Porsche 356

Worldwide, thousands of 356 owners maintain the tradition, preserving their cars and driving them regularly. Although there has historically been little or no gene flow between some human populations such as the aboriginal Australians and black Africans, they a. Today the Porsche 356 is a well regarded collector car that has stood the test of time. Cultural anthropologists believe humans to be monotypic because they argue races gradually fade into one another in many parts of the world. In 2004, Sports Car International named the 356C number ten on the list of Top Sports Cars of the 1960s. Opponents of racial groupings argue that a distinct difference is only one of the two conditions for racial classifiction; the second condition is a lack of significant gene flow between populations. The 356's engine was later re-used to power Porsche's "entry level" 912 model, produced between 1965 and 1969, after customers complained that the 911, at almost twice the price of the 356, was too expensive. 2004).

356 production peaked at 14,151 cars in 1964, the year that the new 911 model went on the market, although the company continued to sell the 356C in North America through the end of 1965 as a lower-cost vehicle (the late Janis Joplin had a 356C cabriolet which was psychedelically painted). To complicate matters further, recent analyses suggest that everyone living today has exactly the same set of genealogical ancestors who lived as recently as a few thousand years in the past, although we have received our genetic inheritance in different proportions from those ancestors (Rohde et al. The final model, the 356C, featured disc brakes and the most powerful pushrod engine Porsche ever produced: the 95HP "SC". Furthermore, the exponentially increasing number of our ancestors makes ancestry a quantitative rather than qualitative trait—5 centuries (or 20 generations) ago, each person had a maximum of >1 million ancestors (Ohno 1996). Coupe and cabriolet models were produced every year up to 1965, with the last 356B Roadster built in early 1963. Misattributed paternity or adoption can separate biogeographical ancestry from socially defined ancestry. While the 356 model changed over time with various mechanical refinements, the basic shape remained the same and was instantly recognizable year to year. 2003).

Production of the Speedster peaked at 1,171 cars in 1957, and it was replaced in 1959 by the Convertible D model, which featured a taller, more practical windshield, glass side windows, and more comfortable seats. In one series of focus groups in the state of Georgia, 40% of ∼100 respondents said they did not know one or more of their four grandparents well enough to be certain how that person(s) would identify racially (Condit et al. (and its sequel Another 48 Hrs.), and Top Gun. When asked about the ancestry of their parents and grandparents, many people cannot provide accurate answers. The now much coveted Speedster (which often sell for over $100,000) was later used in a number of films, including - 48 Hrs. Despite its seemingly objective nature, ancestry also has limitations as a way of categorizing people (Elliott and Brodwin 2002). With it's low, raked windshield (easily removable for weekend racing), bucket seats, and minimal folding top, it was an instant hit. 2004).

The 356 "Speedster" was introduced in late 1954 after Max Hoffman, the sole importer of Porsches into the United States, told the company that they needed a lower cost, racier version for the American market. However, others argue that low levels of differentiation between groups merely make the assignment to groups more difficult, not impossible (Bamshad et al. The original selling price of a late 50's Porsche was nearly $4,000, the price of a Cadillac!. The existence of allelic clines has been offered as evidence that individuals cannot be allocated into genetic clusters (Kittles & Weiss 2003). 356 "Carrera" (with a special racing engine), "Super 90" and "Speedster" models are among the most desirable versions; 356 Carrera models often sell for well over $150,000 USD. This phenomenon is often seen as a cline of allele frequencies. It was initially available as a coupé, cabriolet (luxury convertible) and later a roadster (a stripped down convertible) and went through several evolutions before being retired in 1965. As a result, allele frequencies will be correlated between these groups.

had designed. Populations from neighboring geographic regions typically share more recent common ancestors. The 356 concept was created by Ferdinand "Ferry" Porsche (Ferry being a nickname), styled by Erwin Komenda, and mechanically derived from the Volkswagen Beetle, which Ferdinand Porsche Sr. However, the study of intra-continental ancestry may require a greater number of informative markers. It was preceded by the Porsche 64, which has lead to some argument over which car is officially the first Porsche, although the Type 64 was never mass-produced and was never much more than a driveable test-mule. Genetic techniques that distinguish ancestry between continents can also be used to describe ancestry within continents. The Porsche 356 was a Porsche sports car sold from 1948 through 1965, and Porsche's first production automobile. population.

Porsche 550 Spyder. They conclude that ancient ancestry, which correlates tightly with self-described race and not current residence, is the major determinant of genetic structure in the U.S. ISBN 0-75252-072-5. (2005) identified 4 genetic clusters among 3,636 individuals sampled from 15 locations in the United States, and were able to correctly assign individuals to groups that correspond with their self-described race (white, African American, East Asian, or Hispanic) for all but 5 individuals (an error rate of 0.14%). Parragon. Using 326 genetic markers, Tang et al. Porsche: The Legend. Nevertheless, recent research indicates that self-described race is a near-perfect indicator of an individual's genetic profile, at least in the United States.

Wood, J (1997). Without the use of genotyping, this has been approximated by the self-described ancestry of an individual's grand-parents. In this context, it is becoming more commonplace to describe "race" as fractional ancestry. Likewise, many white Americans have mixed European and African ancestry, where ~30% of whites have less than 90% European ancestry. (2003) found that on average African Americans have ~80% African ancestry.

Shriver et al. For example, self-described African Americans tend to have a mix of West African and European ancestry. Some racial or ethnic groups, especially Hispanic groups, do not have homogenous ancestry. One cause of the reduced power of the assignment of individuals to groups is admixture.

However, in analyses that assign individuals to group it becomes less apparent that self-described racial groups are reliable indicators of ancestry. (2005) were able to assign 1,048 individuals from 52 populations around the globe to one of six genetic clusters, which correspond to major geographic regions. For example, using 993 markers, Rosenberg et al. However, even if group identity is stripped and group identity assigned a posteriori using only genetic data, population structure can still be inferred.

Many such studies are criticized for assigning group identity a priori. These studies usually find that groups of humans living on the same continent are more similar to one another than to groups living on different continents. The inference of population structure from multilocus genotyping depends on the selection of a large number of informative genetic markers. Genetic data can be used to infer population structure and assign individuals to groups that often correspond with their self-identified geographical ancestry.

