I am not normally the sort of person who curls up in front of the fire with a good science book. The only time I found Charles Darwin interesting was in "Inherit the Wind."

But I was still intrigued with Stephen Jay Gould's thoughts about evolution. The Harvard geologist and author of "Ever Since Darwin" has written about natural change in a way that makes sense out of our current lives and not just out of fossils.

Gould thinks Darwin's view of evolution - as a gradual, step-by-step climb up the ladder from microorganism to human - was actually "a philosophy of change, not an indication from nature." He says that "gradualism" was part of the 19th-century prejudice in favor of orderliness. It was an age, after all, that disliked and therefore denied the importance of catastrophe, or of any sudden violent change in determining the course of natural history.

In that sense, I suppose we are all still Darwinians. How many of us harbor the hope that the change of our lives will be gradual, rather like being promoted from the seventh grade to the eighth? We would like our lives to be an accumulation of skills and wisdom, building layer upon layer, growing ever richer and more complex - and, most of all, avoiding disruption and loss. We want to evolve, not to revolt.

This hope is so strong - and the fear of disaster is so great - that it colors our observations. We tend to believe what we hope: that real change is gradual and that "future shock" is no more than a surface change.

But as Gould points out, gradualism is only part of the story of change. This is true whether we're talking about topography, the economy or people. What often appears to be a long and reasonably orderly life is actually punctuated randomly but regularly with some sort of crisis.

The birth of a child, no matter how long awaited, is still an abrupt change in the lives of parents. Even those whose love affairs have disintegrated slowly over years report that the moment of separation still feels like a sudden wrench. No matter how prepared, how welcome-wagoned you are, the change from one city to another means a rupture of friendships and the familiar sense of place.

People may go through the greatest changes in their lives in the shortest chunks of time. I have known someone who, after years of stagnation, raced through a decade of personal growth in the first year in a new career. I have known others who experienced a generation's worth of change in six post-divorce months. We all have lists of names of people whose personalities were transformed by a year of war, or whose lives were irrevocably altered by a death in the family.

In retrospect, or seen from a high altitude, biographies often show a pattern, a kind of internal compass, and the changes seem to be gradual and orderly. We research the history of one crisis and notice the series of events that, we now say, led slowly and "inevitably" to a turning point. We even chronicle the after-effects of a crisis and point out how slowly people absorb a loss.

But at the same time we often underestimate the suddenness, even the randomness, of the change itself.

I suppose that our observations are no more colored than Darwin's. We see gradual change, in part, because we go looking for it. We find it because we need it. Our research into the past reflects our fear of the future. Of the future shock.

In his work, Gould doesn't debunk Darwin, or suggest that the origin of the species was swift. But he reminds us of what scientists now suggest. Inside "gradualism" are long stable periods and sudden overwhelming changes. Evolution includes revolutions.

Natural history is, as he puts it, "a series of plateaus punctuated by rare and seminal events that shift systems from one level to another." In that way, I suspect, people have a lot in common with rocks.