The genetic prehistory of human populations in Central America is largely unexplored leaving an i... more The genetic prehistory of human populations in Central America is largely unexplored leaving an important gap in our knowledge of the global expansion of humans. We report genome-wide ancient DNA data for a transect of twenty individuals from two Belize rock-shelters dating between 9,600-3,700 calibrated radiocarbon years before present (cal. BP). The oldest individuals (9,600-7,300 cal. BP) descend from an Early Holocene Native American lineage with only distant relatedness to present-day Mesoamericans, including Mayan-speaking populations. After ~5,600 cal. BP a previously unknown human dispersal from the south made a major demographic impact on the region, contributing more than 50% of the ancestry of all later individuals. This new ancestry derived from a source related to present-day Chibchan speakers living from Costa Rica to Colombia. Its arrival corresponds to the first clear evidence for forest clearing and maize horticulture in what later became the Maya region.
The Bladen Paleoindian and Archaic archaeological Project (BPAAP) is an ongoing research endeavor... more The Bladen Paleoindian and Archaic archaeological Project (BPAAP) is an ongoing research endeavor focused on excavations from two rock shelters in the Maya Mountains of southern Belize: Maya Hak Cab Pek, and Saki Tzul. Continued use of these rock shelters from the Late Pleistocene to the collapse of Mayan civilization has resulted in a unique perspective on biological variation in Mesoamerica during this this time. This study examines differential stress experiences in a small sample (n=16) of human skeletal remains dating between 8270 – 2265 years B.P. Here, we examine prevalence of non-specific indicators of stress (cribra orbitalia (CO) and porotic hyperostosis (PH)) in conjunction with aDNA to better understand stress differentials between individuals from different migratory waves and with different subsistence strategies. Of these, 12.5% have CO and 37.5% have PH; this higher incidence of PH is a result in keeping with other studies. Overall, few individuals exhibit stress indicators despite reflecting ~6000 years of ecological and social change. Despite the small sample size, these remains represent an important avenue for the exploration of differences in stress and diet in members of various haplogroups throughout the Holocene.
ObjectivesPorous lesions of the orbit (cribra orbitalia [CO]) and cranial vault (porotic hyperost... more ObjectivesPorous lesions of the orbit (cribra orbitalia [CO]) and cranial vault (porotic hyperostosis [PH]) are used as skeletal indicators of childhood stress. Because they are understudied in contemporary populations, their relationship to disease experience is poorly understood. This paper examines the relationship between length of childhood illness and CO/PH formation in a clinically documented sample. “Turning points,” which identify the window for lesion formation for CO/PH, are defined, implications for hidden heterogeneity in frailty are considered.MethodsData are from 333 (199 males; 134 females) pediatric postmortem computed tomography scans. Individuals died in New Mexico (2011–2019) and are 0.5 to 15.99 years (mean = 7.1). Length of illness was estimated using information from autopsy and field reports. Logistic regression was used to estimate predicted probabilities, odds ratios, and the temporal window for lesion formation.ResultsIllness, single bouts, or cumulative e...
Objectives: In previous work examining the etiology of cribra orbitalia (CO) and porotic hyperost... more Objectives: In previous work examining the etiology of cribra orbitalia (CO) and porotic hyperostosis (PH) in a contemporary juvenile mortality sample, we noted that males had higher odds of having CO lesions than females. Here, we examine potential reasons for this pattern in greater detail. Four non-mutually exclusive mechanisms could explain the observed sex differences: (1) sex-biased mortality; (2) sexual dimorphism in immune responses; (3) sexual dimorphism in bone turnover; or (4) sexual dimorphism in marrow conversion. Subjects and methods: The sample consists of postmortem computed tomography scans and autopsy reports, field reports, and limited medical records of 488 individuals from New Mexico (203 females; 285 males) aged between 0.5 and 15 years. We used Kaplan–Meier survival analysis, predicted probabilities, and odds ratios to test each mechanism. Results: Males do not have lower survival probabilities than females, and we find no indications of sex differences in imm...