2005), but in an unknown percentage of cases, they do not (Brodwin 2002; Kaplan 2003). At least among those individuals who participate in biomedical research, genetic estimates of biogeographical ancestry generally agree with self-assessed ancestry (Tang et al. census prior to 1960; it can be identified by an individual from a list of possibilities or with use of terms drawn from that person's experience; or it can be calculated from genetic data by use of loci with allele frequencies that differ geographically, as described above. Ancestry can be ascribed to an individual by an observer, as was the case with the U.S.

The definition of ancestry may recognize a single predominant source or multiple sources. Ancestry may be defined geographically (e.g., Asian, sub-Saharan African, or northern European), geopolitically (e.g., Vietnamese, Zambian, or Norwegian), or culturally (e.g., Brahmin, Lemba, or Apache). An alternative to the use of racial or ethnic categories is to categorize individuals in terms of ancestry. Furthermore, ethnic groups tend to promote marriage within the group, which creates an expectation of biological cohesion regardless of whether that cohesion existed in the past.

Ethnic groups can share a belief in a common ancestral origin (Cornell and Hartmann 1998), which also can be a defining characteristic of a racial group. Finally, despite attempts to distinguish "ethnicity" from "race," the two terms often are used interchangeably (Oppenheimer 2001). 2003). A researcher, clinician, or government official might assign an ethnicity to an individual quite different from the one that person would acknowledge (Kressin et al.

Individuals might change ethnic groups over the course of their lives or identify with more than one group. Ethnic groups may come into existence and then dissipate as a result of broad historical or social trends. 2001). Also, ethnicity, like race, is a malleable concept that can change dramatically in different times or circumstances (Waters 1990; Smelser et al.

Combining these groups into a single category may serve useful bureaucratic or political ends but does not necessarily result in a better understanding of these groups. In the United States, the ethnic group "Hispanic or Latino" contains such subgroups as Cuban Americans, Mexican Americans, Puerto Ricans, and recent immigrants from Central America (Hayes-Bautista and Chapa 1987). First, ascribing an ethnic identity to a group can imply a much greater degree of uniformity than is actually the case. However, as a way of understanding human groups, ethnicity also suffers from several shortcomings.

It may encompass language, diet, religion, dress, customs, kinship systems, or historical or territorial identity (Cornell and Hartmann 1998). Ethnicity typically emphasizes the cultural, socioeconomic, religious, and political qualities of human groups rather than their genetic ancestry. As the problems surrounding the word "race" became increasingly apparent during the 20th century, the word "ethnicity" was promoted as a way of characterizing the differences between groups (Huxley and Haddon 1936; Hutchinson and Smith 1996).
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If "races" is too freighted a term for these basic divisions of humanity then, according to these authorities, new, convenient, non-academic terminology free of spurious valuations of superiority and inferiority should be developed and deployed whether social sensitivities are ruffled or not. Recognition of these groups, and simple ways to refer to them, is especially important in fields like medical research and diagnosis because a rapidly growing list of genetic disorders and predispositions are strongly linked to race and ethnicity (not to geographical "populations"). The basal groups outside the clinal zones on these maps are summarized quite well by longstanding racial and ethnic appellations. This position recently received a boost from genetic studies at the molecular level which show characteristic allele signatures for the groups traditionally identified as the three major races (Africans, Asians and Europeans), resulting in maps that clearly delineate genetic clines (in which the clinal zones are a small part of the total).

They are not convinced by the substitution of the term "population" for the term "race" because it leads to a potentially harmful imprecision in communication (for example, when one could simply say 'white' (or "Caucasian") one is instead compelled to say something like "an individual of the western Eurasian population", and when that individual doesn't happen to currently reside in western Eurasia one must say "an individual whose ancestors were of the western Eurasian population"). Other anthropologists and human geneticists argue that race is indeed a valid and valuable concept and that those holding the opposite view allow their social consciences (laudable per se) to confuse and delay accurate interpretations and applications of empirical data. Bouchard, Jr., Professor of Psychology, University of Minnesota. Louis; and Thomas J.

Holloway, Professor of Anthropology, Columbia University; Arthur Jensen; Joseph Carroll, University of Missouri-St. A number of scientists have supported this currently controversial view, including Ralph L. Vincent Sarich and Frank Miele, in Race: The Reality of Human Differences, write that "racial differences in humans exceed the differences that separate subspecies or even species in such other primates as gorillas and chimpanzees" and that "race is a biologically real phenomenon with important consequences". They claim that race researchers are often attacked as racists, even if they espouse liberal sociopolitical views and claim to be against racism.

Some researchers believe the view that races do not exist is influenced by racial politics and political correctness, not science. This definition requires that a subspecies be genetically differentiated due to barriers to genetic exchange that have persisted for long periods of time; that is, the subspecies must have historical continuity in addition to current genetic differentiation" Templeton (1998). In most contemporary research, races are defined as evolutionary linages: "a subspecies (race) is a distinct evolutionary lineage within a species. They point to the existence of groups determined on the basis of multi-locus genetic analysis as evidence that human population structure does exist and to some extent resembles conventional definitions of race.

Some biologists believe that the view that races are a social construct or not biologically significant is incorrect. 2003). Until the 2000 census, Latinos were required to identify with a single race despite the long history of mixing in Latin America; partly as a result of the confusion generated by the distinction, 42% of Latino respondents in the 2000 census ignored the specified racial categories and checked "some other race" (Mays et al. 2003).

A person's racial identity can change over time, and self-ascribed race can differ from assigned race (Kressin et al. Efforts to track mixing between groups led to a proliferation of categories (such as mulatto and octoroon) and "blood quantum" distinctions that became increasingly untethered from self-reported ancestry. By the standards used in past censuses, many millions of children born in the United States have belonged to a different race than have one of their biological parents. Efforts to sort the increasingly mixed population of the United States into discrete categories generated many difficulties (Spickard 1992).

In other countries in the Americas where mixing among groups was more extensive, social categories have tended to be more numerous and fluid, with people moving into or out of categories on the basis of a combination of socioeconomic status, social class, ancestry, and appearance (Mörner 1967). The decennial censuses conducted since 1790 in the United States also created an incentive to establish racial categories and fit people into those categories (Nobles 2000). An example is the "one-drop rule" implemented in some state laws that treated anyone with a single known African American ancestor as black (Davis 2001). In the United States, social and legal conventions developed over time that forced individuals of mixed ancestry into simplified racial categories (Gossett 1997).

