-Down syndrome groups. Homo floresiensis remains a phenotypically unique, valid species with its roots in Plio-Pleistocene Homo taxa.
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Affiliation(s)
- Karen L. Baab
- Department of Anatomy, Arizona College of Osteopathic Medicine, Midwestern University, 19555 N. 59th Avenue, Glendale, AZ, 85308, United States of America
- * E-mail:
| | - Peter Brown
- Bioanthropology, School of Archaeology & Anthropology, Australian National University, Acton, ACT, 2601, Australia
| | - Dean Falk
- Department of Anthropology, Florida State University, Tallahassee, FL, 32306–7772, United States of America
- School for Advanced Research, Santa Fe, NM, 87505, United States of America
| | - Joan T. Richtsmeier
- Department of Anthropology, Pennsylvania State University, University Park, PA, 16802, United States of America
| | - Charles F. Hildebolt
- Department of Radiology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway, St. Louis, Missouri, 63110, United States of America
| | - Kirk Smith
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, United States of America
| | - William Jungers
- Department of Anatomical Sciences, School of Medicine, Stony Brook University, Stony Brook, NY, 11794–8081, United States of America
- Association Vahatra, BP 3972, Antananarivo 101, Madagascar
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Balzeau A, Charlier P. What do cranial bones of LB1 tell us about Homo floresiensis? J Hum Evol 2016; 93:12-24. [PMID: 27086053 DOI: 10.1016/j.jhevol.2015.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/04/2015] [Accepted: 12/09/2015] [Indexed: 12/01/2022]
Abstract
Cranial vault thickness (CVT) of Liang Bua 1, the specimen that is proposed to be the holotype of Homo floresiensis, has not yet been described in detail and compared with samples of fossil hominins, anatomically modern humans or microcephalic skulls. In addition, a complete description from a forensic and pathological point of view has not yet been carried out. It is important to evaluate scientifically if features related to CVT bring new information concerning the possible pathological status of LB1, and if it helps to recognize affinities with any hominin species and particularly if the specimen could belong to the species Homo sapiens. Medical examination of the skull based on a micro-CT examination clearly brings to light the presence of a sincipital T (a non-metrical variant of normal anatomy), a scar from an old frontal trauma without any evident functional consequence, and a severe bilateral hyperostosis frontalis interna that may have modified the anterior morphology of the endocranium of LB1. We also show that LB1 displays characteristics, related to the distribution of bone thickness and arrangements of cranial structures, that are plesiomorphic traits for hominins, at least for Homo erectus s.l. relative to Homo neanderthalensis and H. sapiens. All the microcephalic skulls analyzed here share the derived condition of anatomically modern H. sapiens. Cranial vault thickness does not help to clarify the definition of the species H. floresiensis but it also does not support an attribution of LB1 to H. sapiens. We conclude that there is no support for the attribution of LB1 to H. sapiens as there is no evidence of systemic pathology and because it does not have any of the apomorphic traits of our species.
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Affiliation(s)
- Antoine Balzeau
- Équipe de Paléontologie Humaine, UMR 7194 du CNRS, Département de Préhistoire, Muséum National d'Histoire Naturelle, Paris, France; Department of African Zoology, Royal Museum for Central Africa, B-3080 Tervuren, Belgium.
| | - Philippe Charlier
- Section of Medical and Forensic Anthropology, UFR of Health Sciences (UVSQ/Paris-Descartes University, AP-HP), Montigny-Le-Bretonneux, France
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KAIFU YOUSUKE, KONO REIKOT, SUTIKNA THOMAS, SAPTOMO EWAHYU, JATMIKO, AWE ROKUSDUE, BABA HISAO. Descriptions of the dental remains of Homo floresiensis. ANTHROPOL SCI 2015. [DOI: 10.1537/ase.150501] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- YOUSUKE KAIFU
- Department of Anthropology, National Museum of Nature and Science, Tsukuba-shi
- Department of Biological Sciences, The University of Tokyo, Tokyo
| | - REIKO T. KONO
- Department of Anthropology, National Museum of Nature and Science, Tsukuba-shi
| | - THOMAS SUTIKNA
- Centre for Archaeological Science, University of Wollongong, Wollongong
- The National Research and Development Centre for Archaeology, Jakarta
| | - E. WAHYU SAPTOMO
- Centre for Archaeological Science, University of Wollongong, Wollongong
- The National Research and Development Centre for Archaeology, Jakarta
| | - JATMIKO
- Centre for Archaeological Science, University of Wollongong, Wollongong
- The National Research and Development Centre for Archaeology, Jakarta
| | - ROKUS DUE AWE
- Centre for Archaeological Science, University of Wollongong, Wollongong
- The National Research and Development Centre for Archaeology, Jakarta
| | - HISAO BABA
- Department of Anthropology, National Museum of Nature and Science, Tsukuba-shi
