Read by QxMD icon Read


Geoffrey H Sperber
This paper reviews the surface ablation of early hominin teeth by attrition, abrasion, and erosive dental wear. The occurrence of these lesions is explored in a sample of South African fossil australopithecine dentitions revealing excessive wear. Interpretation of the nature of the dietary components causing such wear in the absence of carious erosion provides insight into the ecology of the Plio-pleistocene epoch (1-2 million years ago). Fossil teeth inform much of the living past by their retained evidence after death...
June 17, 2017: Dent J (Basel)
Alison S Brooks, John E Yellen, Richard Potts, Anna K Behrensmeyer, Alan L Deino, David E Leslie, Stanley H Ambrose, Jeffrey R Ferguson, Francesco d'Errico, Andrew M Zipkin, Scott Whittaker, Jeffrey Post, Elizabeth G Veatch, Kimberly Foecke, Jennifer B Clark
Previous research suggests that the complex symbolic, technological, and socio-economic behaviors that typify Homo sapiens had roots in the middle Pleistocene <200 ka, but data bearing on human behavioral origins are limited. We present a series of excavated Middle Stone Age sites from the Olorgesailie Basin, southern Kenya, dated ≥295 to ~320 ka by40 Ar/39 Ar and U-Series methods. Hominins at these sites made prepared cores and points, exploited iron-rich rocks to obtain red pigment, and procured stone tool materials from ≥25-50 km distance...
March 15, 2018: Science
Richard Potts, Anna K Behrensmeyer, J Tyler Faith, Christian A Tryon, Alison S Brooks, John E Yellen, Alan L Deino, Rahab Kinyanjui, Jennifer B Clark, Catherine Haradon, Naomi E Levin, Hanneke J M Meijer, Elizabeth G Veatch, R Bernhart Owen, Robin W Renaut
Development of the African Middle Stone Age (MSA) before 300 thousand years ago (ka) raises the question of how environmental change influenced the evolution of behaviors characteristic of early Homo sapiens We use temporally well-constrained sedimentological and paleoenvironmental data to investigate environmental dynamics before and after the appearance of the early MSA in the Olorgesailie Basin, Kenya. In contrast to the Acheulean archeological record in the same basin, MSA sites are associated with a dramatically different faunal community, more pronounced erosion-deposition cycles, tectonic activity, and enhanced wet-dry variability...
March 15, 2018: Science
Oliver C C Paine, Abigale Koppa, Amanda G Henry, Jennifer N Leichliter, Daryl Codron, Jacqueline Codron, Joanna E Lambert, Matt Sponheimer
Discussions about early hominin diets have generally excluded grass leaves as a staple food resource, despite their ubiquity in most early hominin habitats. In particular, stable carbon isotope studies have shown a prevalent C4 component in the diets of most taxa, and grass leaves are the single most abundant C4 resource in African savannas. Grass leaves are typically portrayed as having little nutritional value (e.g., low in protein and high in fiber) for hominins lacking specialized digestive systems. It has also been argued that they present mechanical challenges (i...
April 2018: Journal of Human Evolution
Andrew Best, Jason M Kamilar
Sweating is an unusual thermoregulatory strategy for most mammals, yet is critical for humans. This trait is commonly hypothesized to result from human ancestors moving from a forest to a warmer and drier open environment. As soft tissue traits do not typically fossilize, this idea has been difficult to test. Therefore, we used a comparative approach to examine 15 eccrine gland traits from 35 primate species. For each trait we measured phylogenetic signal, tested three evolutionary models to explain trait variation, and used phylogenetic models to examine how traits varied in response to climate variables...
April 2018: Journal of Human Evolution
Laura Rodríguez, José Miguel Carretero, Rebeca García-González, Juan Luis Arsuaga
The recovery to date of three complete and five partial femora, seven complete tibiae, and four complete fibulae from the Atapuerca Sima de los Huesos site provides an opportunity to analyze the biomechanical cross-sectional properties in this Middle Pleistocene population and to compare them with those of other fossil hominins and recent modern humans. We have performed direct comparisons of the cross-sectional geometric parameters and reduced major axis (RMA) regression lines among different samples. We have determined that Atapuerca Sima de los Huesos (SH) fossils have significantly thicker cortices than those of recent modern humans for the three leg bones at all diaphyseal levels, except that of the femur at 35% of biomechanical length...
