Robert S Walker
Dados Biográficos
| ID | 74203 |
|---|---|
| NOME | Robert S Walker |
| PRENOMES | Robert S |
| SOBRENOME | Walker |
| ASSINATURA | WALKER R S |
| AFILIAÇÕES | University of Missouri |
| ORCID | 0000-0002-1853-4137 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 49 |
| TOTAL DE CITAÇÕES | 348 |
| TOTAL COMO AUTOR | 49 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1987 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2025 |
| ÍNDICE H | 10 |
North American Clovis Point Form and Performance VI
What can lithics tell us about hominin technology's ‘primordial soup’? An origin of stone knapping via the emulation of Mother Nature
The use of stone hammers to produce sharp stone flakes—knapping—is thought to represent a significant stage in hominin technological evolution because it facilitated the exploitation of novel resources, including meat obtained from medium‐to‐large‐sized vertebrates. The invention of knapping may have occurred via an additive (i.e., cumulative) process that combined several innovative stages. Here, we propose that one of these stages was the homin…
Rapoport’s rule and the biogeography of cultural diversity across North America over 13,000 years
A New Method for Classifying Dart and Arrow Projectile Points
A long-standing classification problem in archaeology is determining the type of weapon delivery system used by people in the past. This is usually done by comparing archaeological points to known dart and arrow points from the ethnographic and archaeological record. There are no simple criteria to discriminate between these two states and the challenge is to identify a subset of traits and their interactions to solve this problem. Here we introd…
Iban Kinship and Cooperation
Elliptical Fourier analysis of bullet ricochet impact site plan-view shape in concrete
Bullet ricochets often leave impact sites that can be useful for shooting incident reconstruction. Here, we assess the proposal that these sites can potentially provide information about the design and composition of the projectile and possibly the corresponding firearm. We produced impact sites in concrete from five bullet types fired at two distances, for a total of 10 experimental conditions. Then, using elliptical Fourier analysis, we assesse…
North American Clovis Point Form and Performance V
This study is an assessment of Clovis spear thrusting penetration depth and entry wound size. This work is the fifth contribution in a series of experiments aimed at shedding light on the functional performance of distinct Clovis point forms. Here, using highly controlled and standardized procedures, we had a participant who had previously trained with bayonets and hand-to-hand combat thrust seven spears, each tipped with a distinct Clovis point …
The gravity of Paleolithic hunting
Topographic relief likely played a role in Stone Age hunting. • Hunters may have been able to hunt from on high. • We experimentally assessed the interaction of projectiles with launch height. • As launch height increased, javelin velocity and kinetic energy increased. • Atlatl dart velocity and kinetic energy did not. Topographic relief potentially played an important role in Stone Age hunting from the Middle Paleolithic onwards. Natural physica…
Comparing Clovis and Folsom fluting via scaling analysis
This study examines the fluting of two well‐known Late Pleistocene fluted point types in North America: Clovis and Folsom. Using scaling analyses, we assess the changing relationship between flute length and point length in a large sample of each type. Researchers use scaling to investigate the physical constraints of an object and determine how its dimensions change with size. We compare the strength and consistency of the scaling relationships …
Mapping lateral stratigraphy at Palaeolithic surface sites
Open-air accumulations of chipped stone debris are a common feature in arid landscapes, yet despite their prevalence, such archives are often dismissed as uninformative or unreliable. In the canyonlands of Dhofar, southern Oman, lithic surface scatters are nearly ubiquitous, including extensive, multi-component workshops associated with chert outcrops. These sites typically display chronologically diagnostic features that correspond to distinct t…
Bullet ricochet mark plan-view morphology in concrete
Bullet ricochet impact sites can help with shooting incident reconstruction.A random forest machine learning algorithm classified bullet type from ricochet morphology.Results suggest that unknown bullets can potentially be determined from ricochet impact site morphology.Human identification of bullet types from ricochet sites may be erroneous
Clovis bone versus stone weapon tip penetration
Comparison of four ballistic and thrusting target materials
Researchers use a variety of target materials, and sometimes combinations of materials, in their archaeological experiments to examine thrust‐spear or projectile penetration, impact angle, durability, and other issues involving prehistoric hunting weaponry. This variety of target materials is beneficial to archaeological science in several ways, but it may also hinder the comparison of results because many of these target materials do not necessa…
Experimental assessment of lanceolate projectile point and haft robustness
North American Clovis Point Form and Performance III