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Henneberg M, Eckhardt RB, Chavanaves S, Hsü KJ. Evolved developmental homeostasis disturbed in LB1 from Flores, Indonesia, denotes Down syndrome and not diagnostic traits of the invalid species Homo floresiensis. Proc Natl Acad Sci U S A 2014; 111:11967-72. [PMID: 25092311 PMCID: PMC4143021 DOI: 10.1073/pnas.1407382111] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Human skeletons from Liang Bua Cave, Flores, Indonesia, are coeval with only Homo sapiens populations worldwide and no other previously known hominins. We report here for the first time to our knowledge the occipitofrontal circumference of specimen LB1. This datum makes it possible to link the 430-mL endocranial volume of LB1 reported by us previously, later confirmed independently by other investigators, not only with other human skeletal samples past and present but also with a large body of clinical data routinely collected on patients with developmental disorders. Our analyses show that the brain size of LB1 is in the range predicted for an individual with Down syndrome (DS) in a normal small-bodied population from the geographic region that includes Flores. Among additional diagnostic signs of DS and other skeletal dysplasiae are abnormally short femora combined with disproportionate flat feet. Liang Bua Cave femora, known only for LB1, match interlimb proportions for DS. Predictions based on corrected LB1 femur lengths show a stature normal for other H. sapiens populations in the region.
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Affiliation(s)
- Maciej Henneberg
- School of Medical Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Robert B Eckhardt
- Laboratory for the Study of Morphology, Mechanics and Molecules, Department of Kinesiology, Pennsylvania State University, University Park, PA 16802; and
| | - Sakdapong Chavanaves
- Laboratory for the Study of Morphology, Mechanics and Molecules, Department of Kinesiology, Pennsylvania State University, University Park, PA 16802; and
| | - Kenneth J Hsü
- Kenneth J. Hsü Center for Integrated Hydrological Circuits Development, National Institutes of Earth Sciences, Beijing 100871, China
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Rare events in earth history include the LB1 human skeleton from Flores, Indonesia, as a developmental singularity, not a unique taxon. Proc Natl Acad Sci U S A 2014; 111:11961-6. [PMID: 25092307 DOI: 10.1073/pnas.1407385111] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The original centrally defining features of "Homo floresiensis" are based on bones represented only in the single specimen LB1. Initial published values of 380-mL endocranial volume and 1.06-m stature are markedly lower than later attempts to confirm them, and facial asymmetry originally unreported, then denied, has been established by our group and later confirmed independently. Of nearly 200 syndromes in which microcephaly is one sign, more than half include asymmetry as another sign and more than one-fourth also explicitly include short stature. The original diagnosis of the putative new species noted and dismissed just three developmental abnormalities. Subsequent independent attempts at diagnosis (Laron Syndrome, Majewski osteodysplastic primordial dwarfism type II, cretinism) have been hampered a priori by selectively restricted access to specimens, and disparaged a posteriori using data previously unpublished, without acknowledging that all of the independent diagnoses corroborate the patent abnormal singularity of LB1. In this report we establish in detail that even in the absence of a particular syndromic diagnosis, the originally defining features of LB1 do not establish either the uniqueness or normality necessary to meet the formal criteria for a type specimen of a new species. In a companion paper we present a new syndromic diagnosis for LB1.
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Baab KL, McNulty KP, Harvati K. Homo floresiensis contextualized: a geometric morphometric comparative analysis of fossil and pathological human samples. PLoS One 2013; 8:e69119. [PMID: 23874886 PMCID: PMC3707875 DOI: 10.1371/journal.pone.0069119] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 06/11/2013] [Indexed: 11/19/2022] Open
Abstract
The origin of hominins found on the remote Indonesian island of Flores remains highly contentious. These specimens may represent a new hominin species, Homo floresiensis, descended from a local population of Homo erectus or from an earlier (pre-H. erectus) migration of a small-bodied and small-brained hominin out of Africa. Alternatively, some workers suggest that some or all of the specimens recovered from Liang Bua are pathological members of a small-bodied modern human population. Pathological conditions proposed to explain their documented anatomical features include microcephaly, myxoedematous endemic hypothyroidism (“cretinism”) and Laron syndrome (primary growth hormone insensitivity). This study evaluates evolutionary and pathological hypotheses through comparative analysis of cranial morphology. Geometric morphometric analyses of landmark data show that the sole Flores cranium (LB1) is clearly distinct from healthy modern humans and from those exhibiting hypothyroidism and Laron syndrome. Modern human microcephalic specimens converge, to some extent, on crania of extinct species of Homo. However in the features that distinguish these two groups, LB1 consistently groups with fossil hominins and is most similar to H. erectus. Our study provides further support for recognizing the Flores hominins as a distinct species, H. floresiensis, whose affinities lie with archaic Homo.
