Edward B. Lewis
Born on May 20, 1918, in Wilkes-Barre, PA; died of prostate cancer, July 21, 2004, in Pasadena, CA. Geneticist. A youthful obsession with a simple insect led Edward B. Lewis to become one of the key scientists who deciphered the genetic code that forms all living beings. Lewis used the fruit fly to show how genes control an embryo's development, and researchers have since shown that his discovery holds true in almost every animal, including humans. He won a Nobel Prize in 1995 for his work.
Lewis was born in Wilkes-Barre, Pennsylvania, in 1918. His father was a watchmaker. He began his work on fruit flies as a high school sophomore, when he and a friend spent the school biology club's entire treasury, $4, responding to an ad in Science magazine selling fruit flies at the rate of 100 for $1. Fruit flies are easy creatures to study because they breed easily, have a simple structure, and go from eggs to mature flies in only ten days. Lewis and his friend would visit a school lab every day to look through newly hatched flies with a magnifying glass, searching for mutants, the keys to biology research. One mutant they found, called "held-out," is still used in genetics research.
An accomplished young flute player, Lewis went to Bucknell University for a year on a flute scholarship. But Bucknell did not offer any genetics courses, so he transferred to the University of Minnesota, where he earned a bachelor's degree in 1939. Lewis then enrolled in the California Institute of Technology (Caltech) in Pasadena, California, where received a doctorate in genetics in 1942 and a master's degree in meteorology in 1943. His career at the school was interrupted by service in the United States Army and Army Air Corps; he was stationed in Hawaii and Okinawa, worked as a meteorologist and oceanographer, and reached the rank of captain. He returned to Caltech in 1946, spent a year as a fellow at Cambridge University in Britain from 1947 to 1948, then spent the rest of his career at Caltech.
After the war, Lewis returned to his studies of the fruit fly. One of his supervisors, Thomas Hunt Morgan, had used fruit flies to help prove that chromosomes carry genes, which hold hereditary characteristics, a discovery that won him the Nobel Prize in 1933. But when Lewis began his work, scientists did not know much more than that about how genes worked.
Lewis reached a breakthrough when he bred two mutant flies and produced flies with four wings instead of two. That meant that a whole section of the fly's thorax had been replaced with a duplicate of the section next to it. Not only had a mutant gene caused the change, Lewis realized, but the gene must have controlled the activity of other genes to produce the second wing.
For decades, Lewis bred mutant fruit flies, until he finally identified the genes that controlled the development of each section of the fly. He surprised other scientists by showing that the genes' code was simple: the genes that control early development of the fly embryo (called homeotic genes) lined up on the chromosomes in order, just as the segments they controlled appear on the fly. That order, which scientists call the "colinearity principle," was later proven to be true in humans, mice, and other vertebrates. Lewis' work on homeotic genes, summarized in a major article in 1978, won him the 1995 Nobel Prize for Physiology or Medicine.
"It was as if he made evolution occur in real time," Dr. Gerald R. Fink, a professor of genetics at the Massachusetts Institute of Technology, told the New York Times. "Ed Lewis worked to use genetics to show profound evolutionary strategies. There is no more remarkable evidence of that than his fruit fly with four wings."
In the 1950s, Lewis offered another, very different contribution to science: he examined how the human body reacts to radiation from X-rays, nuclear fallout, and other sources. For his research, he examined medical records from survivors of the atomic bombs the United States dropped on the Japanese cities of Hiroshima and Nagasaki in 1945 during World War II. Lewis concluded that there is no risk-free dose of radiation, and that its effects had been underestimated. He presented his findings to a Congressional committee in 1957. The effects of low-dose radiation are still controversial, and they were even more so in the 1950s, when the United States was testing nuclear weapons as a major part of its military defense. Prominent supporters of nuclear technology, such as Admiral Lewis Strauss, then-chairman of the United States' Atomic Energy Commission, attacked Lewis publicly for his findings. Hurt, Lewis left the public eye and turned back to his research.
Lewis remained a biology professor at Caltech until his 1988, and stayed active at the school as a professor emeritus after his retirement. He provided the entertainment at the Caltech dinner in honor of his Nobel prize in 1995, playing with a chamber music group in the lobby as guests arrived. He was famous on campus for the costumes he wore to the school's Halloween party; once, he came dressed as a mutant fruit fly with two tails. Lewis' schedule at Caltech remained the same until a few months before his death: he got to his office at 8 a.m. and often worked until midnight, with breaks to practice the flute from 10 to 10:30, swim in the pool, and take a mid-afternoon nap.
Lewis died of prostate cancer on July 21, 2004, in Pasadena, California; he was 86. He is survived by his wife, Pamela, an artist he met in the Caltech laboratory, and their sons, Hugh and Keith. A third son died in 1965.
Chicago Tribune, July 27, 2004, sec. 2, p. 11.
Los Angeles Times, July 23, 2004, p. B10.
New York Times, July 26, 2004, p. A14.
Times (London), August 3, 2004, p. 26.
Washington Post, July 26, 2004, p. B4.