Excerpts from Wikipedia.org

Widow's Peak

A widow's peak (widow's brow) is a descending V-shaped point in the middle of the hairline (above the forehead). The trait is inherited genetically and is dominant. A dominant trait is the observed trait. The term comes from English folklore, where it was believed that this hair formation was a sign of a woman who would outlive her husband. The name Widow's Peak, comes from widows, when they lost their husband, they wore a widows veil, a veil that is black with a "V" in the middle of the fore head spot. Widow's peak is a trait that is associated with baldness. Individuals who possess the trait develop baldness prior to other individuals with conventional hairlines.

The peak refers to the beak or bill of a headdress, particularly a widow's hood, making people think a woman was being given a mourning hood for her husband's soon-to-be passing.

Red Hair

Red hair is the rarest type of natural hair color in humans. The pale skin associated with red hair may be of advantage in far-northern climates where sunlight is scarce. Studies by Bodmer and Cavalli-Sforza (1976) hypothesized that lighter skin pigmentation prevents rickets in colder latitudes by encouraging higher levels of Vitamin D production and also allows the individual to retain heat better than someone with darker skin.

Estimates on the original occurrence of the currently active gene for red hair vary from 20,000 to 100,000 years ago.

Red hair is characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin. Approximately 1% to 2% of the human population has red hair. Red hair appears in people with two copies of a recessive gene on chromosome 16 which causes a change in the MC1R protein. It is associated with fair skin color, freckles, and sensitivity to ultraviolet light, as the mutated MC1R protein is found in the skin and eyes instead of the darker melanin.

Today, red hair is most commonly found at the western fringes of Europe. It is associated particularly with those in Scotland, Ireland , Wales, and England. This matches the movement of the Celts and Picts as they were pushed westward and northward in Britain and Ireland during the Roman conquest of Britain, as well as the pattern of Viking settlement in the north of England. Redheads constitute approximately four percent of the European population. Scotland has the highest proportion of redheads, as 13 percent of the population has red hair and approximately 40 percent carries the recessive redhead gene.

The Berber populations of northern Algeria and Morocco have occasional redheads.

In Asia, darker or mixed tinges of red hair can be found sporadically from Northern India, northern Middle East (such as Lebanon, Iran, Syria) and Pakistan, and in rare instances in Japan and the South Pacific. Red hair can be found amongst those of Iranian descent, such as the Pashtuns.

A DNA study has concluded that some Neanderthals also had red hair, although the mutation responsible for this differs from that which causes red hair in modern humans

Most red hair is caused by the MC1R gene and is non-pathological. However, in some cases red hair can be associated with disease or genetic disorder:

* In cases of severe malnutrition, normally dark human hair may turn red or blonde. The condition, part of a syndrome known as kwashiorkor, is a sign of critical starvation caused chiefly by protein deficiency, and is common during periods of famine.

* One variety of albinism (Type 3, aka rufous albinism), sometimes seen in Africans and inhabitants of New Guinea, results in red hair and red-colored skin.

* Red hair is found on people lacking pro-opiomelanocortin.

Epicanthal Fold

An epicanthal fold is a skin fold of the upper eyelid (from the nose to the inner side of the eyebrow) covering the inner corner (medial canthus) of the eye.

the epicanthic fold is common in people of many, though not all groups of East Asian and Southeast Asian descent. It is found in significant numbers amongst Native Americans, the Khoisan (Capoids) of Southern Africa, many Central Asians and some people of Scandinavian, Polish and Sami origin. It also present on people of Tibetan descent, especially Tibetans and North-East Burmese people. Due to classic genetics children of a parent with a pronounced epicanthal fold and one without an epicanthal fold will have varying degrees of epicanthal folds as a result.

All humans initially develop epicanthal folds in the womb. Some children lose them by birth, but epicanthal folds may also be seen in young children of any ethnicity before the bridge of the nose begins to elevate.

In Asian ethnicities, the presence of an epicanthic fold is associated with a less prominent upper eyelid crease, commonly termed "single eyelids" as opposed to "double eyelids". The two features are distinct; a person may have both epicanthal fold and upper eyelid crease, one and not the other, or neither.

