ralph holloway

PREFACE. ACKNOWLEDGMENTS. PART 1: Brain Evolution and Endocasts INTRODUCTION. Lines of Evidence, DIRECT and INDIRECT. Brain Endocasts. The Data. Biobehavioral Significance of Brain Endocasts. Endocranial Morphology and Terminology. Descriptive and Figure Format. PART 2: Methods andMaterials of Endocast Analysis. Total Endocranial Brain Volume. Partial Brain Endocast Volumes. Endocast Volume Reliability. Brain Endocast Volumes by Formula. AsymmetryObservations and Measures. Regional Convolutional Details. Meningeal Patterns. Morphometric Analyses. PART 3: Endocasts of Early Hominids. BOURI. BOU-VP-12/130. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. HADAR. AL 288-1 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. KONSO. KGA-10-525. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. KOOBI FORA. KNM-ER 407 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. MAKAPANSGAT. MLD 1 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. OLDUVAI. OH5. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. OMO. OMOL338Y-6. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. STERKFONTEIN. STS 5 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. SWARTKRANS. SK 1585 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. TAUNG. TAUNG CHILD. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. TURKANA (WEST TURKANA). KNM-WT 17000 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. PART 4A: Africa. BODO. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. JEBEL IRHOUD ( JEBEL IGHOUD). Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. KABWE. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. KOOBI FOR A. KNM-ER 1470 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. KNM-ER 1813 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. KNM-ER 992 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. NARIOKOTOME (WEST TURKANA). KNM-WT 15000. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. OLDUVAI GORGE. OH7 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. OH9 MORPH. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. SALE. Gross Description. Volume and Method. Endocast Details. Morphometric Details. Significance. PART 4B: Asia, Eastern and Central NGANDONG (SOLO). Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. SAMBUNGMACAN. SAMBUNGMACAN 3 (SM 3). Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. SANGIRAN. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. TRINIL. TRINIL 2. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. ZHOUKOUDIAN (CHOUKOUTIEN): LOWER CAVE. SKULL 111 LOCUS E. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. PART 4C: Asia, Western AMUD. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. TESHIK-TASH. PART 4D: Europe ARAGO(TAUTAVEL). Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. BRNO. BRNO II. BRNO III. COMBE CAPELLE. CRO-MAGNON. CRO-MAGNON III. DOLNI VESTONICE. DOLNI VESTONICE III. FELDHOFER GROTTO (NEANDERTHAL). Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. GIBRALTAR. GIBRALTAR I. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. KRAPINA. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. LA CHAPELLE-AUX-SAINTS. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. LA FERRASSIE. LA FERRASSIE I. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. LAQUINA. LAQUINA V. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. LAZARET. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. LE MOUSTIER. LES COTTES. MONTE CIRCEO. Gross Description. Volume and Method. Endocast Details. Morphometric Data. Significance. PODKUMAK. PREDMOSTI. PREDMOSTI 3. PREDMOSTI 4. PREDMOSTI 9. PREDMOSTI 10. Significance. REILINGEN. Gross Description. Volume and Method. Endocast Details. Morphometric Data.…

The evolution of the human brain has been a combination of reorganization of brain components, and increase of brain size through both hyperplasia and hypertrophy during development, underlain by neurogenomic changes. Paleoneurology based on endocast studies is the direct evidence demonstrating volume changes through time, and if present, some convolutional details of the underlying cerebral cortex. Reorganizational changes include a reduction of primary visual cortex and a relative enlargement of posterior association cortex and expanded Broca's regions, as well as cerebral asymmetries. The size of the hominid brain increased from about 450 ml at 3.5 million years ago to our current average volume of 1350 ml. These changes through time were sometimes gradual but not always.

Making endocasts with latex rubber has been around for many years. This chapter describes my methods which were not original and some of the experiences encountered. Other methods, using plaster of Paris, various silicon-based rubbers, and Admold (dental caulk), for sectioned crania are examined and their relative merits and problems compared, such as damage to original specimens, deterioration with time (especially with latex rubber), and tensile strength of silicon-based molds. The resolution is as good as it can get, compared to “virtual” endocasts. These older methods have largely been succeeded by the making of “virtual” endocasts through various scanning procedures, with numerous advantages such as being noninvasive of original fossil specimens, immediate coordinates for morphometric analyses, scan data sharing and replication, and production of actual virtual endocasts through 3-D printing.

