The human body is full of flaws — and this points to evolution more than any other explanation for “how we got here.”
The body may seem magnificent. Various processes may seem wondrous, even miraculous.
But a closer look tells otherwise.
The body can be thought of as an old house that’s been remodeled many times over eons.
Evolution works by modifying existing structures rather than starting over with a completely new design.
Because of this, many parts of the human body are not ideal. They’re workable solutions that developed over millions of years.
Some of the most common health problems are connected to these evolutionary compromises.
Back Pain: the Most Common Non-Fatal Health Ailment
Evolutions explains that our distant ancestors were on four legs that moved through trees and on land.
Their spine was mainly built for flexibility, movement and protecting the spinal cord.
When humans evolved to walk upright, the spine had to take on a completely different responsibility.
It now had to support the weight of the entire upper body, maintain balance and still allow enough movement for daily activities.
The curves of the human spine allow for efficient walking, but they also create weaknesses.
These stresses contribute to common problems such as lower back pain, slipped or herniated discs, and age-related spinal degeneration.
The spine works, but it’s handling a job it wasn’t originally shaped to perform.
You’d think that the evolutionary process would’ve prevented this flaw, but on the other hand, evolution isn’t fool-proof.
A Flaw in Our Eyes
In humans and other vertebrates, the retina is arranged backward.
Light entering the eye must pass through layers of nerve cells before reaching the light-detecting photoreceptors.
The optic nerve also exits through the retina itself, creating a small blind spot where there are no light receptors.
Some people never notice this gap because the brain automatically fills in the missing information.
However, perhaps you’ve had the experience of being in the dark and looking at something across the room — and you discover that if you shift your gaze ever so slightly away from the point you’re wanting to focus on, you can see it a little better.
The blind spot is evidence that the eye developed through modification rather than perfect planning.
Teeth and Especially Wisdom Teeth
There are childhood and adult teeth. Unlike with great white sharks, when we lose adult teeth, they’re not replaced.
Sharks, along with some other animal species, continually replace their teeth throughout life.
Humans, however, inherited a system that worked well for our ancestors but leaves us vulnerable to cavities, damage and tooth loss.
Wisdom teeth show another example of evolutionary mismatch.
Primitive humans had larger jaws and ate tougher foods that required more chewing.
Over time, human diets changed and our jaws became smaller. However, our number of teeth remained the same.
As a result, many people don’t have enough room for their third molars.
Wisdom teeth may become trapped, push against other teeth or cause infections, leading to the need for removal.
The teeth themselves are not useless — they simply no longer fit perfectly within the modern human jaw.
Childbirth and the Evolutionary Trade Off
The pelvis must serve two purposes: allowing efficient upright walking and providing enough space for childbirth.
A narrower pelvis helps peoplewalk more effectively, but it reduces the size of the birth canal.
At the same time, women give birth to babies with unusually large heads because of our large brains.
The result is a difficult birth process compared with many other mammals.
Knee Problems
Does anyone not know at least 10 people with “bad” knees?
It’s been theorized that knee problems are so prevalent because evolution lagged way behind the use of rudimentary canes.
So the knee never had a chance — or rather, a reason — to evolve into something sturdier and not so prone to all sorts of injuries, cartilage degeneration, inflammation, fluid buildup, instability, etc.
Why Flaws in the Human Body Remain
Evolution doesn’t remove a body feature simply because it doesn’t work optimally.
A structure usually disappears only if it creates a significant disadvantage.
This explains why some questionable features remain in people today.
The appendix was once considered a useless leftover from evolution.
Scientists now believe it may have small roles in immune function and maintaining beneficial gut bacteria.
However, it can still become inflamed, causing appendicitis, which can become life threatening.
The sinuses are another example. They may help reduce skull weight, affect voice quality and play other roles, but their design also creates problems.
Their drainage passages connect directly to the nose, which makes them vulnerable to congestion and infection.
Even the small muscles around theears reveal an evolutionary past.
Many mammals use these muscles to rotate their ears toward sounds.
We still have these muscles, but we can’t rotate our ears towards sounds; we must move our entire head.
Human anatomy is a record of millions of years of changes, adjustments and compromises.
Evolution doesn’t create perfection. It creates solutions that are just functional enough to survive.
