Search results
Results From The WOW.Com Content Network
Hair colors can change well into puberty, as some genes aren't "switched on" until the hormones flood the body in adolescence. Eventually, usually in the 30s, human hair stops producing melanin ...
In humans, eye color is a highly sexually dimorphic trait. [18] Several studies have shown that men are more likely to have blue eyes than women, while women are more likely to have darker eye colors (green and brown eyes) than men. [18] [19] Sex is therefore a major factor in the expression of eye color genotypes. [18]
A seven-week-old human baby following a kinetic object. Infant vision concerns the development of visual ability in human infants from birth through the first years of life. The aspects of human vision which develop following birth include visual acuity, tracking, color perception, depth perception, and object recognition.
An organism's "eye color" is actually the color of one's iris, the cornea being transparent and the white sclera entirely outside the area of interest. Melanin is yellowish to dark hazel in the stromal pigment cells, and black in the iris pigment epithelium, which lies in a thin but very opaque layer across the back of the iris.
[50] [51] The differences in color are mainly caused by higher levels of melanin in the skin, hair and eyes in males. [52] [53] In one study, almost twice as many females as males had red or auburn hair. A higher proportion of females were also found to have blond hair, whereas males were more likely to have black or dark brown hair. [54]
Several layers such as the neural tube, neural crest, surface ectoderm, and mesoderm contribute to the development of the eye. [2] [3] [4] Eye development is initiated by the master control gene PAX6, a homeobox gene with known homologues in humans (aniridia), mice (small eye), and Drosophila (eyeless). The PAX6 gene locus is a transcription ...
The Fischer–Saller scale, named after Eugen Fischer and Karl Saller is used in physical anthropology and medicine to determine the shades of hair color. The scale uses the following designations: A (very light blond), B to E (light blond), F to L (), M to O (dark blond), P to T (light brown to brown), U to Y (dark brown to black) and Roman numerals I to IV and V to VI (red-blond).
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!