bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluctuating asymmetry
Authors: DeLeon Valerie Burke
Published: October 2018

Fluctuating asymmetry is used as an estimator of stress and has been applied to studies of health and disease in modern and archaeological contexts. Fluctuating asymmetry refers to the random, subtle deviations from symmetry produced by developmental instability. Asymmetries can be measured throughout the body and provide a vast resource for studying the effects of stress on growth, development, and maintenance of the skeleton and other tissues. However, two major challenges to these studies are (1) distinguishing fluctuating asymmetry due to developmental instability from other types of asymmetry; and (2) measurement error as a significant confounding factor. Common examples of fluctuating asymmetry topics in the field of biological anthropology include studies of health and disease using dental metrics, dermatoglyphics, postcranial osteometrics, and cranial shape.
F
ossey,
D
ian
Authors: Stewart Kelly
Published: October 2018

Dian Fossey (1932–1985) started a long‐term study of mountain gorillas in the Virunga Volcanoes in 1967. Her research center, Karisoke, still operates in Rwanda today. At the end of the 1970s, Fossey helped spark a massive conservation program that stopped the decline of the gorilla population. She was murdered at Karisoke in 1985. She will be remembered as a pioneer who brought mountain gorillas to the attention of the world and helped to save them from extinction.
Functional morphology, teeth
Authors: Teaford Mark F.
Published: October 2018

Primate teeth have been used to gain many insights into primate behavior and evolution. However, the often indecipherable terminology in those analyses has limited the accessibility and general understanding of that work. This chapter presents a brief review of primate incisors, canines, premolars, and molars in order to give a glimpse of what we know about them and how they are employed by humans and by our closest living relatives.
Gene (allele)
Authors: Rubicz Rohina
Published: October 2018

A gene is the basic unit of inheritance. It is a segment of deoxyribonucleic acid (DNA) that contains instructions for a trait or function. The transmission of genes from one generation to the next is the mechanism by which phenotypic traits are inherited. An allele is an alternate form of a gene. Alleles occur in pairs, with one inherited from each parent. Many genes code for traits that are of interest to researchers in the field of biological anthropology, including the ABO blood group system and the sickle cell trait. Most human traits are complex, meaning they are the product of multiple genetic and environmental factors.
Gene genealogy
Authors: Long Jeffrey C.
Published: October 2018

A gene genealogy is the set of descendant–ancestor relationships that links all members of a sample of DNA sequences back to a single ancestor. Geneticists often use tree diagrams to visually interpret gene genealogies. A stochastic process from mathematical probability called coalescent theory provides a rigorous foundation for making inferences from gene genealogies. By using coalescent theory, it is possible to find the expected time elapsed since a set of DNA sequences existed as a single ancestor. In addition, the evolutionary time represented by a gene genealogy determines the number of distinct alleles that will be found in a sample, and it sheds light on the relationship between allele age and allele frequency. The number of segregating sites found in a set of DNA sequences is a useful statistic to make inferences about demographic history and potentially to detect the action of natural selection.
Gene/
QTL
mapping
Authors: Blue Elizabeth
Published: October 2018

The genetic basis of many traits which show familial resemblance has yet to be fully explained. Gene and quantitative trait locus (QTL) mapping uses the correlation between genetic marker data and a hypothetical trait locus to find the genomic regions containing variants influencing the trait of interest. The closer a marker is to the trait variant on the original chromosome, the longer it takes for the correlation to break down. Gene/QTL mapping requires informative markers, a marker map, and subjects with both genotype and phenotype data.
Genomes
Authors: Knapp Leslie A.
Published: October 2018

A genome represents all the genetic information required for an organism to grow, function, and reproduce. For vertebrates, genetic information is passed from parent to offspring. The nuclear genome, the largest part of the human genome, is produced when both parents contribute half of their genetic information to offspring. The mitochondrial genome, which is significantly smaller than the nuclear genome, is contributed solely along the maternal line. Based on extensive studies of both genomes over many decades, scientists know how genetic information is transmitted on chromosomes, where many genes are located on chromosomes, and how some DNA sequences relate to genes. Intensive study of the human genome began in the 1990s and work is ongoing in an effort to gain further knowledge about the human genome, its variability, and what evolutionary forces have contributed to the modern human genome.
G
ould,
S
tephen
J.
Authors: Ruse Michael
Published: October 2018

Stephen Jay Gould was an American paleontologist known for his attacks on Darwinism and for his popular writing.
Hadar
Authors: Reed Kaye
Published: October 2018

Hadar is a Plio‐Pleistocene paleoanthropological site in the lower Awash valley, Afar Regional State, Ethiopia. The site was discovered in the 1970s and has yielded hundreds of fossils of the hominin,
Australopithecus afarensis
, from Lucy (A. L. 288–1) in 1974 to a male (A. L. 444–2) and female (A. L. 822–1) skull in the late 1990s and early 2000s. The nature of the fluvial and lacustrine deposits of the Hadar Formation allowed for extremely well‐documented stratigraphy. There are also Pleistocene sediments from which
Homo
and Oldowan tools have been recovered.
Hands (primate)
Authors: Paciulli Lisa M. , Chennu Lakshmi H.
Published: October 2018

