Human Evolution
Bones, Cultures, and Genes
John H. Langdon Human Biology Program
University of Indianapolis Indianapolis, IN, USA
ISSN 2730-6135
Springer Texts in Social Sciences
ISSN 2730-6143 (electronic)
ISBN 978-3-031-14156-0 ISBN 978-3-031-14157-7 (eBook) https://doi.org/10.1007/978-3-031-14157-7
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To all my ancestors, remembered, forgotten, or undiscovered.
Preface
I fnd the study of paleoanthropology both fascinating and humbling. The fascination begins in the imagination. What would it have been like to be alive in the past? What did the men and women of prehistory experience? What thoughts did they have and why were not they more inventive? Fascination continues with each new discovery. Often the feld has been compared to completing a jigsaw puzzle with 99% of the pieces missing. Almost monthly another piece comes to light, and each one feels like a gift to be unwrapped. Where does it ft? What does it tell us? It may add only a tiny detail, but every few years the picture must be redrawn based on fnds so unexpected that there is no place for them in the old version.
It is humbling to acknowledge how little we know. Many books on this topic try to give the impression that we have the answers – that we know how humans evolved and we are just trying to fll in the details. I sincerely hope this volume does not fall into that category. Good questions are far more important in guiding future understanding than hypothetical answers. Old ideas deserve to be challenged, but to do that effectively, we must be aware of the evidence and reasoning that created them in the frst place. At the end of most chapters are a few “Important questions we cannot answer.” I encourage the reader to add to that list.
It is also humbling to place humankind in a broad context. As a species, Homo sapiens is both trivial and terrifying. We share the earth with about nine million other species today, and these are a tiny part of one percent of those that have ever lived. Recorded history and even the frst villages and crops are so recent that they do not make it into this story. Ours has only been around perhaps 200,000 years since its origin in Africa, but in this time we have both improved the planet for our own purposes and seriously damaged it. Whether other species can avoid extinction depends on how well they can tolerate human activity. Whether we continue, evolve, or become extinct remains for future generations to determine.
My purpose in writing this book has been to bring the account of human evolution up to date with the latest contributions from many disciplines. It explores how recent discoveries are challenging what we thought we knew, and attempts to build a sense of anticipation for the next revelation. The greatest leaps in our understanding occur when we reach beyond the painstaking work of fossil hunting and archaeological excavations to see what other disciplines can contribute. Anatomy, climatology, cultural anthropology, ecology, embryology, ethology, geology, genetics, genomics, chemistry, neuroscience, physics, and physiology all have their place in telling our story.
Indianapolis, IN, USA
John H. Langdon
acknowledgments
This effort could not have been possible without the support of many people. I would like to thank my teachers and students from whom I have learned; friends and colleagues, especially Shawn Hurst; and reviewers of this work in progress. Katherine Langdon, Amy Langdon, and David Strait have been invaluable in assembling illustrations. José María Bermúdez de Castro, Robert Blumenschine, Peter Brown, Ron Clarke, Thure Cerling, Christopher Dean, Eric Delson, Fernando Diez-Martin, Paul John Myburgh, and Christine Baile and Samantha Guenther at the Cleveland Museum of Natural History generously gave permission for the reuse of images.
Most of all, I am indebted to my beloved wife, Terry, for her consistent patience and encouragement.
list of figures
Fig. 1.1 The discovery of weapons signaled the transformation from ape into human, according to the Killer Ape hypothesis. Screen image of an early human ancestor from the feature movie 2001: A Space Odyssey 4
Fig. 1.2 Comparative brain sizes among larger-brained mammals. Comparisons of absolute brain size (left) alone are misleading, because larger mammals can be expected to have larger brains. A simple ratio of brain to body mass (right) does a better job of capturing relative brain development among species, but there are many other factors that will infuence brain size. These will be explored at greater length in Chaps. 5 and 16. Data primarily from (Boddy et al., 2022). Source: author 7
Fig. 1.3 A derivative version of Zallinger’s illustration. Such pictures falsely suggest a linear and purpose-driven view of human evolution. Source: José-Manuel Benitos <https://commons.wikimedia.org/ wiki/File:Human_evolution_scheme.svg> CC BY-SA 3.0, via Wikimedia Commons. Source: Wikimedia Commons 12
Fig. 1.4 Appearance and range of hominin species in time. Colors represent different radiations of hominin species. Source: author 14
Fig. 1.5 Multiregional and Out of Africa models compared. In the Multiregional model, the continental populations are connected through gene fow (red). The origins of this debate lay in competing theories of the origins of human races and the placement of known fossils in human ancestry. Source: author 22
