Is Blue Eyes A Sign Of Inbreeding For Animals And Humans?
Blue eyes are an inherited trait that can be dominant, recessive, or co-dominant and can be caused by multiple genes in different combinations. Blue eyes can also occur when the iris of one eye takes on a different color than the other eye; this happens during the formation of the egg and sperm during embryogenesis and usually results in heterochromia iridium rather than blue eyes as seen here.
Blue Eyes: A Sign of Inbreeding in Animals
If you’ve ever wondered why some animals have blue eyes, wonder no more. Blue eyes signify that an animal or person is closely related to someone else usually very closely related.
Babies with light-colored eyes are often born to parents who share genes for lighter eye color. Many times, though not always, these parents are blood relatives.
A quick look at history reveals how common it is for kings and queens to marry their siblings or cousins (yes, really) and give birth to children with striking (and medically significant) pale-blue peepers.
Icons like Sophia Loren and Audrey Hepburn were just two famous people with unusually pale irises. While blue eyes aren’t a medical concern on their own, they can be a symptom of something else inside your body.
For example, suppose you notice your baby has bluish sclera (the white part around his pupils). In that case, he may have congenital glaucoma which means he has abnormally high pressure inside his eyeballs.
This condition can lead to vision loss if left untreated. So while having light-colored eyes isn’t problematic, they can indicate that something else is wrong with your baby’s body.
Blue Eyes: Is Blue Eyes a Sign of Inbreeding Among Humans?
In nature, eye color ranges from brown to green to grey. In humans, it also varies from blue to green to brown. At one point, scientists thought that since humans had more pigmentation in their irises (known as melanin), only light-colored eyes were possible.
However, studies have shown that we can still produce some melanin because humans are exposed to sunlight much less than many other mammals. As such, different colored eyes are likely to be seen among humans around you!
However, for those who do have blue or green eyes is there anything special about them; You might think so if you’re a Viking descendant! Yes indeed!
Blue Eyes: What Does Science Say?
Your melanin levels determine the color of your peepers and even if you don’t have naturally brown eyes, they can still appear brown if you have low levels of melanin. But that’s not to say that there aren’t other factors regarding eye color. For example, studies suggest that iris coloring can also be genetic.
A published study found that people with heterozygous or dominant alleles had darker-colored irises than those with recessive alleles. If one parent has light-colored eyes, it might be possible for their offspring to inherit a diverse set of genes resulting in unique coloring. It’s worth noting that some research suggests that your ethnicity could also impact eye color.
Researchers have observed lighter-colored eyes among certain ethnicities, including East Asians, Native Americans, Pacific Islanders, and Europeans, compared to other groups like Africans and Hispanics. This isn’t necessarily indicative of genetics, though it could be because lighter eyes are more common in these populations due to environmental influences like sun exposure.
And while we’re on the topic of science: No matter what you may have heard about blue-eyed parents having blue-eyed children all of their lives (or at least most), it’s not true! Genetics doesn’t work like that, but we know what determines whether someone will have dark or light-colored eyes: age!
Why Are Some People More Prone to Having Blue Eyes than Others?
Blue eyes are relatively rare, with only around 10% of people having them. So if you have them, chances are you are part of that lucky 10%. But what is it that causes blue eyes to appear at all; What are their genetic roots; And why do they occur in some people but not others; For most species, eye color is determined by an allele (an alternative form) at a single gene locus.
The OCA2 gene is one such gene that’s involved; it encodes an enzyme called tyrosinase, which plays a significant role in melanin synthesis (melanin being responsible for skin and hair coloring). Mutations (or changes) in the OCA2 gene can cause differences in pigmentation between individuals.
In humans, mutations in OCA2 result in lighter or darker shades of brown or greenish-brown eyes. There are several different alleles for eye color: one for brown eyes (B), two for green/hazel (G), and four for blue eyes (A through D). A person with two copies of any given allele will express that trait—so someone who has two copies of allele A will have blue eyes.
Likewise, someone who has two copies of any other allele will express that trait; someone who has two copies of G will have hazel/green eyes. Suppose a person inherits one document each from both parents. In that case, they’ll be heterozygous for that trait and thus likely to display an intermediate phenotype.
Research has shown that blue-eyed people are more likely to be related. And there are several possible explanations. The first is probably easiest to understand: Blue eyes are likely an indicator of what scientists call inbreeding when people marry close relatives, either because they live near each other or because their pool of potential partners is limited.
This can happen in small towns where there aren’t many options or when populations become isolated, as was common among early Americans who settled together in new colonies around the country. Humans have been marrying cousins (or second cousins) long before anyone started measuring eye color.