Department of Sociology & Anthropology

The estimation of human population size during the Pleistocene is complex, and one which has been dealt with extensively in the literature. However, because many of these previous estimations are based in part on archaeological site distributions, they are more a reflection of present-day geography than of what the Earth looked like in the past. We address this issue by calculating an estimation of habitable land area during the Last Glacial Maximum (between 22 and 19 kya) when sea level was 120 m lower than today using the polygon creation function in Google Earth. We then subtract areas of land that were likely uninhabitable during the LGM – either due to glacier cover, extreme aridity, elevation, or areas at high latitudes. From this, the combined habitable land areas of Eurasia, Africa and the Australian landmass are estimated as 76,959,712.4 km2. This estimation is then coupled with population density data for medium-to large-bodied carnivores, and ethnographic population density data for hunter–gatherers culled from the literature. Total human census population size in the Old World during the Last Glacial Maximum is estimated at 2,117,000–2,955,000 based on carnivore densities and 3,046,000–8,307,000 for hunter–gatherer densities.

A B S T R A C T The movement and dispersal of human populations during the Pleistocene is a complex question, and one that has been addressed extensively in the literature. During Pleistocene glacial periods, landscapes and coastlines altered dramatically, with old routes closing and new routes opening. One of the best understood of these glacial periods, the Last Glacial Maximum (between 22 and 18 ka), is of particular interest with regards to the colo-nization of the New World. Despite decades of study, archaeologists still do not fully understand the timing and tempo of that process. This study contributes to this discussion by presenting an estimation of habitable land area in the New World at the LGM when sea level was 120 m lower than present day using a previously published method for mapping ancient coastlines and calculating land areas in Google Earth. Areas defined as unin-habitable include those areas covered by ice sheets, glaciers, and ice fields, and areas of extreme aridity. Combined habitable land areas of North and South America are estimated as 34,149,094.81 km 2. Added to data from the previous study, a new estimate of global habitable land area at the LGM is calculated to be 111,108,807.21 km 2. Data on paleocoastlines are then used to predict locations where archaeological traces of early human dispersals may potentially be found.

Multiple studies have demonstrated strong links between diet and anemia, but few have explored the impact of food groups on hemoglobin (Hb). We analyzed the correlation between Ghanaian diet and Hb levels to explore reduction of anemia prevalence through dietary interventions. Demographics, food frequency questionnaires (FFQ), and blood samples were obtained from 140 volunteers (ages 18–65) in five locations across Ghana. Hb was measured; estimated iron consumption was calculated. FFQ items were grouped by food type, and a regression analysis was performed to determine the most important dietary predictors of Hb. Moreover, 47% of total participants were anemic; 64% of females and 28% of males. Hb levels were highest in Mole (13.9 g/dL, SD = ±1.9), independent of sex distribution. The regression model revealed a 62.7% adjusted correlation between food groups and Hb levels. Animal foods (β = 0.016, t = 5.08, p < 0.01) and plant protein (β = 0.013, t = 2.86, p < 0.01) were the mo...

The phylogenetic relationships between fossil hominin taxa have been a contentious topic for decades. Recent discoveries of new taxa, rather than resolving the issue, have only further confused it. Compounding this problem are the limitations of some of the tools frequently used by paleoanthropologists to analyze these relationships. Most commonly, phylogenetic questions are investigated using analytical methods such as maximum parsimony and Bayesian analysis. While these are useful analytical tools, these tree-building methods can have limitations when investigating taxa that may have complex evolutionary histories. Exploratory data analysis can provide information about patterns in a dataset that are obscured by tree-based methods. These patterns include phylogenetic signal conflict, which is not depicted in tree-based methods. Signal conflict can have a number of sources, including methodological issues with character choice, taxonomic issues, homoplasy, and gene flow between taxa. In this study, an exploratory data analysis of fossil hominin morphological data is conducted using the tree-based analytical method neighbor-joining and the network-based analytical method neighbor-net with the goal of visualizing phylogenetic signal conflict within a hominin morphological data set. The data set is divided into cranial regions, and each cranial region is analyzed individually to investigate which regions of the skull contain the highest levels of signal conflict. Results of this analysis show that conflicting phylogenetic signals are present in the hominin fossil record during the relatively speciose period between 3 and 1 Ma, and they also indicate that levels of signal conflict vary by cranial region. Possible sources of these conflicting signals are then explored. Exploratory data analyses such as this can be a useful tool in generating phylogenetic hypotheses and in refining character choice. This study also highlights the value network-based approaches can bring to the hominin phylogenetic analysis toolkit.