The procedure of reducing or removing epicanthal folds is epicanthoplasty. It is now an extremely rare procedure. Asian blepharoplasty, however, is a popular form of cosmetic surgery in East Asia.

Dimple

Dimples are visible indentations of the skin, caused by underlying flesh, which form on some people's cheeks when they smile. Dimples are genetically inherited and are a dominant trait. Dimples on each cheek are a relatively common occurrence for people with dimples. A rarer form is the single dimple, which occurs on one side of the face only. Anatomically, dimples may be caused by variations in the structure of the facial muscle called zygomaticus major. Specifically, the presence of a double or bifid zygomaticus major muscle may explain the formation of cheek dimples. This bifid variation of the muscle originates as a single structure from the zygomatic bone. As it travels anteriorly, it then divides with a superior bundle that inserts in the typical position above the corner of the mouth. An inferior bundle inserts below the corner of the mouth.

Dimples are considered attractive in some cultures. Babies commonly have dimples, but sometimes these disappear (or become less noticeable) as the muscles lengthen with age; consequently, dimples are often associated with youth.

Cleft Chin

A cleft chin, chin cleft, dimple chin, chin dimple, or butt chin is a dimple on the chin. It is a Y-shaped fissure on the chin with the underlying bony peculiarity. The chin fissure follows the fissure in the lower jaw bone resulted from the incomplete fusion of the left and right halves of the jaw during the embryonal and fetal development.

This is an inherited trait in humans, where the dominant gene causes the cleft chin while the recessive geneotype presents without a cleft. However, it is also a classic example for variable penetrance with environmental factors or a modifier gene possibly affecting the phenotypical expression of the actual genotype.

Heterochromia

Heterochromia (also known as a heterochromia iridis or heterochromia iridium) is an ocular condition in which one iris is a different color from the other iris (complete heterochromia), or where the part of one iris is a different color from the remainder (partial heterochromia or sectoral heterochromia). It is a result of the relative excess or lack of pigment within an iris or part of an iris, which may be inherited or acquired by disease or injury. This uncommon condition usually results due to uneven melanin content. A number of causes are responsible, including genetics such as chimerism and Waardenburg syndrome. Trauma and certain medications, such as some prostaglandin analogues can also cause increased or decreased pigmentation in one eye. On occasion, the condition of having two different colored eyes is caused by blood staining the iris after sustaining injury.

David Bowie (Jones) is a famous person often wrongly attributed with heterochromia. His apparent condition is due to a teenage injury. (One eye appears darker because the pupil is permanently dilated.) American actress Kate Bosworth has sectoral heterochromia, resulting in a hazel section at the bottom of her right blue eye, while the left is completely blue. American Actress Elizabeth Berkley has sectoral heterochromia; her right eye is half green and half brown, and her entire left eye is green. So does actor Anthony Head - he has a patch of hazel in his left eye where both eyes are blue-green overall. The lead vocalist of American band Rise Against, Tim McIlrath, has heterochromia; his left eye is blue while his right is brown. American actress Mila Kunis also has heterochromia, resulting in one blue eye and one brown-green eye. American Actress Demi Moore also has heterochromia, by having one green eye, and the other hazel.

Supertaster

A supertaster is a person who experiences taste with far greater intensity than average. Women are more likely to be supertasters, as are Asians and Africans. Among individuals of European descent, it is estimated that about 25% of the population are supertasters. The cause of this heightened response is currently unknown, although it is thought to be, at least in part, due to an increased number of fungiform papillae. The evolutionary advantage to supertasting is unclear. In some environments, heightened taste response, particularly to bitterness, would represent an important advantage in avoiding potentially toxic plant alkaloids. However, in other environments, increased response to bitter may have limited the range of palatable foods. In our modern, energy-rich environment, supertasting may be cardioprotective, due to decreased liking and intake of fat, but may increase cancer risk via decreased vegetable intake. It may be a cause of picky eating, but picky eaters are not necessarily supertasters, and vice versa.

