Looking At Our Evolutionary Past To Understand Today's Health Problems

Main Category: Public Health
Also Included In: Pregnancy / Obstetrics
Article Date: 19 Feb 2013 - 1:00 PST


Bunions bothering you? How about lower back pain, or impacted wisdom teeth?

As we humans evolved over the millennia to walk on two legs, grow larger brains and shorter jaws, bear big babies and live longer, we've also experienced some negative consequences on our way to becoming the world's most successful primate, at nearly 7 billion strong.

But keeping our evolutionary history in mind can help us better deal with issues from obesity to difficult childbirth in a much more productive way, according to Karen Rosenberg, professor and chair of the Department of Anthropology at the University of Delaware.

Rosenberg co-organized and spoke on the "Scars of Human Evolution" panel at one of the largest scientific gatherings in the world - the annual meeting of the American Association for the Advancement of Science (AAAS) in Boston.

The panel's title originated from a 1951 Scientific American article by Wilton Krogman that highlighted how our evolutionary history can account for many of the problems associated with the current human condition. Rosenberg and her co-panelists examined areas ranging from obstetrics and orthopedics, to dentistry, gerontology, diet and nutrition.

"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."

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