why do we have different skin colors
Don t have a Sharecare account? Sign up. Already have a Sharecare account? Log in. Forgot Password? Congo, The Democratic Republic of the
Iran, Islamic Republic Of Korea, Democratic People S Republic of Korea, Republic of Macedonia, The Former Yugoslav Republic of Micronesia, Federated States of Moldova, Republic of Palestinian Territory, Occupied Taiwan, Province of China Tanzania, United Republic of Virgin Islands, British Virgin Islands, U. S. I want to receive the latest health news and personalized information from Sharecare. You can change your mind at any time. By creating an account, you agree to the and, including the. You may receive email notifications, alerts and other notices from Sharecare. You can opt-out at any time. -A curious adult from California November 6, 2008 Human skin color can vary from almost translucent to almost black.
This range of colors comes from the amount and type of a pigment called melanin found in the skin. There are two types of melanin--eumelanin and pheomelanin. In general, the more eumelanin in your skin, the darker your skin will be. People who make more pheomelanin than eumelanin tend to have lighter skin with freckles. Like many other traits, the amount and kind of pigment in your skin is controlled by genes. The version you have of each of these genes work together to create the final product -- your skin color. To understand how this works, we'll talk about some of the genes that scientists have found that affect human coloring. And how some fish helped us find these genes! It is also interesting to think about why we have different skin colors. Later on, we'll see how vitamins and where your ancestors lived might have influenced what your skin color is.
Melanin and Your Skin Melanin is made in special cells called melanocytes. These cells are found in the epidermis of your skin. There are at least three ways people can end up with different skin color. One way is if people make less pigment. Less pigment = lighter skin. Another way is when people have fewer melanocytes. Fewer melanocytes mean less pigment overall and so lighter skin. The third way is a bit more complicated and has to do with the kind of pigment someone makes. There are two types of melanin. Eumelanin is black or brown pigment and pheomelanin is red or yellow pigment. People who make lots of pheomelanin tend to have lighter skin, often because of freckling. Freckles happen when melanocytes clump together. Melanocytes are usually spread pretty evenly in the skin.
So when freckles form, some spots of the skin have lots of melanocytes (freckles) and other spots have few or none. Where there are no melanocytes, the skin is very fair. Skin Color Genes Scientists have figured out that several genes are involved in skin color. One of these genes is the melanocortin 1 receptor (MC1R). When MC1R is working well, it has melanocytes convert pheomelanin into eumelanin. If it's not working well, then pheomelanin builds up. Most people with red hair and/or very fair skin have versions of the MC1R gene that don't work well. This means they end up with lots of pheomelanin, which leads to lighter skin. (For more information on MC1R and red hair, check out. ) Two other skin color genes were first identified in fish. One gene was found in stickleback fish and the other in zebrafish.
- Views: 159
why do we feel sleepy in winter
why do my new glasses make me feel dizzy
why do proton pump inhibitors cause osteoporosis
why is second hand smoke worse than smoking
why is ovarian cancer called the silent killer
why is o the universal blood donor
why republic day is celebrated on 26 jan