This study is an experimental assessment of Clovis knife use. This work is the third contribution in a series of experiments aimed at shedding light on the functional performance of distinct Clovis “point” forms. Here, we used seven replica Clovis point forms, representing the average and extremes of observed Clovis form, in two cutting tasks: rope cutting and clay cutting. Statistical comparison of cutting time, our measure of cutting efficiency…
Another tool in the experimental toolbox
Experimental archaeology continues to mature methodologically and theoretically. Around the world, practitioners are increasingly using modern materials that would have been unavailable to prehistoric people in archaeological experiments. The use of a modern material substitute can offer several benefits to experimental method, design, control, replicability, feasibility, and cost, but it should be directly compared to its “traditional” analogue …
Knapping quality of local versus exotic Upper Mercer chert (Ohio, USA) during the Holocene
Stone that fractured conchoidally was an important resource for prehistoric hunter‐gatherers. In recent years, archaeologists have come to realize that rather than defining stone “quality” simply and implicitly as “high” or “low,” a stone's quality can be best defined in several different explicit and often quantitative ways involving production, function, or social benefits. Here, we examine the stone quality—defined as “fracture predictability”…
Experimental assessment of obsidian versus chert lanceolate projectile point durability and robusticity
Stone‐tipped weaponry was important for the survival of past peoples, and many functional and non‐functional factors likely influenced their design. Two functional factors that past peoples likely considered in the design of their stone tips are durability (whether or not a stone tip breaks) and robusticity (how much damage is incurred upon breakage). Many factors have been shown experimentally to influence stone tip influence durability and robu…
North American Clovis Point Form and Performance
In Late Pleistocene North America colonizing hunter-gatherers knapped and used Clovis fluted projectile points. During their expansion the size and shape of Clovis points changed significantly. Archaeologists know that cultural drift contributed to this variation, but is it possible that this single source could alone generate so much variation so quickly? We present the first of several experimental studies exploring whether Clovis size and shap…
Spatiotemporal diversification of projectile point types in western North America over 13,000 years
Scaling the Size, Structure, and Dynamics of Residentially Mobile Hunter-Gatherer Camps
Short-term hunter-gatherer residential camps have been a central feature of human settlement patterns and social structure for most of human evolutionary history. Recent analyses of ethnohistoric hunter-gatherer data show that across different environments, the average size of hunter-gatherer bands is remarkably constant and that bands are commonly formed by a small number of coresident families. Using ethnoarchaeological data, we examine the rel…
Partible Paternity, the Secondary Sex Ratio, and a Possible Trivers-Willard Effect
Partible paternity, the belief that a child can have more than one biological father, is widespread in lowland South America. An analysis of demographic data sets from four lowland tribes (Aché, Barí, Ese Eja, and Surui) reveals a systematic variation in the sex ratios of live births with respect to the number of fathers to whom the births are attributed. Births attributed to only one father show a sex ratio that is unexceptional for South Americ…
Comparative study of reproductive skew and pair‐bond stability using genealogies from 80 small‐scale human societies
OBJECTIVES: Genealogies contain information on the prevalence of different sibling types that result from past reproductive behavior. Full sibling sets stem from stable monogamy, paternal half siblings primarily indicate male reproductive skew, and maternal half siblings reflect unstable pair bonds. METHODS: Full and half sibling types are calculated for a total of 61,181 siblings from published genealogies for 80 small-scale societies, including…
Return rates from intertidal foraging from Blombos Cave to Pinnacle Point
Co-father relationships among the Suruí (Paiter) of Brazil
Partible paternity refers to the conception belief that children can have multiple fathers (“co-fathers”) and is common to indigenous cultures of lowland South America. The nature of social relationships observed between co-fathers reveals information about the reproductive strategies underlying partible paternity. Here we analyze clan, genealogical, and social relationships between co-fathers for the Suruí, an indigenous horticultural population…
Age-dependency in hunting ability among the Ache of Eastern Paraguay
North American Clovis Point Form and Performance
In Late Pleistocene North America colonizing hunter-gatherers knapped and used Clovis fluted projectile points. During their expansion the size and shape of Clovis points changed significantly. Archaeologists know that cultural drift contributed to this variation, but is it possible that this single source could alone generate so much variation so quickly? We present the first of several experimental studies exploring whether Clovis size and shap…
The prey as patch model
Return rates from intertidal foraging from Blombos Cave to Pinnacle Point
Living with Kin in Lowland Horticultural Societies