April 2018: Journal of Human Evolution
Stefan Flohr
About 100 hominin bones were found during excavations at the Liang Bua cave on the island of Flores, Indonesia. More than 60 of them were assigned to the partial skeleton LB1 which was designated as the holotype of a new species, Homo floresiensis . Analyses of skeletal proportions of LB1 led to the conclusion that its foot was exceptionally long relative to femur and tibia, respectively. This ratio was considered a unique feature that contributes to the definition of the new species. The published illustrations of the in situ -situation and the published inventory of the bones suggest a high degree of commingling rather than the presence of larger anatomically joining units that was asserted in the publications on the findings...
March 14, 2018: Anthropologischer Anzeiger; Bericht über die Biologisch-anthropologische Literatur
Diana S Samuel, Sandra Nauwelaerts, Jeroen M G Stevens, Tracy L Kivell
Evolution of the human hand has undergone a transition from use during locomotion to use primarily for manipulation. Previous comparative morphological and biomechanical studies have focused on potential changes in manipulative abilities during human hand evolution, but few have focused on functional signals for arboreal locomotion. Here, we provide this comparative context though the first analysis of hand loading in captive bonobos during arboreal locomotion. We quantify pressure experienced by the fingers, palm and thumb in bonobos during vertical locomotion, suspension and arboreal knuckle-walking...
March 14, 2018: Journal of Experimental Biology
Dean Falk, Christoph P E Zollikofer, Marcia Ponce de León, Katerina Semendeferi, José Luis Alatorre Warren, William D Hopkins
The only direct source of information about hominin brain evolution comes from the fossil record of endocranial casts (endocasts) that reproduce details of the external morphology of the brain imprinted on the walls of the braincase during life. Surface traces of sulci that separate the brain's convolutions (gyri) are reproduced sporadically on early hominin endocasts. Paleoneurologists rely heavily on published descriptions of sulci on brains of great apes, especially chimpanzees (humans' phylogenetically closest living relatives), to guide their identifications of sulci on ape-sized hominin endocasts...
March 13, 2018: Brain, Behavior and Evolution
Luc Doyon, Zhanyang Li, Hao Li, Francesco d'Errico
Most Chinese lithic industries dated between 300,000 and 40,000 are characterized by the absence of Levallois debitage, the persistence of core-and-flake knapping, the rarity of prepared cores, their reduction with direct hard hammer percussion, and the rarity of retouched flakes. Here we report the discovery of seven bone soft hammers at the early hominin Lingjing site (Xuchang County, Henan) dated to 125,000-105,000. These artefacts represent the first instance of the use of bone as raw material to modify stone tools found at an East Asian early Late Pleistocene site...
2018: PloS One
Željko Režek, Harold L Dibble, Shannon P McPherron, David R Braun, Sam C Lin
Temporal variability in flaking stone has been used as one of the currencies for hominin behavioural and biological evolution. This variability is usually traced through changes in artefact forms and techniques of production, resulting overall in unilineal and normative models of hominin adaptation. Here, we focus on the fundamental purpose of flaking stone-the production of a sharp working edge-and model this behaviour over evolutionary time to reassess the evolutionary efficiency of stone tool technology...
March 5, 2018: Nature Ecology & Evolution
Marc R Meyer, Charles Woodward, Amy Tims, Markus Bastir
OBJECTIVES: Uncinate processes are protuberances on the cranial surface of subaxial cervical vertebrae that assist in stabilizing and guiding spinal motion. Shallow uncinate processes reduce cervical stability but confer an increased range of motion in clinical studies. Here we assess uncinate processes among extant primates and model cervical kinematics in early fossil hominins. MATERIALS AND METHODS: We compare six fossil hominin vertebrae with 48 Homo sapiens and 99 nonhuman primates across 20 genera...
February 28, 2018: American Journal of Physical Anthropology
Charles W Helm, Richard T McCrea, Hayley C Cawthra, Martin G Lockley, Richard M Cowling, Curtis W Marean, Guy H H Thesen, Tammy S Pigeon, Sinèad Hattingh
A Late Pleistocene hominin tracksite has been identified in coastal aeolianite rocks on the Cape south coast of South Africa, an area of great significance for the emergence of modern humans. The tracks are in the form of natural casts and occur on the ceiling and side walls of a ten-metre long cave. Preservation of tracks is of variable quality. Up to forty hominin tracks are evident. Up to thirty-five hominin tracks occur on a single bedding plane, with potential for the exposure of further tracks. Five tracks are apparent on a second hominin track-bearing bedding plane...