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Affiliation(s)
- Karen L. Baab
- Department of Anthropology and Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail:
| | - Kieran P. McNulty
- Evolutionary Anthropology Laboratory and Department of Anthropology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Katerina Harvati
- Department of Early Prehistory and Quaternary Ecology, Senckenberg Center for Human Evolution and Paleoecology, Eberhard Karls University of Tübingen, Tübingen, Germany
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Kubo D, Kono RT, Kaifu Y. Brain size of Homo floresiensis and its evolutionary implications. Proc Biol Sci 2013; 280:20130338. [PMID: 23595271 DOI: 10.1098/rspb.2013.0338] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The extremely small endocranial volume (ECV) of LB1, the type specimen of Homo floresiensis, poses a challenge in our understanding of human brain evolution. Some researchers hypothesize dramatic dwarfing of relative brain size from Homo erectus presumably without significant decrease in intellectual function, whereas others expect a lesser degree of brain diminution from a more primitive, small-brained form of hominin currently undocumented in eastern Asia. However, inconsistency in the published ECVs for LB1 (380-430 cc), unclear human intraspecific brain-body size scaling and other uncertainties have hampered elaborative modelling of its brain size reduction. In this study, we accurately determine the ECV of LB1 using high-resolution micro-CT scan. The ECV of LB1 thus measured, 426 cc, is larger than the commonly cited figure in previous studies (400 cc). Coupled with brain-body size correlation in Homo sapiens calculated based on a sample from 20 worldwide modern human populations, we construct new models of the brain size reduction in the evolution of H. floresiensis. The results show a more significant contribution of scaling effect than previously claimed.
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Affiliation(s)
- Daisuke Kubo
- Department of Biological Sciences, The University of Tokyo, , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Brown P. LB1 and LB6 Homo floresiensis are not modern human (Homo sapiens) cretins. J Hum Evol 2012; 62:201-24. [DOI: 10.1016/j.jhevol.2011.10.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 10/09/2011] [Accepted: 10/12/2011] [Indexed: 10/14/2022]
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Craniofacial morphology of Homo floresiensis: Description, taxonomic affinities, and evolutionary implication. J Hum Evol 2011; 61:644-82. [DOI: 10.1016/j.jhevol.2011.08.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Revised: 08/19/2011] [Accepted: 08/21/2011] [Indexed: 11/19/2022]
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Kaifu Y, Zaim Y, Baba H, Kurniawan I, Kubo D, Rizal Y, Arif J, Aziz F. New reconstruction and morphological description of a Homo erectus cranium: Skull IX (Tjg-1993.05) from Sangiran, Central Java. J Hum Evol 2011; 61:270-94. [DOI: 10.1016/j.jhevol.2011.04.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 02/21/2011] [Accepted: 04/03/2011] [Indexed: 11/30/2022]
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Craniometric ratios of microcephaly and LB1, Homo floresiensis, using MRI and endocasts. Proc Natl Acad Sci U S A 2011; 108:14043-8. [PMID: 21825126 DOI: 10.1073/pnas.1105585108] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The designation of Homo floresiensis as a new species derived from an ancient population is controversial, because the type specimen, LB1, might represent a pathological microcephalic modern Homo sapiens. Accordingly, two specific craniometric ratios (relative frontal breadth and cerebellar protrusion) were ascertained in 21 microcephalic infants and children by using MRI. Data on 118 age-equivalent control (normocephalic) subjects were collected for comparative purposes. In addition, the same craniometric ratios were determined on the endocasts of 10 microcephalic individuals, 79 normal controls (anatomically modern humans), and 17 Homo erectus specimens. These ratios were then compared with those of two LB1 endocasts. The findings showed that the calculated cerebral/cerebellar ratios of the LB1 endocast [Falk D, et al. (2007) Proc Natl Acad Sci USA 104:2513-2518] fall outside the range of living normocephalic individuals. The ratios derived from two LB1 endocasts also fall largely outside the range of modern normal human and H. erectus endocasts and within the range of microcephalic endocasts. The findings support but do not prove the contention that LB1 represents a pathological microcephalic Homo sapiens rather than a new species, (i.e., H. floresiensis).
