Better, Stronger, Faster. Not The Six Million Dollar Man -- You.

The New York Times today kicked off a series on the science of aging with a piece on how rapidly humans have changed over the last century or so -- "one of the most striking shifts in human existence — a change from small, relatively weak and sickly people to humans who are so big and robust that their ancestors seem almost unrecognizable."

The article is fascinating. Most people expect to live longer than our great-grandparents, but Gina Kolata's piece shows that is just one piece of many very rapid changes in humans.

The generation-by-generation changes are both visible -- increased height and weight, for instance -- and not. General health, as measured by functioning into old age, continues to improve. Even human minds may be improving -- IQ scores keep going up, and the tests have to be periodically renormalized to 100.

Today's middle aged people, healthy since birth, can expect that to carry through to old age:

And if good health and nutrition early in life are major factors in determining health in middle and old age, that bodes well for middle-aged people today. Investigators predict that they may live longer and with less pain and misery than any previous generation.

“Will old age for today’s baby boomers be anything like the old age we think we know?” Dr. Barker asked. “The answer is no.”

This such a radical change from normal life just 150 years that it deserves the appelation "revolution." The NYT piece cites recent studies of health records of the Union Army in the Civil War, where researchers found that "almost everyone of the Civil War generation was plagued by life-sapping illnesses, suffering for decades. And these were not some unusual subset of American men — 65 percent of the male population ages 18 to 25 signed up to serve in the Union Army."

The unresolved question is: "why?" There is agreement that there are dramatic changes in human health -- across nations and population groups -- but no consensus as to how it's happening.

Some believe that improved care for children under two, including nutrition, is a key factor. The Barker Hypothesis, first published in 1995, holds that "health in middle age can be determined in fetal life and in the first two years after birth." Studies of the children of women who were pregnant during famines associated with World War 2 seem to bear this out -- the children were healthy until middle age, but now suffer from chronic disease at a much higher rate than expected.

Others argue that improvements in occupational safety and the shift away from manual labor likely play some role. Although not mentioned in the NYT piece, heterosis, or "hybrid vigor" (when the offspring of 'mixed' parents are stronger than their parents) may play a role in an increasingly mobile world.

So while there may be days where you don't feel like the pinnacle of human evolution, think back to the lives your great-grandparents faced and be thankful you live when you do.

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It's worth clicking through to the article's charts to see just how much longer people today can expect to live than their recent ancestors.

A future story in the series will cover "who ages well, and why."