What Hidden Traits in Modern Humans Could Come From Extinct Human Species? — Here Are 7 Clues Scientists Have Identified

The modern human species, Homo sapiens have existed for around 200,000 to 300,000 years. However, during all those years, our ancestors did not evolve in isolation; instead, they lived and shared this planet with other humans such as Neanderthals, Denisovans, and more.

These different species’ existence overlapped with each other; some of them lived at the same place our ancestors evolved in, which is thought to be Africa. While some of them, we have met after Homo sapiens migrated to other continents and faraway islands.

Researchers believed that during this time, our ancestors may have interbred with some of these other human species and passed down the genetic traits of these extinct human species to their offspring. To this day, these genes are still affecting certain characteristics in the modern populations. Here are 7 clues scientists often study and explore.

7 Traits in Modern Humans That Could Come From Extinct Human Species

Your Immune System May Carry Ancient Genetic Advantages

We Were Wrong About Our Human Evolution

One of the strongest clues scientists have identified is the immune system of humans, which is thought to include variants inherited from extinct human relatives. These traits may have helped early humans fight off unfamiliar diseases and illnesses when they migrated to a new environment.

Other human species may have been more adapted for specific locations, including having an immune system that could fight off certain sicknesses. So, ancient Homo sapiens who migrated and interbred with these other species could have passed down these important traits to the next generation that allowed them to survive and adapt to their new habitat.

Read more: PBS

Certain Sleep Patterns May Be Linked to Ancient DNA

Researchers also identified some inherited genes from extinct humans that could influence our sleeping patterns and internal biological clocks or circadian rhythm. They found certain genetic variations that appear to be connected to some people naturally preferring to wake up earlier or stay active later in the day.

A possible explanation for this scenario is that those traits helped ancient Homo sapiens adapt to their new environments after migration. These new places will naturally have different daylight conditions, which our ancestors may have needed to adapt to survive.

Pain Sensitivity Could Be Influenced by Ancient Human Genes

Every Other Species of Humans We Encountered

Pain sensitivity is another trait that could have been influenced by genes of other extinct human species. Some inherited genetic traits appear to affect how strong peole experience pain, physical injury, or discomfort.

Researchers believe that this trait was passed down because it may have provided an advantage to our ancestors who lived in a time when injury, hunting, and physical stress were very common due to their way of living.

Your Lungs May Reflect Ancient High-Altitude Adaptations

Scientists have studied modern human populations who have been living in high-altitude environments and found that they have genetic traits that may have come from other extinct human relatives.

These inherited traits may have helped our ancestors survive in colder temperatures and mountainous areas where the oxygen level is lower. These gene variants could have affected how efficient some people’s lungs are at managing oxygen in the body.

Metabolism May Have Been Shaped by Ancient Survival Pressures

How sex with Neanderthals changed us forever - BBC World Service

Ancient human populations sometimes lived in an environment where food supplies were either scarce or unpredictable. Some humans may have interbred with other species and passed down a trait that helped modern humans process fats, store energy, and regulate metabolism.

Over thousands and thousands of years, this efficient energy storage system could have been advantageous enough to have helped our ancestors survive in harsh conditions, and some of these metabolic differences may have actually come from interbreeding with other human species who already possessed the trait.

Bone Structure Could Still Reflect Ancient Human Evolution

Researchers have also studied certain differences in bone structure, skeletal density, and physical robustness in modern humans. Some of them reflect ancient genetic inheritance from different human species.

Back then, the physical demand on the human body was much more enormous and stressful. Those who have survived may have developed specific physical traits that are now seen in modern humans due to interbreeding with archaic ancestors.

Author's Final Thoughts

Although extinct human species disappeared tens of thousands of years ago, their story still lives within us. Our Homo sapiens ancestors may have never survived if they had not met and interbred with them, or at least, our evolutionary history may have turned out differently.

The human body, because of this history of interbreeding and shared evolutionary past, has developed to still contain countless clues that connect modern populations to extinct human relatives. They may have been gone now, but they are still a part of us.

Read next: What Traits in Your Body Could Reveal You Are Built for Long-Distance Hunting Like Ancient Humans? — Here Are 5 Evolutionary Signs