Fig. 1.6 Phylogenetic tree of mtDNA samples from Cann et al. (1987). Each endpoint represents an individual, coded by continent of origin. Because there is greater diversity and earlier divergence among the individuals from Africa, Cann concluded the last common ancestor lived there. Obtained with permission from Nature Springer. Source: Nature permission 25
Fig. 2.1 A hypothetical phylogeny to illustrate concepts of classifcation. See text for explanation 39
Fig. 3.1 The primate face is restr uctured to allow the eyes to face anteriorly. Shown: black howler monkey, Alouatta pigra Photo by the author 56
Fig. 3.2 Primates commonly assume an upright trunk posture. Shown: left, rhesus monkey, Macaca mulatta; right, Geoffroy’s spider monkey, Ateles geoffroyi. Photos by the author 57
Fig. 3.3 Social grooming is a ver y important part of life in most primates. It strengthens individual relationships and cohesion of the larger social group. Shown: Barbary macaque, Macaca sylvanus. Source: Berthold Werner <https://commons.wikimedia.org/wiki/ File:Gibraltar_Barbary_Macaques_BW_2015-10-26_14-07-28. jpg> CC BY-SA 3.0, via Wikimedia Commons 58
Fig. 3.4 Left: Old World monkeys maintain a quadr upedal posture when walking, with a narrow ribcage and limbs of roughly equal length. Shown: rhesus macaque, Macaca mulatta. Right: Apes commonly assume an upright posture in the trees. A broad ribcage with laterally facing shoulders and long arms increase their reach. Shown: dark-handed gibbon, Sources: (left) Md. Tariq Aziz Touhid <https://commons.wikimedia.org/wiki/File:Rhesus_ Macaque_monkey_the_look.jpg> CC BY-SA 4.0, via Wikimedia Commons; (right) Thomas Fuhrmann <https://commons. wikimedia.org/wiki/File:Dark-handed_or_Agile_Gibbon_ (Hylobates_agilis)_Tanjung_Puting_National_Park_Indonesia_1.jpg > CC BY-SA 4.0, via Wikimedia Commons
Fig. 3.5 Mature male orangutan, Pongo pygmaeus. Source: Arifnal0109 <https://commons.wikimedia.org/wiki/File:ORANGUTAN_ SUMATRA_MENGAMBIL_PISANG.jpg> CC BY-SA 3.0, via Wikimedia Commons
Fig. 3.6 Female mountain gorilla with infant, Gorilla gorilla. Source: Charles J Sharp <https://commons.wikimedia.org/wiki/ File:Mountain_gorilla_(Gorilla_beringei_beringei)_female_with_ baby.jpg > CC BY-SA 4.0, via Wikimedia Commons
Fig. 3.7 Common chimpanzee, Pan troglodytes. Source: Tu7uh <https:// commons.wikimedia.org/wiki/File:PanTroglodytesAtZooNegara. jpg> CC BY-SA 3.0, via Wikimedia Commons
Fig. 3.8 Bonobos, Pan paniscus. Source: Pierre Fidenci <https:// commons.wikimedia.org/wiki/File:Pan_paniscus11.jpg> CC BY-SA 2,5, via Wikimedia Commons
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Fig. 4.1 Timeline for Chap. 3. Source: author 74
Fig. 4.2 A human phylogeny from 1915 including known hominin fossils Pithecanthropus, Neanderthals, and Eoanthropus (the Piltdown hoax), as drawn by Sir Arthur Keith. The human lineage diverges from the great apes in the Oligocene, which is now dated to 30 million years ago. From (Keith, 1915), public domain. Source: public domain
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Fig. 4.3 Partial maxilla YPM 13799 with P3-M2, type specimen of Ramapithecus punjabicus from the Siwalik Mountains of northern India (cast). In the 1960s this was argued to be the oldest known hominin. It is now recognized as a female Sivapithecus sivalensis about 12.2 Ma. Photo by Katherine Langdon 76
Fig. 4.4 Gorilla, chimpanzee, and human mandibles. The large canines on the ape’s jaws shape the front of the mouth into a wide “U” shape with parallel sides. The human jaw is narrow in front and the molar rows are diverging to create a parabolic arcade. Photo by author 76
Fig. 4.5 The impact of the molecular clock on hominin classifcation in the 1970s. Left: a phylogeny according to then-current interpretations of the fossil record. Human diverged early and all living lineages are distinct and visible among the middle Miocene fossils. O = orangutan, G = gorilla, C = chimpanzee, H = humans. Right: A phylogeny according to the molecular clock. Humans, chimpanzees, and gorillas are equally related and descended from a recent common ancestor about 5 Ma. Source: author 79
Fig. 4.6 GSP 15000, the face of Sivapithecus sivalensis from the Siwalik Mountains of northern Pakistan next to a recent orangutan cranium. The similarities overwhelmingly linked the Asian thick-enameled hominoids to the orang clade and not to humans. Photo by author 82
Fig. 4.7 Occur rence of Miocene hominoid fossils and the Fayum site. Source: author 86
Fig. 4.8 TM 266–01–060-1 Sahelanthropus tchadensis from Toros-Menalla, Chad (model). Photo by Katherine Langdon 92
Fig. 5.1 The Taung infant, type specimen of Australopithecus africanus from Taung quarry, South Africa, about 3.0–2.6 Ma (cast). Source: Didier Descouens <https://commons.wikimedia.org/ wiki/File:Australopithecus_africanus_-_Cast_of_taung_child.jpg> CC BY-SA 4.0, via Wikimedia Commons 104
Fig. 5.2 Australopithecus africanus cranium, “Mrs. Ples” Sts 5 from Sterkfontein Cave, South Africa, about 2.5 Ma. Source: José Braga; Didier Descouens <https://commons.wikimedia.org/ wiki/File:Mrs_Ples_Global.jpg> CC BY-SA 4.0, via Wikimedia Commons 106
Fig. 5.3 Paranthropus robustus cranium SK 48, from Swartkrans Cave, South Africa, about 2.2–1.8 Ma. Sources: left, author; right S. Nawrocki 107
Fig. 5.4 SK 53, Paranthropus robustus mandible SK 23, from Swartkrans Cave, South Africa. Photo by author 107
Fig. 5.5 Relative tooth size in A. africanus, P. robustus, chimpanzee, and human. From left to right, upper frst incisor through lower third molar. Australopithecus and Paranthropus are more similar to one another than either is to a living species. Data from (Berger et al., 2015; Grine & Strait, 1994; Irish et al., 2016; Kaifu et al., 2015).