2003). university, ∼30% were estimated to have <90% European ancestry (Shriver et al. In a survey of college students who self-identified as white in a northeastern U.S. Similarly, many people who identify as European American have some African or Native American ancestors, either through openly interracial marriages or through the gradual inclusion of people with mixed ancestry into the majority population.

1998). In the United States, for example, most people who self-identify as African American have some European ancestors—in one analysis of genetic markers that have differing frequencies between continents, European ancestry ranged from an estimated 7% for a sample of Jamaicans to ∼23% for a sample of African Americans from New Orleans (Parra et al. In the Americas, the immigrant populations began to mix among themselves and with the indigenous inhabitants of the continent. The immigrants to the New World came largely from widely separated regions of the Old World—western and northern Europe, western Africa, and, later, eastern Asia and southern and eastern Europe.

In parts of the Americas, the situation was somewhat different. 54). In the Old World, the gradual transition in appearances from one group to adjacent groups emphasized that "one variety of mankind does so sensibly pass into the other, that you cannot mark out the limits between them," as Blumenbach observed in his writings on human variation (Marks 1995, p. Even as the idea of "race" was becoming a powerful organizing principle in many societies, the shortcomings of the concept were apparent.

Moreover, they argue that biology will not explain why or how people use the idea of race: history and social relationships will. As such it cannot be a useful analytical concept; rather, the use of the term "race" itself must be analyzed. Since the 1960s, some anthropologists and teachers of anthropology have re-conceived "race" as a cultural category or social construct, in other words, as a particular way that some people have of talking about themselves and others. In particular, populationists claim that:.

The "populationist" view does not deny that there are physical differences among peoples; it simply claims that the historical conceptions of "race" are not particularly useful in accounting for these differences scientifically. Populations are, in a sense, simply statistical clusters that emerge from the choice of variables of interest; there is no preferred set of variables. This substitution is not simply a matter of exchanging one word for another. For example, some scientists developed the notion of "population" to take the place of race.

These developments had important consequences. There can be as much difference between two ethnicities grouped into a single "race" as there can be between ethnicities grouped (often arbitrarily) into an another "race". Instead of classing people into one "group", say "Caucasians" or Europeans you have Britons, Frenchmen, Germans, Nords, western Slavs and Celts rather than having a term implying a (possible) ancestory group in the Caucasus which is definitely too distant for any real consideration, and moreover reaching to groups including eastern Slavs, Roma, as well as Georgians, and others who differ notably, both in culture, and to a noteworthy extent in physical appearance, from the aforementioned ethnic groups. Some argue it is preferable when considering biological relations to think in terms of populations, and when considering cultural relations to think in terms of ethnicity, rather than of race.

In much of Europe groups such as Roma and Turks are commonly defined as racially distinct from White Europeans, though these groups could be considered "Caucasian" by old physical anthropological methods which employed finite nose measurements as the standard form of racial classifaction. In the United States, in what is referred to as the one-drop rule, the term Black subsumes people with a broad range of ancestries under one label, even though many who are termed Black could be more accurately described as white through simple anthropologic or taxonomic method. In Europe, such a distinction, suggesting that South Europeans are not European or white, would seem odd at least or possibly even insulting. For instance in many parts of the United States, categories such as Hispanic or Latino are viewed to constitute a race, though others see Hispanic as a linguistic and cultural grouping coming from a variety of backgrounds.

In everyday speech, race often describes populations better defined as ethnic groups, often leading to discrepancies between scientific views on race and popular usage of the term. For example, most babies born with Tay-Sachs in North America at present are not from Jewish families, despite stereotypes to contrary. This is fortunate, as increasing interracial marriage is reducing the predictive power of race. As genetic tests for such conditions become cheaper, and as detailed haplotype maps and SNP databases become available, the need to resort to race should diminish.

Regardless of the name, a working concept of sub-species grouping can be useful, because in the absence of cheap and widespread genetic tests, various race-linked gene mutations (see Cystic fibrosis, Lactose intolerance, Tay-Sachs Disease and Sickle cell anemia) are difficult to address without recourse to a category between "individual" and "species". This may either be a matter of semantics, or an effect of an underlying cultural significance of race in racist societies. Even those who reject the formal concept of race, however, still use the word race in day-to-day speech. Historians, anthropologists and social scientists often describe human races as a social construct, preferring instead the term population, which can be given a clear operational definition.

However, any given physical characteristic generally is found in multiple groups (Lahr 1996), and demonstrating that environmental selective pressures shaped specific physical features will be difficult, since such features may have resulted from sexual selection for individuals with certain appearances or from genetic drift (Roseman 2004). Considerable speculation has surrounded the possible adaptive value of other physical features characteristic of groups, such as the constellation of facial features observed in many eastern and northeastern Asians (Guthrie 1996). 2003). In Brazil, for example, skin color is not closely associated with the percentage of recent African ancestors a person has, as estimated from an analysis of genetic variants differing in frequency among continent groups (Parra et al.

2004). Furthermore, in some parts of the world in which people from different regions have mixed extensively, the connection between skin color and ancestry has been substantially weakened (Parra et al. Sub-Saharan Africans, tribal populations from southern India, and Indigenous Australians have similar skin pigmentation, but genetically they are no more similar than are other widely separated groups. Because skin color has been under strong selective pressure, similar skin colors can result from convergent adaptation rather than from genetic relatedness.

Melanin which serves as the pigment, is located in the epidermis of the skin, and is based on hereditary gene expression. 2000). However, the vitamin D hypothesis is not universally accepted (Aoki 2002), and lighter skin in high latitudes may correspond simply to an absence of selection for dark skin (Harding et al. 2005).

Evidence for this includes the finding that a substantial portion of the differences of skin color between Europeans and Africans resides in a single gene, SLC24A5 the threonine-111 allele of which was found in 98.7 to 100% among several European samples, while the alanine-111 form was found in 93 to 100% of samples of Africans, East Asians and Indigenous Americans (Lamason et al. A leading hypothesis for the selection of lighter skin in higher latitudes is that it enables the body to form greater amounts of vitamin D, which helps prevent rickets (Jablonski 2004). 2001; Rees 2003). Darker skin appears to be strongly selected for in equatorial regions to prevent sunburn, skin cancer, the photolysis of folate, and damage to sweat glands (Sturm et al.

