December 18: The Mathematician of Biology

Mathematician Samuel Karlin, whose wide-ranging interests included mathematical applications for DNA analysis, game theory, economics, and population studies, died at 83 on this date in 2008. The author of 10 books and 450 scientific papers, he made significant contributions to the understanding of how random variables are governed by the laws of probability, how mathematical elements are arranged into sets, how DNA matches (as between a fruit fly and a human being) can be ranked in statistical significance, and numerous other phenomena. “Karlin intentionally changed his major line of research every seven years to stay fresh and learn new topics,” according to the Stanford Report of Stanford University, where he taught for many years. “After his death, a group of his colleagues wrote that ‘to describe the collection of his students as astonishing in excellence and breadth is to understate the truth of the matter. It is easy to argue — and Sam Karlin participated in many a good argument — that he was the foremost teacher of advanced students in his fields of study in the 20^th century.” Polish-born, Karlin was raised an Orthodox Jew and “would tell his children that walking down the street without a yarmulke on his head for the first time was a milestone in his life.” He was awarded the National Medal of Science in 1989. All three of his kids, two sons and a daughter, became scientists.

“The purpose of models is not to fit the data but to sharpen the questions.” —Samuel Karlin