Source: author 109
Fig. 5.6 Known Australopith sites. The distribution in Africa is almost entirely in the East African Rift Valley and South Africa. Source: author 111
Fig. 5.7 The East African Rift Valley. Plio-Pleistocene fossil sites are concentrated between the fault lines (in red) in Tanzania, Kenya, and Ethiopia 114
Fig. 5.8 Olduvai Gorge, northern Tanzania. Source: Elitre <https:// commons.wikimedia.org/wiki/File:Olduvai_2012_05_31_2823_ (7522639084).jpg> CC BY-SA 2.0, via Wikimedia Commons 115
Fig. 5.9 OH 5 Zinjanthropus boisei OH 5 cranium from Olduvai Gorge, Tanzania about 1.8 Ma (cast). Photo by Katherine Langdon 116
Fig. 5.10
Cranium of A. anamensis MRD-VP-1/1 from Woranso-Mille, Ethiopia, about 3.8 Ma. Photo courtesy of the Cleveland Museum of Natural History 118
Fig. 5.11 The canine honing mechanism in a chimpanzee (cast). The upper canine rubs and sharpens against the lower premolar while the lower canine hones against the upper canine. Photo by Katherine Langdon 120
Fig. 5.12 Tooth area in early hominins. The lower frst premolar (LP3) increases in size as the honing mechanism is lost. The molars increase in area to a smaller extent. Data from (Berger et al., 2015; Suwa et al., 2009; Ward et al., 2020) 120
Fig. 5.13 A. bahrelghazali KT 12/H1 partial mandible from Koro Toro, Bahr-el-ghazal, Chad, about 3.6 Ma. Figure from (Brunet et al., 1995). Obtained with permission from Nature Springer. 121
Fig. 5.14 A. deyieremeda BRT-VP-3.1from Woranso-Mille, Afar Region, Ethiopia, about 3.5–3.3 Ma. Top row: views of maxilla; bottom row: mandible. Figure from (Haile-Selassie et al., 2015). Obtained with permission from Nature Springer.
Fig. 5.15 Maxillar y tooth areas. A. garhi shows an unusual combination of large postcanine dentition and unreduced anterior teeth. Data from (Asfaw et al., 1999; Berger et al., 2015; Leakey & Leakey, 1978; Wood, 1991)
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Fig. 5.16 The skeleton of Stw 573, A. prometheus, partially excavated, from Sterkfontein Cave, South Africa, possibly 3.67 Ma. Source: Wits University <https://commons.wikimedia.org/wiki/File:Littlle_ Foot-2.jpg> CC BY-SA 4.0, via Wikimedia Commons 123
Fig. 5.17 The cranium of MH 1, A. sediba, from Malapa Cave, South Africa, about 1.98 Ma. Source: Brett Eloff <https://commons. wikimedia.org/wiki/File:Australopithecus_sediba.JPG> courtesy of Prof. Berger and Wits University GNU Free Documentation License via Wilimedia Commons 124
Fig. 5.18 Kenyanthropus platyops, KNM-WT 40000 from West Turkana, Kenya, about 3.5 Ma (cast). Photo by Katherine Langdon 125
Fig. 5.19 Features that distinguish the robust cranium of P. robustus (SK 48) on the right from the gracile cranium of A. africanus (Sts 5) on the left. A. Anterior. Photos (left) S. Nawrocki; (right) author. B. Inferior view. Photos by author. C. Mandibles. Photos by author 126
Fig. 5.20 Anterior and posterior tooth row lengths in australopiths (=sum of mean MD lengths). Ardipithecus does not exhibit the postcanine expansion of the australopiths. Paranthropus has relatively small incisors and enlarged molars. Data sources: (Asfaw et al., 1999; Berger et al., 2015; Brunet et al., 1995; Grine & Strait, 1994; Haile-Selassie et al., 2015; Irish et al., 2016; Kaifu et al., 2015; Leakey & Leakey, 1978; Schuman & Brace, 1954; Suwa et al., 2009; Ward et al., 2020)
Fig. 5.21
Fig. 5.22
Posterior view of KNM-ER 23000 P. boisei showing the characteristic bell shape of the braincase. Specimen from East Turkana, Kenya, about 1.9 Ma (cast). Photo by Katherine Langdon
KNM-ER 406 P. boisei cranium from East Turkana, Kenya, about 1.7 Ma (cast). Photo by Katherine Langdon
Fig. 5.23 P. boisei mandible from Peninj, Tanzania, about 1.5–1.3 Ma (cast). Photo by Katherine Langdon.
Fig. 5.24
KNM-WT 17000 P. aethiopicus cranium from West Turkana, Kenya, about 2.5 Ma (cast). Photo by Katherine Langdon
Fig. 5.25 LH 4 mandible from Laetoli, type specimen of A. afarensis, about 3.6 Ma (cast). Photo by Katherine Langdon
Fig. 6.1 There are many forms that a savanna can present. Here are three views of the East African grasslands taken on the same day at Nairobi National Park, Kenya. Photos by author
Fig. 6.2 Comparison of C3 and C4 photosynthesis pathways. C4 pathways require an extra step of capturing CO2 in one cell and transporting it to another. The effciency of this transport system results in the incorporation of more 13C. Source: Wang et al. (2012) <https:// www.researchgate.net/fgure/A-schematic-diagram-of-C3-andC4- photosynthesis_fg11_257881531> CC BY-SA 2.0, via Wikimedia Commons
Fig. 7.1 The palate of A. afarensis AL 200 “Lucy” displaying the megadontia characteristic of australopiths (cast). Photo by Katherine Langdon
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Fig. 7.2 Total postcanine (P3-M3) tooth area in australopithecines (sum mean MD length x BL breadth). Light gray is the upper tooth row; black is the lower tooth row. Data sources: (Asfaw et al., 1999; Berger et al., 2015; Brunet et al., 1995; Grine & Strait, 1994; Haile-Selassie et al., 2015; Irish et al., 2016; Kaifu et al., 2015; Leakey & Leakey, 1978; Schuman & Brace, 1954; Suwa et al., 2009; Ward et al., 2020; Wood, 1991). Source: author 168
Fig. 7.3 KNM-ER 406 P. boisei showing the extreme development of chewing muscles. (a) The shaded area represents the origin of temporalis. The wide zygomatic arches support the attachment of masseter muscle and allow the passage of temporalis between the arch and the braincase. (b) Temporalis muscle has expanded its attachment area (shaded area). Where the right and left muscles meet, the sagittal crest is created to provide additional bone surface. Photos by Katherine Langdon 170
Fig. 7.4 Microwear pattern on Sts 56 A. africanus molar. The density pits and scratches is indicative of the coarseness of food eaten recently. This image also shows a high degree of anisotropy (random direction to the scratches) consistent with a frugivorous diet.
Image by Frank L. Williams and Christopher Schmidt 171
Fig. 7.5 13C signature of diet in early hominins from dental enamel. Ar. ramidus has the smallest proportion of 13C. The ratio of 13C: 12C in South African australopiths is intermediate between those for browsers and grazers, but it is fairly stable through time. P. boisei has a signifcantly higher component of C3 plants in the diet.
