Serpentine Hot Springs,Alaska: results of excavations and implications for the age and significance of northern fluted points

The dispersal of Homo sapiens across the New World is one of the greatest chapters in the history of our species; however, major questions about this late Pleistocene diaspora remain unanswered. Two contentious issues are the timing of colonization of the Bering Land Bridge and origin of Clovis, which at 13,000 calendar years ago is the earliest unequivocal complex of archaeological sites in temperate North America, known by its specialized fluted spear points. One hypothesis is that fluting technology emerged in Beringia and from there was carried southbound, with fluted points becoming the diagnostic “calling card” of early Paleoindians spreading across the Western Hemisphere. Fluted points have long been known from Alaska, yet until now they have never been found in a datable geologic context, making their relationship to Clovis a mystery. Here we show that a new archaeological site at Serpentine Hot Springs, Bering Land Bridge National Preserve, Alaska, contains fluted points in a stratified geologic deposit dating to no earlier than 12,400 calendar years ago. Our results suggest that Alaska's fluted-point complex is too young to be ancestral to Clovis, and that it instead represents either a south-to-north dispersal of early Americans or transmission of fluting technology from temperate North America. These results suggest that the peopling of the Americas and development of Paleoindian technology were much more complex than traditional models predict.     

Production Skill and Paleoindian Workgroup Organization in the Medicine Creek Drainage,Southwestern Nebraska

Extremely skillful stoneworking is widely cited as an important characteristic of the Paleoindian period in North America. This paper considers differences in finished and unfinished projectile points and bifaces from two Paleoindian sites in the Medicine Creek drainage of southwestern Nebraska with this in mind, arguing that these differences reflect significant differences in the overall level of skill of the stoneworkers who used these sites. Recognizing variability in Paleoindian flintknapping skill has implications for the organization of landuse in the Medicine Creek region and for our understanding of the archaeology of the Paleoindian period in general.     

Pattern or bias? A critical evaluation of Midwestern fluted point distributions using raster based GIS

Because the abundance and distribution of fluted points has long played a critical role in interpreting various colonization and settlement scenarios of North America, correlations made between fluted point distribution and patterns of Early Paleoindian land use need to be critically evaluated. Gauging not just the source, but also nature of bias within distributional data of this sort is important if we are to improve the accuracy and reliability of our inferences concerning the timing, source, and mode of the radiation of human populations throughout the western Hemisphere. In this study, I employ a raster based GIS approach using a continuous non-site distribution of fluted biface distributions across a twenty-nine county (46,000 km²) study area of northern Illinois. The results suggest that when sources of bias are revealed and controlled for, significant settlement patterning can not only be identified, but more accurately interpreted.     

The diversity of North American projectile-point types,before and after the bow and arrow

Mimicking paleobiological studies of biodiversity, changes in the diversity of temporal types of North American projectile points are modeled to reveal evolutionary patterns of origination and extinction. Origination is modeled as rapid innovation of multiple point types (high diversity), and extinction is modeled as gradual winnowing of less-efficient types. Introduction of the bow and arrow as a new weapon-delivery system is modeled as an increase in point diversity. Six sequences of points (dart + arrow), six sequences of dart points, and six sequences of arrow points from western North America best match the model when the number of time periods ?5 and the number of types is >3.     

Pre-pottery farmers on the Pacific coast of southern Mexico

Large island-like shell mounds along the southern coast of Mexico are the earliest known archaeological sites on the Pacific margin of Mesoamerica. These aceramic deposits date to between 7500 and 3800 cal BP and have been interpreted as locations where foragers, living elsewhere seasonally on the coastal plain, harvested shellfish and other estuarine resources. Based on an accumulation of paleoecological data from elsewhere in the lowland Neotropics of Mesoamerica, southern Central America and South America we pose and provide a first test of an alternative subsistence model: that the Archaic Period populations in this area were slash and burn farmers. Burned maize phytoliths first appear in these sedimentary records at 6500 cal BP in association with macroscopic charcoal and forest disturbance plant taxa. Periodic burning and forest disturbance, consistent with farming activities, are also evident in the macroscopic charcoal record between 6500 and 4700 cal BP. Pollen, phytolith and charcoal records all point to sustained burning, forest disturbance and the cultivation of maize between 4700 and 3800 cal BP. These data suggest that people were slash and burn farming during the Archaic Period prior to the adoption of pottery and the proliferation of Early Formative Period villages and full-fledged agriculture based on near or total reliance on crop plants after ∼3800 cal BP.     