This distribution of skin color and its geographic patterning—with people whose ancestors lived predominantly near the equator having darker skin than those with ancestors who lived predominantly in higher latitudes—indicate that this attribute has been under strong selective pressure. Approximately 10% of the variance in skin color occurs within groups, and ~90% occurs between groups (Relethford 2002). A prominent exception to the common distribution of physical characteristics within and among groups is skin color. For example, ∼90% of the variation in human head shapes occurs within every human group, and ∼10% separates groups, with a greater variability of head shape among individuals with recent African ancestors (Relethford 2002).

The distribution of many physical traits resembles the distribution of genetic variation within and between human populations (American Association of Physical Anthropologists 1996; Keita and Kittles 1997). 2004). Even with large numbers of markers, information for estimating admixture proportions of individuals or groups is limited, and estimates typically will have wide CIs (Pfaff et al. 1994; Hoerder 2002).

2004), these estimates may assume a false distinctiveness of the parental populations, since human groups have exchanged mates from local to continental scales throughout history (Cavalli-Sforza et al. 2003; Bamshad et al. Although genetic analyses of large numbers of loci can produce estimates of the percentage of a person's ancestors coming from various continental populations (Shriver et al. In many parts of the world, groups have mixed in such a way that many individuals have relatively recent ancestors from widely separated regions.

2004). Thus, the genetically based "biogeographical ancestry" assigned to any given person generally will be broadly distributed and will be accompanied by sizable uncertainties (Pfaff et al. Furthermore, because human genetic variation is clinal, many individuals affiliate with two or more continental groups. Thus, samples taken from India and Pakistan affiliate with Europeans or eastern Asians rather than separating into a distinct cluster.

They point out, for example, that major populations considered races or subgroups within races do not necessarily form their own clusters. Other observers disagree, saying that the same data undercut traditional notions of racial groups (King and Motulsky 2002; Calafell 2003; Tishkoff and Kidd 2004). 2002). They argue that the continental clusterings correspond roughly with the division of human beings into sub-Saharan Africans; Europeans, western Asians, and northern Africans; eastern Asians; Polynesians and other inhabitants of Oceania; and Native Americans (Risch et al.

Some commentators have argued that these patterns of variation provide a biological justification for the use of traditional racial categories. 2003). 2002; Bamshad et al. For example, computer analyses of hundreds of polymorphic loci sampled in globally distributed populations have revealed the existence of genetic clustering that roughly is associated with groups that historically have occupied large continental and subcontinental regions (Rosenberg et al.

Although the genetic differences among human groups are relatively small, these differences in certain genes such as duffy, ABCC11, SLC24A5, called ancestry-informative markers (AIMs) nevertheless can be used to reliably situate many individuals within broad, geographically based groupings or self-identified race. These questions are particularly pressing for biomedicine, where self-described race is often used as an indicator of ancestry (see race in biomedicine below). However, other researchers still debate whether evolutionary lineages should rightly be called "races". A large majority of researchers endorse the view that continental groups do not constitute different subspecies.

Most of the controversy surrounds the question of how to interpret these new data, and whether conclusions based on existing data are sound. New data on human genetic variation has reignited the debate surrounding race. In general, however, the recency of our common ancestry and continual gene flow among human groups have limited genetic differentiation in our species. 2000b; Bamshad and Wooding 2003).

For example, population processes associated with colonization, periods of geographic isolation, socially reinforced endogamy, and natural selection all have affected allele frequencies in certain populations (Jorde et al. Many other geographic, climatic, and historical factors have contributed to the patterns of human genetic variation seen in the world today. Second, new polymorphisms that arose in one group were less likely to be transmitted to other groups as gene flow was restricted. First, smaller (founder) populations experience greater genetic drift because of increased fluctuations in neutral polymorphisms.

The expansion of humans from Africa affected the distribution of genetic variation in two other ways. The effect of this assortative mating is to reduce gene flow between geographical groups, and to increase the genetic distance between groups. Second, as founders become more geographically separated, the probability that two individuals from different founder populations will mate becomes smaller. First, the so-called founder effect occurs when founder populations bring only a subset of the genetic variation from their ancestral population.

The rapid expansion of a previously small population has two important effects on the distribution of genetic variation. 2,000 generations). 5,000 generations), followed by a European-Asian divergence about 40,000 years ago (ca. It is believed that humans passed through a population bottleneck before a rapid expansion coinciding with migrations out of Africa leading to an African-Eurasian divergence around 100,000 years ago (ca.

In the field of population genetics, it is believed that the distribution of neutral polymorphisms among contemporary humans reflects human demographic history. In contrast, populations that have undergone dramatic size reductions or rapid expansions in the past and populations formed by the mixture of previously separate ancestral groups can have unusually high levels of linkage disequilibrium (Nordborg and Tavare 2002). 2002). For example, in addition to having higher levels of genetic diversity, populations in Africa tend to have lower amounts of linkage disequilibrium than do populations outside Africa, partly because of the larger size of human populations in Africa over the course of human history and partly because the number of modern humans who left Africa to colonize the rest of the world appears to have been relatively low (Gabriel et al.

Our history as a species also has left genetic signals in regional populations. In the field of population genetics, it is believed that the distribution of neutral polymorphisms among contemporary humans reflects human demographic history. This distribution of genetic variation differs from the pattern seen in many other mammalian species, for which existing data suggest greater differentiation between groups (Templeton 1998; Kittles and Weiss 2003). 2005).

2000a; Hinds et al. In general, however, 5%–15% of genetic variation occurs between large groups living on different continents, with the remaining majority of the variation occurring within such groups (Lewontin 1972; Jorde et al. The details of this distribution are impossible to describe succinctly because of the difficulty of defining a "population," the clinal nature of variation, and heterogeneity across the genome (Long and Kittles 2003). The distribution of variants within and among human populations also differs from that of many other species.