The A.L. 444-2 skull was found on 26 February 1992, during a strategic paleontological survey of Kada Hadar Member sediments that are stratigraphically situated between BKT-1 and BKT-2 tephras, on the eastern edge of the Awash River’s Kada Hadar tributary. Yoel Rak discovered two fragments of hominin occipital bone (A.L. 444-1) at the base of a steep hill composed of Kada Hadar Member silts and clays capped by a weathered sandstone remnant. Subsequent examination of the upslope surface revealed additional hominin skull fragments (the temporal bones and maxillae) clustered together and partially exposed in a narrow gully that dissected the face of the hill. During the next seven days, probing and dry sieving of the gully infill and hillside colluvium over a 77 m2 area led to the recovery of fragments representing about 75%–80% of a single hominin skull. It was immediately apparent that the upslope finds duplicated the anatomical parts represented by the two A.L. 444-1 occipital fragm...

Among the largest Plio-Pleistocene hominin skulls found to date, A.L. 444-2 is bigger, though not by much, than an average female gorilla’s skull. At first glance, A.L. 444-2 assumes a somewhat simian appearance, the outcome of a relatively small braincase combined with an inclined frontal squama and prognathic jaws. However, this apelike appearance is offset by several distinctive hominin features: a very tall face that is much less prognathic than would be expected from the skull’s general simian-like appearance; a deep, vertical mandibulosymphyseal profile; delicate supraorbital elements; and the absence of a supratoral sulcus intervening between the frontal squama and the forward-jutting supraorbital element. Nevertheless, the characteristics that account for the skull’s hominin appearance demonstrate a certain uniqueness, which is manifested in the disproportion between the considerable total height of the face and the great size of its constituent elements (primarily the zygomatic and maxillary bones), on the one hand, and the delicateness of the supraorbital element and the almost negligible degree of its anterior projection, on the other. An apparent unevenness emerges along the vertical axis of the face between its upper portion—the orbits, including the elements above and between them—and its lower portion, that is, the elements below the level of orbitale down to gnathion. Undoubtedly, part of this appearance stems from the heavy, somewhat vertical, deep, and anteriorly bulbous symphyseal region of the mandible. The corresponding region in the African apes, in contrast, is transversely pinched, as its two sides converge downward toward the midline. Furthermore, the region slopes inferoposteriorly; in anterior view, it is tucked under the alveolar element and hence is less exposed than in A.L. 444-2. The preservation of the mandible of A.L. 444-2 and its occlusion with the upper dental arcade afford a unique opportunity to evaluate some of the characteristics of an entire A. afarensis skull. Two standard measurements can be recorded: the distance between gnathion and the estimated site of nasion—a measure of the total height of the face—which is 150 mm, and the distance between gnathion and basion, estimated at 157 mm.

The book is the most in-depth account of the fossil skull anatomy and evolutionary significance of the 3.6-3.0 million year old early human species Australopithecus afarensis. Knowledge of this species is pivotal to understanding early human evolution, because 1) the sample of fossil remains of A. afarensis is among the most extensive for any early human species, and the majority of remains are of taxonomically inormative skulls and teeth; 2) the wealth of material makes A. afarensis an indispensable point of reference for the interpretation of other fossil discoveries; 3) the species occupies a time period that is the focus of current research to determine when, where, and why the human lineage first diversified into separate contemporaneous lines of descent. Upon publication of this book, this species will be among the most thoroughly documented extinct ancestors of humankind. The main focus of the book - its organizing principle - is the first complete skull of A. afarensis (specimen number A.L. 444-2) at the Hadar site, Ethiopia, the home of the remarkably complete 3.18 million year old skeleton known as "Lucy," found at Hadar by third author D. Johanson in 1974. Lucy and other fossils from Hadar, together with those from the site of Laetoli in Tanzania, were controversially attributed to the then brand new species A. afarensis by Johanson, T. White and Y. Coppens in 1978. However, a complete skull, which would have quickly resolved much of the early debate over the species, proved elusive until second author Y. Rak's discovery of the 444 skull in 1992. The book details the comparative anatomy of the new skull (and the cast of its brain, analyzed by R. Holloway and M. Huan) , as well as of other skull and dental finds recovered during the latest, ongoing field work at Hadar, and analyzes the evolutionary significance of A. afarensis in the context of other critically important discoveries of earliest humans made in recent years. In essence, it summarizes the state of knowledge about one of the central subjects of current paleoanthropological investigation.