Holocene paleoshorelines,water levels and submerged prehistoric site potential of Rice Lake (Ontario,Canada)

Rice Lake, located in the eastern Great Lakes of North America, has a high density of prehistoric (11–0.5 ka BP) terrestrial archaeological sites. It has been speculated that a large number of sites are submerged on the lakebed, as lake levels have risen >9 m since the arrival of Early Paleoindian peoples (∼11 ka BP). In order to better understand the submerged landscape and its archaeological potential, a detailed bathymetric survey and sediment-coring program was conducted across a 30-km² area of northeastern Rice Lake. Changes in Holocene water levels and shoreline positions were reconstructed by integrating core data with a digital elevation and bathymetric model (DEBM) that accounted for differential isostatic uplift and basin sedimentation. The DEBM was used to generate a series of maps showing changes in the lake paleobathmetry and paleogeography and areas of prehistoric archaeological potential.     

Projectile points,people, and Plains Paleoindian perambulations

Archaeologists generally agree that Paleoindian residential groups moved regularly over extremely large ranges. However, on the Great Plains, this argument depends substantially on datasets derived largely or entirely from projectile points rather than from systematic analysis of a wide range of artifacts. This paper argues that projectile points differ from most Paleoindian tools in ways that make such datasets unlikely to be reliable sources of information on range sizes. Furthermore, evidence from Paleoindian tool caches and the condition of discarded points suggest strongly that the raw material used to produce projectile points at least sometimes moved across the Plains independently of material used to make most other kinds of flaked stone tools. This, in turn, implies that not all stone used during Paleoindian times was procured by visits of whole residential groups to raw material sources, raising serious questions about the validity of widespread views of Paleoindian mobility.     

The origins of lithic projectile point technology: evidence from Africa,the Levant,and Europe

Projectile weaponry is a human cultural universal, but its origins and antiquity remain poorly understood. Stone- and bone-tipped projectile weapons have long been treated as emergent features of the "Upper Paleolithic" behavioral revolution. Recently it has been proposed that projectile technology was in widespread use among Homo sapiens populations in Africa during Middle Stone Age (MSA) times. One obstacle to researching the origins of projectile point technology is that the criteria archaeologists employ for recognizing plausible and implausible stone projectile points are largely subjective (overall tool shape, microwear traces). Tip cross-sectional area (TCSA) is a ballistically significant dimension that works well at discriminating North American stone projectile points (spearthrower dart tips and arrowheads) from spear points. This paper compares the TCSA values of ethnographic North American stone projectile points to hypothetical Middle and Upper Paleolithic stone projectile points from Africa, the Levant, and Europe. The results of this comparison do not support the hypothesis of widespread use of stone-tipped projectiles in Africa, the Levant, or Europe prior to 40 Ka. In the New World and in Australia, where we have the richest ethnographic record of stone projectile point use, these implements are largely employed in big-game hunting and in warfare. One or both of these factors may have played a role in the widespread adoption of stone projectile point technology after 40 Ka.     