It is estimated that about 10 million SNPs exist in human populations, where the rarer SNP allele has a frequency of at least 1% (see International HapMap Project). Most of these single nucleotide polymorphisms (SNPs) are neutral, but some are functional and influence the phenotypic differences between humans. However, with a genome of approximate 3 billion nucleotides, on average two humans differ at approximately 3 million nucleotides. Two random humans are expected to differ at approximately 1 in 1000 nucleotides, whereas two random chimpanzees differ at 1 in 500 nucleotide pairs.

2004). 2003; Fischer et al. 2002; Yu et al. For example, the chimpanzee subspecies living just in central and western Africa have higher levels of diversity than do humans (Ebersberger et al.

2001). First, compared with many other mammalian species, humans are genetically less diverse—a counterintuitive finding, given our large population and worldwide distribution (Li and Sadler 1991; Kaessmann et al. But the data gathered to date suggest that human variation exhibits several distinctive characteristics. A thorough description of the differences in patterns of genetic variation between humans and other species awaits additional genetic studies of human populations and nonhuman species.

Note that vertical distances are not meaningful in this representation. Formation of species and subspecies is also indicated, and the formation of "races" is indicated in the green rectangle to the right (note that only a very rough representation of human phylogeny is given). Chimpanzees and humans belong to different genera, indicated in red. Horizontal distance corresponds to two things:.

The tree is rooted in the common ancestor of chimpanzees and humans, which is believed to have originated in Africa. Individuals from the various continental groups tend to be more similar to one another than to people from other continents. These single-locus sources of DNA do not recombine and are almost always inherited from a single parent, with only one known exception in mtDNA (Schwartz and Vissing 2002). Often mitochondrial DNA or Y chromosome sequences are used to study ancient human demographics.

A phylogenetic tree like the one shown above is usually derived from DNA or protein sequences from populations. Sequence data for hundreds of loci from widely distributed worldwide populations eventually may clarify the population processes associated with the appearance of anatomically modern humans (Wall 2000), as well as the amount of gene flow among modern humans since then. The observation that most genes studied to date coalesce in African populations points toward the importance of Africa as the source of most modern genetic variation, perhaps with some subdivision in the ancestral African population (Satta and Takahata 2002). 2004).

2001; Serre et al. 1997; Nordborg 1998; Takahata et al. In addition, studies of mtDNA from archaic and modern humans and extant Y chromosomes suggest that any surviving genetic contributions of archaic humans outside Africa must be small, if they exist at all (Krings et al. However, distinguishing possible contributions to the gene pool of modern humans from archaic humans outside Africa is difficult, especially since many autosomal loci coalesce at times preceding the separation of archaic human populations (Pääbo 2003).

2001). As a result, they say, autosomal DNA from archaic human populations living outside Africa persists in modern populations, and modern populations in various parts of the world still bear some physical resemblance to the archaic populations that inhabited those regions (Wolpoff et al. 2003). 2000; Eswaran 2002; Templeton 2002; Ziętkiewicz et al.

They contend that humans bearing modern traits emerged several times from Africa, over an extended period, and mixed with archaic humans in various parts of the world (Hawks et al. However, several groups of researchers cite fossil and genetic evidence to argue for a more complex account. 2000; Stringer 2002). 1999), and many (though not all) autosomal regions (Harpending and Rogers 2000) support the "Out of Africa" account of human history, in which anatomically modern humans appeared first in eastern Africa and then migrated throughout Africa and into the rest of the world, with little or no interbreeding between modern humans and the archaic populations they gradually replaced (Tishkoff et al.

2000), portions of the X chromosome (Kaessmann et al. 2000), the Y chromosome (Underhill et al. Studies of mtDNA (Ingman et al. Aspects of the relationship between anatomically modern and archaic humans remain contentious.

1998). Patterns of genetic variation suggest an earlier population expansion in Africa followed by a subsequent expansion in non-African populations, and the dates calculated for the expansions generally coincide with the archaeological record (Jorde et al. The genetic variation seen outside Africa is generally a subset of the variation within Africa, a pattern that would be produced if the migrants from Africa were limited in number and carried just part of African genetic variability with them (Cavalli-Sforza and Feldman 2003). 2002; Tishkoff and Verrelli 2003).

African populations exhibit greater genetic diversity than do populations in the rest of the world, implying that humans appeared first in Africa and later colonized Eurasia and the Americas (Tishkoff and Williams 2002; Yu et al. Existing data on human genetic variation support and extend conclusions based on the fossil evidence. 2003). To date, the earliest anatomically modern skeleton discovered from Europe comes from the Carpathian Mountains of Romania and is dated to 34,000–36,000 years ago (Trinkaus et al.

1999). 2003), although studies of environmental changes in Australia argue for the presence of modern humans in Australia >55,000 years ago (Miller et al. One of the earliest modern skeletons found outside Africa is Mungo Man, from Australia, and has been dated to ∼42,000 years ago (Bowler et al. Groups of anatomically modern humans appear to have moved outside Africa permanently sometime >60,000 years ago.

Fossils of the earliest anatomically modern humans found outside Africa are from two sites in the Middle East and date to a period of relative global warmth, ∼100,000 years ago, though this region was reinhabited by Neandertals in later millennia as the climate in the northern hemisphere again cooled (Lahr and Foley 1998). 1994). Much larger populations of archaic humans lived elsewhere in the Old World, including the Neandertals in Europe and an earlier species of humans, Homo erectus, in Asia (Swisher et al. 1998).

At that time, the population of anatomically modern humans appears to have been small and localized (Harpending et al. 2005). 2003; McDougall et al. Early fossils with these characteristics have been found in eastern Africa and have been dated to ∼160,000–200,000 years ago (White et al.

2002), the generally agreed-upon physical characteristics of anatomical modernity include a high rounded skull, facial retraction, and a light and gracile, as opposed to heavy and robust, skeleton (Lahr 1996). Although it is not easy to define "anatomically modern" in a way that encompasses all living humans and excludes all archaic humans (Lieberman et al. The existing fossil evidence suggests that anatomically modern humans evolved in Africa, within the last ∼200,000 years, from a pre-existing population of humans (Klein 1999). Most other groups, including Europeans, Asians, and Native Americans, were found to be a single related (monophyletic) group resulting from a later out-migration from Africa, which could reasonably be divided into West and East Eurasian groups.

