Tracy Sonneborn

Education Sonneborn attended the Baltimore City Public Schools and graduated from the Baltimore City College (high school) in 1922. As an adolescent, Sonneborn was interested in the humanities and considered becoming a rabbi. After taking a biology course taught by E. A. Andrews, his interest in literature was eclipsed by his interest in science. He earned a B.A. from Johns Hopkins University in 1925 and a Ph.D. in 1928. His graduate work, supervised by Herbert S. Jennings, focused on the flatworm Stenostomum. the American Academy of Arts and Sciences in 1949, and the American Philosophical Society in 1952. In 1964 he was elected as a Foreign Member of the Royal Society. His books "Methods in the general biology and genetics of Paramecium aurelia" (1950) and "Methods in Paramecium research" (1970) were highly cited and provided ongoing value to investigators.

Sonneborn also conducted a series of experiments studying the synchronised movement of the paramecium's cilia. These hair-like projections move together like dancers in a ballet and enable the single-celled organism to "swim" through the liquid in which it lives. Sonneborn surgically rotated a small section of the cell wall by 180 degrees and found that the replaced section continued to 'wave' in the same direction it had before surgery, i.e. now in antiphase to the others. The paramecium's daughters showed the same trait of a reverse phase wave if the reversal overlapped the division plane. If it did not overlap the division plane only one of the progeny showed the inverted sequence.

Sonneborn as teacher Sonneborn was an innovative teacher. He taught a course entitled "Heredity, Evolution and Society" that dealt with the science of genetics and the implications that technological advancements in that field held for society. One of his popular lectures involved students enacting the process of protein synthesis during which the genetic code is translated into the sequential addition of amino acids to form a polypeptide. His enthusiasm was infectious, and his lectures inspired students to study protozoa and algae.

Personal life Sonneborn married Ruth Meyers in 1929. Though educated as a social worker, Meyers concentrated on supporting her husband's career. They had two sons: Lee (1929–2004), a mathematician, and David (b. 1934), a biologist.