User:TheDudeHotep/Biological anthropology

Biological Anthropology
Of the four fields of Anthropology (cultural, biological, linguistic, archaeology), Biological Anthropology focuses mainly on "human evolution, including our biology, our close primate relatives, our fossil ancestry, and our current similarities and differences." [1] It consists of an interdisciplinary approach to the study of the biology of homo sapiens as well as "biological characteristics, our evolution, our variation, our relationship with our environment, and our behavior including our ability to have culture."[3] Biological Anthropology is a field of anthropology that is heavily reliant on the scientific method and empirical science due to its biological component. Research is conducted in laboratory settings as well as in the field studying primates or collecting and analyzing fossils.[1]

Genetics and Evolutionary Theory
Studying the Evolutionary Theory and Genetics is critical for insight into how adaptive genetic traits are passed down to members within a species and the environmental or biological factors which effect them. Cell division, genomics, and DNA replication research allows biological anthropologists to trace ancestries with accuracy, filling in holes of the story of our evolutionary past. Individual gene sequences which reflect specific adaptive traits can be identified and inheritance patterns can be better understood.

The four forces of evolution are mutation, natural selection, genetic drift, and gene flow. Mutation refers to the crossover of chromosomes during replication resulting in genetic information being in the wrong place and modifying an organism with a possible adaptive trait. Natural selection is the theory that beneficial traits will cause reproductive success and proliferate among a species. Genetic Drift takes into account the changing landscape of dominant and recessive alleles in a population and how/why that happens. Gene Flow is a situation that occurs when two previously isolated populations merge and begin to mate and share genetic information between them.[1]

Specializations in this field:
Evolutionary biology is the study of the evolutionary processes that produced the diversity of life on Earth, starting from a single common ancestor. These processes include natural selection, common descent, and speciation.

Evolutionary psychology is the study of psychological structures from a modern evolutionary perspective. It seeks to identify which human psychological traits are evolved adaptations – that is, the functional products of natural selection or sexual selection in human evolution.

Human behavioral ecology is the study of behavioral adaptations (foraging, reproduction, ontogeny) from the evolutionary and ecologic perspectives (see behavioral ecology). It focuses on human adaptive responses (physiological, developmental, genetic) to environmental stresses.

Primatology
Humans share the taxonomic order Primate with other living non-human primates and descend from a common ancestor. Notable traits which belong to primates are mammary glands, terrestial/arboreal habitats, mostly diurnal cycles, opposable thumbs, uniparous (birth to lone offspring), forward facing eyes, and sizable brains. [1] Classification of modern primates and analysis of homologous and analogous traits which divide species further informs biological anthropology by providing clues to human evolution and biology. [2] Phylogenic methods are used by primatologists to determine which traits belong to humans and which adaptations are primate-specific. When comparing humans to other primates, bonobos, baboons, and chimpanzees contain the most homologies (traits derived from a common ancestor) and through research into their behavior, primatologists can shed light onto behavior of ancestral species as well as ourselves. For example, by studying the relationship between social organization and sexual dimorphism among primates, biologists can make predictions about the social organization of extinct species. Baboons, having branched off 20 million years ago, serve as an inferior comparison to chimpanzees (having branched off 12 million years ago) or bonobos (branching of from chimpanzees 1-2 million years ago). [3]

The study of primate behavior has also informed the field of biological anthropology. Through the use of affiliative behaviors (cooperative behaviors such as grooming or embracing) social bonds among primate groups are strengthened.[1] Clark states that by studying primate behavior one can see that "the early hominids of Africa may very well have been highly social creatures and that their social organization was built around differing interpersonal relationships, a family unit, conscious sexuality, recognition of group membership and territory, and mutual care at both the individual and the group level."[3]

Paleoanthropology
Due to the decay of soft-tissue over time bones become the majority of discovered remains and an intimate knowledge of osteology is needed to understand the fossils that are found. By observing skeletal remains of our ancestors, paleopathologists can discover the presence of diseases such as osteoporosis, arthritis, tuberculosis, anemias, leprosy, tumors and other cancers, syphilis, as well as various infections and marks left from injuries both antemortem and perimortem. [3] Paleoanthropologists can use fossil findings to distinguish animal from human bones, to find the minimum number of individuals represented by a bone assemblage, estimate the likely stature, sex and age at death and use the genetic information found in skeletons to determine probably ancestry.[5]