Postmarital residence patterns in traditional human societies figure prominently in models of hominid social evolution with arguments for patrilocal human bands similar in structure to female-dispersal systems in other African apes. However, considerable flexibility in hunter-gatherer cultures has led to their characterization as primarily multilocal. Horticulturalists are associated with larger, more sedentary social groups with more political i…
Life-History Consequences of Density Dependence and the Evolution of Human Body Size
Previous attempts to explain variation in human growth and development emphasize the energetic constraints imposed by malnutrition and disease. However, this approach does not address the evolutionary effects of mortality risk on ontogenetic variation, a common theme in life-history studies. The conventional approach can be reconciled with life-history theory by considering the effect of mortality on the rates and timing of maturity in subsistenc…
Life in the slow lane revisited
This study investigates the evolution of human growth by analyzing differences in body mass growth trajectories among three populations: the Ache of eastern Paraguay, the US (NHANES, 1999–2000), and captive chimpanzees. The relative growth statistic “A” from the mammalian growth law is allowed to vary with age and proves useful for comparing growth across different ages, populations, and species. We demonstrate ontogenetic separation between chim…
Scaling the Size, Structure, and Dynamics of Residentially Mobile Hunter-Gatherer Camps
Short-term hunter-gatherer residential camps have been a central feature of human settlement patterns and social structure for most of human evolutionary history. Recent analyses of ethnohistoric hunter-gatherer data show that across different environments, the average size of hunter-gatherer bands is remarkably constant and that bands are commonly formed by a small number of coresident families. Using ethnoarchaeological data, we examine the rel…
Knapping quality of local versus exotic Upper Mercer chert (Ohio, USA) during the Holocene
Stone that fractured conchoidally was an important resource for prehistoric hunter‐gatherers. In recent years, archaeologists have come to realize that rather than defining stone “quality” simply and implicitly as “high” or “low,” a stone's quality can be best defined in several different explicit and often quantitative ways involving production, function, or social benefits. Here, we examine the stone quality—defined as “fracture predictability”…
Late Archaic Bison Hunters in Northern Colorado
Limited excavations at a Late Plains Archaic arroyo trap along the Cache la Poudre River near Windsor in northern Colorado have exposed the remains of an estimated 200 bison. The bonebed was uncovered during construction activities, which removed an estimated 4 m vf sediment from above tlie upper surface of the bone bed. Partial excavation of an 18.5 m2 cross-sectional portion of the arroyo has produced an assemblage of over 4000 bison bones. An …
North American Clovis Point Form and Performance III
This study is an experimental assessment of Clovis knife use. This work is the third contribution in a series of experiments aimed at shedding light on the functional performance of distinct Clovis “point” forms. Here, we used seven replica Clovis point forms, representing the average and extremes of observed Clovis form, in two cutting tasks: rope cutting and clay cutting. Statistical comparison of cutting time, our measure of cutting efficiency…
Relatedness, Co-residence, and Shared Fatherhood among Ache Foragers of Paraguay
Hypotheses on the benefits of the practice of partible paternity are tested using demographic data for Ache foragers of Paraguay. Partible paternity refers to the institution of multiple males considered to contribute to the conception of a single offspring. Analyses focus on patterns of primary and secondary co-fatherhood among men, genealogical relationships between co-fathers, and relation between band co-residence and co-fatherhood. Results i…
Evolution of brain size and juvenile periods in primates
Mapping lateral stratigraphy at Palaeolithic surface sites
Open-air accumulations of chipped stone debris are a common feature in arid landscapes, yet despite their prevalence, such archives are often dismissed as uninformative or unreliable. In the canyonlands of Dhofar, southern Oman, lithic surface scatters are nearly ubiquitous, including extensive, multi-component workshops associated with chert outcrops. These sites typically display chronologically diagnostic features that correspond to distinct t…
Another tool in the experimental toolbox
Experimental archaeology continues to mature methodologically and theoretically. Around the world, practitioners are increasingly using modern materials that would have been unavailable to prehistoric people in archaeological experiments. The use of a modern material substitute can offer several benefits to experimental method, design, control, replicability, feasibility, and cost, but it should be directly compared to its “traditional” analogue …
Experimental assessment of lanceolate projectile point and haft robustness
Experimental assessment of obsidian versus chert lanceolate projectile point durability and robusticity
Stone‐tipped weaponry was important for the survival of past peoples, and many functional and non‐functional factors likely influenced their design. Two functional factors that past peoples likely considered in the design of their stone tips are durability (whether or not a stone tip breaks) and robusticity (how much damage is incurred upon breakage). Many factors have been shown experimentally to influence stone tip influence durability and robu…