Objectives: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs)... more Objectives: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs) classically associated with iron-deficiency anemia in bioarchaeological contexts. However, recent studies indicate a need to reassess the interpretation of PCLs. This study addresses the potential health correlates of PCLs in a contemporary sample by examining relationships between the known cause of death (COD) and PCL presence/absence. Methods: This study includes a sample of 461 juvenile individuals (6 months to 15 years of age) who underwent examination at the University of New Mexico's Office of the Medical Investigator between 2011 and 2019. The information available for each individual includes their sex, age at death, and their COD and manner of death. Results: Odds ratio of having CO (OR = 3.92, p < .01) or PH (OR = 2.86, p = .02) lesions are increased in individuals with respiratory infections. Individuals with heart conditions have increased odds of having CO (OR = 3.52, p = .03) lesions, but not PH. Conclusion: Individuals with respiratory infection are more likely to have CO and/or PH. CO appears to have a greater range of health correlates than PH does, as indicated by the heart condition results. However, individuals with congenital heart defects are at higher risk for respiratory infections, so bony alterations in cases of heart conditions may be due to respiratory illness. Since respiratory infection remains a leading cause of mortality today, CO and PH in bioarchaeological contexts should be considered as potential indicators of respiratory infections in the past. KEYWORDS cribra orbitalia, contemporary sample, etiology, porotic hyperostosis, postmortem computed tomography, respiratory infection, skeletal indicators of stress
Objectives: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs)... more Objectives: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs) classically associated with iron-deficiency anemia in bioarchaeological contexts. However, recent studies indicate a need to reassess the interpretation of PCLs. This study addresses the potential health correlates of PCLs in a contemporary sample by examining relationships between the known cause of death (COD) and PCL presence/absence. Methods: This study includes a sample of 461 juvenile individuals (6 months to 15 years of age) who underwent examination at the University of New Mexico's Office of the Medical Investigator between 2011 and 2019. The information available for each individual includes their sex, age at death, and their COD and manner of death. Results: Odds ratio of having CO (OR = 3.92, p < .01) or PH (OR = 2.86, p = .02) lesions are increased in individuals with respiratory infections. Individuals with heart conditions have increased odds of having CO (OR = 3.52, p = .03) lesions, but not PH. Conclusion: Individuals with respiratory infection are more likely to have CO and/or PH. CO appears to have a greater range of health correlates than PH does, as indicated by the heart condition results. However, individuals with congenital heart defects are at higher risk for respiratory infections, so bony alterations in cases of heart conditions may be due to respiratory illness. Since respiratory infection remains a leading cause of mortality today, CO and PH in bioarchaeological contexts should be considered as potential indicators of respiratory infections in the past. KEYWORDS cribra orbitalia, contemporary sample, etiology, porotic hyperostosis, postmortem computed tomography, respiratory infection, skeletal indicators of stress
During the Holocene, what is now the state of South Australia experienced a shift to a drier
clim... more During the Holocene, what is now the state of South Australia experienced a shift to a drier climate with more frequent droughts c. 4 ka. The ‘intensification model’ in Australian archaeology proposes that Aboriginal people adopted subsistence strategies that exploited resources with high processing costs, while the ‘risk minimization’ model posits that people adopted more flexible foraging strategies. The purpose of this study is to determine whether human groups in South Australia demonstrate evidence for intensification or risk minimisation in response to declining patch quality by examining bone properties of the upper limb in a Holocene skeletal sample from Roonka. Cross-sectional geometry of the humeri and radii was used to examine temporal trends of diaphyseal rigidity and bilateral asymmetry in both sexes. Women show a significant temporal increase in robusticity and rigidity of the upper limbs; men have similar measurements between time periods. Neither sex exhibits a difference in bilateral asymmetry of the humeri and radii over time. These results support risk minimisation at Roonka. In the late Holocene, it is possible that men hunted large game, while women had mixed foraging strategies that involved hunting small game, digging tubers, processing seeds, and collecting shellfish to mitigate high resource variance.
