Is There A Neanderthal In The House?

 

Karen Rosenberg

Photo by Kathy F. Atkinson

“We need to understand our evolutionary history in order to understand why we have some of the maladies that we have,” Rosenberg says. “They either helped us in a previous environment, or they are trade-offs from adaptations that did confer important advantages like our obstetrical and orthopedic problems that are side effects of walking on two legs rather than four.”

Today, the industrialized world faces rising obesity rates. Yet eons ago, food was scarce, and foraging was a constant activity to survive. The more fats and sugars that could be gained from food back then, the more energy to fuel those ever-expanding hominid brains. 

The cavewoman of 100,000 years ago didn’t have 10-pound babies, take drugs, smoke, or have hypertension, diabetes and other problems associated with a modern lifestyle, Rosenberg notes. 

But, Rosenberg asserts, our prehistoric ancestors likely gave birth with others present for protection and encouragement, a practice still important in today’s world where ever-larger babies squeeze through a “twisty-turny” birth canal, and infant mortality is still a serious problem in many nations.

“Studies show that women who give birth with a doula present — to provide emotional support — have significantly lower rates of obstetric intervention and shorter labors,” Rosenberg notes. “This maternal care during birth and the help we give in caring for children of family and friends comprise some of the most important aspects of our humanness.”

Although some may interpret the word “evolve” to mean we are moving toward perfection, Rosenberg reminds us that there is no direction to evolution. 

“What’s best today, probably won’t be in the future,” she says. “There’s no inevitable directionality to it. Evolution is a tinkerer, not a designer. I would never be willing to predict where we will go next. Knowing what is advantageous in today’s world doesn’t tell us what will be advantageous in the future.”

“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,” Latimer said. “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.”

But applying Darwinian evolutionary theory to the human condition offers a window to why humans suffer from physical ailments that no other animals do, said Latimer, who is on the faculty in the Department of Orthodontics at Case Western Reserve.

Evolving from four-footed walking has created issues from flat feet and bunions to slipped discs, hernias and fallen pelvic floors. And as bizarre as it sounds, rising from four to two feet resulted in reshaping the face and head, which is why humans suffers with such dental problems as wisdom teeth with no room to grow.

Latimer’s talk will focus on physical problems of the spine, which developed into an S-shaped structure as humans shifted from quadrapedal walking to bipedal walking. But changes to the spine also resulted in protecting the body’s most important area, the birth canal, which allowed the species to procreate.

As the spine developed in curves, it became stressed at certain points, resulting in such conditions as lordosis (swayed backs), kyphosis (rounded upper back or hunch back) and scoliosis (sideway curve).

The spine also takes a beating from how people walk—one foot forward at a time with the opposite side arm swinging in step.

“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, Latimer explained.

Few early species of ancient human hominids lived beyond 50 years. Most died between 30 and 40, Latimer said. The human body really takes a physical beating, and most people will struggle with some kind of pain as the body ages.

“The original design specs for the human body were designed to last about 40 years,” he said.

Contacts and sources:
Andrea Boyle Tippett
University of Delaware