Indigenous Australians are believed to be an early out-group that remained isolated. 1987). Studies of human genetic variation imply that Africa was the ancestral source of all modern humans, and that Homo sapiens migrated out of Africa and displaced Homo erectus between 140,000 and 290,000 years ago (Cann et al. Thus, the concept of "race" afforded by these techniques is synonymous with ancestry, broadly understood.

The technique of multilocus genotyping has been used to determine patterns of human demographic history. These data have led to an examination of the biological validity of races as evolutionary lineages and the description of races in cladistic terms. 2004). Since the 1990s, it has become common to use multilocus genotypes to distinguish different human groups and to allocate individuals to groups (Bamshad et al.

Although both sources of information are fragmentary, they have been converging in recent years on the same general story. Information about the history of our species comes from two main sources: the paleoanthropological record and historical inferences based on current genetic differences observed in humans. Regional variations in these features can thus be taken as evidence for long term differences among genus Homo individuals that prefigure different races among present-day Homo sapiens individuals. Leiberman and Jackson (1995), however, have noted that this model depends on several findings relevant to race: (1) that marked morphological contrasts exist between individuals found at the center and at the perimeter of Middle Pleistocene range of the genus Homo; (2) that many features can be shown to emerge at the edge of that range before they develop at the center; and (3) that these features exhibit great tenacity through time.

The most important element of this model for theories of race is that it allows a million years for the evolution of Homo sapiens around the world; this is more than enough time for the evolution of different races. They further argue that this model is consistent with clinal patterns (Wolpoff 1993). They argue that very strong genetic similarities among all humans do not prove recent common ancestry, but rather reflect the interconnectedness of human populations around the world, resulting in relatively constant gene flow (Thorne and Wolpoff 1992). 1993), the multiregional continuity evolution model, cite as evidence anatomical continuity in the fossil record in South Central Europe (Smith 1982), East Asia and Australia (Wolpoff 1993) (anatomical affinity is taken to suggest genetic affinity).

Advocates of the first scenario (see Frayer et al. Each model suggests different possible scenarios for the evolution of distinct races. The debate hinges on whether Homo erectus evolved into Homo sapiens more or less simultaneously in Africa, Europe, and Asia, or whether Homo sapiens evolved only in Africa, and eventually supplanted Homo erectus in Europe and Asia. About a million years ago Homo erectus migrated out of Africa and into Europe and Asia.

There has been considerable debate among anthropologists as to the origins of Homo sapiens. Modern research in molecular biology, however, has provided evolutionary scientists with a whole new kind of data, which adds considerably to the knowledge of our past. Their models seldom provided a firm basis for drawing inferences about the origin of races. For much of the 20th century, however, anthropologists relied on an incomplete fossil record for reconstructing human evolution.

Any biological model for race must account for the development of racial differences during human evolution. On the other hand, the EEOC explicitly defines Hispanics as a separate and distinct "race."¹. Census. 2000 census was based solely on self-identification, did not pre-suppose disjointedness, and did not include a category "Hispanic," which is considered an ethnicity, rather than a race, by the U.S.

Racial classification in the U.S. Census)). The United States government has provided definitions regarding race (see for example Race (U.S. See also the American Anthropological Association's Statement on Race [2].

Moreover, they understood these shared beliefs to mean that religion, nationality, and race itself are social constructs and have no objective basis in the supernatural or natural realm (Gordon 1964). In the face of this rejection of race by evolutionary scientists, many social scientists have replaced the word race with the word "ethnicity" to refer to self-identifying groups based on beliefs in shared religion, nationality, or race. The concepts of population and cline are not, however, mutually exclusive and both are used by many evolutionary scientists. Other evolutionary scientists have abandoned the concept of race in favor of cline (meaning, how the frequency of a trait changes along a geographic gradient).

In the face of these issues, some evolutionary scientists have simply abandoned the concept of race in favor of "population." What distinguishes population from previous groupings of humans by race is that it refers to a breeding population (essential to genetic calculations) and not to a biological taxon. This questioning gained momentum in the 1960s during the American Civil Rights Movement and the emergence of numerous anti-colonial movements worldwide. Alongside empirical and conceptual problems with "race" following the Second World War, evolutionary and social scientists were acutely aware of how beliefs about race had been used to justify discrimination, apartheid, slavery, and genocide. Lieberman and Jackson (1994) have pointed out that "the weakness of this statement is that if one gene can distinguish races then the number of races is as numerous as the number of human couples reproducing." Moreover, anthropologist Stephen Molnar has suggested that the discordance of clines inevitably results in a multiplication of races that renders the concept itself useless (Molnar 1992).

Mid-century, anthropologist William Boyd defined race as:. These empirical challenges to the concept of race forced evolutionary sciences to reconsider their definition of race. Meanwhile, neo-Marxists such as David Harvey (1982, 1984, 1992) believe that race is a social construct that in reality does not exist, used instead to extenuate class differences. However, because of technical limitations of F_ST, many geneticists now believe that low F_ST values do not invalidate the suggestion that there might be different human races (Edwards, 2003).

Some researchers report the variation between racial groups (measured by Sewall Wright's population structure statistic F_ST) accounts for as little as 5% of human genetic variation². This view is described by its opponents as Lewontin's Fallacy. Finally, geneticist Richard Lewontin, observing that 85 percent of human variation occurs within populations, and not between populations, argued that neither "race" nor "subspecies" was an appropriate or useful way to describe populations (Lewontin 1973). As anthropologists Leonard Lieberman and Fatimah Linda Jackson observe, "Discordant patterns of heterogeneity falsify any description of a population as if it were genotypically or even phenotypically homogeneous" (Lieverman and Jackson 1995).

In 1964, biologists Paul Ehrlich and Holm pointed out cases where two or more clines are distributed discordantly—for example, melanin is distributed in a decreasing pattern from the equator north and south; frequencies for the haplotype for beta-S hemoglobin, on the other hand, radiate out of specific geographical points in Africa (Ehrlich and Holm 1964). Thus, anthropologist Frank Livingstone's conclusion that, since clines cross racial boundaries, "there are no races, only clines" (Livingstone 1962: 279). This point called attention to a problem common to phenotypic-based descriptions of races (for example, those based on hair texture and skin color): they ignore a host of other similarities and difference (for example, blood type) that do not correlate highly with the markers for race. Loring Brace's observation that such variations, insofar as they are affected by natural selection, migration, or genetic drift, are distributed along geographic gradations called "clines" (Brace 1964).

