What determines human skin color and physical traits?
The sun determines skin color, specifically the amount of melanin being produced by the cells. The production of melanin is triggered by high amounts of UV (ultraviolet) radiation, which means those with lighter skin have less melanin in order to protect themselves from deleterious effects such as cancer and vitiligo –the destruction and loss of pigment in patches on the human skin.
Different genetic receptors, such as MC1R, code for skin color and hair types. Obviously enough, people with a certain type of receptor will continue to mate with one another because they both share the same shared genetic trait. The mix of those genes creates continually-mutating physical traits.
Medication use can also cause changes in gene expression that affect the body’s natural production or how it absorbs and/or metabolizes vitamins and minerals. This can also impact skin coloring…
Actual exposure to sunlight can have a tanning effect on skin too…a darker complexion is often due to more melanin in the top layers of your epidermis (higher levels in response to sun exposure).
For a wide range of species, including humans, the skin color of offspring is the result of combining two different parental colors and patterns. For human males, skin pigmentation largely depends on how many X chromosomes he inherits from his father.
Lets break this down a bit more and take note that there are different types of melanin in your body: brown pigment eumelanin becomes more prevalent with increased exposure to ultraviolet radiation (UVR) which leads to tanning while blackish-yellow pheomelanin is abundant in people who have blond hair or those who lack sufficient exposure to UVR (less than 10 minutes per day). Generally speaking lighter shades come from higher concentrations of temporary white-tanning agents (sebum and carotenoids) while darker shades come from higher concentrations of melanin.
But the question still remains: why is there such a great range in skin tones? The answer lies within our genetics; we inherit two sets of genes for each trait—one set inherited from our parents and one set that “we get to make up for ourselves.”
The best answer is that they are determined through a combination of genetics and geography.
In order to fully appreciate why skin color is different, it’s important to understand how genes work for the entire human population. Genes come in pairs – maternal and paternal copies – and because they exist in pairs, they can be inherited differently between generations. Specifically on the legs, the brown-pigmented MC1R gene may produce darker skin if one copy comes from your mother or father originally while having two copies of non-browning allele will make light skin tone. Skin pigment production is regulated by melanin. Epidermal cells produce an enzyme known as tyrosine (or pheomelanin), which adds a yellow-reddish pigment to the skin. Melanin, which is much rarer in surface cells (dermal) and gives rise to a brown-black or black coloration, is produced by an entirely different enzyme named tyrosinase. And this is where things get interesting: For one, having more than two brown alleles will result in darker skin tone and it also follows that if both copies of MC1R gene come from your mother’s side, you would have very light skin.
The scientific consensus for explaining such variants of human skin pigmentation generally focuses on the role played by natural selection in relation to sun exposure. According to this view, lighter skin has evolved near the equator as an evolutionary adaptation to greater Ultraviolet B (UVB) radiation exposure, which damaged the skin and reduced the chances of survival of folate. The genes that cause light skin color in higher latitudes have been maintained because darker, more pigmented skin would absorb too much sunlight and increase vitamin D depletion from frequent sun exposure. However, there is no evidence for this hypothesis as it relates to human genetics.
The primary determining factor in skin color is melanin. Melanin from the cell’s surface will absorb ultraviolet (UV) radiation and reflect visible light, so that it acts as a natural SPF reducing UV damage to the skin cells below.
At this point, scientists believe what determines skin color is more of a combination of genetics and environmental playing fields such as intensity of sunlight exposure or ionizing radiation. Those with pale complexions have lower levels of Vitamin D production in their skins and few people are exposed to enough sun for long periods – both situations may cause a vitamin imbalance which can darken under-pigmented cells. Bodies produce chemicals called pteridine cofactors that act like photo developers to change beta-carotene into Vitamin A, which gives skin an orange tint.
Also, the number of melanocytes (cells that create and store melanin) differ between racial groups; African Americans have more than double the number of these cells as white individuals. As a result, people with darker complexions have been found to be less likely to develop sun-induced skin cancers because melanin is actually a protective shield against UV radiation. In whitemen’s bodies, it does not reach this level naturally because their bodies do not contain nearly as many melanocytes as dark-skinned men do. Light-skinned women have even lower levels of these cells so they are more susceptible to developing cancerous lesions from too much exposure to or tanning beds…can you say “Cancer Risks”???
Human skin color and physical traits are determined by variations in the amount of pigment (melanin) produced by cells called melanocytes. Melanin is a brown or black pigment that plays an important role in photo-protection.