The nearly complete cranium DAN5/P1 was found at Gona (Afar, Ethiopia), dated to 1.5–1.6 Ma, and assigned to the species Homo erectus. Its size is, nonetheless, particularly small for the known range of variation of this taxon, and the cranial capacity has been estimated as 598 cc. In this study, we analyzed a reconstruction of its endocranial cast, to investigate its paleoneurological features. The main anatomical traits of the endocast were described, and its morphology was compared with other fossil and modern human samples. The endocast shows most of the traits associated with less encephalized human taxa, like narrow frontal lobes and a simple meningeal vascular network with posterior parietal branches. The parietal region is relatively tall and rounded, although not especially large. Based on our set of measures, the general endocranial proportions are within the range of fossils included in the species Homo habilis or in the genus Australopithecus. Similarities with the genus Homo include a more posterior position of the frontal lobe relative to the cranial bones, and the general endocranial length and width when size is taken into account. This new specimen extends the known brain size variability of Homo ergaster/erectus, while suggesting that differences in gross brain proportions among early human species, or even between early humans and australopiths, were absent or subtle.

One of the more vexing problems with hominoid endocasts has been to secure reliable information that goes beyond their volumes. One method is explored here, where a large number ( N = 171) of radial distances from a homologous internal central point to the dorsal endocast surface are measured in a polar coordinate system. From two pilot studies, one with a hominoid sample of N = 64, and the other with an enlarged sample of N = 92, the following results can be mentioned tentatively: (1) there are residual data that differ taxonomically in different cortical regions once overall endocast size is corrected in allometric fashion; (2) the major cortical regions where these differences appear most strongly are in the lower parietal lobule, anterior occipital zone, and the dorsoanterior region of the frontal lobe; (3) the method shows excellent promise in objectively and quantitatively depicting taxa-specific shape differences in functionally understood cortical regions through multivariate statistical analyses.

... and inhibitoryrelationships, such as Ashby'sla analysis, is impossible for primate evolution, basedon present ... up to the 1920'shas been reviewed by Bianchi~, another frontal lobe devotee.) Most ... compara-tive quantitative data on this cerebral division within the primate order. ...

The goal of this study is to investigate intra-skeletal variation in measures of cortical bone strength in the radius and tibia in non-osteoporotic males. The range of variation in bone quality for individuals deemed “skeletally healthy” through traditional methods needs to be explored. Left and right radii and tibiae were excised from 30 male cadavers ranging in age from 33 to 79 years (64.13 ± 11.31) and with DXA lumbar spine T-scores qualifying them as non-osteoporotic(>-2.5). Quantitative clinical CT was performed on ex vivo elements to calculate volumetric bone mineral density (vBMD) at 30% radius and 38% tibia sites. Total area (Tt.Ar), cortical area (Ct.Ar), section modulus for both the anterior (Zant) and posterior (Zpost) cortices and robusticity (Tt.Ar/bone length) were quantified. Paired samples t-tests indicate significant differences in Tt.Ar (p<0.01), Ct.Ar (p<0.005), robusticity (p<0.01), SSIant (p<0.05) and SSIpost (p<0.01) between left and right el...