Objectives: The strengthening of the El Ni~ no Southern Oscillation (ENSO) in the mid-Holocene ca... more Objectives: The strengthening of the El Ni~ no Southern Oscillation (ENSO) in the mid-Holocene caused significant changes in climate, vegetation, and faunal assemblages in South Australia. The appearance of a light, flexible backed-artifact toolkit 4 kya has been interpreted as evidence for changes in foraging behavior in response to this event. Optimal foraging theory supports a risk minimization strategy for South Australian hunter-gatherers in which increased mobility was used to cope with effects of a dryer, unstable environment in the late Holocene. Whether this event caused changes in foraging mobility will be tested by examining lower limb external diaphyseal shape between pre-ENSO and post-ENSO skeletons from Roonka Flat, South Australia. Materials and Methods: Anteroposterior and mediolateral diameters were used to construct diaphyseal shape indices for Roonka Flat femora and tibiae. If populations living in South Australia became more mobile over time, then post-ENSO skeletons should exhibit higher shape indices. Results: The pooled-sex post-ENSO sample has significantly higher femoral shape indices than the pre-ENSO sample. Males do not show significant diaphyseal shape differences over time, but females significantly increase. Discussion: These data are consistent with the risk minimization model, indicating that South Australians became more mobile post-ENSO to better exploit a less productive environment by expanding their foraging radii. The temporal shift toward more elliptical diaphyses is more notable in females than males, which is consistent with Aboriginal ethnographies that show both sexes being intensely involved in hunting and capturing game animals.
The genetic prehistory of human populations in Central America is largely unexplored leaving an i... more The genetic prehistory of human populations in Central America is largely unexplored leaving an important gap in our knowledge of the global expansion of humans. We report genome-wide ancient DNA data for a transect of twenty individuals from two Belize rock-shelters dating between 9,600-3,700 calibrated radiocarbon years before present (cal. BP). The oldest individuals (9,600-7,300 cal. BP) descend from an Early Holocene Native American lineage with only distant relatedness to present-day Mesoamericans, including Mayan-speaking populations. After ~5,600 cal. BP a previously unknown human dispersal from the south made a major demographic impact on the region, contributing more than 50% of the ancestry of all later individuals. This new ancestry derived from a source related to present-day Chibchan speakers living from Costa Rica to Colombia. Its arrival corresponds to the first clear evidence for forest clearing and maize horticulture in what later became the Maya region.
The Bladen Paleoindian and Archaic archaeological Project (BPAAP) is an ongoing research endeavor... more The Bladen Paleoindian and Archaic archaeological Project (BPAAP) is an ongoing research endeavor focused on excavations from two rock shelters in the Maya Mountains of southern Belize: Maya Hak Cab Pek, and Saki Tzul. Continued use of these rock shelters from the Late Pleistocene to the collapse of Mayan civilization has resulted in a unique perspective on biological variation in Mesoamerica during this this time. This study examines differential stress experiences in a small sample (n=16) of human skeletal remains dating between 8270 – 2265 years B.P. Here, we examine prevalence of non-specific indicators of stress (cribra orbitalia (CO) and porotic hyperostosis (PH)) in conjunction with aDNA to better understand stress differentials between individuals from different migratory waves and with different subsistence strategies. Of these, 12.5% have CO and 37.5% have PH; this higher incidence of PH is a result in keeping with other studies. Overall, few individuals exhibit stress indicators despite reflecting ~6000 years of ecological and social change. Despite the small sample size, these remains represent an important avenue for the exploration of differences in stress and diet in members of various haplogroups throughout the Holocene.