Hands are one of the most used and useful parts and tools of the body. They assist in everyday functions—from obtaining food, scaring off predators, locomoting, grasping, and climbing to communicating and interacting socially. The hand is the most terminal structure of the forelimbs, and articulates (joins) with the two bones that form the forearm (the radius and ulna). The general skeleton of the primate hand consists of more than 27 bones, comprised of eight carpals (wrist bones), five metacarpals (palm bones), and 14 phalanges (finger bones). There may also be extra bones called sesamoids (bones in a tendon or muscle) in the hand. Characteristics that distinguish primate (lemurs, monkeys, apes, and humans) hands from their predecessors are a combination of the presence of nails instead of claws, thumbs, and padding on the ends of the fingers. While these features in total are distinctive to the Order Primates, many species' hands vary from the basic primate hand pattern, which is primitive compared to other mammalian hands. Interestingly, primates appear to have preserved the ancestral vertebrate hand‐form with five digits that evolved approximately 450 million years ago.
Hard tissue chemistry
Authors: Giblin Julia I.
Published: October 2018

Chemical signatures recorded in the hard tissues of past human and animal populations via dietary sources can indirectly provide important information aboutwhereandwhenthose resources were acquired. Isotopic tracers, like strontium, oxygen, lead, sulfur, and hydrogen, are particularly useful in this regard due to the geological and climatic information about the environment that they can record. These elements are incorporated into hard tissues (such as bone, teeth, and hair) at varying times in an organism's life cycle and can reflect acquired resources across an individual's lifespan. From an anthropological perspective, these chemical signatures have the potential to shed light on a wide range of social processes beyond diet, including residence patterns, trade, kinship, and economic organization.
Hemoglobin variants
Authors: Williams Heather S.
Published: October 2018

Hemoglobin variants are responsible for the most common single gene disorders observed among human groups. The most well‐known hemoglobin variant‐related disorders are sickle cell trait and thalassemia. The highest frequencies of these disorders commonly overlap with the geographical distribution of malaria, an infectious disease caused by the
Plasmodium
parasite. Some hemoglobin variants can provide protection against severe and lethal malarial infections, indicating that malaria exerts a strong selective pressure for hemoglobin variants. Thus, the primary mechanism driving the high frequency of hemoglobin variants among human populations is natural selection. While the mechanism for maintaining high frequencies of hemoglobin variants has been established, much less is understood about the mechanisms by which hemoglobin variants confer protection against malaria infection. Current research is directed towards better understanding how each hemoglobin variant‐related disorder provides protection against malaria, and how this can inform global health policy.
Heterozygosity
Authors: Knapp Leslie A.
Published: October 2018

Heterozygosity refers to the amount of diversity found at one or more genetic loci in a population. Heterozygosity is often measured by genotyping microsatellites and single nucleotide polymorphisms in the genome. Population geneticists use the Hardy–Weinberg equilibrium (HWE) equation to compare observed and expected levels of heterozygosity. If heterozygosity is higher than expected, evolutionary forces such as natural selection may be contributing to the diversity in the study population.
Health and well‐being, history of
Authors: Buzon Michele R.
Published: October 2018

The history of health and well‐being has been a primary topic of bioarchaeology, the excavation and analysis of human skeletal remains. Paleopathology (the study of diseases in the past) has elucidated our understanding of how humans have adapted to changing circumstances in their physical and sociocultural environments. Transitions in human behavior, such as changes in subsistence, settlement patterns, and contact between groups, have had profound effects on health and well‐being. While shifting conditions do not always result in a decline in health, it is often juvenile individuals and those with fewer socioeconomic resources who are adversely affected. Through the use of a bioarchaeological approach that uses varying types of data to reconstruct the context of past human experiences, in addition to standard data collection and methodological advancements, the variation in susceptibility to disease and adaptability of individuals and groups to transitions provides comprehensive interpretations of past human health.
Hominoidea
Authors: Begun David R.
Published: October 2018

The current consensus on hominoid taxonomy is presented here along with a general description of the distribution, diet, positional behavior, socioecology, conservation status, and some unique behaviors of living hominoids. On the surface, hominoids would appear to be thriving today, with many species and multiple genera. However, nearly all of these species are endangered or critically endangered. Most of the taxonomic diversity within each family and genus has been determined based on behavioral, soft tissue, or genetic analysis and not morphology, the only criterion available to evaluate diversity in the past. If these same criteria could be applied to fossil apes, the author estimates that the diversity of living apes today is at least an order of magnitude (ten times) lower than in the past. In addition to suggesting a huge loss in diversity, which needs to be explained, this presents a great challenge for paleoanthropologists. They rely on comparisons with living apes to make conclusions about extinct apes and humans, but it is doubtful that living ape diversity is representative of the past. Much but perhaps not all of the loss of diversity in living apes is due to human activity. It may also be a result of long‐term interactions with Old World monkeys and perhaps other animals competing for the same resources.
Homo
Authors: Hawks John
Published: October 2018