Data from (Lee-Thorp et al., 2012). Source: author 173
Fig. 7.6 The deep robust mandible of P. boisei (cast of SL 7A-125 from Omo Shungura Formation deposits, Ethiopia) supported hypermegadont molars and powerful chewing muscles. Photo by Katherine Langdon 175
Fig. 7.7 Estimates of EQ using dif ferent body size estimates. Data from Table 7.2. Source: author 179
Fig. 7.8 Tooth crown formation time in days as an estimate for maturation rate (mesiolingual cusp of the upper frst molar). Enamel deposition ceases upon eruption of the tooth. The thick enamel of the australopiths, and especially Paranthropus, was laid down at a faster rate than in living species and the teeth erupted at a younger age. Data from (Smith et al., 2015). Source: author 181
Fig. 8.1 Footprints of A. afarensis at Laetoli, Tanzania, about 3.6 Ma. Source: Fidelis T Masao and colleagues. https://commons. wikimedia.org/wiki/File:Test-pit_L8_at_Laetoli_Site_S.jpg. CC BY-SA 4.0, via Wikimedia Commons 192
Fig. 8.2 Selected prints from trackways “A” (above) and “G” below at Laetoli. The G trackway is assumed to have been made by A. afarensis and the A trackway by a different, unknown bipedal hominin. The differences in the shape of the foot and placement of feet within the gait pattern indicate signifcant diversity. Source: (McNutt et al., 2021). https://commons.wikimedia.org/wiki/ File:Laetoli_Footprints_Site_A_(2).jpg. CC BY-SA 4.0, via Wikimedia Commons
Fig. 8.3 AL 288 A reconstruction of the A. afarensis skeleton “Lucy,” from Hadar, Afar Region, Ethiopia, about 3.2 Ma. Also see Fig. 8.6. Photo courtesy of the Cleveland Museum of Natural History
Fig. 8.4 The skeleton of A. prometheus Sts 573 “Little Foot” from Sterkfontein Cave, South Africa. Source: Paul John Myburgh, courtesy of Paul John Myburgh and Ronald Clarke
Fig. 8.5 Sts 14 A. africanus partial skeleton from Sterkfontein, South Africa, about 2.5 Ma. Photo by S. Nawrocki
Fig. 8.6 The two known skeletons of A. sediba, MH1 juvenile (left) and MH 2 adult (right), from Malapa Cave, South Africa, about 1.98 Ma compared with the skeleton of Lucy (AL 288 A. afarensis).
Source: Profberger https://commons.wikimedia.org/wiki/ File:Australopithecus_sediba_and_Lucy.jpg CC BY-SA 3.0, via Wikimedia Commons
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Fig. 8.7 OH 8 par tial foot of Paranthropus boisei from Olduvai Gorge, Tanzania, about 1.8 Ma (cast). Photo by Katherine Langdon 198
Fig. 8.8 Cur vatures of the human spinal column. The curvatures help to balance the center of mass and provide shock absorption. Upright posture in hominins creates lumbar lordosis and decreases the sacral angle. Image in public domain 199
Fig. 8.9 Embr yonic somites develop into vertebrae and related tissues. The differentiating factors include retinoic acid, which diffuses from cranial to caudal; fbroblast growth factor (FGF), which diffuses from caudal to cranial, and the products of Hox genes produced by cells within the somites. Hox gene activation is triggered by local ratios of retinoic acid and FGF. The activitiy of Hox genes that are key to differentiating regions of the spine is depicted. Changes in the control and expression of the Hox genes can quickly change the positions of boundaries between spinal regions. Image of spine from SMART-Servier Medical Art, part of Laboratoires Servier© CC BY-SA 3.0, via Wikimedia Commons 202
Fig. 8.10 The position of the foramen magnum, indicated by the yellow dots, is related to the balance of the head in an upright posture. Australopiths (center, Sts 5 A. africanus) show an intermediate position of the foramen between that of the chimpanzee (left) and human (right). Photos by Katherine Langdon. Center photo by author 203
Fig. 8.11 The major muscles of abduction of the hip in posterior view. The lateral fare of the iliac blade brings the origin of the muscles over the femur for greater lever action in balance. Source of skeleton outline: LadyofHats released into public domain via Wikimedia Commons. Source of skeleton outline: https://commons. wikimedia.org/wiki/File:Human_skeleton_back_no-text_no-color. svg released into public domain via Wikimedia Commons. 206
Fig. 8.12 The lateral fare of the pelvic blade places the hip abductors directly over the joint for more effective control. This is exaggerated in australopiths and most other fossil hominin specimens. (a). Modern human. (b). Reconstruction of AL 288 A. afarensis from Hadar, Ethiopia. (c). Chimpanzee. Photos by Katherine Langdon 207
Fig. 8.13 Chimpanzee (left) and human (right) femurs aligned at the knee. The carrying angle of the shaft of the human femur brings the knees and feet closer to the center of mass. Photo by Katherine Langdon 208
Fig. 8.14 The anterior to posterior length of the pelvis determines lever arms for muscles of fexion and extension. The ilium anteriorly creates leverage for hip fexors and the ischium posteriorly supports the hamstrings for extension. The human pelvis is reshaped to strengthen the extensors despite the upright orientation. (a) Chimpanzee. (b) Human. Also see Fig. 7.20 for comparative lengths. Photos by Katherine Langdon
Fig. 8.15 The longitudinal arch of the human foot (top) is elevated and strengthened during gait to provide critical leverage. This does not occur in the chimpanzee foot (below). Source: (Elftman & Manter, 1935), in public domain
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Fig. 8.16 Chimpanzee and human feet compared, scaled to the same length. Note the human great toe is elongated, rotated, immobilized and more robust. Source: (Morton, 1922), in public domain 211
Fig. 8.17 The transverse arch. While the heads of the metatarsals (solid outlines) rest on the ground, the bases of the same bones (dotted outlines) are elevated at midfoot into the transverse arch. The transverse arch of the human foot is more pronounced and gives further support against midfoot bending. (a) Human foot. (b) Chimpanzee foot. Source: (Morton, 1924) in public domain 212
Fig. 8.18 The toes of the human foot go into hyperextension as the heel rises during gait. Attached ligaments and tendons tug against the rear of the foot, pulling joints into more stable positions and elevating the arch. Source: (Hicks, 1954) in public domain 214