Clovis bone versus stone weapon tip penetration
Causes, Consequences, and Kin Bias of Human Group Fissions
Comparing Clovis and Folsom fluting via scaling analysis
This study examines the fluting of two well‐known Late Pleistocene fluted point types in North America: Clovis and Folsom. Using scaling analyses, we assess the changing relationship between flute length and point length in a large sample of each type. Researchers use scaling to investigate the physical constraints of an object and determine how its dimensions change with size. We compare the strength and consistency of the scaling relationships …
North American Clovis Point Form and Performance V
This study is an assessment of Clovis spear thrusting penetration depth and entry wound size. This work is the fifth contribution in a series of experiments aimed at shedding light on the functional performance of distinct Clovis point forms. Here, using highly controlled and standardized procedures, we had a participant who had previously trained with bayonets and hand-to-hand combat thrust seven spears, each tipped with a distinct Clovis point …
Partible Paternity, the Secondary Sex Ratio, and a Possible Trivers-Willard Effect
Partible paternity, the belief that a child can have more than one biological father, is widespread in lowland South America. An analysis of demographic data sets from four lowland tribes (Aché, Barí, Ese Eja, and Surui) reveals a systematic variation in the sex ratios of live births with respect to the number of fathers to whom the births are attributed. Births attributed to only one father show a sex ratio that is unexceptional for South Americ…
The gravity of Paleolithic hunting
Topographic relief likely played a role in Stone Age hunting. • Hunters may have been able to hunt from on high. • We experimentally assessed the interaction of projectiles with launch height. • As launch height increased, javelin velocity and kinetic energy increased. • Atlatl dart velocity and kinetic energy did not. Topographic relief potentially played an important role in Stone Age hunting from the Middle Paleolithic onwards. Natural physica…
Comparison of four ballistic and thrusting target materials
Researchers use a variety of target materials, and sometimes combinations of materials, in their archaeological experiments to examine thrust‐spear or projectile penetration, impact angle, durability, and other issues involving prehistoric hunting weaponry. This variety of target materials is beneficial to archaeological science in several ways, but it may also hinder the comparison of results because many of these target materials do not necessa…
Iban Kinship and Cooperation
A Guide to Post-Cranial Bones of East African Mammals
Conference Eve Plenary
The Sixteenth and Seventeenth Century Miniatures in the Collection of Her Majesty The Queen
Richard Walker; The Sixteenth and Seventeenth Century Miniatures in the Collection of Her Majesty The Queen, Journal of the History of Collections, Volume 12, I
Late Archaic Bison Hunters in Northern Colorado
Limited excavations at a Late Plains Archaic arroyo trap along the Cache la Poudre River near Windsor in northern Colorado have exposed the remains of an estimated 200 bison. The bonebed was uncovered during construction activities, which removed an estimated 4 m vf sediment from above tlie upper surface of the bone bed. Partial excavation of an 18.5 m2 cross-sectional portion of the arroyo has produced an assemblage of over 4000 bison bones. An …
Age-dependency in hunting ability among the Ache of Eastern Paraguay
Modeling growth and senescence in physical performance among the ache of eastern paraguay
This article seeks to partially fill a paucity of available data on physical performance in hunter–gatherer societies. Quantitative data are presented on various physical performance measures conducted on the Ache of eastern Paraguay, hunter–gatherers up to the 1970s and now part‐time foragers and horticulturists. The performance battery was conducted on most individuals over 10 years of age, allowing for cross‐sectional examination of growth and…
Methods in human growth research
The prey as patch model
Growth rates and life histories in twenty‐two small‐scale societies
This study investigates variation in body growth (cross‐sectional height and weight velocity) among a sample of 22 small‐scale societies. Considerable variation in growth exists among hunter‐gatherers that overlaps heavily with growth trajectories present in groups focusing more on horticulture. Intergroup variation tends to track environmental conditions, with societies under more favorable conditions displaying faster growth and earlier puberty…
Life in the slow lane revisited
This study investigates the evolution of human growth by analyzing differences in body mass growth trajectories among three populations: the Ache of eastern Paraguay, the US (NHANES, 1999–2000), and captive chimpanzees. The relative growth statistic “A” from the mammalian growth law is allowed to vary with age and proves useful for comparing growth across different ages, populations, and species. We demonstrate ontogenetic separation between chim…
The Cambridge Encyclopedia of Hunters and Gatherers . Richard B. Lee , Richard Daly
Evolution of brain size and juvenile periods in primates
Life-History Consequences of Density Dependence and the Evolution of Human Body Size
