You might think your hair and eye color arepermanent, but in reality, they could change at ANY TIME. And it definitely already changedonce. Greetings programs, Trace here for DNews.Many babies are born with blue eyes, and then their eyes change color as their genes continueto develop. Hair color is the same way, sometimes, babies are born with very light colored hairwhich gradually darkens. We got a few questions on this, so we did the digging! The colored part of the eye is the iris, itcontrols how much light is let into the eyeball and it's color is determined by melanin, justlike skin and hair. Darker colors absorb more
light, and lighter colors reflect more. Eye color is determined by a few differentgenetic factors, the most important being OCA2. OCA2 produced melanocytes, or melaninproducing cells. Melanin is the protein that creates skin, eye, and hair color. More melaninmeans darker eyes, hair, or skin. The COLOR of the melanin in the eyes is determined bythree OTHERa genes, EYCL1, 2 and 3. Together, they account for browngreenblue but nothazel or grey eyes, science is still working on how we get those. All blueeyed peoplecan trace their ancestry back to a single human born between 6 and 10,000 years ago.Due to a genetic mutation, a human was born
with a tiny switch right before the OCA2 gene,that limits the expression of the melanin, kind of like diluting the stream of the protein.Individuals with albinism or Albinos have the OCA2 gene completely shut off so theirskin, eyes, and hair have no melanin at all! With this in mind, let's apply it to babies.When we're born, our genetics are decided, but the body hasn't necessarily acted on allthe genes in your DNA. When it comes to eye color, the melanin controlled by the OCA2gene is diluted and thus we all have blue eyes. For those with that blueeye gene mutationthey eyes stay blue. But for the vast majority of us, once we're born the OCA2 gene kicksinto gear, creating melanocytes to make proteins
and the eyes turn a different color, somewherebetween 9 months and two years after birth. A medium amount of the melanin makes eyesgreen or hazel, a large amount makes them brown. With regard to hair, the melanin builds upthe same as in eyes, creating a dark color. As babies age, their melanin levels increaseand their hair will darken. Hair colors can change well into puberty, as some genes aren'tquot;switched onquot; until the hormones flood the body in adolescence. Eventually, usually inthe 30s, human hair stops producing melanin and begins to turn grey. Basically, it stopsadding color to the hair. Gray hair tends
to occur earlier in Caucasians and later inAsians. It's important to point out, that not ALLbabies are born with blue eyes. This mainly occurs with Caucasian babies, maybe becauseof the lower levels of overall melanin due to the lighter skin tone. Babies of Asian,African and Hispanic genetic heritages will likely be born with dark eyes that stay dark. Funnily enough, 1015 percent of Caucasiansreport their eye color continued to change into adulthood, so it's possible your peepersare still not settled! What's your favorite eye coloré What do youwish you hadé
Tell us in the comments and make sure yousubscribe to DNews for more science! We're here twice a day, every day of the year. Doyou have questionsé Let us know on Twitter @DNews or me @TraceDominguez. Thanks so muchfor watching!.
Why Do We Have Birthmarks
Once upon a time, a pregnant woman wishedfor strawberries, when she did not receive them, her daughter born a few months later,a strawberry shaped mark on her forehead. Or so the story goes in much of ancient history. Hey Guys, Julia here for DNews Birthmarks can often be a source of embarrassmentfor some. A mistake of DNA can lead to an deposit of melanin or a tangle of veins. Butsurprisingly, not a lot is known about them. Scientists split birthmarks into two maincategories, vascular and pigmented. Caused by increase in melanin in one spot,pigmented birthmarks are mostly harmless.
Moles, Café au lait spot, and mongolian spotsare the big three kinds. Pigmented Nevi, or more commonly known asmoles, are dark skin cells that grow in clusters. Cafe au lait, are a little more spread outand a lighter brown or tan. Mongolian spots, are bluish purplish spotsand appear when melanocytes get trapped in a deeper layer of skin. And are typicallyfound in people of East Asian descent. They go away as kids get older and are almost alwaysgone by puberty. More is known about vascular birthmarks however, The most common are stork bites, pink or tanpatches that appear on babies' neck. It's
estimated that as many as half of all newbornsget one. Similar to spider veins, the stretching of some capillaries causes the patches toappear, and they too usually go away after 18 months or so. Another type of common birthmark are littlestrawberry like marks called infantile hemangiomas. These are basically benign tumors in the cellsthat line blood vessels. One study published in Journal of al Investigation foundthat these marks originate in one type of cell which express a protein, CD133. Fromthese cells blood vessels form, but then they disappear leaving behind fat cells which makethe marks stick out. Another study published
in Pediatric Dermatology found a connectionbetween oxygen depletion in the placenta and the development of these type of birthmarks.Yet some research from The Medical College of Wisconsin and Children's Research Institutesuggests that low birth weight is the single greatest factor in developing an infantilehemangioma. Most of them disappear after a few months, but up to 10% of them can causesome problems, like getting so big it impacts vision or breathing. Some birthmarks indicate a serious underlyingissue. Portwine birthmarks are pretty common, about one million people in the United Statehave the reddish elevated spots.
Like stork bits and hemangiomas, they formwhen capillaries don't grow correctly, yet these can grow and thicken over time. Theycan sometimes be a hallmark of SturgeWeber syndrome, in which patients have abnormalblood vessels in the skin, brain and eyes, which cause the symptoms of the disorder.One study published in the New England Journal of Medicine found a single genetic mutationon the gene GNAQ is associated with the disorder. From this run down, it's clear more researchis need, get on it science! Alright guys, do you have a weird birthmarkéLet us know in the comments below. While you're at it don't forget to hit those like andsubscribe buttons and keep coming back here