ObjectivesPorous lesions of the orbit (cribra orbitalia [CO]) and cranial vault (porotic hyperost... more ObjectivesPorous lesions of the orbit (cribra orbitalia [CO]) and cranial vault (porotic hyperostosis [PH]) are used as skeletal indicators of childhood stress. Because they are understudied in contemporary populations, their relationship to disease experience is poorly understood. This paper examines the relationship between length of childhood illness and CO/PH formation in a clinically documented sample. “Turning points,” which identify the window for lesion formation for CO/PH, are defined, implications for hidden heterogeneity in frailty are considered.MethodsData are from 333 (199 males; 134 females) pediatric postmortem computed tomography scans. Individuals died in New Mexico (2011–2019) and are 0.5 to 15.99 years (mean = 7.1). Length of illness was estimated using information from autopsy and field reports. Logistic regression was used to estimate predicted probabilities, odds ratios, and the temporal window for lesion formation.ResultsIllness, single bouts, or cumulative e...
Objectives: In previous work examining the etiology of cribra orbitalia (CO) and porotic hyperost... more Objectives: In previous work examining the etiology of cribra orbitalia (CO) and porotic hyperostosis (PH) in a contemporary juvenile mortality sample, we noted that males had higher odds of having CO lesions than females. Here, we examine potential reasons for this pattern in greater detail. Four non-mutually exclusive mechanisms could explain the observed sex differences: (1) sex-biased mortality; (2) sexual dimorphism in immune responses; (3) sexual dimorphism in bone turnover; or (4) sexual dimorphism in marrow conversion. Subjects and methods: The sample consists of postmortem computed tomography scans and autopsy reports, field reports, and limited medical records of 488 individuals from New Mexico (203 females; 285 males) aged between 0.5 and 15 years. We used Kaplan–Meier survival analysis, predicted probabilities, and odds ratios to test each mechanism. Results: Males do not have lower survival probabilities than females, and we find no indications of sex differences in imm...
Objectives: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs)... more Objectives: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs) classically associated with iron-deficiency anemia in bioarchaeological contexts. However, recent studies indicate a need to reassess the interpretation of PCLs. This study addresses the potential health correlates of PCLs in a contemporary sample by examining relationships between the known cause of death (COD) and PCL presence/absence. Methods: This study includes a sample of 461 juvenile individuals (6 months to 15 years of age) who underwent examination at the University of New Mexico&#39;s Office of the Medical Investigator between 2011 and 2019. The information available for each individual includes their sex, age at death, and their COD and manner of death. Results: Odds ratio of having CO (OR = 3.92, p &lt; .01) or PH (OR = 2.86, p = .02) lesions are increased in individuals with respiratory infections. Individuals with heart conditions have increased odds of having CO (OR = 3.52, p = .03) lesions, but not PH. Conclusion: Individuals with respiratory infection are more likely to have CO and/or PH. CO appears to have a greater range of health correlates than PH does, as indicated by the heart condition results. However, individuals with congenital heart defects are at higher risk for respiratory infections, so bony alterations in cases of heart conditions may be due to respiratory illness. Since respiratory infection remains a leading cause of mortality today, CO and PH in bioarchaeological contexts should be considered as potential indicators of respiratory infections in the past. KEYWORDS cribra orbitalia, contemporary sample, etiology, porotic hyperostosis, postmortem computed tomography, respiratory infection, skeletal indicators of stress
Objectives: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs)... more Objectives: Cribra orbitalia (CO) and porotic hyperostosis (PH) are porous cranial lesions (PCLs) classically associated with iron-deficiency anemia in bioarchaeological contexts. However, recent studies indicate a need to reassess the interpretation of PCLs. This study addresses the potential health correlates of PCLs in a contemporary sample by examining relationships between the known cause of death (COD) and PCL presence/absence. Methods: This study includes a sample of 461 juvenile individuals (6 months to 15 years of age) who underwent examination at the University of New Mexico's Office of the Medical Investigator between 2011 and 2019. The information available for each individual includes their sex, age at death, and their COD and manner of death. Results: Odds