Homois a biological genus including living humans and closely related fossil hominins. The genusHomooriginated before 2 million years ago in Africa, and subsequently diversified into several different species distributed throughout much of the world. Species withinHomoshare adaptations related to a higher‐quality diet, they are all associated with the capacity for stone tool manufacture, and some of them have evolved larger brain sizes than any other hominins. The relationships withinHomoare not entirely clear, although the diversity of the genus has increased over time since its origin. During the history of biology, the definition ofHomohas changed many times. New fossil discoveries continue to challenge our understanding of human relatives within our genus.
Homology
Authors: Cartmill Matt
Published: October 2018

Any sort of comparison between organisms presupposes that the things being compared are in some sense the same sort of thing. The correspondence that justifies the comparison may involve similarities in structure, function, or both. When there are correspondences in function with no detailed correspondence in structure, the similarities are called
analogies
—for example, the functional similarities between the wings of bees and bats. When there is a detailed correspondence in structure, with or without correspondences in function, the similarities are called
homologies—
for example, the correspondences between a human hand and a bat's wing. The similarities between homologous structures reflect underlying historical continuities in developmental mechanisms, which can be attributed in many cases to shared evolutionary derivation from similar mechanisms in an ancestor.
Human uniqueness
Authors: Brown Kaye , Cartmill Matt
Published: October 2018

Humans are commonly held to be qualitatively different from other animals, especially in their unique mental abilities. Darwinian theory, which provides the only known way of explaining the origin of complex adaptations, assumes that evolution works on quantitative variation within species. It therefore affords no way of explaining qualitative uniqueness. Anthropologists have attributed human uniqueness to cognitive capacity, symbols and language, prosociality, cumulative culture, and complex imitation, and have tried to explain these faculties as the historical products of various combinations of tool use, cooperative hunting and breeding, fire and cooking, and brain enlargement. Because human traits with no nonhuman precursors are not amenable to evolutionary explanation, these debates can be expected to persist so long as anthropology defines itself and its mission in terms of the animal–human boundary.
Indels
Authors: Schurr Theodore G.
Published: October 2018

Insertions and deletions (indels) are small changes in the nucleotide sequence of a gene or segment of DNA that add or subtract one to several base pairs. Such changes are largely neutral in their effects on genetic function, and add to the overall sequence variation in human and primate populations. Indels occurring in genic regions may affect genetic expression and possibly inactivate the loci in which they appear. The presence of indels reflects the dynamic process of sequence replication and remodeling that has been taking place in primate and human genomes for millions of years.
Infanticide
Authors: Borries Carola
Published: October 2018

Infanticide is the killing of a young conspecific which is still dependent on its mother. In most cases, a recently immigrated adult male kills an unrelated infant so that the mother resumes cycling sooner and the male has the chance to sire her next offspring. Based on sexual selection theory, infanticide is interpreted as a male reproductive strategy. Infanticide has few costs for attackers but is costly for females who lose an offspring. Consequently, females have developed several counterstrategies. In contrast, between‐group infanticide is less well understood. In humans, infanticide is closely connected to the termination of the unusually long period of infant dependency with parents themselves, sometimes eliminating offspring with poor prospects. Similar to predation, infanticide is an omnipresent if uncommon threat that probably contributed to permanent male–female associations in primates.
Birth intervals
Authors: Leslie Paul W.
Published: October 2018

Birth intervals (and closely related terms including birth spacing, interbirth interval, and interpregnancy interval) are of interest in biological anthropology and other population sciences because the timing and pace of childbearing both reflect and influence a range of demographic, biological, and social processes. Birth intervals vary greatly among human populations and this variation can be understood in terms of pathways linking behavior and environmental conditions to reproductive physiology. In noncontracepting populations, the most important proximate determinants of birth intervals operate through their influence on the fecundity‐suppressing effects of lactation and the waiting time to conception once postpartum fecundity has returned. Short birth intervals are associated with increased morbidity and mortality of fetuses and children on both ends of an interval, and with a variety of health risks for mothers.
Isolation by distance
Authors: Fehren‐Schmitz Lars
Published: October 2018

The term “isolation by distance” (IBD) describes a number of models that explore patterns of population genetic variation resulting from spatially limited gene flow. The key assumption of IBD is that genetic similarity between individuals of a population decreases as the geographic distance between them grows. On a global scale, IBD is observed in human populations consistent with a sequential colonization of the world by our species out of Africa and limited migration and mating distances between the regions occupied by our species.
Karyotype
Authors: Stanyon Roscoe , Bigoni Francesca
Published: October 2018

