In your genes

You might be a human relic if you have any of these 12 traits

Image: Cade Proulx

You may have never met your great-great-grandparents, but their biological legacy lives on in you in ways you might not expect. From tiny quirks in your body to odd preferences and physical features, ancestral survival and lifestyle choices have shaped what you carry today. Here are 12 surprising traits that science has linked to deep genetic inheritance.

Image: Katya Ross

A thumb that bends backward at the top joint is known as a hitchhiker’s thumb. It results from a single gene variant.

This trait is controlled by a variation in the gene responsible for joint flexibility. Some people have it in both thumbs, while others only in one. It's a harmless variation that may have been more common in populations requiring greater dexterity.

Image: Max Leveridge

Some babies are born with blue or gray eyes that change color over time. The way this shift unfolds is written in your DNA.

After birth, melanin production in the iris increases over time. Genetic variants in the OCA2 and HERC2 genes regulate melanin levels. These subtle changes can take months or even years to settle into a final eye color.

Image: Alex Guillaume

The ability to roll your tongue into a tube shape is often thought to be purely genetic, and that’s partially true. While you can learn to do it with a lot of practice, studies show it’s also influenced by genes.

Some populations have a higher percentage of tongue rollers, and the trait may have originally been a byproduct of muscle control needed for speech or food manipulation in early humans.

Image: Tim Trad

Acrophobia, or intense fear of heights, has a genetic link tied to survival instincts from your prehistoric ancestors.

People with heightened depth perception or balance issues may inherit a stronger fight-or-flight response to elevation. This reaction likely helped early humans avoid dangerous cliffs or falling from trees.

Image: KaLisa Veer

Strange as it sounds, redheads often experience pain differently. Some studies suggest they have a higher threshold for certain types of pain, while others indicate increased sensitivity to specific stimuli like cold or heat.

This is linked to ancient adaptations in the MC1R gene, which influences melanin production and also affects pain modulation through opioid receptors in the brain. Variants of this gene were more common in populations from colder regions, such as prehistoric Europe.

Image: Chermiti Mohamed

Freckles are genetic, but they bloom with sun exposure due to the way ancestral DNA interacts with UV light.

In fact, the same MC1R gene involved in red hair also influences how melanin clusters into freckles. This is because freckling was advantageous for fair-skinned populations needing some UV protection without full pigmentation.

Image: Anita Jankovic

The ability to digest milk into adulthood is a relatively recent mutation in human history. Populations with pastoralist ancestors—such as Northern Europeans and some East Africans—evolved lactase persistence, the continued production of the enzyme lactase that enables them to digest milk throughout adulthood.

Most of the world remains lactose intolerant, but those with this mutation can thank their ancestors for a genetic advantage linked to dairy-based survival.

Image: Thomas Park

Weirdly enough, some people sneeze when exposed to sunlight or even just bright lights. This phenomenon, known as the "photic sneeze reflex," affects 18–35% of people and is linked to genetics.

While this inherited quirk is harmless, it likely results from crossed nerve signals between the optic and trigeminal nerves, the latter of which controls facial sensations and reflexes like sneezing.

Image: Claudia Love

Also called Morton’s toe, this feature was once thought to improve balance or running efficiency. The trait is hereditary and common in certain populations.

Greek statues often depict this toe shape, suggesting it was either idealized or prevalent in ancient Mediterranean groups. Biomechanical studies show mixed results, but some suggest that a longer second toe can affect posture and gait.

Image: Mika Ruusunen

People with ancestry from colder regions often have inherited a better tolerance to cold. Adaptations such as higher basal metabolic rates, subcutaneous fat distribution, and heat-conserving blood vessel responses are linked to genetic clusters in populations like the Inuit or Sámi.

Genes like UCP1, which influence fat burning and thermogenesis, are more active in these populations.

Image: Marco Bianchetti

Some people have a vestigial muscle in the forearm that others lack entirely. Called the palmaris longus, it once helped tree-climbing primates enhance their arm strength.