Primate Evolution
The study of primate evolution begins 200 MYA when a small nocturnal rodent inhabited a reptile dominant earth until the asteroid collided with the planet 66MYA leaving conditions favorable to the rodent.[1] This moment was the beginning of the rise of the mammal, or Cenozoic Era, and the small nocturnal rodent would adapt and evolve in the niches left vacant by the dying off of the reptiles. By the end of the Eocene (56 to 34 MYA) there are fossil records of mammals with anthropoid traits similar to small modern primates such as lemurs. The Miocene marks the appearance of the oldest known relative of old world monkeys occuring around 23 MYA and by 13 MYA there were numerous species of apes marking the emergence of the taxonomic family Hominidae of which humans will eventually belong. [1]

The first member of family Hominidae to appear is the Genus Australopithecus. The fossils remains were located in eastern and southern Africa and date between 4 and 1 MYA. Australopithecus demonstrated bipedal/arboreal abilities, was small-brained with slender cranial features, and ate a mixture of fruits and vegetables. [3] Between 4 and 1 MYA the genus would continue to change and exhibit larger cranial capacity, zygomatic arches, smaller teeth, and mandibles more similar to modern humans. [2]

Genus Homo
The genus homo emerges around 1.9-1.4 MYA with Homo ergaster found exclusively in Kenya. The features which mark our genus are an enlargement of the brain over previous hominids, flattening of the face, smaller teeth and jaws, refined bipedalism, new body proportions with a notable decrease in arm size, more reliant on culture to adapt, environmental manipulation, and finally global migration. [3] Around the same time period as Homo ergaster is Homo erectus which had inhabited an area that ranged from africa to asia as well as possibly southern europe. Both of these species had modern post-cranial skeletons nearly meeting the modern range as well as evidence of advanced stone tool use and culture including fire use. The next species, Homo heidelbergensis (also known as Homo habilis), is dated from 700 to 200 kya and is found primarily in Spain and had modern brain size but had a primitive skull. They are responsible for mass producing tools using an advanced technique found at Levallois and was dated 200kya. Finally, Homo neanderthalensis was found in Europe and Southwest Asia and the fossils date back 225 kya to 28 kya. They had a large prognathus face with a ruggedly built skull, and a robust muscular body. Among the finds there is evidence of retouched flaked tools, and cultural evidence of ritual burial and care for the infirm. The first fully modern humans are found in Africa around 300 kya and remains were found in southeast asia as early as 160 kya. From there humans populated the pacific islands, europe, and the Americas. Larsen states that there are six notable steps to humanness: bipedalism (6 MYA), nonhoning canine tooth (5.5 MYA), material culture (3.3 MYA), speech (2.5 MYA), hunting (1 MYA), and dependence on domesticated foods (11KYA). [3]

Specialization in this field:
Paleoanthropology is the study of fossil evidence for human evolution, mainly using remains from extinct hominin and other primate species to determine the morphological and behavioral changes in the human lineage, as well as the environment in which human evolution occurred.

Paleopathology is the study of disease in antiquity. This study focuses not only on pathogenic conditions observable in bones or mummified soft tissue, but also on nutritional disorders, variation in stature or morphology of bones over time, evidence of physical trauma, or evidence of occupationally derived biomechanic stress.

Bioarchaeology is the study of past human cultures through examination of human remains recovered in an archaeological context. The examined human remains usually are limited to bones but may include preserved soft tissue. Researchers in bioarchaeology combine the skill sets of human osteology, paleopathology, and archaeology, and often consider the cultural and mortuary context of the remains.

Modern Human Biology
Biological Anthropologists study the modern human population to better understand race and skin color, altitude and climate adaptations, the evolutionary forces at work, and the cultural influences on our shared traits. Early physical anthropologists focused on race as a dividing factor, but when genetic data is observed, the largest differences are happening within racial categories and not without. Skin color is studied as a biological adaptation to sun environmental intensity; whereas the pigment melanin (which darkens the skin) protects the individual from overexposure to UV radiation. In areas of high altitude humans have displayed adaptive responses to low oxygen by having more red blood cells, better breathing ability, or improved flow in the cardiovascular system which provides more oxygen. Body shape is also influenced by environment and humans in colder areas grew shorter and had stockier limbs to conserve heat, and populations near the equator developed longer limbs to increase skin surface area and ventilation. Blood type distribution across the globe creates observable patterns and can be used to better understand population trends in our past. Lactose Tolerance is known as the most recent evolutionary adaptation humans posses. In populations which descended from largely pastoral cultures it is much more common to find lactose tolerance.