Previous attempts to explain variation in human growth and development emphasize the energetic constraints imposed by malnutrition and disease. However, this approach does not address the evolutionary effects of mortality risk on ontogenetic variation, a common theme in life-history studies. The conventional approach can be reconciled with life-history theory by considering the effect of mortality on the rates and timing of maturity in subsistenc…
Evolutionary History of Hunter-Gatherer Marriage Practices
BACKGROUND: The universality of marriage in human societies around the world suggests a deep evolutionary history of institutionalized pair-bonding that stems back at least to early modern humans. However, marriage practices vary considerably from culture to culture, ranging from strict prescriptions and arranged marriages in some societies to mostly unregulated courtship in others, presence to absence of brideservice and brideprice, and polyandr…
Correlates of Reticulation in Linguistic Phylogenies
This paper discusses phylogenetic reticulation using linguistic data from the Automated Similarity Judgment Program or ASJP (Holman et al., 2008; Wichmann et al., 2010a). It contributes methodologically to the examination of two measures of reticulation in distance-based phylogenetic data, specifically the δ score of Holland et al. (2002) and the more recent Q -residuals of Gray et al. (2010). It is shown that the δ score is a more adequate measu…
Body counts in lowland South American violence
Living with Kin in Lowland Horticultural Societies
Postmarital residence patterns in traditional human societies figure prominently in models of hominid social evolution with arguments for patrilocal human bands similar in structure to female-dispersal systems in other African apes. However, considerable flexibility in hunter-gatherer cultures has led to their characterization as primarily multilocal. Horticulturalists are associated with larger, more sedentary social groups with more political i…
Amazonian horticulturalists live in larger, more related groups than hunter–gatherers
Marrying kin in small‐scale societies
OBJECTIVES: Marriages among kin have the dual effect of both increasing average group relatedness as well as reducing the total number of kin by eliminating more genealogically and geographically distant individuals from kinship networks. Marriage decisions therefore face a tradeoff between density of kin, or formation of intensive kinship systems, and the diversity of kin, or extensive kinship systems. This article tests the hypothesis that exte…
Amazonian societies on the brink of extinction
Objectives: Greater Amazonia harbors as many as 100 locations of isolated indigenous peoples. Few options are available to assess the demographic health of these populations given their limited contact with the outside world. Remote sensing offers one option. Methods: An isolated village in Brazil near the Peruvian border is visible with Google Earth imagery from 2006. The area of the fields and village, as well as the living area of the four lon…
Causes, Consequences, and Kin Bias of Human Group Fissions
Relatedness, Co-residence, and Shared Fatherhood among Ache Foragers of Paraguay
Hypotheses on the benefits of the practice of partible paternity are tested using demographic data for Ache foragers of Paraguay. Partible paternity refers to the institution of multiple males considered to contribute to the conception of a single offspring. Analyses focus on patterns of primary and secondary co-fatherhood among men, genealogical relationships between co-fathers, and relation between band co-residence and co-fatherhood. Results i…
Human Residence Patterns
This essay addresses the significance and evidence surrounding the debate about how hunter‐gatherers and other humans organize their residential groups. In most species of mammals, either males or female remain in their natal group (the philopatric sex) while the other sex disperses at maturity (the dispersing sex). Sex‐biased philopatry and dispersal has many downstream effects on all aspects of social bonds and organization. Recent genetic data…
Co-father relationships among the Suruí (Paiter) of Brazil
Partible paternity refers to the conception belief that children can have multiple fathers (“co-fathers”) and is common to indigenous cultures of lowland South America. The nature of social relationships observed between co-fathers reveals information about the reproductive strategies underlying partible paternity. Here we analyze clan, genealogical, and social relationships between co-fathers for the Suruí, an indigenous horticultural population…
Comparative study of reproductive skew and pair‐bond stability using genealogies from 80 small‐scale human societies
OBJECTIVES: Genealogies contain information on the prevalence of different sibling types that result from past reproductive behavior. Full sibling sets stem from stable monogamy, paternal half siblings primarily indicate male reproductive skew, and maternal half siblings reflect unstable pair bonds. METHODS: Full and half sibling types are calculated for a total of 61,181 siblings from published genealogies for 80 small-scale societies, including…
Biology (23 obras) · Geography (22 obras) · Archaeology (21 obras) · Geology (19 obras) · Sociology (19 obras) · Pleistocene-Era Hominins and Archaeology (18 obras) · Ecology (16 obras) · Demography (15 obras) · Archaeology and ancient environmental studies (14 obras) · Evolutionary Psychology and Human Behavior (13 obras)