All People With Blue Eyes Have A Single, Common Ancestor

Calendar October 10, 2022 | Posted by admin

According to the Cleveland Clinic, up until some 10,000 years ago, it’s believed everyone in the world had brown eyes. Now, an estimated 8-10% of people in the world have blue eyes. How did that come to be? As it turns out, researchers now believe blue eyes all started with a single person who passed on a genetic mutation that spread across the world. In other words, everyone with blue eyes shares a single, common ancestor.

Back in 2008, researchers with the University of Copenhagen examined the exact genetic mutation that resulted in blue eyes all those years ago. Their research was published in the The Journal of Human Genetics. According to Science Daily, the study’s lead author, Professor Hans Eiberg, explained that humans originally had brown eyes, and a gene mutation “turned off” the ability to produce brown eyes – resulting in some people having blue eyes. The press release elaborated that the affected gene, the OCA2 gene, regulates brown pigment in the eyes. If the OCA2 gene had been completely destroyed or “turned off” then the affected humans would be without any melanin in their hair, eyes, or skin color (a condition known as albinism). But with the specific mutation, the body has a limited ability to produce melanin in the iris, resulting in a blue iris, rather than a brown iris. The genetic mutation isn’t a positive or negative trait.

“Mutations can affect things like freckles, balding patterns, hair color, and more“. “It simply shows that nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so,” explained Eiberg.

According to the College of Physicians of Philadelphia, researchers studied the mitochondrial DNA of individuals with blue eyes from various countries, such as Jordan, Denmark, and Turkey. The researchers found that over 97% of the blue-eyed people in the study shared a single haplotype – a grouping of genomic variants that are usually inherited. Because of this, researchers believe that the mutation is passed on genetically, meaning that everyone with blue eyes is related.

“From this, we can conclude that all blue-eyed individuals are linked to the same ancestor. They inherited the same switch at the same spot in their DNA,” said Eidberg in a press release, shared in EurekaAlerta!,

Source: https://blog.thebreastcancersite.greatergood.com

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How To Create a Spectrum of Natural-looking Hair Colors

Calendar November 2, 2020 | Posted by admin

We’ve long been warned of the risks of dyeing hair at home and in salons. Products used can cause allergies and skin irritation — an estimated one percent of people have an allergy to dye. Furthermore, repeated use of some dyes has been linked to cancer. But there soon may be a solution for the growing list of salons and hair color enthusiasts searching for natural alternatives to dyes and cosmetics.

Northwestern University researchers have developed a new way to create a spectrum of natural-looking hair colors, ranging from blond to black, by using enzymes to catalyze synthetic melanin. Melanin is an enigmatic and ubiquitous material often found in the form of brown or black pigment. Northwestern’s Nathan Gianneschi, the research lead and associate director for the International Institute for Nanotechnology, said every type of organism produces melanin, making it a readily available and versatile material to use in the lab.

Synthetic melanin can create colors ranging from blond to black

“In humans, it’s in the back of our eye to help with vision, it’s in our skin to help with protecting skin cells from UV damage,” Gianneschi said. “But birds also use it as a spectacular color display — peacock feathers are made of melanin entirely.”

Gianneschi is Professor of Chemistry in Northwestern’s Weinberg College of Arts and Sciences and a professor of materials science and engineering and biomedical engineering in Northwestern Engineering. Claudia Battistella, a postdoctoral fellow in Gianneschi’s lab, is the paper’s first author.

The research was published in the journal Chemistry of Materials.

Source: https://www.mccormick.northwestern.edu/

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