The term originates with experimental psychologist Dr. Linda Bartoshuk who has spent much of her career studying genetic variation in taste. In the early 1990s, Bartoshuk and her colleagues noticed some individuals tested in the laboratory seemed to have an elevated taste response and took to calling them supertasters.

Wet / Dry Earwax

There are two distinct genetically determined types of earwax: the wet type, which is dominant, and the dry type, which is recessive. Asians and Native Americans are more likely to have the dry type of cerumen (grey and flaky), whereas Caucasians and Africans are more likely to have the wet type (honey-brown to dark-brown and moist). Cerumen type has been used by anthropologists to track human migratory patterns, such as those of the Inuit.

The difference in cerumen type has been tracked to a single base change (a single nucleotide polymorphism) in a gene known as "ATP-binding cassette C11 gene." In addition to affecting cerumen type, this mutation also reduces sweat production. The researchers conjecture that the reduction in sweat was beneficial to the ancestors of East Asians and Native Americans who are thought to have lived in cold climates.

Blood Types in Japanese Culture

There is a popular belief in Japan that a person's ABO blood type is predictive of their personality, temperament, and compatibility with others, similar to the Western world's astrology. Type A blood is the most common in Japan at about 40%.

The ABO blood group system is widely credited to have been discovered by the Austrian scientist Karl Landsteiner, who found three different blood types in 1900. Ethnic studies did show different blood group distributions across the world (e.g. Asian people having a higher percentage of Type B). This fact was used by early Nazis to further ideas of supremacy over different races.

The theory first reached Japan in 1927 in Takeji Furukawa's paper "The Study of Temperament Through Blood Type" in the scholarly journal Psychological Research. The idea quickly took off with the Japanese public despite his lack of credentials, and the militarist government of the time commissioned a study aimed at breeding the soldiers. In another study, Furukawa compared the distribution of blood types among two different ethnic groups, the Formosans (Taiwanese) in Taiwan and the Ainu who live in Northeast Asia, especially Hokkaidō. His motivation for the study appears to have derived from a political incident. After the Japanese occupation of Taiwan following Japan's victory over China in 1895, the inhabitants tenaciously resisted their occupiers. Insurgencies in 1930 and in 1931 killed hundreds of Japanese settlers. The purpose of Furukawa's studies was to "penetrate the essence of the racial traits of the Taiwanese, who recently revolted and behaved so cruelly". Based on the finding that 41.2% of a Taiwanese sample had type O blood, he assumed that their rebelliousness was genetically determined. The reasoning was supported by the fact that among the Ainu, whose temperament was characterized as submissive, only 23.8% had type O. In conclusion, Furukawa suggested that the Taiwanese should intermarry more with the Japanese in order to reduce the number of individuals with type O blood.

The craze faded in the 1930s as its unscientific basis became evident. It was revived in the 1970s with a book by Masahiko Nomi who has been heavily assailed by the Japanese psychological community, although his books are phenomenally popular.

Inheritance of ABO Blood Group

Blood groups are inherited from both parents. The ABO blood type is controlled by a single gene with three alleles: i, IA, and IB. The gene encodes a glycosyltransferase—that is, an enzyme that modifies the carbohydrate content of the red blood cell antigens. The gene is located on the long arm of the ninth chromosome (9q34).

IA allele gives type A, IB gives type B, and i gives type O. IA and IB are dominant over i, so ii people have type O, IAIA or IAi have A, and IBIB or IBi have type B. IAIB people have both phenotypes because A and B express a special dominance relationship: codominance, which means that type A and B parents can have an AB child. A type A and a type B couple can also have a type O child if they are both heterozygous (IBi,IAi) Therefore, an O child is not a direct proof of illegitimacy, just as a child with blond hair could be born from parents who both had brown hair.

Blood Type Diet

The blood type diet is a diet advocated by Peter D'Adamo and outlined in his book Eat Right 4 Your Type. Its basic premise is that ABO blood type is the most important factor in determining a healthy diet. "Lectins" which interact with the different ABO type "antigens" are described as incompatible and harmful, therefore the selection of different foods for A, AB, B, and O types to minimize reactions with these lectins.