The karyotype is the ordered image of chromosomes found in the cell nucleus. The human karyotype is composed of 22 pairs of autosomes and one pair of sex chromosomes for a diploid number of 46. Chromosome can be studied using classical staining, chromosome banding, and molecular methods such as fluorescence in situ hybridization (FISH). Karyotypes can be used to characterize cells, individuals, or species, and to analyze phylogenomic and evolutionary relationships.
Kinzey, Warren
Authors: Garber Paul A.
Published: October 2018

Warren G. Kinzey (1935–94) was a biological anthropologist who made significant and pioneering contributions to the fields of functional anatomy, evolution, and primate behavioral ecology. His field research onAteles,Callicebus,Cebuella,Chiropotes, andPitheciahighlighted the use of New World monkeys as important primate models for studying human evolution, human mating systems, and human social behavior. His commitment to field research inspired a generation of New World primatologists.
K
ummer,
H
ans
Authors: Cords Marina
Published: October 2018

Hans Kummer (1930–2013), a Swiss zoologist, pioneered the study of primate behavior in wild and captive settings, emphasizing proximate mechanisms of social organization as a research theme and the critical role of experiments as a method. Trained in the intellectual domain of European ethologists, Kummer contributed to the study of primate behavior by introducing new perspectives and methods to a research area dominated by anthropologists, and providing a deep understanding of the exceptional society of hamadryas baboons based on field and laboratory study.
Laughlin,WilliamS.
Authors: Meier Robert J.
Published: October 2018

William Sceva Laughlin (1919–2001) was recognized by the 1960s to be a leading authority regarding Aleut (Unangax) prehistory and physical anthropology. His sustained and committed study of the Aleut was highlighted in a case studyAleuts: Survivors of the Bering Land Bridge. Laughlin's work clearly exemplified a multidisciplinary approach as he incorporated and integrated the findings that he and his colleagues had accumulated from their fieldwork in physical anthropology, biology, geology, demography, ethnography, linguistics, archaeology, and ecology. He viewed these varied endeavors as windows through which to better understand the interactions of language, culture, human biology, and environment that underlay Aleut adaptation.
Learning
Authors: Graham Kerrie Lewis
Published: October 2018

Learning is how an animal acquires and modifies information and skills, a process that in turn impacts its behavior. While learning can involve differing degrees of cognition, it need not necessarily be cognitive. Learning is usually discussed with reference to classical and operant conditioning (associative learning), habituation and sensitization (nonassociative learning), modeling or social learning (observational learning), and, to some degree, play behavior.
Life history (human)
Authors: Trevathan Wenda
Published: October 2018

For most mammals, the period between conception and death can be divided into four phases: gestation, infancy, juvenility (childhood), and adulthood. For humans two additional phases are necessary to fully understand the life course: adolescence and a post‐reproductive period. Life history theory provides a way of viewing life course traits such as length of gestation, duration of lactation, onset of puberty and developmental state at birth through the lens of evolution. Given that energy for growing and reproducing is available in limited supply, life history theory argues that natural selection has shaped life history traits in ways that increase reproductive success. It helps predict what will be traded for what, under certain environmental conditions, including social and cultural circumstances, and enhances understanding of the human trade‐off of quality of offspring over quantity. For humans, life history must be considered in the context of both biology and culture.
M
atson,
G
.
A
lbin
Authors: O'Rourke Dennis H.
Published: October 2018

G. Albin Matson (1899–1991) was a geneticist who provided classical marker allele frequency data on many indigenous populations throughout the Americas. The number of loci reported for each population studied increased over time, as new systems were discovered. In addition to the early demonstration of the degree of genetic variation in Native American populations, Matson was among the first to demonstrate that not all indigenous populations of the hemisphere were monomorphic for blood type O, an early assumption shared by many until his work beginning in the 1930s.
Mayr, Ernst
Authors: Little Michael A.
Published: October 2018

Ernst Mayr (1904–2005) was a major contributor to a neo‐Darwinian synthesis of evolution in the twentieth century. Whereas geneticists brought population and mathematics into evolution in the 1920s and 1930s, evolution at the species and higher taxonomic levels was a focus during the later synthesis in the 1930s and 1940s. Mayr was one of the major contributors to this latter period of synthesis, as well as contributing regularly to original evolutionary ideas for the next half‐century.
Human biological variation, measuring
Authors: Brown Daniel E.
Published: October 2018

Understanding of both intra‐ and interpopulation variation in human biology depends heavily upon the use of objective, quantitative measures. Qualitative measures, such as the presence or absence of specific alleles or phenotypic traits, are also utilized by biological anthropologists. The measurements used must be repeatable, accurate, and appropriate for the circumstances of the research project in which they are employed. Contemporary human biology research utilizes both measures that have been used for many decades, but also may employ new technology that permits measurement of phenomena that were impossible to quantify in the past. Field conditions may limit what measurements can be used.
Medicinal plant use by nonhuman primates
Authors: Huffman Michael A. , Pebsworth Paula A.
Published: October 2018