One of the crucial innovations in reconceptualizing genotypic and phenotypic variation was anthropologist C. Claude Lévi-Strauss's Race and History (UNESCO, 1952) enforced this cultural relativist thesis, by the famous metaphor of cultures as trains crossing each other in different directions, thus each one seeing the others as immobile while they themselves are progressing. Brown then challenged the concept from the perspective of general systematics, and further rejected the claim that "races" were equivalent to "subspecies" (Wilson and Brown 1953). Wilson and W.

Zoologists Edward O. The first to challenge the concept of race on empirical grounds were anthropologists Franz Boas, who demonstrated phenotypic plasticity due to environmental factors (Boas 1912) and [1], and Ashley Montagu (1941, 1942), who relied on evidence from genetics. in the human species.". The concept of 'race' has no validity .

Race simply cannot be tested or proven scientifically," and that, "It is clear that human populations are not unambiguous, clearly demarcated, biologically distinct groups. The American Anthropological Association, drawing on biological research, states that "The concept of race is a social and cultural construction. The validity of human races is a subject of much debate. Those who came to reject the validity of the concept, race, did so for four reasons: empirical, definitional, the availability of alternative concepts, and ethical (Lieberman and Byrne 1993).

Then, the rise of population genetics led some mainstream evolutionary scientists in anthropology and biology to question the very validity of race as scientific concept describing an objectively real phenomenon. At the beginning of the 20th century, anthropologists questioned, and subsequently abandoned, the claim that biologically distinct races are isomorphic with distinct linguistic, cultural, and social groups. Although this attempt at conceptual precision gained currency with many biologists, especially zoologists, evolutionary scientists have criticized it on a number of fronts. Groups incapable of producing fertile offspring with each other are universally considered distinct species, and not merely different "races" of the same species.

Although different species can sometimes interbreed to a limited extent, the converse is not true. This classification reflects separate groups that are clearly distinct from one another and do not generally interbreed (although there may be a relatively narrow hybridization zone), but which would interbreed freely if given the chance to do so. A polytypic species has two or more races (or, in current parlance, two or more sub-types). Monotypic species can occur in several ways:.

A monotypic species has no races, or rather one race comprising the whole species. For these biologists, a race is a recognizable group forming all or part of a species. With the advent of the modern synthesis in the early 20th century, biologists developed a new, more rigorous model of race as subspecies. Campaigns of oppression and genocide often used supposed racial differences to motivate inhuman acts against others (Horowitz 2001).

In many parts of the world, the idea of race became a way of rigidly dividing groups by use of culture as well as physical appearances (Hannaford 1996). The eugenics movement of the late 19th and early 20th centuries, inspired by Arthur Gobineau's An Essay on the Inequality of the Human Races (1853-1855), Vacher de Lapouge's "anthroposociology" and Herder's theories, asserted as self-evident the biological inferiority of particular groups (Kevles 1985). Their understanding of race was usually both essentialist (defining something by a list of characteristics) and taxonomic (hierarchical). Some groups might be the result of mixture between formerly distinct populations, but careful study can distinguish the ancestral races that had combined to produce admixed groups.

According to this ideology, races are primordial, natural, enduring, and distinct. From the 17th through the 19th centuries, the merging of folk beliefs about group differences with scientific explanations of those differences produced what one scholar has called an "ideology of race" (Smedley 1999). Initially, scholars focused on cataloging and describing "The Natural Varieties of Mankind," as Johann Friedrich Blumenbach entitled his 1775 text (which established the five major divisions of humans still reflected in some racial classifications). In the 18th century, the differences between human groups became a focus of scientific investigation (Todorov 1993).

The first post-Classical published classification of humans into distinct races seems to be François Bernier's Nouvelle division de la terre par les différents espèces ou races qui l'habitent ("New division of Earth by the different species or races which inhabit it"), published in 1684. The first scientific attempts to categorize race date from the 17th century, along with the development of European imperialism and colonization around the world. See From "racial theory" to "racism". Although similar ideas can be found in other cultures (Lewis 1990; Dikötter 1992), they appear not to have had as much influence on social structures as they did in Europe and the parts of the world colonized by Europeans.

A set of "folk beliefs" took hold that linked inherited physical differences between groups to inherited intellectual, behavioral, and moral qualities (Banton 1977). Drawing on classical sources and on their own internal interactions—for example, the hostility between the English and Irish was a powerful influence on early thinking about the differences between people (Takaki 1993)—Europeans began to sort themselves and others into groups associated with physical appearance and with deeply ingrained behaviors and capacities. The rise of the African slave trade, which gradually displaced an earlier trade in slaves from throughout the world, created a further incentive to categorize human groups to justify the barbarous treatment of African slaves (Meltzer 1993). As Europeans encountered people from different parts of the world, they speculated about the physical, social, and cultural differences between human groups.

The English word "race", along with many of the ideas now associated with the term, were products of the European era of exploration (Smedley 1999). Marxists also seized this historical and political discourse, transforming the essentialist biological notion of "race" into the concept of "class struggle.". At the end of the 19th century, the notion of "race" was, according to Foucault, incorporated by racists biologists and eugenicists, who gave it the modern sense of "biological race", which was then be integrated to "state racism". In France, Boulainvilliers, Nicolas Fréret, and then Sieyès, Augustin Thierry and Cournot reappropriated this discourse.

In England, it was used by Edward Coke and John Lilburne against the monarchy. According to him, these debates initated a form of "popular history" based on ethnic identity, as opposed to the classical juridical and philosophical discourse of sovereignty. In Society Must be Defended (1978-79), Michel Foucault traced the "historical and political discourse" of "race struggle" to the 1688 "Glorious Revolution" in England and Louis XIV's reign in France, during which conflicing political values were ascribed to ancestral ethnicites (Saxon, Norman, Frankish etc). The ultimate origin of the word is unknown; suggestions include Arabic ra'is meaning "head", but also "beginning" or "origin".

continued use of "the human race"). The modern meaning, "one of the major divisions of mankind", dates to the late 18th century, but it never became exclusive (cf. The meaning "tribe" or "nation" emerged in the 17th century. Meanings of the term in the 16th century included "wines with a characteristic flavour", "people with common occupation", and "generation".

