Traces of Civilization
The Economic Origins of Government
Robert Allen, Mattia Bertazzini & Leander Heldring
American Economic Review, October 2023, Pages 2507-2545
Abstract:
We test between cooperative and extractive theories of the origins of government. We use river shifts in southern Iraq as a natural experiment, in a new archeological panel dataset. A shift away creates a local demand for a government to coordinate because private river irrigation needs to be replaced with public canals. It disincentivizes local extraction as land is no longer productive without irrigation. Consistent with a cooperative theory of government, a river shift away led to state formation, canal construction, and the payment of tribute. We argue that the first governments coordinated between extended households which implemented public good provision.
The political economy of imperial power successions in ancient China
Yaguang Zhang, Sitian Yu & Shengyi Zhang
Public Choice, October 2023, Pages 137–166
Abstract:
This paper studies the succession of power between emperor and crown prince in imperial China as a political game. We begin by developing a model of the succession game that defines the probability of a crown prince being deposed as a function of the strength of the ruling emperor. The model predicts an inverted U-shaped relationship between the probability of crown prince-deposition and the strength of the ruler. We then test the model’s implication against the historical evidence. We find that from the Western Han Dynasty to the Ming Dynasty (206 BC–1644 AD), the power of crown princes first increased, then fluctuated and finally decreased. This trend was linearly correlated to changes in relative imperial power.
The evolution of same-sex sexual behaviour in mammals
José Gómez, Adela Gónzalez-Megías & Miguel Verdú
Nature Communications, October 2023
Abstract:
Same-sex sexual behaviour has attracted the attention of many scientists working in disparate areas, from sociology and psychology to behavioural and evolutionary biology. Since it does not contribute directly to reproduction, same-sex sexual behaviour is considered an evolutionary conundrum. Here, using phylogenetic analyses, we explore the evolution of same-sex sexual behaviour in mammals. According to currently available data, this behaviour is not randomly distributed across mammal lineages, but tends to be particularly prevalent in some clades, especially primates. Ancestral reconstruction suggests that same-sex sexual behaviour may have evolved multiple times, with its appearance being a recent phenomenon in most mammalian lineages. Our phylogenetically informed analyses testing for associations between same-sex sexual behaviour and other species characteristics suggest that it may play an adaptive role in maintaining social relationships and mitigating conflict.
Independent age estimates resolve the controversy of ancient human footprints at White Sands
Jeffrey Pigati et al.
Science, 6 October 2023, Pages 73-75
Abstract:
Human footprints at White Sands National Park, New Mexico, USA, reportedly date to between ~23,000 and 21,000 years ago according to radiocarbon dating of seeds from the aquatic plant Ruppia cirrhosa. These ages remain controversial because of potential old carbon reservoir effects that could compromise their accuracy. We present new calibrated 14C ages of terrestrial pollen collected from the same stratigraphic horizons as those of the Ruppia seeds, along with optically stimulated luminescence ages of sediments from within the human footprint–bearing sequence, to evaluate the veracity of the seed ages. The results show that the chronologic framework originally established for the White Sands footprints is robust and reaffirm that humans were present in North America during the Last Glacial Maximum.
Abu Hureyra, Syria, Part 3: Comet airbursts triggered major climate change 12,800 years ago that initiated the transition to agriculture
Andrew Moore et al.
Airbursts and Cratering Impacts, September 2023
Abstract:
This study investigates the hypothesis that Earth collided with fragments of a disintegrating comet, triggering Younger Dryas climate change 12,800 years ago. This collision created environmental conditions at Abu Hureyra, Syria, that favored the earliest known continuous cultivation of domestic-type grains and legumes, along with animal management, adding to the pre-existing practice of hunting-and-gathering. The proposed airburst coincided with a significant decline in local populations and led to architectural reorganizations of the village. These events immediately followed the deposition of the Younger Dryas Boundary layer that contains peak concentrations of high-temperature meltglass, nanodiamonds, platinum, and iridium. These proxies provide evidence of a nearby low-altitude airburst by a comet-like fragment of a former Centaur, one of many <300-km-wide bodies in unstable orbits between the giant planets. This large body is proposed to have undergone cascading disintegrations, thus producing the Taurid Complex containing Comet Encke and ~90 asteroids with diameters of ~1.5 to 5 km. Here, we present substantial new quantitative evidence and interpretations supporting the hypothesis that comet fragments triggered near-global shifts in climate ~12,800 years ago, and one airburst destroyed the Abu Hureyra village. This evidence implies a causative link between extraterrestrial airbursts, environmental change, and transformative shifts in human societies.
More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia
Vinicius Peripato et al.
Science, 6 October 2023, Pages 103-109
Abstract:
Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.
Human occupations of upland and cold environments in inland Spain during the Last Glacial Maximum and Heinrich Stadial 1: The new Magdalenian sequence of Charco Verde II
Javier Aragoncillo-del Río et al.
PLoS ONE, October 2023
Abstract:
The settlement of cold and arid environments by Pleistocene hunter-gatherers has been a heated topic in Paleolithic Archaeology and the Quaternary Sciences for years. In the Iberian Peninsula, a key area for studying human adaptations to such environments is composed by the large interior and upland regions of the northern and southern plateaus (Mesetas) and bordering areas. As, traditionally, these regions have been relatively under-investigated compared to the ecologically more favored coastal areas of the peninsula, our knowledge of the human settlement of the whole Iberian hinterland remains scarce for the Last Glacial. In this paper we present the discovery and first geoarcheological, paleoenvironmental and chronometric evidence obtained at Charco Verde II, a new site close to the southwestern foothills of the Iberian system range (Guadalajara province, Spain), bearing a sequence of Magdalenian human occupations starting at least at 20.8–21.4 ka cal BP during the Last Glacial Maximum, and covering Greenland Stadial 2 until ∼15.1–16.6 ka cal BP, including Heinrich stadial 1. As this site is located in an upland region which today faces one of the harshest climates in Iberia, such occupation sequence, occurred during some of the coldest and most arid phases of the Last Glacial, has relevant implications for our understanding of human-environment-climate interactions and population dynamics in Iberia and Western Europe. These findings support the hypothesis that the Iberian hinterland was not avoided by Upper Paleolithic hunter-gatherers due to ecological constraints, but it hosted a complex and relatively dense settlement at least in some areas, even during cold periods. This suggest, one more time, that the historical scarcity of Upper Paleolithic sites in inland Iberia is, to a significant extent, an artifact of research bias.
Evidence for a large late-Holocene Strewn Field in Kiowa County, Kansas, USA
Kenneth Barnett Tankersley et al.
Airbursts and Cratering Impacts, October 2023
Abstract:
The Brenham/Haviland meteor crater is just one of a plethora of impact features comprising a large (~800 ha) late-Holocene-age strewn field in Kiowa County, Kansas. More than 10,000 kg of pallasites, a rare class of stony meteorites, have been recovered from impact features and the surface of the strewn field. Six AMS radiocarbon ages demonstrate there is a 95.4% probability that the impact event occurred within a range of 1497 BCE to 419 BCE and most likely between 754 BCE and 419 BCE. The impact event is well described in Pawnee oral histories and illustrated in petroglyphs near the strewn field. The age and geographic extent of the Kiowa County, Kansas, strewn field increases our understanding of the frequency of cosmic impact events on Earth and their influence on people and culture change.