Primates use medicinal plants and other non‐nutritive substances to maintain and/or regain health homeostasis. Four different behavioral strategies have been identified: (1) avoidance or reduction of contact with infective agents, (2) passive prevention, (3) therapeutic self‐medication, (3) body anointment, and/or (4) living space fumigation. These strategies, either directly or indirectly, promote health and/or improve reproductive fitness.
Monophyly
Authors: Cartmill Matt
Published: October 2018

A taxon (a formally named classificatory grouping of organisms) is regarded as monophyletic (from Greek, meaning “single stock”) if the last (most recent) common ancestor (LCA) of its members was also a member of the group. A taxon is strictly monophyletic (holophyletic) if it includes all the descendants of the LCA. If it includes the LCA and some of its descendants but excludes others, it is called paraphyletic. A strictly monophyletic taxon is called a clade. Current fashions in systematics forbid paraphyletic “wastebasket” taxa and require that every taxon must be a clade. A taxon that is not monophyletic in either the strict or the loose sense is called polyphyletic.
M
ourant,
A. E.
Authors: Mielke James H.
Published: October 2018

Arthur Ernest Mourant (1904–94) is recognized as a leading pioneer in the study of human blood groups, human genetic variation, and adaptation. His interests ranged from medicine, genetics, chemistry, and hematology to geology and archaeology. Among other degrees, he completed a Doctor of Philosophy in geology in 1931 and earned a Doctor of Medicine in 1948. In 1946, he founded and became the first director of the Blood Group Reference Laboratory in London, holding that position for 20 years. His researches resulted in hundreds of articles and books, including the widely cited
Distribution of Human Blood Groups
(1954), which mapped what was then known about the gene frequencies of blood groups across the world. Probably more importantly, this publication, and others that followed, initiated many biological anthropology studies that focused on genetic relationships among populations and the historical and evolutionary reasons for the variation and distributions. A Fellow of the Royal Society, Mourant was honored many times for his contributions to hematology, anthropology, genetics, and prehistory. He died on August 29, 1994.
Ontogeny
Authors: Cofran Zachary
Published: October 2018

Evolutionary changes in morphology arise from modifications of growth and development, or ontogeny. Given the prominent role of ontogeny in effecting evolutionary change, it is of great interest to human paleontologists. This article reviews some (but not all) approaches and findings in the study of ontogeny in paleoanthropology, focusing first on teeth and then on bones. In general, ontogenetic studies of fossil hominins indicate important roles of both pre‐ and postnatal development in contributing to anatomical differences between species, and that the human pattern of “slow” growth is probably evolutionarily recent.
Owen,Richard
Authors: Cartmill Matt
Published: October 2018

Richard Owen (1804–92) was a leading British paleontologist and comparative anatomist of the nineteenth century. Famed during his lifetime for his writings on the concept of homology, Owen also described and named the parasite that causes trichinosis, coined the word “dinosaur,” and was instrumental in the founding of the British Natural History Museum. Although he is chiefly remembered today for his intransigent and egocentric early opposition to Charles Darwin's theory of evolution, Owen became a supporter of evolutionary ideas in later life.
Paleoecology
Authors: Reed Kaye
Published: October 2018

Paleoecology is the study of ancient organisms and their interactions with one another and the environment. Thus paleoecologists can reconstruct the behavior of one organism, or the behaviors and interactions of an entire community of animals as represented by the fossil assemblage. As this research also concerns the environment, habitats in which organisms existed are also reconstructed with a variety of paleoecological methods. These methods include investigating both fauna and flora, through a variety of techniques such as species diversity indices, species abundances, multivariate analyses, ecomorphology, dental microwear, dental mesowear, stable isotope examination of teeth and carbonates in soils, and analysis of pollen and phytoliths. Paleoecology is a discipline that requires the integration of all of these methodologies to arrive at the context in which the evolution of primates, including hominins, occurs.
Paleogenetics
Authors: O'Rourke Dennis H.
Published: October 2018

Paleogenetics is a rapidly growing area of investigation; it is based on the recognition that DNA, although degraded, persists in tissues long after the death of an organism. These DNA fragments can be recovered, characterized, and used to investigate a variety of questions about prehistoric populations, paleoenvironments, pathogen evolution, and the evolutionary mechanisms that structured genetic variation in the past. The earliest ancient DNA analyses were conducted on preserved soft tissue from extinct organisms and mummified human remains. Laboratory techniques improved and the field quickly adopted the new technique of polymerase chain reaction, while pivoting to samples from hard tissue like bone and teeth. In the years leading up to 2010, the field was again at the forefront of using new technology by incorporating next generation sequencing. As costs have declined, newer studies are using genomic analytical methods to characterize whole genomes, so that the term “paleogenomics” is now in common usage.
Paleopathology
Authors: Buikstra Jane E.
Published: October 2018