Specializations in this field:
Forensic anthropology is the application of the science of physical anthropology and human osteology in a legal setting, most often in criminal cases where the victim's remains are in the advanced stages of decomposition.

Human biology is an interdisciplinary field of biology, biological anthropology, nutrition and medicine, which concerns international, population-level perspectives on health, evolution, anatomy, physiology, molecular biology, neuroscience, and genetics.

Origins
Johann Friedrich Blumenbach

Franz Boas

Biological Anthropology looks different today than it did even twenty years ago. The name is even relatively new, having been 'physical anthropology' for over a century, with some practitioners still applying that term. Biological anthropologists look back to the work of Charles Darwin as a major foundation for what they do today. However, if one traces the intellectual genealogy back to physical anthropology's beginnings—before the discovery of much of what we now know as the hominin fossil record—then the focus shifts to human biological variation. Some editors, see below, have rooted the field even deeper than formal science.

Attempts to study and classify human beings as living organisms date back to ancient Greece. The Greek philosopher Plato ( c. 428– c. 347 BC) placed humans on the scala naturae, which included all things, from inanimate objects at the bottom to deities at the top. This became the main system through which scholars thought about nature for the next roughly 2,000 years. Plato's student Aristotle ( c. 384–322 BC) observed in his History of Animals that human beings are the only animals to walk upright and argued, in line with his teleological view of nature, that humans have buttocks and no tails in order to give them a cushy place to sit when they are tired of standing. He explained regional variations in human features as the result of different climates. He also wrote about physiognomy, an idea derived from writings in the Hippocratic Corpus. Scientific physical anthropology began in the 17th to 18th centuries with the study of racial classification (Georgius Hornius, François Bernier, Carl Linnaeus, Johann Friedrich Blumenbach).

Physical Anthropology continued to pursue methods racial classification for much of its adolescence, but this research is being replaced with a focus on skin color as a spectrum of biological adaptation and less as a division within our species. [2]

"New Physical Anthropology"
In 1951 Sherwood Washburn, a former student of Hooton, introduced a "new physical anthropology." He changed the focus from racial typology to concentrate upon the study of human evolution, moving away from classification towards evolutionary process. Anthropology expanded to include paleoanthropology and primatology. The 20th century also saw the modern synthesis in biology: the reconciling of Charles Darwin’s theory of evolution and Gregor Mendel’s research on heredity. Advances in the understanding of the molecular structure of DNA and the development of chronological dating methods opened doors to understanding human variation, both past and present, more accurately and in much greater detail.

Notable biological anthropologists

 * Zeresenay Alemseged
 * John Lawrence Angel
 * George J. Armelagos
 * William M. Bass
 * Caroline Bond Day
 * Jane E. Buikstra
 * William Montague Cobb
 * Carleton S. Coon
 * Robert Corruccini
 * Raymond Dart
 * Egon Freiherr von Eickstedt
 * Linda Fedigan
 * A. Roberto Frisancho
 * Jane Goodall
 * Earnest Hooton
 * Aleš Hrdlička
 * Sarah Blaffer Hrdy
 * Anténor Firmin
 * Dian Fossey
 * Birute Galdikas
 * Richard Lynch Garner
 * Colin Groves
 * Yohannes Haile-Selassie
 * Ralph Holloway
 * William W. Howells
 * Donald Johanson
 * Robert Jurmain
 * Melvin Konner
 * Louis Leakey
 * Mary Leakey
 * Richard Leakey
 * Frank B. Livingstone
 * Owen Lovejoy
 * Jonathan M. Marks
 * Robert D. Martin
 * Russell Mittermeier
 * Desmond Morris
 * Douglas W. Owsley
 * David Pilbeam
 * Kathy Reichs
 * Alice Roberts
 * Pardis Sabeti
 * Robert Sapolsky
 * Eugenie C. Scott
 * Meredith Small
 * Phillip V. Tobias
 * Douglas H. Ubelaker
 * Sherwood Washburn
 * David Watts
 * Tim White
 * Milford H. Wolpoff
 * Richard Wrangham
 * Teuku Jacob
 * Biraja Sankar Guha