AMS C dating of early human occupation of southern South America

The time of appearance of a persistent and demographically-viable hunter-gatherer population in late Pleistocene southern South America must be determined by evaluating evidence from as large as possible a sample of candidate archaeological sites in the region. We co-ordinated the AMS dating of multiple bone and charcoal samples from previously-excavated strata at the following sites: Arroyo Seco 2, Paso Otero 5, Piedra Museo, and Cueva Tres Tetas (all in Argentina), and Cueva del Lago Sofia 1 and Tres Arroyos (both in Chile). With one possible exception, we did not obtain new results to confirm earlier observations of pre-Clovis-age cultural activity at any of the sites considered in this study. The possible exception, Arroyo Seco 2, is considered in detail elsewhere [Politis G., Gutierrez M.A., Scabuzzo, C. (Eds), in press. Estado actual de las Investigaciones en el sitio 2 de Arroyo Seco (región pampeana, Argentina). Serie Monográfica INCUAPA 5. Olavarría]. However, our results for the samples which were the most preferred indicators of cultural events (hearth charcoal and cut-marked bone) confirm that people were in the southern cone of South America at or soon after 11,000 BP (13,000 cal BP). Considered alongside recent age estimates for the Clovis culture in North America, these results imply the contemporaneous emergence of a consistent and archaeologically-robust human occupation signal at widely-separated locations across the Western Hemisphere. Such findings suggest that Palaeoindian demic expansion may have involved more than one terminal Pleistocene dispersal episode.     

Flake scar patterns of Clovis points analyzed with a new digital morphometrics approach: evidence for direct transmission of technological knowledge across early North America

Clovis points are the principal diagnostic artifacts of a Clovis complex that spread across North America between ca. 11,050–10,800 radiocarbon years before present. Clovis may be the best documented Paleoamerican culture in North America, but much remains to be learned about the movement and interactions of Clovis peoples. Similarities among Clovis points from geographically diverse locations have led some researchers to suggest that a uniform projectile point technology existed across North America during Clovis times. Others have rejected this idea, proposing local and independent technological adaptations to different regional environments. To investigate these ideas, we used digital morphometrics to analyze 50 Clovis points from nine different contexts. First, 3D surface models of the points were created with a portable laser scanner. Next, these models were digitally cross-sectioned through both faces, yielding two-dimensional isoheight contours of flake scar patterns that reflect the original reduction techniques used to shape the projectile points. In the final step, the contours were transformed with elliptic Fourier analysis into Fourier coefficient series, and patterns of variation and symmetry were explored with principal components analysis. When compared to modern Clovis point replicas made by an expert knapper, the flake scar contours of the ancient Clovis points showed little morphological variation and a large degree of bifacial symmetry. Our results support the existence of a widespread standardized “Clovis” knapping technique, most likely transmitted through direct interaction between knappers from different groups.     

Spatiotemporal dynamics of the Clovis–Folsom transition

Despite the importance of the Clovis–Folsom transition for understanding the history of western North America, its spatiotemporal dynamics remains unclear. Here we report a three-part study in which we investigated the transition using radiocarbon dates from Clovis and Folsom sites. In the first part of the study, we used dates from Folsom site-phases to determine when and where Folsom originated. In the second part of the study, we employed Clovis and Folsom dates in analyses designed to determine whether Folsom spread via demic diffusion or cultural diffusion. In the third part of the study we investigated the velocity of the Clovis–Folsom transition. The analyses suggest that Folsom first appeared around 12,800 calBP in the northern High Plains and spread north and south from there. They also suggest that the spread of Folsom was, at least in part, the result of population expansion. In addition, the analyses indicate that the spread of Folsom was relatively fast for a prehistoric diffusion but well below the maximum velocity that has been estimated for such events. These findings, in turn, have implications for the hypotheses that have been put forward to explain the Clovis–Folsom transition. They refute the idea that the Clovis–Folsom transition resulted from an extraterrestrial impact over northern North America at 12,900 ± 100 calBP but are consistent with the alternative proposal that the transition was a response to climate-driven environmental change.     

Design Space and Cultural Transmission: Case Studies from Paleoindian Eastern North America

Tool design is a cultural trait—a term long used in anthropology as a unit of transmittable information that encodes particular behavioral characteristics of individuals or groups. After they are transmitted, cultural traits serve as units of replication in that they can be modified as part of a cultural repertoire through processes such as recombination, loss, or partial alteration. Artifacts and other components of the archaeological record serve as proxies for studying the transmission (and modification) of cultural traits, provided there is analytical clarity in defining and measuring whatever it is that is being transmitted. Our interest here is in tool design, and we illustrate how to create analytical units that allow us to map tool-design space and to begin to understand how that space was used at different points in time. We first introduce the concept of fitness landscape and impose a model of cultural learning over it, then turn to four methods that are useful for the analysis of design space: paradigmatic classification, phylogenetic analysis, distance graphs, and geometric morphometrics. Each method builds on the others in logical fashion, which allows creation of testable hypotheses concerning cultural transmission and the evolutionary processes that shape it, including invention (mutation), selection, and drift. For examples, we turn to several case studies that focus on Early Paleoindian–period projectile points from eastern North America, the earliest widespread and currently recognizable remains of hunter–gatherers in late Pleistocene North America.     