February 28, 2018: Scientific Reports
Peter Gärdenfors, Marlize Lombard
With this contribution we analyze ancient hunting technologies as one way to explore the development of causal cognition in the hominin lineage. Building on earlier work, we separate seven grades of causal thinking. By looking at variations in force dynamics as a central element in causal cognition, we analyze the thinking required for different hunting technologies such as stabbing spears, throwing spears, launching atlatl darts, shooting arrows with a bow, and the use of poisoned arrows. Our interpretation demonstrates that there is an interplay between the extension of human body through technology and expanding our cognitive abilities to reason about causes...
2018: Frontiers in Psychology
Kerryn A Warren, Terrence B Ritzman, Robyn A Humphreys, Christopher J Percival, Benedikt Hallgrímsson, Rebecca Rogers Ackermann
Hybridization occurs in a number of mammalian lineages, including among primate taxa. Analyses of ancient genomes have shown that hybridization between our lineage and other archaic hominins in Eurasia occurred numerous times in the past. However, we still have limited empirical data on what a hybrid skeleton looks like, or how to spot patterns of hybridization among fossils for which there are no genetic data. Here we use experimental mouse models to supplement previous studies of primates. We characterize size and shape variation in the cranium and mandible of three wild-derived inbred mouse strains and their first generation (F1 ) hybrids...
March 2018: Journal of Human Evolution
Ovi Chris Rouly
This article describes simulation research based on the Hamiltonian theory of gene-based altruism. It investigates the origin of semipermanent breeding bonds during hominin evolution. The research framework is based on a biologically detailed, ecologically situated, multi-agent microsimulation of emergent sociality. The research question tested is whether semipermanent breeding bonds (an emergent homoplastic social construct) might emerge among primate-like agents as the consequence of a mutation capable of supporting involuntary prosocial behavior...
March 2018: Journal of Human Evolution
I G Stanistreet, H Stollhofen, J K Njau, P Farrugia, M C Pante, F T Masao, R M Albert, M K Bamford
Archaeological excavations at the DK site in the eastern Olduvai Basin, Tanzania, age-bracketed between ∼1.88 Ma (Bed I Basalt) and ∼1.85 Ma (Tuff IB), record the oldest lahar inundation, modification, and preservation of a hominin "occupation" site yet identified. Our landscape approach reconstructs environments and processes at high resolution to explain the distribution and final preservation of archaeological materials at the DK site, where an early hominin (likely Homo habilis) assemblage of stone tools and bones, found close to hominin specimens OH24 and OH56, developed on an uneven heterogeneous surface that was rapidly inundated by a lahar and buried to a depth of 0...
March 2018: Journal of Human Evolution
L E Copes, H Schutz, E M Dlugsoz, S Judex, T Garland
OBJECTIVES: To use a mouse model to investigate the relationships among the components of the systemic robusticity hypothesis (SRH): voluntary exercise on wheels, spontaneous physical activity (SPA) in cages, growth hormones, and skeletal robusticity, especially cranial vault thickness (CVT). MATERIALS AND METHODS: Fifty female mice from lines artificially selected for high running (HR) and 50 from nonselected control (C) lines were housed in cages with (Active) or without wheels (Sedentary)...
February 23, 2018: American Journal of Physical Anthropology
Andrew Du, Andrew M Zipkin, Kevin G Hatala, Elizabeth Renner, Jennifer L Baker, Serena Bianchi, Kallista H Bernal, Bernard A Wood
A large brain is a defining feature of modern humans, yet there is no consensus regarding the patterns, rates and processes involved in hominin brain size evolution. We use a reliable proxy for brain size in fossils, endocranial volume (ECV), to better understand how brain size evolved at both clade- and lineage-level scales. For the hominin clade overall, the dominant signal is consistent with a gradual increase in brain size. This gradual trend appears to have been generated primarily by processes operating within hypothesized lineages-64% or 88% depending on whether one uses a more or less speciose taxonomy, respectively...
February 28, 2018: Proceedings. Biological Sciences
Jiyun M Moon, David M Aronoff, John A Capra, Patrick Abbot, Antonis Rokas
Sialic acids are nine carbon sugars ubiquitously found on the surfaces of vertebrate cells and are involved in various immune response-related processes. In humans, at least 58 genes spanning diverse functions, from biosynthesis and activation to recycling and degradation, are involved in sialic acid biology. Because of their role in immunity, sialic acid biology genes have been hypothesized to exhibit elevated rates of evolutionary change. Consistent with this hypothesis, several genes involved in sialic acid biology have experienced higher rates of non-synonymous substitutions in the human lineage than their counterparts in other great apes, perhaps in response to ancient pathogens that infected hominins millions of years ago (paleopathogens)...
February 21, 2018: G3: Genes—Genomes—Genetics
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"