IT MAY have helped turn us into the advanced human species we are today, but evolution is also responsible for giving us bunions, slipped discs and hernias, scientists believe.
Everything from sore feet to backache could be as a result of our evolution from using four feet to standing on two, according to experts in the United States.
The scientists found that applying Darwin’s theory of evolution could provide answers to why humans are afflicted by physical conditions that are not seen in other animals.
A conference in Boston will hear that evolving from four-footed walking has created problems including flat feet, hernias and fallen pelvic floors.
Experts will also say that rising from four feet to two additionally resulted in reshaping the face and head, which is why humans suffer from dental problems such as wisdom teeth with no room to grow.
Professor Bruce Latimer, an anthropologist from the Case Western Reserve University School of Dental Medicine in the United States, said: “If an engineer were given the task to design the human body, he or she would never have done it the way humans have evolved.
“Unfortunately, we can’t go back to walking on four feet. We’ve undergone too much evolutionary change for that – and it is not the answer to our problems.”
Prof Latimer’s presentation will focus on physical problems of the spine, which developed into an S-shaped structure as our ancestors shifted from walking on all fours to walking on two limbs.
But changes to the spine also resulted in protecting the body’s most important area – the birth canal – which allowed the species to reproduce.
The spine is also affected by the way that people walk – one foot forward at a time with the arm swinging on the opposite side.
Prof Latimer said: “This creates a twisting motion that, after millions of twists over time, the discs between the vertebrae begin to wear out and break down resulting in herniated discs.
“In addition, age related bone loss [osteoporosis, the brittle bone disease], also a human condition, further complicates problems.”
Few early species of ancient humans lived beyond 50 years, with most living between 30 and 40, Prof Latimer said.
“The original design specs for the human body were designed to last about 40 years,” he added.
Darwin’s theory states that evolution happens by natural selection, with the members of a species most adapted to their environments surviving to pass their genes to their offspring, while other member do not survive.
So, while the change from four feet to two helped the human race thrive in certain areas to perform best within its environment, the consequence was the various ailments that have now become common.
And the human species, like others, continues to evolve, though experts believe future changes may not be as dramatic as those seen in the past.
Biochemist Nick Lane, author of Life Ascending: The Ten Great Inventions of Evolution, believes the human mind may be the focus of future changes.
“It is impossible to stop change, so we are undoubtedly continuing to evolve in some ways. But those ways might not be very interesting,” he said.
“Our brains can’t get any larger, as a baby’s skull only just fits through the mother’s hips; unless everyone has a Caesarean section, that’s it. But the human mind may evolve in more subtle ways, related to urbanisation or the use of computers.”