The original endocast of A.L. 444-2 consisted of a single plastic cast, colored to show the original fragments (light brown) and the reconstructed missing parts (black). This we label the Rak-Kimbel endocast, which was based on the reconstruction of cranial and facial fragments. Because distortion was severe enough to interfere with morphological description and measurements, and especially the assessment of endocranial capacity, a plaster endocast was received from Yoel Rak in 1998 for purposes of modification. This newer plaster endocast formed the basis for the original endocast reconstruction done by R.L.H., who based the reconstruction on the less distorted side (left) and then doubled its water-displaced volume to achieve the final endocranial volume. As will become clear in our descriptions, this first method required several additions and subtractions to compensate for missing portions, for flash lines left from the casting process, and for distortion remaining in the reconstruction. We concluded that a more accurate reconstruction would result if the portions of the original endocast were separated from reconstructed elements and approximated on a plasticene “core” so that distortion could be effectively eliminated. The second method, which was accomplished mostly by M.S.Y. with minimal guidance from R.L.H., permitted a range of possible reconstructions of the actual brain endocast pieces and provided a range of endocast volumes. This reconstruction methodology, referred to as the “dissection method,” eliminated most of the distortion and obviated the need to correct for flash lines. Although both methods provide a final endocranial capacity very close to what must have been the actual living brain volume of A.L. 444-2, we consider the dissection method to be the more accurate one. Distortion of the endocranial cast mirrors that of the cranium. While the right parietotemporal area appears to be depressed, the left parietotemporal area shows signs of bulging in compensation. In addition, due to a gap that runs anteroposteriorly along the left temporal lobe, there is an artificial increase in the distance between the base of the endocast and its apex of about 3–8 mm on the left side.

Brain Endocasts is the only comprehensive, single-volume work dealing exclusively and uniformly with fossil hominid brain endocasts. Never-beforepublished photographs come together with easily accessible, coherent descriptions to create a detailed reference on the paleoneurological evidence for human evolution. Each entry offers essential information related to the location, dating, associations, and morphology of a given endocast. The text also covers the latest methodologies and techniques available for studying endocasts. In addition, a concise summary shows how these fossil records contribute to our understanding of human evolution and behavior.

A.L. 444-2 is the first specimen to preserve the cranium and mandible of a single adult individual of A. afarensis. Pairing this specimen with A.L. 417-1, which includes a mandible and maxilla, enables us to compare comprehensively the craniofacial morphology of male and female individuals of the species for the first time. The occluded mandibles and maxillae of A.L. 444-2 and A.L. 417-1 reveal a distinctive hominoid snout contour, combining a strongly inclined, convexly sloping nasoalveolar clivus with a relatively upright mandibular symphysis, a straight to slightly rounded anterior symphyseal outline, and an anteriorly placed gnathion. Both A. afarensis specimens feature a very deep mandibular corpus, whose height occupies close to 70% of the orbitoalveolar height of the face. In the African great apes, this value ranges from 36% to 54%, and in modern humans, it is 66%. The high value in humans is due to a short orbitoalveolar region rather than to a deep mandible. A. afarensis appears to share a relatively deep corpus with A. robustus (the only robust species in which the feature can be determined for a single individual) but not with A. africanus. Relative to the calvarial length, the A.L. 444-2 braincase height is apelike, falling between the tall modern human braincase and the low braincase of A. boisei and A. aethiopicus. In A. africanus (Sts. 5) and H. habilis (KNMER 1813) the relative braincase height is like that of A.L. 444-2 and the great apes. According to Le Gros Clark’s (1950) index expressing the height of the calvaria above the roof of the orbit as a percentage of total calvarial height, Sts. 5 and KNM-ER 1813 have tall, “humanlike” braincases, whereas A.L. 444-2, A. boisei, A. aethiopicus, and the African great apes group together with low braincases. In contrast to the rounded, nearly circular midsagittal outline of the chimpanzee calvaria, the posterior parietal/ occipital arc in A.L. 444-2 is steep and deviates anteriorly from the circle. This is also true of the A. boisei calvaria. As expected from the calvarial height comparison, the slope of the A.L. 444-2 frontal squama is smaller than that of A. africanus and H. habilis.

Having calculated the brain volumes of several australopithecine and early Homo fossil hominid brain endocasts ([1][1]–[3][2]), I read with considerable interest the report by Glen C. Conroy et al. (12 June, p. [1730][3]) and the commentary by Dean Falk (Perspectives, Science 's Compass, 12 June,