Blood group O is believed by D'Adamo to be the hunter, the earliest human blood group. The diet recommends that these supposedly muscular, active people eat a meat-rich diet.

Blood group A is called the cultivator by D'Adamo, who believes it to be a more recently evolved blood type, dating back from the dawn of agriculture. The diet recommends that individuals of blood group A eat a diet emphasizing vegetables and free of red meat, a more vegetarian food intake.

Blood group B is, according to D'Adamo, the nomad, associated with a strong immune system and a flexible digestive system. The blood type diet claims that people of blood type B are the only ones who can thrive on dairy products.

Blood group AB, per D'Adamo, the enigma, the most recently evolved type. In terms of dietary needs, his blood type diet treats this group as an intermediate between blood types A and B.

In the article "Genetic of the ABO blood system and its link with the immune system", Luiz C. de Mattos and Haroldo W. Moreira point out that D'Adamo's assertion that the O blood type was the first human blood type requires that the O gene evolved before the A and B genes in the ABO locus. Instead, phylogenetic networks of human and non-human ABO alleles show that the A gene was the first to evolve. The authors argue that, in the evolutionary sense, it would be extraordinary for normal genes (those for types A and B) to have evolved from abnormal genes (for type O).

In May 2004, Transfusion published a study which concluded that: "Assuming constancy of evolutionary rate, diversification of the representative alleles of the three human ABO lineages (A101, B101, and O02) was estimated at 4.5 to 6 million years ago." This finding declares that ABO did not evolve in the near past, essentially contradicting that which D'Adamo suggests.

Morton's Toe

Morton's toe is the common term for the second toe (second from innermost) extending further than the great toe (Hallux). In reality, this is not entirely true, as Morton's toe is typically due to a lengthened 2nd metatarsal. This promotes an anterior position of the 2nd metatarsal-phalangeal (MTP) joint in relation to the Hallux.

Although commonly described as a disorder, it is sufficiently common to be considered a normal variant of foot shape (its prevalence varies with different populations, but around 10% of feet worldwide have this form). The main symptom experienced due to Morton's toe is discomfort and callusing of the second metatarsal head. This is because the first metatarsal head is intended to bear the majority of a person's body weight during the propulsive phases of gait. However, these forces are transfered to the 2nd (smaller) metatarsal head because of it's anterior positioning. In shoe-wearing cultures it can be problematic: for instance, in causing nail problems from wearing shoes with a profile that doesn't accommodate the longer second toe.

It has a long association with disputed anthropological and ethnic interpretations. Morton called it Metatarsus atavicus, considering it an atavism recalling prehuman grasping toes. In statuary and shoe fitting it has been called the Greek foot (as opposed to the Egyptian foot, where the great toe is longer). It was an idealised form in Greek sculpture, and this persisted as an aesthetic standard through Roman and Renaissance periods and later (the Statue of Liberty has toes of this proportion). The French call it pied ancestral or pied de Néanderthal.

Mole

A mole, technically known as a melanocytic nevus, is a small, dark spot on human skin. According to the American Academy of Dermatology, the majority of moles appear during the first two decades of a person’s life while about one in every 100 babies are born with moles.

Almost everyone with light skin has at least one or two moles somewhere on their bodies while large numbers can be concentrated on the back, chest, and arms. Darker skin shades, however, tend to have fewer moles.

Genes can have an influence on a person's moles.

Dysplastic nevi and atypical mole syndrome is a hereditary condition which causes the person to have a large quantity of moles (often 100 or more) with some larger than normal or atypical. This often leads to a higher risk of melanoma, a serious skin cancer.

A beauty mark or beauty spot is a dark facial mole that some people consider attractive, usually when it is within about an inch of the upper lip or around the eyes. Doctors call them melanocytic nevus, more specifically the compound variant.

False beauty spots can be applied to the face as a form of make-up. Beauty marks were particularly highly regarded during the eighteenth century and creating false ones became common, often in fanciful shapes such as hearts. Marilyn Monroe's beauty mark generated a new vogue for them during the twentieth century. In recent years, fashion model Cindy Crawford's prominent mole has helped revive the look. Madonna's facial mole -- below her right nostril -- has been surgically removed.