It wasn't until the 16th century that the word race entered the English language, from the French race - "race, breed, lineage" (which in turn was probably a loan from Italian razza). Furthermore, after the discovery of the New World, Bartolomé de Las Casas opposed the conquistadores theories, upheld by Sepúlveda, on the pretended Amerindians's absence of souls. At the end of the Reconquista, the Spanish Inquisition persecuted Jews and Muslims, theorizing a limpieza de sangre ("Cleanliness of blood") doctrine. Medieval models of race mixed Classical ideas with the notion that humanity as a whole was descended from Shem, Ham and Japheth, the three sons of Noah, producing distinct Semitic (Asian), Hamitic (African), and Japhetic (European) peoples.

But in many ancient civilizations, individuals with widely varying physical appearances could become full members of a society by growing up within that society or by adopting the society's cultural norms (Snowden 1983; Lewis 1990). Some Roman writers adhered to an environmental determinism in which climate could affect the appearance and character of groups (Isaac 2004). Such categories often also included fantastical human-like beings that were supposed to exist in far-away lands. Ancient Greek and Roman authors also attempted to explain and categorize visible biological differences between peoples known to them.

Classical civilizations from Rome to China tended to invest much more importance in family or tribal affiliations than in physical appearance (Dikötter 1992; Goldenberg 2003). However, such distinctions tended to merge differences defined by features such as skin color, with tribal and national identity. The division of humanity into distinct "races" can be traced as far back as the Ancient Egyptian sacred text the Book of Gates, which identifies four categories that are now conventionally labelled "Egyptians", "Asiatics", "Libyans", and "Nubians". But different societies have attributed markedly different meanings to these distinctions.

Given our visual acuity and complex social relationships, humans presumably have always observed and speculated about the physical differences among individuals and groups. . Many scientists believe that when properly used, the division of humanity into races can be valid and useful. These scientists have made arguments that splitting humanity into separate races in this way is valid when races are understood as fuzzy sets, clusters, or extended families.

Since the 1990s, data and models from genomics and cladistics, and the discovery of ancestry-informative markers have resulted in a revolution in our understanding of human evolution, which has led some to propose a new "lineage" definition of race. Other scientists, however, have argued that this position is motivated more by political than scientific reasons. They further maintain that race is best understood as a social construct. They argue that race definitions are imprecise, arbitrary, derived from custom, and that the races observed vary according to the culture examined.

Many evolutionary and social scientists think common race definitions, or any race definitions pertaining to humans, lack taxonomic rigour and validity. Since the 1940s, evolutionary scientists have rejected the view of race according to which a number of finite lists of essential characteristics could be used to determine a like number of races. Legal definitions, common usage, and scientific meaning can all be confounded, and care must be taken to note the context in which it is used. Conceptions of race, as well as specific racial groupings, vary by culture and time and are often controversial due to their impact on social identity and identity politics.

The most widely used human racial categories are based on visible traits (especially skin color and facial features), genes, and self-identification. The term race is commonly used to distinguish a population of humans from other populations, although the biological term race does not apply to the differences inside the race Homo sapiens sapiens. are the Japanese a distinct race, a mixture of races, or part of the East Asian race? and what about the Ainu?) but has also exposed disagreement about the criteria for making decisions— the selection of phenotypic traits seemed arbitrary. focusing on race has historically led not only to seemingly insoluble disputes about classification (e.g.

Africa, or the people of northern India) who have phenotypes that do not neatly fit into the standard race categories. W. in general, the world-wide distribution of human phenotypes exhibits gradual trends of difference across geographic zones, not the categorical differences of race; in particular, there are many peoples (like the San of S. knowing a person's skin color, which is generally acknowledged to be one of the markers of race (or taken as a defining characteristic of race), does not allow good predictions of a person's blood type to be made.

knowing someone's "race" does not provide comprehensive predictive information about biological characteristics, and only absoltuely predicts those traits that have been selected to define the racial categories, e.g. The mitochondrial most recent common ancestor of modern humans lived roughly 200,000 years ago, latest common ancestors of humans and chimps between four and seven million years ago. Rough estimates are given above the diagram, in millions of years. Temporal remoteness of the most recent common ancestor.

Given below the diagram, the genetic difference between humans and chimps is roughly 2%, or 20 times larger than the variation among modern humans. Genetic distance. Populations that have a steady, substantial gene flow between them are likely to represent a monotypic species even when a fair degree of genetic variation is obvious. Such clinal variation always indicates substantial gene flow between the apparently separate groups that make up the population(s).

The variation between individuals is noticeable and follows a pattern, but there are no clear dividing lines between separate groups: they fade imperceptibly into one another. The individuals vary considerably but the variation is essentially random and largely meaningless so far as genetic transmission of these variations is concerned (many plant species fit into this category, which is why horticulturists interested in preserving, say, a particular flower color avoid propagation from seed, and instead use vegetative methods like propagation from cuttings). All members of the species are very similar and cannot be sensibly divided into biologically significant subcategories. For example, using anthropometrics, invented by Francis Galton and Alphonse Bertillon, they measured the shapes and sizes of skulls and related the results to group differences in intelligence or other attributes (Lieberman 2001).

But as the science of anthropology took shape in the 19th century, European and American scientists increasingly sought explanations for the behavioral and cultural differences they attributed to groups (Stanton 1960). Anthropology. Moreover, races were almost universally considered to reflect group differences in moral character and intelligence. Races were distinguished by skin color, facial type, cranial profile and size, texture and color of hair.

These scientists made three claims about race: first, that races are objective, naturally occurring divisions of humanity; second, that there is a strong relationship between biological races and other human phenomena (such as forms of activity and interpersonal relations and culture, and by extension the relative material success of cultures); third, that race is therefore a valid scientific category that can be used to explain and predict individual and group behavior. Natural Scientists on race: In the 19th century a number of natural scientists wrote on race: Charles Darwin, Alfred Wallace, Francis Galton, Georges Cuvier, James Cowles Pritchard, Louis Agassiz, Charles Pickering, and Johann Friedrich Blumenbach.