THE GENETIC STRAND: EXPLORING A FAMILY HISTORY THROUGH DNA, by Edward Ball, Simon and Schuster, 265 pages, $25.

Edward Ball, who won a National Book Award for "Slaves in the Family" in 1998, has tried a new, fascinating approach to family history by examining locks of hair for DNA from his ancestors.

After living for years in New York City, Ball moved to Charleston, S.C., in 2000 to become closer to his ancestry.

He filled his home with heirloom pieces from his relatives. In an old family desk, he found a drawer sealed probably since the Civil War. When he opened it, he found several locks of hair, labeled and dated in separate enclosures. He wondered what DNA science would suggest about the identities of the people behind the hair.

The result is what Ball calls a "genetic memoir," which combines crime-scene investigation with genealogical findings. Ball writes, "Although a strand of hair wasn't a bone, it was a bit of a person, probably the only thing left of them, the rest having turned to dust in the ground. A few of the locks had started to disintegrate, but most had been well preserved in the lightless and airless recesses of the secret drawer, their miniature tomb."

Through forensic investigation, Ball has pieced together the lives outlined by the locks of hair. Aunt Betsy Scott, for instance, born in 1792, started the hair collection. Betsy married at age 20 and raised several children. In her 50s, she published four books on South Carolina "society."

According to the author, his family is "thoroughly white" with no Jews, blacks, Latinos, Asians, Arabs or American Indians to be found. But forensic evidence suggested a different conclusion. Aunt Betsy, for instance, can be traced to French Huguenot and American Indian ancestry. Kate Fuller, Ball's great-grandmother, had one white parent and one black parent, so she was mixed race.

Ball makes a number of other assertions of ancestry other than white, much of it tied to DNA evidence.

Isaac and Eliza Ball married in their mid-20s, were unable to have children, so they adopted. Later, Eliza had four children in five years. In 1824, two of the children died, and it was then that the Balls started snipping locks of hair from family members as mementos — or visual keepsakes of their loved ones.

Isaac died at age 40 of malaria. It was then that the Ball family stopped snipping hair. The author found, nevertheless, that labeling and dating hair was normal for the time period. Godey's Lady's Book magazine contained an article in the mid-1850s saying that "Hair survives us ... like love. With a lock of hair belonging to a child, we may almost look up to heaven and compare notes with angelic nature, may almost say, 'I have a piece of thee here."'

Ball's book is heavily detailed, but the detail is important to his conclusions, and he writes it in such a fluent way as to thoroughly involve the reader.