Mongolian Spot

A Mongolian Spot is a benign flat congenital birthmark with wavy borders and irregular shape, most common among East Asians and Turks, and named after Mongolians. It is also extremely prevalent among East Africans and Native Americans. It normally disappears three to five years after birth and almost always by puberty. The most common color is blue, although they can be blue-gray, blue-black or even deep brown.

The blue colour is caused by melanocytes, melanin-containing cells, that are deep under the skin. Usually, as multiple spots or one large patch, it covers one or more of the lumbosacral area (lower back), the buttocks, flanks, and shoulders. It results from the entrapment of melanocytes in the dermis during their migration from the neural crest to the epidermis during embryonic development.

The condition is not linked to sex; and male and female infants are equally predisposed to Mongolian spot. The spots are harmless.

Among those who are not aware of the background of the Mongolian spots, it may sometimes be mistaken for a bruise.

Mongolian spot is most prevalent among Mongols, Turks, and other Asian groups, such as the Chinese, Koreans and Japanese. Nearly all East Asian infants are born with one or more Mongolian spots. The incidence of Mongolian spot among East Asian infants is 95-100%. It is also common if only one of the parents is East Asian.

Among East African infants it is found at rates between 90-95%, and 85-90% of Native American infants.

The incidence among Caucasians, that is, the indigenous peoples of Europe, the Middle East, North Africa and the Indian subcontinent (Pakistan, India, Bangladesh, Sri Lanka) is between 1-10%. However, it has been found to be prominent among Europeans that have had extensive interaction with Hun cultures, most notably Hungarians who have a 22.6% occurrence rate among their population.

Additionally, there is an incidence of 50-70% among Latin-Americans, presumably as a result of the Native American admixture found in mestizos (people of mixed European and Native American ancestry) who comprise the largest racial group among Latin-Americans.

Skin Color

Human skin colour can range from almost black to nearly colorless (appearing pinkish white due to the blood in the skin) in different people. Skin color is determined by the amount and type of melanin, the pigment in the skin.

Melanin comes in two types: pheomelanin (red) and eumelanin (dark brown to nearly black). Both amount and type are determined by four to six genes which operate under incomplete dominance. One copy of each of those genes is inherited from each parent. Each gene comes in several alleles, resulting in a great variety of different skin tones.

The evolution of the different skin tones is thought to have occurred as follows:the haired ancestors of humans, like modern great apes, had light skin under their hair. Once they encountered baldness, they evolved dark skin, needed to prevent low folate levels since they lived in sun-rich Africa. When humans migrated to less sun-intensive regions in the north, low vitamin D3 levels became a problem and light skin color re-emerged.

The Inuit and Yupik are special cases: even though they live in an extremely sun-poor environment, they have retained their relatively dark skin. This can be explained by the fact that their traditional animal-based diet provides plenty of vitamin D.

Tracking back the statistical patterns in variations in DNA among all known people sampled who are alive on the Earth today, it appears that from 1.2 million years ago for a million years, the ancestors of all people alive were as dark as today's Africans.

According to (Norton et al., 2006), white skin observed in Europeans, South Asians and East Asians is due to independent genetic mutations in at least three loci. They concluded that light pigmentation in Europeans is at least partially due to sexual selection.

Light-skinned persons have about a tenfold greater risk of dying from skin cancer under equal sunlight exposure, with redheads having the greatest risk. While dark skin better preserves vitamin B, it can lead to vitamin D deficiency in dark skin people which can lead to being at a higher risk of certain kinds of deadly cancers such as colon, lung and prostate, dark skin people are at higher risk for the bone disease rickets, also dark skin people are at higher risk of cardiovascular disease, diabetes and multiple sclerosis.

Shapes of the Human Nose

Human noses can take many different shapes. Several attempts have been made towards a classification of noses. The following examples are from Nasology by Eden Warwick (pseudonym of George Jabet). This 19th century tract associated nose shapes with character traits in a way akin to phrenology, in a somewhat ironic way, as the booklet was intended to mock the popular but highly controversial subject of phrenology.