Paleopathology, the study of ancient disease in humans and other mammals, began as an avocational interest of anatomists and medical doctors during the 16th–18th centuries. By the 19th century, the field focused attention explicitly on diseased bones and diagnosis. Aided by biomedical advances and theoretical sophistication from the social sciences, paleopathology has matured since the late 1800s into a field that is profoundly interdisciplinary, considering topics ranging from the phylogeography of specific diseases to community health under changing climatic, social, economic, and dietary conditions.
Peopling of the New World
Authors: Auerbach Benjamin M.
Published: October 2018

The peopling of the Americas was a process that unfolded over more than 15,000 years. Geological, archaeological, genetic, skeletal, and linguistic evidence reveal information about this process on different scales. The preponderance of the evidence points to humans migrating from Asia into Beringia by the Last Glacial Maximum (ca. 24,000 years BP), and to humans having settled in subglacial regions of the Americas by 15,000 years ago. Genetic evidence, and accumulating archaeological evidence, suggest that the ancestors for all native groups in the Americas diversified in Beringia. Geological and archaeological evidence strongly support that early movement into the Americas occurred along the Pacific coast and, later, through inland routes to reach subglacial regions. These people were linguistically and culturally diverse, and are likely to have rapidly developed technologies to adapt to local environments, driving further diversification.
Phenotype
Authors: Kuzawa Christopher
Published: October 2018

The phenotype is the set of physical or behavioral characteristics of an organism. Whereas the genotype is hereditary material encoded in nucleotide sequences (DNA), the phenotype is the product of the genotype developing within, and interacting with, the social and physical environment. Environmental influences on the phenotype range from relatively modest, as exemplified by Mendelian traits with high genetic penetrance (e.g., eye color), to substantial, as in highly plastic traits that develop in response to patterns of experience (e.g., the central nervous and immune systems). The environment can influence the phenotype by modifying growth and development, or by transiently or durably modifying the functional state or structure of the adult body across the life course. Research also increasingly demonstrates that the environment can modify epigenetic and other factors that are transferred between generations, thereby impacting phenotypes of one or more future generations. The phenotype has crucial evolutionary significance: it comprises the tangible features of the organism that determine its fit with the environment. The heritable component of trait variability thus serves as the raw material upon which natural selection operates.
Phenotype (genetics)
Authors: Norton Heather L.
Published: October 2018

Phenotype, composed of the observable physical properties of an organism, is determined by a combination of genetic and environmental factors. The genetic contribution to an individual's phenotype is known as the genotype. Relatively simple phenotypic traits may be determined by a mutation at a single gene, while more complex phenotypes may be affected by mutations at multiple genetic loci and/or environmental effects. Some phenotypic traits can be classified into discrete categories, while others exhibit a continuous range of variation. The expression of a given phenotype may be influenced by several factors, including epistatic interactions with other loci and variation in environmental conditions. Phenotypic variation can be shaped by a number of evolutionary forces, including natural and sexual selection and gene–culture coevolution.
Phylogenetics
Authors: Turner Trudy R.
Published: October 2018

Phylogenetics is the study of the evolutionary relationships of organisms. The end result of a phylogenetic analysis is a phylogeny which defines the ancestral–descendent relationships between groups of organisms. There are multiple ways to construct phylogenies that utilize either phenotypic, morphological, or genetic similarities. Methods of constructing phylogenies have changed over time depending on theoretical orientation and evolving technologies and statistical methodologies.
Prehensile tail
Authors: Bezanson Michelle
Published: October 2018

A prehensile tail is a tail that is capable of grasping a substrate and sustaining the entire mass of an individual. Six primate genera exhibit tail prehensility:
Alouatta
(howling monkeys),
Ateles
(spider monkeys),
Brachyteles
(muriquis),
Cebus/Sapajus
(capuchin monkeys), and
Lagothrix
(woolly monkeys). It appears that the prehensile tail has evolved twice in these Neotropical primates, once in the common ancestor of the Atelidae (
Alouatta
,
Ateles
,
Brachyteles
, and
Lagothrix
) and once in
Cebus
/
Sapajus
. In the Atelidae, the tail is relatively long and features a ventrodistal friction pad that is covered in dermatoglyphics. In
Cebus
/
Sapajus
, the tail is relatively shorter and fully furred. The prehensile tail is often described as a “fifth limb” that aids in support, balance, and maneuverability during feeding, foraging, travel, rest, and social behaviors. All prehensile‐tailed primates use their tail in both above‐branch and below‐branch feeding postures.
Ateles
and
Brachyteles
also employ their tail during below‐branch suspensory locomotion.
Pre‐sapiens theory
Authors: Smith Fred H.
Published: October 2018