Fig. 8.19 The cur vature of a long bone refects forces applied to it. In this example of a fnger, the fexor tendon is represented by the gray band. The tendon is held in place by a retinaculum anchored along the length of the bone (blue). When the fexor muscle contracts, the retinaculum redirects the forces to be perpendicular to the bone tissue (arrows). These forces are best resisted by an architectural arch. Shown: Proximal third phalanx of the hand of H. naledi 215
Fig. 8.20 Human and chimpanzee pelvis scales to similar interacetabular distance. The human ilium and sacrum are greatly reduced in height to bring the sacroiliac and hip joints closer together for more effcient weight transfer between them. Photos by Katherine Langdon 217
Fig. 8.21 The reconstructed pelvis of AL 288 A. afarensis from Hadar, Ethiopia (model). The reduction in height exceeds that of humans. Photo by Katherine Langdon
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Fig. 8.22 Chimpanzee and human proximal femora. The human femur has a larger head and neck and a more obtuse angle between the neck and the shaft. Photo by Katherine Langdon 219
Fig. 8.23 Lateral view of calcanei of (a). chimpanzee, (b). human, (c). AL 333-8 A. afaransis from Hadar, and (d). Omo 33-74-896 P. boisei from Omo (casts of fossils). Photo by author 221
Fig. 8.24 The calcaneal tuberosity in posterior view of (a). chimpanzee, (b). human, and (c). Omo 33-74-896 P. boisei from Omo. Humans have developed a medial tubercle to broaden the base for balance and support. This feature is variable among australopith species. Photo by author
Fig. 8.25 Tyrannosaurs rex and other dinosaurs achieved a bipedal posture by balancing the trunk with a massive tail. Keeping the trunk horizontal did not require a redesign of the pelvis. Note the disproportion of the limbs. Source: Greg Goebel https:// commons.wikimedia.org/wiki/File:T-Rex_skeleton_%22Big_ Mike%22_at_Museum_of_the_Rockies_White_Background.jpg CC BY-SA 2.0, via Wikimedia Commons
Fig. 8.26 Cur rent evidence indicates substantial diversity of body plan among earlier hominins represented in this summary image
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Fig. 9.1 The geographic distribution of early fossils of genus Homo in Africa. Source: author 252
Fig. 9.2 OH 7 mandible, type specimen of H. habilis from Olduvai Gorge, Tanzania, about t1.75 Ma (cast). Photo by Katherine Langdon 253
Fig. 9.3 OH 13 H. habilis from Olduvai Gorge, Tanzania, about 1.7 Ma (cast). Photo by Katherine Langdon 254
Fig. 9.4 OH 16 H. habilis from Olduvai Gorge, Tanzania, about 1.7 Ma (cast). Photo by Katherine Langdon 254
Fig. 9.5 Comparison of individual tooth area (mean length x mean breadth). H. habilis is very close to A. afarensis in area, but later Homo is smaller. Data from (Berger et al., 2015; Brown & Walker, 1993; Kaifu et al., 2015; Leakey & Leakey, 1978; Wood, 1991; Wood & Leakey, 2011). Source: author 255
Fig. 9.6 Features of the lower jaw and dentition that differentiate Homo (right) from Australopithecus (left). Left, AL 400 A. afarensis; right, OH 13 H. habilis (casts). Photos by Katherine Langdon 258
Fig. 9.7 Features of the cranium that differentiate Australopithecus from Homo. Left, Sts 5, A. africanus; right, KNM-ER 3373, H. ergaster. Sources: left, S. Nawrocki; right, Katherine Langdon
Fig. 9.8 Variation in Homo crania from East Turkana, Kenya, established the coexistence of multiple species. From left to right, KNM-ER 1813 H. habilis, KNM-ER 1470 H. rudolfensis, KNM-ER 3733 H. ergaster (casts). (a). Anterior view. (b). Lateral view. Photos by Katherine Langdon
Fig. 9.9 Interpretations of early human diversity in East Africa. (a) A standard model about 1980 and (b) a current best interpretation of the African fossils. Source: author
Fig. 9.10 Cranium OH 24 cf. H. habilis from Olduvai Gorge, Tanzania, about 1.8 Ma (cast). Photo by Katherine Langdon
Fig. 9.11 OH 65 habiline lower face from Olduvai Gorge, Tanzania, about 1.8 Ma, in anterior and inferior views. The fossils is contemporary with specimens of H. habilis, but the great breadth of the anterior mouth and palate closely resembles H. rudolfensis. Courtesy of Robert Blumenschine and Ron Clarke
Fig. 9.12
KNM-ER 60000 mandible, similar to the H. rudolfensis tooth row, but adding to the variation within early Homo. Figure from (M. G. Leakey et al., 2012). Obtained with permission from Nature Springer
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Fig. 9.13 SK 847 H. gautengensis or a small-brained Australopithecus from Swartkrans, South Africa, about 1.8–1.3 Ma. Photo by author 264
Fig. 9.14 Cranial capacities of early hominins. Dif ferences are apparent between Australopithecus and early habilines and between all the early species and H. ergaster
Fig. 9.15
Paleoclimate indicators for East Africa show local fuctuations within long-term trends. Carbon isotope ratios from paleosols in the Omo River basin (Shungura Formation) and the Lake Turkana basin correlate with diminishing tree cover across a spectrum of habitats. Source: (Cerling et al., 2011)
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Fig. 10.1 Early presence of humans in Africa and western Asia. Blue = early Homo. Red = Mode 1 tools. Purple = both. Source: author 278
Fig. 10.2 Oldowan core and fake tools, each shown in three views. A. Early chopper from Melka Kunture, Ethiopia. B. Flake chopper from Saint-Clar-de-Rivière, Haute Garonne, France. Source Didier Descouens. https://commons.wikimedia.org/wiki/File:Pierre_ taill%C3%A9e_Melka_Kunture_%C3%89thiopie.jpg and https:// commons.wikimedia.org/wiki/File:Galet_MHNT_ PRE.2009.0.200.1.jpg CC BY-SA 4.0, via Wikimedia Commons 283
Fig. 10.3 Spheroid hammerstones from Bed I, Olduvai Gorge, Tanzania. Source (Diez-Mar tín et al., 2021), with permission courtesy of Fernando Diez-Martin
Fig. 10.4 Chimpanzee hand (left) and human hand (right) compared. The relatively long human thumb allows fngertip opposition and much greater dexterity. Source: Denise Morgan. https://commons. wikimedia.org/wiki/File:Chimp_and_human_hands.jpg via Wikimedia Commons
Fig. 10.5 The hand of A. sediba from Malapa Cave, South Africa. Source: Profberger. https://commons.wikimedia.org/wiki/File:Hand_ and_arm_Australopithecus_sediba_on_black.jpg CC BY-SA 3.0, via Wikimedia Commons