ratio of having CO (OR = 3.92, p < .01) or PH (OR = 2.86, p = .02) lesions are increased in individuals with respiratory infections. Individuals with heart conditions have increased odds of having CO (OR = 3.52, p = .03) lesions, but not PH. Conclusion: Individuals with respiratory infection are more likely to have CO and/or PH. CO appears to have a greater range of health correlates than PH does, as indicated by the heart condition results. However, individuals with congenital heart defects are at higher risk for respiratory infections, so bony alterations in cases of heart conditions may be due to respiratory illness. Since respiratory infection remains a leading cause of mortality today, CO and PH in bioarchaeological contexts should be considered as potential indicators of respiratory infections in the past. KEYWORDS cribra orbitalia, contemporary sample, etiology, porotic hyperostosis, postmortem computed tomography, respiratory infection, skeletal indicators of stress
During the Holocene, what is now the state of South Australia experienced a shift to a drier
clim... more During the Holocene, what is now the state of South Australia experienced a shift to a drier climate with more frequent droughts c. 4 ka. The ‘intensification model’ in Australian archaeology proposes that Aboriginal people adopted subsistence strategies that exploited resources with high processing costs, while the ‘risk minimization’ model posits that people adopted more flexible foraging strategies. The purpose of this study is to determine whether human groups in South Australia demonstrate evidence for intensification or risk minimisation in response to declining patch quality by examining bone properties of the upper limb in a Holocene skeletal sample from Roonka. Cross-sectional geometry of the humeri and radii was used to examine temporal trends of diaphyseal rigidity and bilateral asymmetry in both sexes. Women show a significant temporal increase in robusticity and rigidity of the upper limbs; men have similar measurements between time periods. Neither sex exhibits a difference in bilateral asymmetry of the humeri and radii over time. These results support risk minimisation at Roonka. In the late Holocene, it is possible that men hunted large game, while women had mixed foraging strategies that involved hunting small game, digging tubers, processing seeds, and collecting shellfish to mitigate high resource variance.
Objectives: The strengthening of the El Ni~ no Southern Oscillation (ENSO) in the mid-Holocene ca... more Objectives: The strengthening of the El Ni~ no Southern Oscillation (ENSO) in the mid-Holocene caused significant changes in climate, vegetation, and faunal assemblages in South Australia. The appearance of a light, flexible backed-artifact toolkit 4 kya has been interpreted as evidence for changes in foraging behavior in response to this event. Optimal foraging theory supports a risk minimization strategy for South Australian hunter-gatherers in which increased mobility was used to cope with effects of a dryer, unstable environment in the late Holocene. Whether this event caused changes in foraging mobility will be tested by examining lower limb external diaphyseal shape between pre-ENSO and post-ENSO skeletons from Roonka Flat, South Australia. Materials and Methods: Anteroposterior and mediolateral diameters were used to construct diaphyseal shape indices for Roonka Flat femora and tibiae. If populations living in South Australia became more mobile over time, then post-ENSO skeletons should exhibit higher shape indices. Results: The pooled-sex post-ENSO sample has significantly higher femoral shape indices than the pre-ENSO sample. Males do not show significant diaphyseal shape differences over time, but females significantly increase. Discussion: These data are consistent with the risk minimization model, indicating that South Australians became more mobile post-ENSO to better exploit a less productive environment by expanding their foraging radii. The temporal shift toward more elliptical diaphyses is more notable in females than males, which is consistent with Aboriginal ethnographies that show both sexes being intensely involved in hunting and capturing game animals.
Uploads
Papers by Ethan C Hill
PCL presence/absence.
Methods: This study includes a sample of 461 juvenile individuals (6 months to
15 years of age) who underwent examination at the University of New Mexico's Office of the Medical Investigator between 2011 and 2019. The information available for each individual includes their sex, age at death, and their COD and manner of death.
Results: Odds ratio of having CO (OR = 3.92, p < .01) or PH (OR = 2.86, p = .02)
lesions are increased in individuals with respiratory infections. Individuals with heart conditions have increased odds of having CO (OR = 3.52, p = .03) lesions, but not PH.
