"Hidden Life" was such a surprise success that you might have thought its author had dropped from the sky, but writing brilliantly about dogs was only Thomas' most recent accomplishment, and not her first 15 minutes of fame.

Much of Thomas' work is connected to a transformative experience, a series of unusual African sojourns her family undertook in the early 1950s.

Thomas' father, Laurence Marshall, was a co-founder of Raytheon, started in 1922 as a refrigerator company and now one of the largest industrial corporations in the United States. Raytheon made the first microwave ovens, and Thomas remembers hulking early models her father brought home. The adults tried to devise practical recipes, while Thomas and her younger brother, John, preferred exploding eggs.

Her mother, Lorna Marshall, born in 1898 in the Arizona Territory, was teaching English literature at Mount Holyoke when she married Laurence Marshall.

Elizabeth, born in 1931, was a child mad about animals, from family cats and dogs to the stuffed tigers in the museum. She went to Smith in 1949, but didn't stay long, because her newly retired father was restless. During the war years Laurence Marshall had been preoccupied with Raytheon's production of magnetron tubes for shipboard radar on Allied ships. "He felt time had passed and he hadn't got to know his family," Thomas told me. "He was a very imaginative person. Things didn't seem impossible to him. They seemed doable, and it was just a question of how."

Getting to know his family seemed doable, even though Elizabeth was in college and John was only a year younger. Since John was interested in Africa, Marshall packed up the family and took them to the Kalahari Desert.

Anthropologist friends had told them that little was known about the Bushmen of the Kalahari, so the Marshalls went looking for them, accompanied by various linguists, interpreters and biologists, traveling in four large trucks and a jeep. It took weeks to traverse roadless land to reach the area where the Juwa Bushmen lived, along the borders of what are now Namibia and Botswana.

(It's not true, as at least one anthropologist has taught, that the Marshalls were "in search of a supposed lost city in the center of the Kalahari." "I wonder where you read that," said Thomas austerely. "No, we never thought there was a lost city in the center of the Kalahari. Nor is there one.")

The Juwa Bushmen had a traditional hunting and gathering culture, little affected by the outside world. They traded for knife blades and for wire, which they hammered into arrowheads, and this was their only metal.

"The first time we came to the Kalahari, we spent several months looking for Bushmen," Thomas wrote later. "It was very hard for us to find them because they are shy of any stranger. If they believe that you are coming, they run away like foxes to hide in the grass until you have gone."

The Bushmen eventually revealed themselves, and none of the Marshalls was ever the same. They returned again and again, visiting for as much as a year at a time. Lorna Marshall retrained as an anthropologist, and has written two classic accounts of the Juwa Bushmen. Laurence Marshall spent years in efforts to support the Bushmen through changing often disastrous government policies toward them, principally through importing dryland farming techniques. John Marshall became an anthropologist and a documentary filmmaker (he co-directed, with Frederick Wiseman, the famous "Titicut Follies," shot at a hospital for the criminally insane) and has devoted much of his life to recording the culture of the Juwa and advocating for them, so persistently that from 1958 to 1978 the South African Colonial Administration banned him from Namibia.

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