Peopling
Entropic Cities: The Paradox of Urbanism in Ancient Mesopotamia
Guillermo Algaze
Current Anthropology, February 2018, Pages 23-54
Abstract:
The growth of cities in antiquity is paradoxical: before modern health and sanitation standards, early urban dwellers suffered high mortality as a result of epidemics and chronic diseases arising, respectively, from propinquity and poor sanitation. At the same time, lower-status individuals within those cities would have endured depressed birth rates because, typically, many toiled in partially or fully dependent occupations not conducive to early marriage or stable families. The interplay between these compounding forces implies that early cities would not have been viable over the long term and could not have grown without a continual flow of immigrants. The early cities of Mesopotamia were no exception. In an earlier publication, I argued that the growth of the first centers that emerged in the alluvial lowlands of the Tigris and Euphrates Rivers during the fourth millennium BC was predicated on migratory inflows that took place, in part, in the context of self-amplifying cycles whereby the replacement of imported commodities with locally made, mass-produced substitutes catalyzed increases in specialization, employment, market size, and trade (Smithian growth). In this article, I expand on these ideas, explore their applicability to later periods of Mesopotamian history, and consider further iterations of substitution-fueled growth cycles in those periods.
A neurochemical hypothesis for the origin of hominids
Mary Ann Raghanti et al.
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
It has always been difficult to account for the evolution of certain human characters such as language, empathy, and altruism via individual reproductive success. However, the striatum, a subcortical region originally thought to be exclusively motor, is now known to contribute to social behaviors and "personality styles" that may link such complexities with natural selection. We here report that the human striatum exhibits a unique neurochemical profile that differs dramatically from those of other primates. The human signature of elevated striatal dopamine, serotonin, and neuropeptide Y, coupled with lowered acetylcholine, systematically favors externally driven behavior and greatly amplifies sensitivity to social cues that promote social conformity, empathy, and altruism. We propose that selection induced an initial form of this profile in early hominids, which increased their affiliative behavior, and that this shift either preceded or accompanied the adoption of bipedality and elimination of the sectorial canine. We further hypothesize that these changes were critical for increased individual fitness and promoted the adoption of social monogamy, which progressively increased cooperation as well as a dependence on tradition-based cultural transmission. These eventually facilitated the acquisition of language by elevating the reproductive advantage afforded those most sensitive to social cues.
Early hominids may have been weed species
Richard Meindl, Morgan Chaney & Owen Lovejoy
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
Panid, gorillid, and hominid social structures appear to have diverged as dramatically as did their locomotor patterns as they emerged from a late Miocene last common ancestor (LCA). Despite their elimination of the sectorial canine complex and adoption of bipedality with its attendant removal of their ready access to the arboreal canopy, Australopithecus was able to easily invade novel habitats after florescence from its likely ancestral genus, Ardipithecus sp. Other hominoids, unable to sustain sufficient population growth, began an inexorable decline, culminating in their restriction to modern refugia. Success similar to that of earliest hominids also characterizes several species of macaques, often termed "weed species." We here review their most salient demographic features and find that a key element is irregularly elevated female survival. It is reasonable to conclude that a similar feature characterized early hominids, most likely made possible by the adoption of social monogamy. Reduced female mortality is a more probable key to early hominid success than a reduction in birth space, which would have been physiologically more difficult.
The earliest modern humans outside Africa
Israel Hershkovitz et al.
Science, 26 January 2018, Pages 456-459
Abstract:
To date, the earliest modern human fossils found outside of Africa are dated to around 90,000 to 120,000 years ago at the Levantine sites of Skhul and Qafzeh. A maxilla and associated dentition recently discovered at Misliya Cave, Israel, was dated to 177,000 to 194,000 years ago, suggesting that members of the Homo sapiens clade left Africa earlier than previously thought. This finding changes our view on modern human dispersal and is consistent with recent genetic studies, which have posited the possibility of an earlier dispersal of Homo sapiens around 220,000 years ago. The Misliya maxilla is associated with full-fledged Levallois technology in the Levant, suggesting that the emergence of this technology is linked to the appearance of Homo sapiens in the region, as has been documented in Africa.
The evolution of modern human brain shape
Simon Neubauer, Jean-Jacques Hublin & Philipp Gunz
Science Advances, January 2018
Abstract:
Modern humans have large and globular brains that distinguish them from their extinct Homo relatives. The characteristic globularity develops during a prenatal and early postnatal period of rapid brain growth critical for neural wiring and cognitive development. However, it remains unknown when and how brain globularity evolved and how it relates to evolutionary brain size increase. On the basis of computed tomographic scans and geometric morphometric analyses, we analyzed endocranial casts of Homo sapiens fossils (N = 20) from different time periods. Our data show that, 300,000 years ago, brain size in early H. sapiens already fell within the range of present-day humans. Brain shape, however, evolved gradually within the H. sapiens lineage, reaching present-day human variation between about 100,000 and 35,000 years ago. This process started only after other key features of craniofacial morphology appeared modern and paralleled the emergence of behavioral modernity as seen from the archeological record. Our findings are consistent with important genetic changes affecting early brain development within the H. sapiens lineage since the origin of the species and before the transition to the Later Stone Age and the Upper Paleolithic that mark full behavioral modernity.
The genetic prehistory of the Baltic Sea region
Alissa Mittnik et al.
Nature Communications, January 2018
Abstract:
While the series of events that shaped the transition between foraging societies and food producers are well described for Central and Southern Europe, genetic evidence from Northern Europe surrounding the Baltic Sea is still sparse. Here, we report genome-wide DNA data from 38 ancient North Europeans ranging from ~9500 to 2200 years before present. Our analysis provides genetic evidence that hunter-gatherers settled Scandinavia via two routes. We reveal that the first Scandinavian farmers derive their ancestry from Anatolia 1000 years earlier than previously demonstrated. The range of Mesolithic Western hunter-gatherers extended to the east of the Baltic Sea, where these populations persisted without gene-flow from Central European farmers during the Early and Middle Neolithic. The arrival of steppe pastoralists in the Late Neolithic introduced a major shift in economy and mediated the spread of a new ancestry associated with the Corded Ware Complex in Northern Europe.
Ethnogenesis and Social Difference in the Andean Late Intermediate Period (AD 1100-1450): A Bioarchaeological Study of Cranial Modification in the Colca Valley, Peru
Matthew Velasco
Current Anthropology, February 2018, Pages 98-106
Abstract:
It has long been recognized that the Inka incorporated diverse peoples into their empire, but how these ethnic groups developed historically during the political upheaval of the preceding Late Intermediate Period (LIP; AD 1100-1450) is only now receiving commensurate attention. This study explores how changes in cranial modification, a correlate of embodied identity in the Andes, made possible new forms of political solidarity and social inequality in the late prehispanic Colca Valley. Bioarchaeological and radiometric data reveal a sharp rise in modification prevalence, from 39.2% (N = 97) during the early LIP (AD 1150-1300) to 73.7% (N = 114) during the late LIP (AD 1300-1450). Greater standardization of head-shaping practices echoes broader patterns of identity formation across the south-central highlands and may have provided a symbolic basis for the cooperation of elite groups during an era of intensive conflict. However, additional lines of archaeological and bioarchaeological data suggest that the formation of a more encompassing identity did not homogenize lived experiences. The symbolic boundaries enacted by head shaping intersected other forms of collective identity and likely contributed to growing social inequality prior to the period of Inka imperial expansion.