• * Class I: The Roman, or Aquiline nose, which is rather convex, but undulating as its name aquiline imports. Aquiline is a word that means a "nose hooked like a bird's".
• * Class II: The Greek or Straight nose, which is perfectly straight
• * Class III: The Nubian, or Wide-nostrilled nose, wide at the end, thick and broad, gradually widening from below the bridge. The other noses are seen in profile, but this one in full face.
• * Class IV: The Hawk nose, which is very convex, and preserves its convexity like a bow. It is thin and sharp
• * Class V: The Snub nose
• * Class VI: The Turn-up or Celestial nose, with a continuous concavity from the eyes to the tip

Many individuals of African or East Asian descent, and others with non-European looking noses, choose to have an aesthetic rhinoplasty. Although techniques and methods employed during rhinoplasty surgeries are the same regardless of race, there are some trends that apply to patients of certain ethnic backgrounds.

Phrenology

Phrenology is a defunct field of study, once considered a science, by which the personality traits of a person were determined by "reading" bumps and fissures in the skull. Developed by German physician Franz Joseph Gall around 1800, the discipline was very popular in the 19th century. In 1843, François Magendie referred to phrenology as "a pseudo-science of the present day." Phrenological thinking was, however, influential in 19th-century psychiatry and modern neuroscience.

Phrenology is based on the concept that the brain is the organ of the mind, and that certain brain areas have localized, specific functions (see in particular, Brodmann's areas) or modules (see modularity of mind). Phrenologists believed that the mind has a set of different mental faculties, with each particular faculty represented in a different area of the brain. These areas were said to be proportional to a person's propensities, and the importance of the given mental faculty. It was believed that the cranial bone conformed in order to accommodate the different sizes of these particular areas of the brain in different individuals, so that a person's capacity for a given personality trait could be determined simply by measuring the area of the skull that overlies the corresponding area of the brain.

Phrenology was a complex process that involved feeling the bumps in the skull to determine an individual's psychological attributes.

Phrenology is currently dismissed as quackery by the scientific community.

Phrenology, which focuses on personality and character, should be distinguished from craniometry, which is the study of skull size, weight and shape, and physiognomy, the study of facial features. However, these disciplines have claimed the ability to predict personality traits or intelligence (in fields such as anthropology/ethnology), and were sometimes posed to scientifically justify racism.

Race and Intelligence

The study of race and intelligence seeks to determine whether or not human intellectual abilities vary between races and/or the causes of any differences that appear in the measurements.

Theories about a relationship between race and intelligence have been the subject of speculation and debate since the 16th century. The contemporary debate focuses on the nature, causes, and importance, or lack of importance, of ethnic differences in intelligence test scores and other measures of cognitive ability, and whether race is a meaningful biological construct. The question of the relative roles of nature and nurture in causing individual and group differences in cognitive ability is seen as fundamental to understanding the debate.

The modern controversy surrounding intelligence and race focuses on the results of intelligence quotient (IQ) studies conducted during the second half of the 20th century in the United States, Western Europe, and other industrialized nations. There are also controversies over the definition of race, the definition of intelligence, and whether the intelligence quotient is a satisfactory measure of intelligence; see the respective articles on those subjects for more information.

The publication of The Bell Curve in 1994, which included a discussion of racial differences in intelligence, received much attention in the popular press and ignited renewed debate within academia and amongst the general public. The Bell Curve is a controversial, best-selling 1994 book by American psychologist Richard Herrnstein and American Enterprise Institute political scientist Charles Murray. Its central point is that intelligence is a better predictor of many factors including financial income, job performance, unwed pregnancy, and crime than parents' socioeconomic status or education level. Also, the book argued that those with high intelligence (the "cognitive elite") are becoming separated from the general population of those with average and below-average intelligence, and that this was a dangerous social trend. Much of the controversy concerned Chapters 13 and 14, in which the authors wrote about the enduring racial differences in intelligence and discuss implications of those differences. The authors were reported throughout the popular press as arguing that these IQ differences are genetic, although they state no position on the issue in the book, and write in the introduction to Chapter 13 that "The debate about whether and how much genes and environment have to do with ethnic differences remains unresolved."