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Jungers WL, Kaifu Y. On dental wear, dental work, and oral health in the type specimen (LB1) of Homo floresiensis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2011; 145:282-9. [DOI: 10.1002/ajpa.21492] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 12/28/2010] [Indexed: 11/06/2022]
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Bernstein RM. The big and small of it: How body size evolves. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2010; 143 Suppl 51:46-62. [DOI: 10.1002/ajpa.21440] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Aiello LC. Five years of Homo floresiensis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2010; 142:167-79. [PMID: 20229502 DOI: 10.1002/ajpa.21255] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Since Homo floresiensis was first described in October 2004 there has been a lively debate over its status. Is it a late surviving species of early Homo or merely a modern individual afflicted with disordered growth and one of the many syndromes resulting in microchephaly? Recently the discovery team has published a series of articles providing detailed descriptions of the hominin material, its geomorphological context, and the associated archaeology and faunal material (Morwood and Jungers: J Hum Evol 57 (2009) 437-648). In addition, other researchers have put forward new hypotheses for possible pathologies including Laron's Syndrome and Myxoedematous Endemic (ME) Cretinism. Here I review this new information and conclude that the evidence supports the hypothesis that Homo floresiensis is a late-surviving species of early Homo with its closest morphological affinities to early African pre-erectus/ergaster hominins. Although this hypothesis requires fundamental paradigm changes in our understanding of human evolution, it provides a more economical explanation for H. floresiensis than do the alternatives. None of the current explanations for microcephaly and disordered growth account for the range of features observed in H. floresiensis. Neither do they provide explanations for why a pathological condition in modern humans would mimic so closely the morphology observed in earlier hominins. This conclusion is based on the current evidence for H. floresiensis and on the particular pathological explanations that have appeared in the literature. There is no doubt that controversy over H. floresiensis will continue until new and conclusive evidence is available to settle the debate one way or another.
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Affiliation(s)
- Leslie C Aiello
- Wenner-Gren Foundation for Anthropological Research, New York, NY 10016, USA.
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Eckhardt RB, Henneberg M. LB1 from Liang Bua, Flores: craniofacial asymmetry confirmed, plagiocephaly diagnosis dubious. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2010; 143:331-4; discussion 355-42. [PMID: 20809509 DOI: 10.1002/ajpa.21369] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Falk D, Hildebolt C, Smith K, Brown P, Jungers W, Larson S, Sutikna T, Prior F. Nonpathological asymmetry in LB1 (Homo floresiensis): A reply to Eckhardt and Henneberg. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2010. [DOI: 10.1002/ajpa.21392] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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McNulty KP, Baab KL. Keeping asymmetry in perspective: A reply to Eckhardt and Henneberg. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2010. [DOI: 10.1002/ajpa.21393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kaifu Y, Kaneko T, Kurniawan I, Sutikna T, Saptomo EW, Jatmiko, Awe RD, Aziz F, Baba H, Djubiantono T. Posterior deformational plagiocephaly properly explains the cranial asymmetries in LB1: A reply to Eckhardt and Henneberg. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2010. [DOI: 10.1002/ajpa.21387] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Morwood MJ, Jungers WL. Conclusions: implications of the Liang Bua excavations for hominin evolution and biogeography. J Hum Evol 2010; 57:640-8. [PMID: 19913680 DOI: 10.1016/j.jhevol.2009.08.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 08/31/2009] [Indexed: 11/15/2022]
Abstract
Excavations at Liang Bua, on the Indonesian island of Flores, have yielded a stratified sequence of stone artifacts and faunal remains spanning the last 95k.yr., which includes the skeletal remains of two human species, Homo sapiens in the Holocene and Homo floresiensis in the Pleistocene. This paper summarizes and focuses on some of the evidence for Homo floresiensis in context, as presented in this Special Issue edition of the Journal of Human Evolution and elsewhere. Attempts to dismiss the Pleistocene hominins (and the type specimen LB1 in particular) as pathological pygmy humans are not compatible with detailed analyses of the skull, teeth, brain endocast, and postcranium. We initially concluded that H. floresiensis may have evolved by insular dwarfing of a larger-bodied hominin species over 880k.yr. or more. However, recovery of additional specimens and the numerous primitive morphological traits seen throughout the skeleton suggest instead that it is more likely to be a late representative of a small-bodied lineage that exited Africa before the emergence of Homo erectus sensu lato. Homo floresiensis is clearly not an australopithecine, but does retain many aspects of anatomy (and perhaps behavior) that are probably plesiomorphic for the genus Homo. We also discuss some of the other implications of this tiny, endemic species for early hominin dispersal and evolution (e.g., for the "Out of Africa 1" paradigm and more specifically for colonizing Southeast Asia), and we present options for future research in the region.
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Affiliation(s)
- M J Morwood
- GeoQuEST Research Centre, University of Wollongong, NSW, Australia.
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