Evaluation of the Early Paleo-Indian zooarchaeological record as evidence of diet breadth

Early Paleo-Indians in North America are historically hypothesized to have been large-game specialists. Despite decades of research, Early Paleo-Indian diets are alternately portrayed as of either specialist or generalist. Though some suggest that these terms are not useful, debate over the nature of these diets continues. Authors who have studied Early Paleo-Indian archaeofaunas from North America have analyzed either a conservative dataset, consisting only of taxa whose remains meet criteria indicating they were part of Early Paleo-Indian diet, or a liberal dataset which includes all taxa regardless of the presence or absence of evidence that represented taxa were part of the diet. Camp sites are assumed to be more indicative of long-term, average Early Paleo-Indian diet, but single-event kill sites and multiple-event kill sites are included in analyses. Richness, evenness, and heterogeneity of mammalian taxa and of body size classes for conservative and liberal datasets show that many assemblages cannot be categorized as representing either specialist or generalist diets regardless of dataset used or diversity measure employed. Early Paleo-Indian diet breadth was diverse and in some cases more diverse than during the subsequent Archaic.     

The Peopling of the New World: Present Evidence, New Theories, and Future Directions

The prevailing archaeological consensus on Paleoindian origins and colonization of the Americas has been shaken by recent wide acknowledgment of pre-Clovis occupation at Monte Verde, Chile, and by claims that ostensibly non-Mongoloid skeletal remains might represent a precursor population. Recent mitochondrial DNA studies have been interpreted by some as indicating an earlier and more complex peopling of the continent. This paper reviews the current archaeological and biological evidence, in America and northern Asia, for the origins of Native Americans, assesses models of the colonization process in the light of new data and a revised chronology, and suggests avenues for future research.     

A Model for Paleoamerican Coastal Zone Preference for the Atlantic Slope of Eastern North America Since the Last Glacial Maximum

Paleoamerican colonization models have emphasized the importance of coastal zones for provisioning hunter gatherers with a diverse range of subsistence resources. This article expands on recent research by Lowery et al. 2012, and presents a model to explain the distribution of Clovis points across the Atlantic slope of Eastern North America. Marine transgression since the last glaciation has submerged large tracts of the Atlantic continental shelf. Global bathymetric data was used to estimate the Clovis age shoreline from Delaware to Florida. Clovis biface data for modern coastal areas, obtained from the Paleoindian database of the Americas, was compared to the slope of the paleo-shoreline to predict coastal zone preference. Results indicate a relationship between point distribution and coastal zone type. Areas where major rivers with high-quality tool-stone intersect broad coastal zones served important roles to Clovis subsistence adaptations. The potential exists for early Paleoamerican sites along the continental shelf submerged beneath 55–75 m of the Atlantic Ocean. Modern coastal regions with high densities of Clovis points may serve as analogues for identifying earlier sites that have been submerged as a result of marine transgression.     

Would North American Paleoindians have Noticed Younger Dryas Age Climate Changes?

Paleoindian groups occupied North America throughout the Younger Dryas Chronozone. It is often assumed that cooling temperatures during this interval, and the impact these would have had on biotic communities, posed significant adaptive challenges to those groups. That assessment of the nature, severity and abruptness of Younger Dryas changes is largely based on ice core records from the Greenland ice sheet where changes were indeed dramatic. This paper reviews climatic and environmental records from this time period in continental North America. We conclude that, on the Great Plains and in the Rocky Mountains, conditions were in reality less extreme. It therefore follows that conditions during the Younger Dryas interval may not have measurably added to the challenge routinely faced by Paleoindian groups who, during this interval, successfully (and perhaps rapidly) dispersed across the diverse habitats of Late Glacial North America.     