The pre‐sapiens “theory” was a multilineal perspective on human evolution that postulated the existence of a lineage leading to modern humans that was distinctly different from the lineage culminating in the Neandertals. While it clearly began as a European concept in the late nineteenth century, pre‐sapiens thinking was expanded to other parts of the Old World in the first half of the twentieth century as the non‐European fossil record expanded. The pre‐sapiens lineage was thought to have split from the lineage(s) leading to archaic humans, particularly the Neandertals, during the lower or early Middle Pleistocene. Thus, establishing an antiquity for the modern human anatomical form was key for supporters of pre‐sapiens thinking, as was emphasizing the distinctiveness of archaic forms—again particularly the Neandertals. Despite attempts to keep this perspective viable, accumulated evidence finally brought it to an end by the 1980s.
Primate genomics
Authors: Ting Nelson
Published: October 2018

Since the completion of the human genome project, numerous nonhuman primate genomes have been sequenced and assembled. As a result, we are beginning to understand how primate genome content, structure, and function differ across species, and how these genomic differences relate to morphological, physiological, and behavioral differences among taxa from across the Order Primates. Genomic data have also been used to more accurately infer population history and patterns of genetic diversity within primate species. Primate genomics is therefore an important tool for the study of primate ecology, evolution, and behavior, as well as a valuable resource in biomedical research where some primates are used as models for human disease. The power and potential of primate genomics is rapidly increasing as technologies improve and the cost of genomic data acquisition and analysis drops, and therefore holds great promise for biological anthropology as a whole.
Primate origins
Authors: Cartmill Matt
Published: October 2018

Theories purporting to explain primate origins began to take shape in the early twentieth century. Early theories invoked varying combinations of orthogenesis and Darwinian natural selection. By mid‐century, they had been drawn together into a synthetic theory that depicted primate peculiarities as trends, generated in multiple parallel lineages by the selection pressures imposed by arboreal life. Since the 1970s, this theory has been discarded and a contentious literature has grown up around three alternative accounts, which respectively explain primate synapomorphies as having originated as adaptations to visually directed predation, leaping locomotion, and feeding on fruit and flowers. If primate apomorphies were acquired sequentially, different explanations may obtain for different stages of the process.
Radiography/nondestructive analysis
Authors: Garofalo Evan M.
Published: October 2018

Nondestructive and radiographic analyses are powerful tools for a wide range of biological analyses and complex modeling. Computed tomography (CT), microCT, magnetic resonance imaging (MRI), and optical coherence tomography (OCT) technologies are penetrative modalities allowing for visualization and analysis of internal and surface structures, and 2D and 3D models reconstruction. Laser surface scanning is nonpenetrative and produces 3D surface model. These modalities have unique imaging capabilities, advantages, and trade‐offs for specific research questions and samples. Each modality has differing specifications for image acquisition/processing time, specimen size, ideal tissue type, detail resolution, cost, and portability. These technologies, together with powerful computing and postprocessing software, enable researchers to address complex morphological and functional questions and share specimen data more easily digitally (and with 3D printing).
R‐matrix analysis
Authors: Melton Phillip E.
Published: October 2018

R‐matrix is a useful tool for biological anthropology, as it can be used for several different types of data, including genetic, quantitative traits, surname, and migration data. This entry describes the underlying mathematical concepts in the construction of the R‐matrix, its extensions, and some examples from the literature.
R
obinson,
J
ohn
T
albot
Authors: Smith E. O.
Published: October 2018

John Robinson contributed significantly to our knowledge of the South African australopithecines. His collaboration with Robert Broom yielded an almost complete cranium of
Australopithecus africanus
and a partial skeleton of the same species. His work on the dentition of the australopithecines gave rise to the “dietary hypothesis,” which suggested fundamental differences between the robust and gracile South African forms.
Saltation and stasis
Authors: Lampl Michelle
Published: October 2018

Saltation and stasis is the biological process of normal growth: size increases by episodic saltations separated by intervals of no growth. Decisions regarding “when” and “how much” to grow reflect chemically‐mediated repression and de‐repression regulatory activities. Saltations involve cellular proliferation, synthetic and expansion events that occur in time frames on the order of minutes. Intervening stasis intervals range from minutes to days and months. Saltation frequency and amplitude vary within and between individuals, characterize fetal life through adolescence, and underlie the diversity of human growth patterns and size: relatively tall individuals have more frequent or larger saltations than relatively short individuals, or both. Modulation of saltation frequency and amplitude is a robust adaptive strategy to the growing organism in the face of environmental challenges, enabling facultative responses and the options of delay and rebound. Mechanisms that control the release of saltation and reestablish stasis are important targets for research, including cancer controls.
Schultz,AdolphH.
Authors: Smith E. O.
Published: October 2018

Adolph Schultz (1891–1976) was a pioneer in the study of the comparative anatomy, skeletal biology, embryology, and evolution of primates. Schultz is known for his numerous well‐organized and beautifully illustrated publications, as well as for the collection and publication of large datasets that have served as a resource for generations of future scholars.
Secular trends
Authors: Cameron Noël
Published: October 2018

