What Percentage Of The World Has Brown Eyes?
The most common – It probably comes as no surprise that the most common eye color around the world is brown. A whopping 55 to 79 percent of the worldwide population has brown eyes! In fact, about 10,000 years ago, researchers believe we all had brown eyes.
What European countries have brown hair?
Geographic distribution – Brown-haired individuals predominate in most parts of Europe, In northern and central Europe medium to light brown shades are the most common, while darker shades prevail in the rest of the continent. Brown hair, mostly medium to light brown shades, are also dominant in Australia, Canada, South Africa among White South Africans and the United States among European Americans from the Northern, Central and Eastern European ( British, Scandinavian, Baltic, Dutch / Flemish, German (including Swiss-German and Austrian ), Slovenian, Polish, Ukrainian and Russian ) as well as Southern ( Italian, Spanish, Greek, Portuguese ) and Southeastern European ( Bulgarian, Croatian, Serbian ). Afghan children with brown hair Similarly to blond hair, brown hair occurs commonly among Australian Aboriginal and Melanesian populations. Dark brown hair is predominant in the Mediterranean parts of Europe, the Middle East, North Africa, Central Asia, and South Asia,
- Very dark brown hair, easily mistaken for black hair, can be found occasionally in parts of East Asia,
- This is also true of Southern Cone of South America ( Chile, Argentina, Uruguay, Paraguay, central-southern Brazil ), Colombia, Andean Region of Venezuela, Costa Rican Central Valley and Puerto Rico,
Dark brown hair also may occasionally be found among Indigenous Siberians and Americans ;(formerly) especially for mostly populations in Southeast Asia due to pigment changes (such as the Philippines, Malaysia and Vietnam ) for example particularly when they are young, as well as in many other groups
What is the 2 rarest eye color?
Of those four, green is the rarest. It shows up in about 9% of Americans but only 2% of the world’s population. Hazel/amber is the next rarest of these.
What genes are inherited from father only?
#3 Y-Linked Inheritance (for Sons) – All men inherit a Y chromosome from their father, which means all traits that are only found on the Y chromosome come from dad, not mom. The Supporting Evidence : Y-linked traits follow a clear paternal lineage. A mutation on the Y chromosome can only be passed from father to son, and they’re all considered “dominant” in that there’s no second Y chromosome from mom to alter or mitigate the effects.
Hypertrichosis – Excessive hair growth on the outer ear Syndactyly – “Webbed toes,” where the skin between one or more toes is fused Chromosome infertility – Can affect the male’s sperm production
The Big Picture : For the most part, there’s no real indication that boys take after their dads in looks any more than they look like mom, but Y-linked traits are the exception to this rule.
Is brown hair or blonde hair more dominant?
How can two brown-haired parents have a blond child? The genetics of hair color is still a bit of a mystery, but we do know a few things. I’ll give you a mostly-true answer first, and then dive into the ugly details if you’re still with me. If two brunette parents have a blond child, that means they had to have instructions for making blond hair hidden in their DNA.
- How could blond-making DNA be hiding in every cell of a brunette person’s body without them growing any blond hair? The answer lies in understanding ‘dominant’ and ‘recessive’ features.
- You probably know that DNA is organized into small pieces called genes, which help control how our bodies are built.
And your genes can come in different versions, called alleles, Let’s pretend that there’s just one gene that controls hair color, with a ‘brown’ and a ‘blond’ allele. Seems simple enough, right? You have the blond allele, you have blond hair. Brown allele, brown hair.
But there’s a catch – you have two copies of each of your genes. You got one from each of your parents. What happens if you got a ‘brown’ allele from your mother, and a ‘blond’ one from your father? It turns out that brown hair is dominant, That means that even if only one of your two alleles is for brown hair, your hair will be brown.
The blond allele is recessive, and gets covered up. If two brunette parents have a blond child, they had to have instructions for making blond hair hidden in their DNA. You can think of recessive alleles as t-shirts, and dominant ones as jackets. If you wear one of each, only the jacket will be visible.
In the same way, features created by recessive alleles only show up if there isn’t a dominant allele around. Since you have two copies of each gene, that means the only way to have a recessive feature like blond hair is for both of them to be the recessive allele. Having one of each will leave your hair brown, even though you’ll secretly be carrying the blond allele in every cell of your body.
This is what both of our brown-haired parents had going on. They were secretly wearing blond shirts under their brunette jackets, and when it came time for each of them to pass down one item of clothing to their kid, they both gave the shirt! 
Image by G. Riesen With this analogy, you can also see how two blond parents should never have a brown-haired child. Since they’re both blond, they must each have two blond t-shirts and no brunette jacket. No matter which genes they pass down, their kid should end up blond.
- That being said, don’t dust off your family tree just yet – remember I said there were ugly details? For the most part the idea of a single brown/blond gene matches how hair colors are really passed down.
- If you add in a second gene with a recessive allele that makes red hair you’ve got a decent model of most hair colors and a nice story to go with it.
But as usual when it comes to nice stories, reality isn’t quite so simple. To get to the root of things, we’ll need to learn about the cells that color our hair: melanocytes. Melanocytes make the pigment that gives our body color: melanin, There are two types of melanin in your hair, eumelanin and pheomelanin, 
Image by G. Riesen So what controls how much of each type of melanin your melanocytes make? As you might imagine, lots of different genes can impact how these cells work. In fact, dozens of genes involved in everything from building your hair’s roots to repairing DNA have been found to affect hair color.
- Unlike in our mostly-true model, there isn’t just one gene that controls melanin levels.
- Skin and hair color are both what we call polygenic features: they depend on a bunch of different genes working together, with more still being discovered.
- To make things worse, two people can have all of the same genes but still have different hair colors! Hormones can change the way that genes work, which often causes blond hair to get darker as children get older.
With more age, melanocytes can start to die off, leading to inkless, gray/white hair. Stress, sunlight, smoking, and eating poorly can also cause hair color to fade. It’s a bit like those little printers are breaking, or simply running out of ink! I bet there’s a whole lot of money to be made in hair, if only someone could figure out how to keep melanocytes healthy longer As you can see, there’s a lot going on here.
- Hair color is just one feature that comes from the combined efforts of all of a person’s genes plus their environment.
- We can identify some big-picture patterns like the dominance of brown hair over blond, but we need more detailed models to explain colors like strawberry blond or how color changes with age.
Lots of scientists are still working to build better models of how people’s genes create their hair colors and other features. If you really want to know exactly how it works, you’ll have to join them and do your own research – maybe you’ll discover how to un-gray hair, or even reverse aging itself! These kinds of mysteries show up at the bottom of any question, if you dig far enough.
Is hazel brown or green?
What Are Hazel Eyes? What Is the Hazel Eye Color? – The defining feature of hazel eyes is their mix of colors. All hazel eyes will have some combination of brown/gold and green coloring, sometimes with flecks of blue as well. This is why hazel eyes appear different than brown, green, or blue eyes, which are a solid color.
Hazel eyes are often lighter/more green in one part of the iris (either the center or the edges of the iris) and darker/more brown in the other part. There are two main types of hazel eyes: those with brown as the dominant color in the iris and those with green as the dominant color. While all hazel eyes will have a combination of green and brown colors, the difference in dominant colors is why hazel eyes can appear either mostly green or mostly brown.
This variety in color can cause some confusion, but as long as there is a mixture of green and brown in the iris, the eyes are hazel.