Fig. 12.1 The human brain has approximately three times the volume of the chimpanzee brain. This fgure only compares the cerebrums. Source: Todd Preuss. https://commons.wikimedia.org/wiki/ File:Human_and_chimp_brain.png. CC BY-SA 2.5, via Wikimedia Commons
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Cranial capacities (cc) of fossil hominins through time. H. naledi and H. forensis are on the lower right. The habilines, including Dmanisi fossils, do not align with the trajectory of later species of Homo
Cranial capacities (cc) of fossil hominins through time, including only the fossils most likely to be on the direct lineage of H. sapiens. This plot is more linear than Fig. 12.2 and suggests a more continuous increase in genus Homo through time
Fig. 12.4 Expected and obser ved human visceral organ masses. The additional investment in brain tissue is matched by the reduction in the mass of the liver and intestine. Data from (Aiello & Wheeler, 1995). Source: author
Fig. 12.5 The lobes of the cerebral cortex. The insula is hidden deep to folds of the frontal, parietal and temporal lobes. Source: (Gray, 1912). https://commons.wikimedia.org/wiki/File:Lobes_of_ the_brain_NL.svg in public domain through Wikimedia Commons
Fig. 12.6 Decision-making in the prefrontal cortex. Emotional motivation may compete with social and other concerns. Possible actions and outcomes are valuated and compared to determine a course of action. Source: author
Fig. 12.7 Reorganization of the human brain. The chimpanzee (left) and human brain (right) are approximately to scale. The topography of
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each has been averaged from many specimens to indicate to remove individual variation. A. The human brain displays a relative expansion of the prefrontal cortex, especially in its inferior regions. The lateral orbital frontal cortex now contributes to the operculum (folds of cortex obscuring the insula). The inferior parietal cortex has also increased its relative area.
B. Reorganization of the orbital region of the brain. The expansion of the lateral frontal orbital cortex has pushed insular cortex posterior, to be covered by the frontal operculum. Source: Shawn Hurst
Fig. 12.8 Approximate language areas of the left hemisphere. These areas perform other funcitons, as well. Brain outline by Hankem. https://commons.wikimedia.org/wiki/File:Human_Brain_ sketch_with_eyes_and_cerebrellum.svg released into public domain via Wikimedia Commons
Fig. 12.9 The human vocal tract. The descent of the larynx, enlarging the pharynx, is necessary for the full range of human speech sounds. By separating the palate and epiglottis, it also makes it easier for humans to choke on food and drink. Source: author
Fig. 13.1 Evidence of early Homo. While we started our story in Africa, people had also entered Asia at an early date. Source: author
Fig. 13.2 Important sites in Chap. 9. Source: author
Fig. 13.3 Ruins of the castle and cathedral at Dmanisi. The oldest hominin fossils outside of Africa were discovered during archaeological excavation of this citadel. Source: Larry V. Dumlao. https:// commons.wikimedia.org/wiki/File:Ruins_of_Dmanisi_Castle.jpg. CC BY-SA 4.0, via Wikimedia Commons
Fig. 13.4 Mandible D2600 from Dmanisi, Republic of George, about 1.8 Ma (cast). The massive build and early date led to the naming of a new species, Homo georgicus. Source: Gerbil. https:// commons.wikimedia.org/wiki/File:D2600.jpg. CC BY-SA 4.0, via Wikimedia Commons
Fig. 13.5 A digital reconstruction of the fve skulls from Dmanisi, apparently from a single population, from (Lordkipanidze et al., 2013). The range sizes and morphology challenges our expectations of normal species variation. Obtained with permission from Science
Fig. 13.6 Excavations in the cave at Liang Bua on Flores, where H. foresiensis was discovered. Source: Rosino. https://commons. wikimedia.org/wiki/File:2016032812 2708_-_The_inside_of_ the_Liang_Bua_hobbit_cave_(homo_foresiensis)_ (26066080056).jpg. CC BY-SA 2.0, via Wikimedia Commons
Fig. 13.7 Wallace’s Line separates the Asian and Australian continental plates. During much of the Pleistocene, Sumatra, Java and Borneo were connected to the mainland. Land animals crossed the water and colonized the more eastern islands, including Sulawesi, and Flores, only rarely by chance events. Source: author
Fig. 13.8 Cranium of LB1 Homo foresiensis from Liang Bua, Flores, Indonesia, about 76 Ka (model). Photo by Katherine Langdon
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Fig. 14.1 Erectine sites in Asia referred to in this chapter. Source: author 392
Fig. 14.2 Possible explanations for the distribution of erectines. (a). African and Asian populations diverged from a broad initial distribution of hominins. This conventional view glosses over problems of chronology and the question of where the species arose. (b). African and Asian populations descended independently from the initial migration of primitive Homo. The only skeletal evidence of this migration, at Dmanisi, is too late and too primitive to be a good ancestor. The model assumes they are distinct species and we can explain similarities in morphology through parallel evolution and a high level of population variation, particularly in Africa. Gene fow maintains coherence of the species. (c). African populations descended from H. erectus in Asia via a back migration. This model is contradicted by the fact that H. ergaster in Africa predates known H. erectus in Asia. (d). Asian populations descended from H. ergaster in Africa via a second migration. However, there is no independent evidence for a second migration. Source: author
Fig. 14.3 Franz Weidenreich’s rendering of skull XII Homo erectus from Zhoukoudian, China, about 750 BP. (a). Anterior view. (b). Lateral view. (c). Superior view. (d). Posterior view. Images in public domain via Wikimedia Commons. https://commons. wikimedia.org/wiki/File:Sinanthropus_Skull_XII_norma_ frontalis.png. https://commons.wikimedia.org/wiki/ File:Sinanthropus_Skull_XII_lateralis_sinistra.png. https:// commons.wikimedia.org/wiki/File:Sinanthropus_Skull_XII_ norma_verticalis.png. https://commons.wikimedia.org/wiki/ File:Sinanthropus_Skull_XII_norma_occipitalis.png
Fig. 14.4 Mandible of H. erectus ZKG D1 from Zhoukoudian (cast).