Secular trends in human growth and adult morphology are characterized by a change in absolute size and by differences in the timing and magnitude of critical somatic and developmental landmarks such as peak height velocity and age at menarche (first menstruation). Positive trends are reflected by an increase in absolute size and acceleration in the rate of growth such that children appear to be larger and mature earlier, while a negative trend results in a decrease in absolute size and deceleration in the rate of growth such that children appear to mature later and be smaller. Such changes are described as “secular trends” under the assumption that they are short‐term reversible changes occurring between generations rather than permanent alterations to the genetic potential for human growth and development. The causes of positive secular trends are thought to lie within improved health and nutrition, although some discussion has centered on whether heterosis or hybrid vigour may be a contributing factor. It seems highly likely that secular changes follow a fluctuating pattern, with both positive and negative trends occurring over the last two millennia.
S
ergi,
S
ergio
Authors: Marchi Damiano
Published: October 2018

Sergio Sergi (1878–1972) was an Italian physical anthropologist. His studies extended into primatology, comparative anatomy, anthropometry, and paleoanthropology. Sergi is known for his interpretation of human evolution, seen as a succession of “cicli di forme” (shape cycles, referring to the shape of the skull). He also supported the “pre‐Neanderthal” model of modern human origins. His works in anthropology are still widely cited in the scientific literature, particularly his monographs on the skulls of Monte Circeo, Saccopastore 1, and Saccopastore 2. He expanded the traditional scope of biological anthropology by extending his comparative studies to all systems of the anthropoid body, including the limbs, the tegumental system, the muscles of facial expression, and the mechanism of respiration, and conducted systematic research on the spinal cord of chimpanzees.
Sexual dimorphism (nonhuman primates)
Authors: Paciulli Lisa M.
Published: October 2018

Sexual dimorphism is a difference in secondary sex characteristics between males and females of the same species. Secondary sex differences are those not directly related to sexual structures or organs, mating, and/or parental investment (which are primary sex differences). Secondary sex differences include body size/mass, shape, color, and behavior, and are highly variable. In primates, sexual dimorphism is common in anthropoids (monkeys, apes, and humans) and less so in prosimians (lemurs, lorises, galagos, and tarsiers).
S
impson,
G
eorge
G
aylord
Authors: Cartmill Matt
Published: October 2018

G. G. Simpson (1902–84) was a twentieth‐century US paleontologist who wrote authoritative studies of mammal evolution. His writings in the 1930s and 1940s on systematics, mammal classification, and evolutionary processes were regarded as canonical for almost four decades, and made him one of the leading contributors to mid‐century primatology and neo‐Darwinian evolutionary theory.
S
inger,
R
onald
Authors: Oxnard Charles
Published: October 2018

Ronald Singer, a South‐African‐born physician and anthropologist from Cape Town University, made most of his career from 1962 onwards at the University of Chicago. His research contributions were in anatomy, anthropology, archaeology, and paleontology especially of the Pleistocene. He was also a powerful figure in the anti‐apartheid movement in South Africa. He developed a model anatomy department with research strength in all areas, and with strong teaching programs.
Skeletal biology in anthropology
Authors: Agarwal Sabrina C.
Published: October 2018

Skeletal biology is the study of how bone works at the cellular, tissue, and organ level. Anthropologists study the skeletal biology of humans and nonhuman primates. By looking at bone microstructure in ancient bones, anthropologists can reconstruct the influences of age, sex, lifestyle, and disease over the life course that are recorded in the bony tissue, and can explore variation in bone health in human populations temporally and geographically.
Social learning
Authors: Davis Sarah , Whiten Andrew
Published: October 2018

Social learning is common not only in humans but also in other primates. The ability to both innovate and socially learn can help a species adjust and survive in temporally and spatially changing environments, and the relative speed of social learning can offer individuals increased fitness benefits over and above genetically guided and individually learned behavior alone. Social learning allows some primates to create and maintain cultures, based on shared traditions and group‐typical behavior patterns, affording social and technical skills that many individuals would not have otherwise attained.
Socioecological model
Authors: Isbell Lynne A.
Published: October 2018

The “socioecological model” is a conceptual approach used to explain the diversity of social organizations among primates by identifying the ecological and social determinants responsible for such diversity. Historically, ecological determinants have been focused on predation pressure and food abundance/distribution, and social determinants on male participation in grouping behavior. More recently, the trend has been toward increasingly detailed predictions of female social behavior within certain types of social organizations. This has produced largely unsatisfactory results, and some have recommended that socioecology and its conceptual models be abandoned and replaced by approaches that involve phylogenetic, or internal, constraints. A more recent socioecological model follows in the footsteps of traditional socioecological models in considering only broad levels of diversity in social organization. It differs from other models by including both ecological determinants and evolved energetic constraints, the latter likely having a phylogenetic footprint.