Today, about 14% of people are born without it in one or both arms. It has little to no effect on grip strength, making it a living fossil of human evolution. Interestingly, when present, it’s often harvested for surgical grafts because its absence doesn’t impair function.

Image: Bethany Beck

Clockwise or counterclockwise hair whorls are influenced by genetics, and some studies link their direction to the same genes that affect handedness. However, identical twins can sometimes have opposite whorl patterns, suggesting a mix of genetics and early fetal environment.

This trait has no known survival function but may serve as a visible marker of underlying developmental processes during early embryonic growth.

Deep roots

11 everyday words with indigenous roots

English is a very welcoming language in the sense that it incorporates terms from many other languages from all over the world. And, as it couldn’t be otherwise, Native American languages have lent many of their words and terms to English speakers. Some traveled through Spanish or French before settling into English, and others arrived directly through early contact and trade, helping shape the way we speak today. Did you know about these 11 terms?

The word "canoe" comes from the Taino term canoa, which was first used by Caribbean islanders long before Europeans arrived. Early explorers adopted it to describe the slim, sturdy boats they saw.

Over time, "canoe" became the standard English word for a small paddled craft. Today it still carries that sense of simplicity and closeness to nature.

The word "barbecue" comes from barbacoa, another Taino term for a wooden frame used for cooking meat over fire. Europeans adopted it and applied it to both the method and the gathering itself.

Today, "barbecue" means everything from a backyard cookout to a regional cooking style. Its origins highlight the deep culinary influence of Native Americans in the nation's current culture.

"Skunk" comes from the Algonquian word squnk, which means "urinating fox" (quite a fitting term, indeed). This was an obvious reference to the animal’s strong defensive spray. Early settlers adopted the term directly.

Since English had no better name for the creature, the Native word stuck. Today, the word skunks is also used as playful slang.

The word "moose" originates from Eastern Abenaki, a part of the Algonquian family, where it meant "he strips off bark." Yes, it described the animal’s habit of tearing bark from trees.

The name entered English quickly because settlers relied on Native knowledge of local fauna. The word remains unchanged because of its accuracy and usefulness.

"Raccoon" comes from the Powhatan word arakun, meaning "he scratches with his hands." It described the animal’s clever, humanlike front paws.

Settlers adopted the term because it captured the creature’s behavior beautifully. Today, the raccoon is used as a household symbol of curiosity, not unlike the animal itself.

The term "chipmunk" most probably comes from the Ojibwe word ajidamoo, which means "one who descends trees headfirst." Early English settlers adapted the sound into today’s form.

Though the spelling changed over time, the lively image of a chipmunk racing down a tree face-first stayed.

The word "caribou" comes from the Mi’kmaq term qalipu, which means "snow shoveler," referring to the animal’s habit of digging through snow for food.

French settlers brought the word into English, keeping its descriptive nature. The name still connects the modern animal to the winter landscapes it belongs to.

"Totem" comes from the Ojibwe word ototeman, which means "kinship group." It described symbols representing clans and shared roots.

English adopted it to describe carved poles and symbolic elements. Though broader in modern usage, it still hints at the original sense of community, identity, and heritage.

"Coyote" comes from the Nahuatl word coyōtl, which was used by Indigenous tribes of central Mexico. Spanish speakers adopted it, and English borrowed later.

The word kept its meaning, and it remains one of the most direct links between the English language and Nahuatl.

The tasty avocado’s name traces to the Nahuatl word ahacatl, which refers to the fruit and to a body part as well. Spanish speakers transformed it into aguacate.

Later on, English speakers adapted it to avocado. While the name sounds contemporary and culinary, it has ancient Native roots.

The last Nahuatl word and also the last word on the list comes from the term xocolātl, which describes a bitter cacao drink that was consumed long before Europeans arrived in America. The name traveled from Spanish to English.

Though the product changed dramatically, the word survived. Today, chocolate is a universal symbol of sweetness, with rich and deeply indigenous roots.