Melanosomes within these cells produce a variety of packages, containing melanin which vary in their levels of expression, size and structure. The number of packages created will depend on two things – how sensitive the area is to UV radiation and how active are the cells producing it. When more skin cells produce melanoctes (cells engaged in pigment production), as needed for darker pigmentation, larger amounts of melanoblast (cells diverging from certain neural crest precursor at birth) are born which migrate and expand forming a larger network. This means that regions of the body which are mainly exposed to UV radiation will have a darker complexion, while those areas which are not exposed or slightly exposed will be lighter.
Skin color is the most evident of the many physical traits humans possess. It varies widely from person to person within families and between populations, being most evident in people inhabiting sunny regions of the earth. In many areas, skin color has been closely tied to climate, making it a useful marker for patterns of human migration and social boundaries.
It depends on the geographical location and cultural exposure.
The genetic mutations and phenotypical expression are heavily influenced by the environment in which that person lives–a little sun, a lot of sun, proximity to water or mountainsides, etc. The color of someone’s skin has changed over time due to this mutation-influenced environmental effect. That is why different ethnicities have varying skin colors; they come from different regions with their own light spectrum levels and races developed these differing colors as a result.”
In other words, it depends specifically where you live (geographical location).
Another factor determining human skin color is the amount of melanin produced in the person’s body (biological factors).
Skin color and physical traits are determined by the pigments in the skin cells. We usually take a look at two of these substances, melanin and carotene.
Melanin is produced by photoreceptor cells as a response to strong ultraviolet radiation, such as sunlight (specifically UV-B). These include black, brown, pink or red. Those with high levels of melanin may be less likely to get sunburned than those with low levels of melanin because over-exposure to UV radiation can damage DNA and lead to skin cancer. Carotene is an orange pigment that determines our yellow/golden skin tones; those who lack this pigment will have what’s called “pink undertones”.
The primary determinant of skin color is melanin, which determines our pigmentation and protects our skin from ultraviolet damage from the sun.
Pigment cells in the human body produce several kinds of melanin that give people their skin tone not only on the outside but also on the inside. There are 3 different types of pigment cells in your body: Eumelanin, phaeomelanin, and pheomelanin.
Each type causes a person to produce different colors when they’re exposed to UV light. Eumelanin gives someone brown or black skin while phaeomelanus gives someone yellow or lighter brown shades like tanning while pheomelans all have red tones.
Skin color is determined by the amount of melanin that’s in a person’s skin. The more melanin, the darker you will be and vice versa. People with very little melanin in their bodies will burn easily while people who have high levels of it protect themselves from further sun damage and even cosmetic cosmetic problems like freckles and age spots.
Melanin also determines our hair color. Our hair contains 2 kinds of pigment called eumelanin and phaeomelanism, which determine the darkness of our hair, with black being the darkest and red being the lightest. See here for more information .
By studying skin pigmentation, scientists have discovered that skin color is less about where your ancestors were born and more about how close they were to the equator.
People who live near the equator are naturally much darker because their skin protects them from intense sunlight that can damage it.
Speaking of which, humans evolved at the equator, but then migrated out of Africa into colder climates. We developed lighter skin that could absorb more sunlight, which helped us survive in colder regions.
The closer you are to the equator, the less time your ancestors spent in cold climates, so the darker your skin color will be. This is why people who live near the equator often have dark skin, thick hair and full lips.
People who live very far from the equator, like those who live in northern Europe or Canada tend to have lighter skin that can absorb more sunlight. This is because their ancestors spent thousands of years living in colder climates where it wasn’t safe for dark-skinned people to go out without a lot of protective clothing and sunscreen.
It’s also important to note that there are many different types of Asians and Europeans and not all Asians look the same and not all Europeans look the same either. So just because someone has light eyes or blonde hair doesn’t mean they’re European. There are too many different ethnicities within those groups as well as within Asian countries themselves such as China, Japan, Korea, etc.
However, generally speaking, people from countries closer to the equator tend to have darker skin and eyes while those from colder climates tend to have lighter skin and eye colors. But this isn’t a hard rule because so many other factors determine our appearance as well.
The color and shape of human skin and other physical traits in humans are due to variations in melanin, or the pigment that produces shades or colors on the surface of human skin, hair, and eyes.
Many people mistakenly think that white hair is just another name for gray hair; however there is a vast difference between the two. Gray hair refers to what happens when bits of “lichen” (dead cells) mixed with fluids from sweat glands attach themselves on your hairs while they grow long enough to capture light under them. White hairs either have translucent scales which do not allow any light rays through; this means these hairs reflect all light seen by their root attachment point making them appear white from above while still being black if looked at from the side.
