Craniofacial Anthropometry
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Craniofacial anthropometry is a technique used in physical anthropology comprising precise and systematic measurement of the bones of the human skull. Among its more important applications are: forensics, facial reconstruction, and paleoanthropology. The field of phylogeography, on the other hand, once relied heavily on this technique but no longer does so.[1] Craniofacial anthropometry is a sub-field of Craniometry, which see for more detail and history.
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[edit] In Forensic Anthropology
See main article: Forensic anthropology.
Forensic anthropologists study the human skeleton in a legal setting, most often in criminal cases where the victim's remains are more or less skeletonized. A forensic anthropologist can also assist in the identification of deceased individuals whose remains are decomposed or otherwise unrecognizable. The adjective "forensic" refers to the application of this subfield of science to a court of law. Craniofacial anthropometry of a person's remains can help determine what the person looked like when alive. Also, due to the requirements of the U.S. judicial system[citation needed], U.S. forensic practitioners are sometimes asked to classify remains into one of the U.S. socially-enforced endogamous groups: Black, White, or East Asian. In legal practice, these are sometimes termed, respectively, "Negroid," "Caucasoid," and "Mongoloid," or even the older "Caucasian," "Negro," and "Oriental." Nowadays, the terms "Black," "White," and "East Asian" are the more common usage.
"Caucasoids" are generalized to have the lowest degree of projection of the alveolar ridge bones which contain the teeth, a notable size prominence of the cranium and forehead region, and a projection of the midfacial region. "Negroid" traits are generalized to include more rounded eye sockets; broader, more rounded nasal cavity; a forward-slanting facial profile (prognathism); and a dolichocephalic skull (proportionally longer from front to back).
[edit] In Medicine
Surgeons employ the methods of craniofacial anthropometry in order to reconstruct a patient's face, when necessary, to fit within the limits of what society expects.
[edit] In Paleoanthropology
Paleoanthropologists employ craniofacial anthropometry in the study of fossilized hominid bones in order to identify the species. Specimens of Homo erectus and athletic specimens of Homo sapiens, for example, are virtually identical from the neck down but their skulls can easily be told apart.
[edit] In Phylogeography
Phylogeography (see main article) is the science of identifying and tracking major long-distance migrations that bands of humans undertook, especially in prehistoric times. For a detailed account of Human migrations see that article. Linguistics can follow the movement of languages and archaeology can follow the movement of artifact styles, but neither can tell whether a culture's spread was due to a source population's physically migrating or to a destination population's simply copying the technology and learning the language. Craniofacial anthropometry helped resolve this because a people's physiognomy does not change rapidly due to mere migration.
Carleton S. Coon, the greatest craniofacial anthropometrist of the 20th century, used the technique for his groundbreaking The Origin of Races (New York: Knopf, 1962). Because of the inconsistencies in the old three-part system (Caucasoid, Mongoloid, Negroid), Coon adopted a five-part scheme. He discarded the term "Negroid" as useless or misleading since it implied a dark skin-tone, which is found low lattitudes around the globe. As shown in the map, he defined "Caucasoid" as a pattern of skull measurements typical of humans indigenous to an area including Europe, South Asia, West Asia, of North Africa, Central Asia, and parts of sub-Saharan Africa (Senegal, Gambia, Chad, Burkina Faso, Ethiopia, and Somalia). He defined skulls typic of equatorial Africa as "Congoid" and those of southern Africa as "Capoid." Finally, he split "Australoid" from "Mongoloid" along a line roughly similar to the modern distinction between sinodonts in the north and sundadonts in the south.
In another great work, The Races of Europe, Coon classified Caucasoids into "races" named after regions or archeological sites such as Brünn, Borreby, Alpine, Ladogan, East Baltic, Neo-Danubian, Lappish, Mediterranean, Atlanto-Mediterranean, East African, Irano-Afghan, Nordic, Hallstatt, Keltic, Tronder, Dinaric, Noric and Armenoid. This extremely typological view of "race" was, even at the time of publication in 1939, becoming seen as very much out of date among many anthropologists.
With the discovery that many blood proteins vary consistently among populations, followed by the discovery of the DNA code, the invention of the polymerase chain reaction that amplifies trace amounts of DNA, and the decoding of the human genome, phylogeographers switched almost entirely away from craniofacial anthropometry whenever DNA is available. This is because DNA findings are more replicable.
[edit] Racial Determination Example
That craniofacial anthropometry is not as replicable as other ways of tracking human variation makes its findings difficult to explain.[citation needed] Here is a trivial example: imagine that you are handed a U.S. skull and asked to determine whether the person was White, Black, or Asian (that is, Euro-American, African American, or Asian American). Place the skull face down on a tabletop. Now try to rock it from side to side. If it fails to rock, but instead sits high on its cheekbones, with a face too flat to let the nose portion touch the table, then the chances are that it is of east Asian ancestry. If it rocks from side to side because the midline of the face protrudes past the cheekbones like the bow of a boat, then it is probably of either African or European ancestry. Now stand the skull upright so that it rests on the neck opening. If the face slopes down and forwards because the mouth protrudes farther forward than the forehead, then it is likely of west African ancestry. If the face is vertical, it is probably of European ancestry. In practice, many other tests are necessary in order to hazard a determination but, in the end, it works because there are consistent differences among U.S. endogamous groups. A skull that matches the group of features associated with African-American ancestry is called "Negroid." Skulls with traits suggesting European and Asian ancestry are called, respectively "Caucasoid" and "Mongoloid."
[edit] Challenges
There are three challenges to using the technique. First, many of the measurements are exceedingly subtle and subjective. Some measurements regularly give four widely different results if four equally well-trained experts measure the same skull. Other measurements are more objective but unfortunately these do not vary among U.S. endogamous groups.
Second, such methods work less well on foreign populations. Most Ethiopians and Somalis, for example, along with almost all of the inhabitants of India have mainly or partially Caucasoid skulls, while the Khoisan people indigenous to southwestern Africa have partially Mongoloid skulls (Capoid). Hence, the skull designations of people outside the United States often fail to match their "race" as seen by some Americans.
Third, it is important to understand that the terminology reflects the skull, and not the ethnic group with which the person was affiliated in life. Many White Americans have partially Negroid or Mongoloid skulls, many Black Americans have partially Caucasoid or Mongoloid skulls, many Asian Americans have partially Caucasoid or Negroid skulls, and U.S. Hispanics have skulls that span the entire range of human variation. One can say that the "race" of a skull need not always match the "race" of its owner in life. The "race" of the skull is much less ambiguous. As Dr. Stan Rhine put it, "...it is clear that race does mean different things to different people. In the context of forensic anthropology, the term race is unambiguous."[2]
See the main article Race.
[edit] Footnotes
- ^ The current standard reference is John C. Kolar and Elizabeth M. Salter, Craniofacial Anthropometry: Practical Measurement of the Head and Face for Clinical, Surgical, and Research Use (Springfield IL: C.C. Thomas, 1997).
- ^ http://medstat.med.utah.edu/kw/osteo/forensics/race.html.