Variation in North American dart points and arrow points when one or both are present

The appearance of the bow and arrow in North America as a weapon-delivery system is predicted to have prompted an increase in variation among antecedent projectile points that tipped darts propelled by atlatls. Attributes of dart points are expected to display greater variation with the appearance of the bow as prehistoric artisans experimentally sought points that worked effectively as arrow points. Attributes of arrow points are predicted to also initially display much variation. Subsequent to the initial burst of variation, less-effective variants of attributes were winnowed out, causing a reduction in variation of attributes of both dart points and arrow points. Both coefficients of variation for individual attributes and summed coefficients of variation for multiple attributes of three sequences of projectile points from evolutionarily independent areas in North America confirm these predictions.     

Waterfowl and Lunate Crescents in Western North America: The Archaeology of the Pacific Flyway

California and Great Basin archaeologists have long discussed and debated the function of chipped stone crescents found in Terminal Pleistocene and Early Holocene sites in the Far West of North America. Because they are found over a vast area, in sites occupied over a period spanning at least 4,000 years (~12,000–8,000 cal BP), it may be that crescents were used for a variety of purposes. Here we focus on lunate crescents and their strong association with wetland localities (lakes, marshes, estuaries, and islands). We reconsider whether crescents could have been used as transverse projectile points to hunt waterfowl. We also assess the biogeographical legacies of migrating birds to propose that as many as four species of large anatids (tundra swan, greater white-fronted goose, snow goose, Ross’s goose) that now breed in the Canadian High Arctic once bred in the Great Basin and adjacent regions during the Late Pleistocene and Early Holocene. We propose that crescents were used primarily in the taking or processing of geese and swans, some of which may have bred and molted in what are now temperate latitudes. After the Laurentide ice sheet retreated, these four species established High Arctic breeding grounds and no longer bred in the Great Basin. In this scenario, the absence of some populations of molting geese and swans helps explain why crescents fell out of the archaeological record after ~8,000 cal. BP. When crescents were used, Native Americans in the Far West may have had access to millions of large waterfowl.     

Shifting stones and changing homes: using toolstone ratios to consider relative occupation span in the northwestern Great Basin

Like Paleoindian populations elsewhere in North America, Pre-Archaic groups in the Great Basin are assumed to have been highly mobile and far ranging. This view is commonly based on analyses of lithic technology and source provenance studies. While these approaches have added to our knowledge of Pre-Archaic lifeways, they have rarely focused on occupation span – an aspect of hunter–gatherer behavior directly related to mobility. Here, I use the proportions of local and nonlocal toolstone in Pre-Archaic and later Archaic assemblages to consider occupation span with the assumption that assemblages should become increasingly dominated by local materials as occupation span increases. The results suggest that residential mobility was high and occupations short before 7500 radiocarbon years ago. Conversely, between 7500 and 1300 radiocarbon years ago, residential mobility decreased and many locations were occupied for extended periods. Occupation span once again decreased as residential mobility increased after 1300 radiocarbon years ago. These trends were likely influenced by changes in the environmental and demographic climate of the Holocene.     

High-Tech Foragers? Folsom and Later Paleoindian Technology on the Great Plains

Archaeologists generally argue that early (ca. 11,000–8000 B.P. populations on the North American Great Plains moved over very large areas, relying on sophisticated, biface-based flaked stone technology and on extensive resharpening and recycling of tools to cope with unpredictable access to raw material sources. This paper reviews the development of this reconstruction and considers the degree to which data from assemblages of Paleoindian flaked stone tools support it. Published information implies that patterns of raw material use vary greatly over the Plains, that bifaces were not the centerpiece of Paleoindian technology, that there are no published efforts to document an unusual degree of resharpening or recycling, and that the data that are available on these topics do not suggest that either was important. Detailed analysis of one assemblage, from the Allen site in southwestern Nebraska, carried out with these issues in mind, shows similar patterns. The great difference between what the literature says about Paleoindian technology and the documented character of that technology suggests that Paleoindian lifeways were far more variable than current discussions suggest.