Photo by Katherine Langdon
Fig. 14.5 H. erectus cranium from Lantian Gongwangling, China, about 1.6 Ma. Source: Woo Ju-Kang. https://commons.wikimedia.org/ wiki/File:Gongwangling_norma_verticalis.png in public domain, via Wikimedia Commons
Fig. 14.6 H. erectus cranium from Hexian, China, about 412 Ka. Photo courtesy of Peter Brown
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Cranial capacities through time for the lineage of Asian hominins. Not the discontinuities at the start and end of H. erectus, suggesting population replacements
Dubois’ illustration of the frst specimens of Pithecanthropus erectus from Trinil, Java. In public domain
Sangiran 2 Homo erectus cranium from Sangiran, Java (cast).
Photo by Katherine Langdon
Sangiran 17 Homo erectus cranium from Java, about 1.2 Ma (model). Photo by Katherine Langdon
Fig. 14.11 Mandibular fragment of Meganthropus palaeojavanicus from Sangiran, Java. Von Koenigswald believed this was a new hominin similar to robust australopiths. It is now believed to be an extinct ape. Source: Senckenberg Research Institute and Natural History Museum. https://commons.wikimedia.org/ wiki/
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File:Meganthropus_palaeojavanicus.jpg. CC BY-SA 4.0, via Wikimedia Commons 407
Skull IV late H. erectus from Ngandong, Java, about 110 Ka (cast). Photo by Katherine Langdon 410
Skull IX late H. erectus from Ngandong, Java, about 110 Ka. Source: Franz Weidenreich, in public domain via Wikipedia Commons 411
Fig. 14.14 Sambungmacan 3 late H. erectus from Sambungmacan, Java, perhaps 100 Ka (cast). Photo by Katherine Langdon 411
Fig. 15.1 Sites referred to in this chapter. (a) African sites. (b) European sites. Source of outline map. Source: author 420
Fig. 15.2 Mauer 1, type specimen of H. heidelbergensis from near Heidelberg, Germany, about 600 Ka. Source: (MacCurdy, 1924) in public domain 421
Fig. 15.3 The reconstructed skull of “Eoanthropus dawsoni,” the notorious Piltdown forgery created from parts of a human cranium and an orangutan mandible. Source: Wellcome Collection Gallery with permission https://commons.wikimedia.org/wiki/File:Skull_of_ the_%22Eoanthropus_Dawsoni%22_(Piltdown_Man)_Wellcome_ M0013579.jpg. via CC BY-SA 4.0, via Wikimedia Commons
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Fig. 15.4 KNM-ER 3883 H. ergaster from East Turkana, Kenya, about 1.6 Ma (cast). Photo by Katherine Langdon 425
Fig. 15.5
KNM-WT 15000 cranium of the H. ergaster skeleton from Nariokotome, Kenya, about 1.6 Ma (cast). Photo by Katherine Langdon
Fig. 15.6 OH 9 H. ergaster (or H. erectus) from Olduvai Gorge, Tanzania, about 1.7 Ma (cast). Photo by Katherine Langdon
Fig. 15.7 Homo heidelbergensis cranium from Kabwe, Zambia, about 300 Ka. Photos by author
Fig. 15.8 H. heidelbergensis cranium from Bodo, Ethiopia, about 632 Ka (cast). Photo by Katherine Langdon
Fig. 15.9 Schematic section of the route in Rising Star Cave from the closest entrance to the Dinaledi Chamber. Early hominins repeatedly brought the bodies of deceased members through this tortuous passage. Source: Paul H. G. M. Dirks et al. https://commons. wikimedia.org/wiki/File:Geological_map_and_cross-section_of_ the_Rising_Star_cave_system.jpg. CC BY-SA 4.0, via Wikimedia Commons
Fig. 15.10 DH 1 cranial bones of the type specimen of H. naledi from the Dinaledi Chamber of Rising Star Cave, South Africa, about 300 Ka. This includes U.W. 101–1473 cranial bones, U.W. 101–1277 maxilla, and U.W. 101–1261 mandible. Source: Berger et al., 2015 https://commons.wikimedia.org/wiki/File:Homo_naledi_ holotype_specimen_(DH1).jpg. CC BY-SA 4.0, via Wikimedia Commons
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Fig. 15.11 LES 1 cranium of H. naledi from the Lesedi Chamber of Rising Star Cave, South Africa. Source: John Hawks, Marina Elliott, Peter Schmid et al. https://commons.wikimedia.org/wiki/ File:Homo_naledi_LES1_cranium.jpg. CC BY-SA 4.0, via Wikimedia Commons 434
Fig. 15.12 Part of the initial recovery of bones from the Dinaledi Chamber arranged into a composite skeleton. Source: Lee Roger Berger research team. https://commons.wikimedia.org/wiki/ File:Homo_naledi_skeletal_specimens.jpg. CC BY-SA 4.0, via Wikimedia Commons 435
Fig. 15.13 Articulated bones of the right hand of H. naledi (front and back). Note the robusticity, particularly of the thumb and the broad tufts at the tips of all the digits. Source: Tracy L. Kivell, Andrew S. Deane, Matthew W. Tocheri, Caley M. Orr, Peter Schmid, John Hawks, Lee R. Berger & Steven E. Churchill. https://commons. wikimedia.org/wiki/File:Homo_naledi_hand.jpg. CC BY-SA 4.0, via Wikimedia Commons 436
Fig. 15.14 ATE9-1: Mandible fragment from the TE9 level of the Sima del Elefante cave site (Sierra de Atapuerca, Spain). This fossil has been dated between 1.1 and 1.3 million years using the cosmogenic nucleide method. This fossil has been attributed to Homo sp. With permission, courtesy and © José María Bermúdez de Castro 439