Shortly after publication, many people rallied both in criticism and defense of the book. Some critics denounced the book and its authors as supporting scientific racism. A number of critical texts, including The Bell Curve Debate and The Mismeasure of Man (second edition), were written in response to the book.

Widow's peak

Red-headed, blue-eyed Central Asian (Tocharian) and East-Asian Buddhist monks, Eastern Tarim Basin, China, 9th-10th century

Red hair has also been found in Asia, notably among the Tocharians who occupied the northwesternmost province of what is modern-day China. The 2nd millennium BC caucasian Tarim mummies in China were found with red and blonde hair and most likely were of European origin..

The Kyrgyz people of central Asia once had predominantly red hair. Some today still retain this trait.

Genghis Khan traditionally and by some scattered accounts is said to have had red hair.

Hair color: There are two types (three subtypes) of pigment that give hair its color: eumelanin and phaeomelanin. Eumelanin is black and brown while phaeomelanin is red. A low concentration of brown eumelanin in the hair will make it blonde, whereas more brown eumelanin will give it a brown color. Much higher amounts of black eumelanin will result in black hair, and a low concentration of black eumelanin in the hair will make it gray. All humans have phaeomelanin in their hair.

Epicanthal fold

Shirley Temple

William McKinley

Heterochromia

Eye color is a polygenic trait and is determined primarily by the amount and type of pigments in the eye's iris. Humans and animals have many phenotypic variations in eye color. In humans, these variations in color are attributed to varying ratios of eumelanin produced by melanocytes in the iris.

Eye colors can range from most common, brown, to least common, green. Rare genetic mutations can even lead to unnatural eye colors like black, red, and violet.

Often, paler newborns have blue eyes, which change to green, hazel, light brown or dark brown. This is possibly the origin of the idiom "being blue-eyed" (i. e. naïve; gullible). It is thought that exposure to light after birth triggers the production of melanin in the iris of the eye.

Phenylthiocarbamide

Some individuals found phenylthiocarbamide (PTC) to be bitter while others found it tasteless. Most estimates suggest 25% of the population are nontasters, 50% are medium tasters, and 25% are supertasters.

Movement of the jaw helps the ears' natural cleaning process, so chewing gum and talking can both help. Cotton swabs push most of the earwax further into the ear canal and remove only a small portion of the top layer of wax that happens to adhere to the fibers of the swab.

Zodiacs

The distribution of the blood groups A, B, O and AB varies across the world according to the population.

In the UK the distribution of blood type frequencies through the population still shows some correlation to the distribution of placenames and to the successive invasions and migrations including Vikings, Danes, Saxons, Celts, and Normans who contributed the morphemes to the placenames and the genes to the population.

There are six common alleles that produce one's blood type

Eat Right 4 Your Type : The Individualized Diet Solution to Staying Healthy, Living Longer and Achieving Your Ideal Weight by Peter J. D'Adamo

Greek sculpture

Marilyn Monroe

Photos by Hironao Numabe

Atlantic Slave Trade

The term race refers to the concept of dividing people into populations or groups on the basis of various sets of characteristics. The most widely used human racial categories are based on visible traits (especially skin color, cranial or facial features and hair texture), and self-identification.

The word "race", along with many of the ideas now associated with the term, were products of European imperialism and colonization during the age of exploration. The rise of the Atlantic slave trade, which gradually displaced an earlier trade in slaves from throughout the world, created a further incentive to categorize human groups in order to justify the subordination of African slaves.

Cyrano de Bergerac

Plot summary: Cyrano de Bergerac is a brash, strong-willed man of many talents. In addition to being a remarkable duelist, he is a gifted poet and is also shown to be a musician. However, he has an extremely large nose, which is a target for his own self-doubt. This doubt prevents him from expressing his love for his distant cousin, the beautiful Roxanne.

A 19th-century phrenology chart. The inscription on the neck reads, "Know yourself."

The Bell Curve by Richard J. Herrnstein and Charles Murray

The Mismeasure of Man by Stephen Jay Gould

Frames of Mind: The Theory of Multiple Intelligences by Howard Gardner