Conclusion: Individuals with respiratory infection are more likely to have CO and/or PH. CO appears to have a greater range of health correlates than PH does, as indicated by the heart condition results. However, individuals with congenital heart defects are at higher risk for respiratory infections, so bony alterations in cases of heart conditions may be due to respiratory illness. Since respiratory infection remains a leading cause of mortality today, CO and PH in bioarchaeological contexts should be considered as potential indicators of respiratory infections in the past.
KEYWORDS
cribra orbitalia, contemporary sample, etiology, porotic hyperostosis, postmortem computed tomography, respiratory infection, skeletal indicators of stress
climate with more frequent droughts c. 4 ka. The ‘intensification model’ in Australian archaeology
proposes that Aboriginal people adopted subsistence strategies that exploited resources
with high processing costs, while the ‘risk minimization’ model posits that people
adopted more flexible foraging strategies. The purpose of this study is to determine whether
human groups in South Australia demonstrate evidence for intensification or risk minimisation
in response to declining patch quality by examining bone properties of the upper limb
in a Holocene skeletal sample from Roonka. Cross-sectional geometry of the humeri and
radii was used to examine temporal trends of diaphyseal rigidity and bilateral asymmetry in
both sexes. Women show a significant temporal increase in robusticity and rigidity of the
upper limbs; men have similar measurements between time periods. Neither sex exhibits a
difference in bilateral asymmetry of the humeri and radii over time. These results support
risk minimisation at Roonka. In the late Holocene, it is possible that men hunted large
game, while women had mixed foraging strategies that involved hunting small game, digging
tubers, processing seeds, and collecting shellfish to mitigate high resource variance.
PCL presence/absence.
Methods: This study includes a sample of 461 juvenile individuals (6 months to
15 years of age) who underwent examination at the University of New Mexico's Office of the Medical Investigator between 2011 and 2019. The information available for each individual includes their sex, age at death, and their COD and manner of death.
Results: Odds ratio of having CO (OR = 3.92, p < .01) or PH (OR = 2.86, p = .02)
lesions are increased in individuals with respiratory infections. Individuals with heart conditions have increased odds of having CO (OR = 3.52, p = .03) lesions, but not PH.
Conclusion: Individuals with respiratory infection are more likely to have CO and/or PH. CO appears to have a greater range of health correlates than PH does, as indicated by the heart condition results. However, individuals with congenital heart defects are at higher risk for respiratory infections, so bony alterations in cases of heart conditions may be due to respiratory illness. Since respiratory infection remains a leading cause of mortality today, CO and PH in bioarchaeological contexts should be considered as potential indicators of respiratory infections in the past.
KEYWORDS
cribra orbitalia, contemporary sample, etiology, porotic hyperostosis, postmortem computed tomography, respiratory infection, skeletal indicators of stress
climate with more frequent droughts c. 4 ka. The ‘intensification model’ in Australian archaeology
proposes that Aboriginal people adopted subsistence strategies that exploited resources
with high processing costs, while the ‘risk minimization’ model posits that people
adopted more flexible foraging strategies. The purpose of this study is to determine whether
human groups in South Australia demonstrate evidence for intensification or risk minimisation
in response to declining patch quality by examining bone properties of the upper limb
in a Holocene skeletal sample from Roonka. Cross-sectional geometry of the humeri and
radii was used to examine temporal trends of diaphyseal rigidity and bilateral asymmetry in
both sexes. Women show a significant temporal increase in robusticity and rigidity of the
upper limbs; men have similar measurements between time periods. Neither sex exhibits a
difference in bilateral asymmetry of the humeri and radii over time. These results support
risk minimisation at Roonka. In the late Holocene, it is possible that men hunted large
game, while women had mixed foraging strategies that involved hunting small game, digging
tubers, processing seeds, and collecting shellfish to mitigate high resource variance.