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ATD6-15 and ATD6-69 human fossil remains (Individual 3) from the Gran Dolina cave site, level TD6. Various dating methods conclude that this level is approximately 0.85 million years old (MIS 21). These fossils have been attributed to the species Homo antecessor. With permission, courtesy and © José María Bermúdez de Castro 440
Fig. 15.16 Atapuerca 5 cranium early H. neanderthalensis from Sima de los Huesos, Spain, about 450–430 Ka (cast). Photo by Katherine Langdon 441
Fig. 15.17 The cranium from Petralona, Greece, an example of a robust specimen of H. heidelbergensis, about 305–150 Ka. With permission, courtesy and © of Eric Delson
Fig. 15.18 Cranium of H. heidelbergensis from Ceprano, Italy in superior and lateral views, about 460–430 Ka. Source: UtaUtaNapishtim. https://commons.wikimedia.org/wiki/File:Ceprano_Argil.jpg. CC BY-SA 4.0, via Wikimedia Commons
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Fig. 15.19 Cranium from Steinheim, Germany, an example of a gracile specimen of H. heidelbergensis, about 150 Ka (model). Photos by Katherine Langdon 446
Fig. 15.20 The gracile morph of H. heidelbergensis (left) has a smaller and more lightly built face and smaller braincase. Left: Steinheim (cast); right: Petralona. Sources: (left) photo by Katherine Langdon; (right) photo courtesy and © of Eric Delson 446
Fig. 15.21 The gracile morph of H. heidelbergensis (right) has a smoothly rounded occipital region, while the robust form has a strong occipital torus and a pronounced nuchal plane. Left: Petralona; right: Steinheim (cast). Sources (left) photo courtesy and © of Eric Delson; (right) photo by Katherine Langdon 446
Fig. 15.22 (Above) Arago XX1 H. heidelbergensis cranium from Tautavel, France, about 450 Ka (cast). Source: Luna04. https://commons. wikimedia.org/wiki/File:Homme_de_Tautavel.jpg. CC BY-SA 4.0, via Wikimedia Commons. (Below) Arago XIII and Arago II H. heidelbergensis mandibles from Tautavel, France (casts). Source:
Gerbil. https://commons.wikimedia.org/wiki/File:Tautavel_ UK_2.JPG. CC BY-SA 2.0, via Wikimedia Commons. Check for new scan 447
Fig. 15.23 Two interpretations of phylogeny in Africa and Europe. On the left, Middle Pleistocene fossils in both continents are place is a single species connected by occasional migration and gene fow. (The existence of parallel lineages such as H. naledi is ignored.). The fgure on the right places the hominins into separate lineages. Roksandic et al., 2021 propose to merge H. heidelbergensis with Neanderthals and to name the African lineage H. bodoensis
Fig. 16.1 The presence of Acheulean cultures (orange) and hominin species (blue and green). Source: author
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Fig. 16.2 Location of sites discussed in this chapter. Source: author 462
Fig. 16.3 An adult human tapeworm of the species Taenia saginata. The head, by which it clings to the wall of the intestine, is on the right. Source: Center for Disease Control. https://commons.wikimedia. org/wiki/File:Taenia_saginata_adult_5260_lores.jpg. in public domain via Wikimedia Commons
Fig. 16.4 Examples of Lower Paleolithic bifacial tools. A. Flint handaxe from England. Source: https://commons.wikimedia.org/wiki/ File:ESS-4444B5_Palaeolithic_Axe_(FindID_228769).jpg. CC BY-SA 2.0, via Wikimedia Commons. B. A fnely shaped handaxe from Israel. Source: A fnely shaped handaxe from Israel. Source: Guyassaf. https://commons.wikimedia.org/wiki/File:Hand_ ston_1.jpg in public domain via Wikimedia Commons. C. Two more crudely made bifaces from South Korea. Source: Ismoon. https://commons.wikimedia.org/wiki/File:Paleolithic_ Handaxe._Seoul_National_University_Museum.jpg. CC BY-SA 4.0, via Wikimedia Commons
Fig. 16.5 How a modest-sized handaxe might be used. Source: https:// commons.wikimedia.org/wiki/File:Lower_Palaeolithic_Bifacial_ Hand_Axe_from_Kelstern_(FindID_386979-287331).jpg. via Wikimedia Commons
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Fig. 16.6 Excavated handaxes in situ at Olorgesalie, Kenya, about 700 Ka. Source: Rossignol Benoît. https://commons.wikimedia.org/ wiki/File:Olorgesailiesite1993(1).jpg. CC BY-SA 3.0, via Wikimedia Commons 477
Fig. 16.7 Elephant bones (Palaeoloxodon) exposed at Ambrona, Spain, about 350 Ka. Source: PePeEfe. https://commons.wikimedia. org/wiki/File:Palaeoloxodon_antiquus_-_in_situ_fossil_bones_Ambrona.JPG. CC BY-SA 2.0, via Wikimedia Commons 479
Fig. 16.8 One of the wooden spears from Schoeningen, Germany, about 300 Ka. These are the oldest wooden weapons yet discovered. Source: P. Pfarr NLD. https://commons.wikimedia.org/wiki/ File:Sch%C3%B6ningen_Speer_VII_im_
