Not By the Numbers

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May 31, 2013

Not By the Numbers

Trinity math professor Peter Olofsson studies probability, heads international department

By Susie P. Gonzalez

Peter OlofssonSAN ANTONIO – Peter Olofsson, professor and chair of mathematics at Trinity University, would like to point out a fact that is obvious to mathematicians but often lost on others: math is indeed a universal language that is more often spoken with letters and symbols than with numbers.

As proof (pun intended), he gestures to the symbols and letters written on the white board in his campus office. “It’s more that we are looking for abstract structures that are often inspired by numbers,” Olofsson said, “than the numbers themselves. Mathematicians are not necessarily any better than others in computing a tip on a restaurant check.”

Still, the universality of math speaks to people in any country with its unique alphabet. The formula will be the same – it’s only the language that changes. This truism is reinforced by the fact that Trinity’s math department is “very cosmopolitan,” Olofsson noted, with nine faculty members from eight different nations that span five continents. The represented counties include Brazil, Cameroon, Croatia, Mexico, Palestine, Sweden, United States, and Vietnam. “It’s fun to have that international flavor,” he said. “And it just happened. We try to hire the best.”

Beauty and probability
Math is known as a foundation for many science fields and can be used to explain many natural phenomena, but it also encapsulates qualities of the humanities in the sense that the inner beauty of a mathematical formula can be enjoyed like a poem or a painting. “You would be surprised how often mathematicians use the word ‘beautiful,’” Olofsson said. This dual aspect of mathematics – applicability and elegance – is what fascinates him the most.

One example, he said, is the area he studies – probability. “It was started to study gambling and games of chance and has grown into a rich area with deep and sophisticated theory as well as numerous applications.” Olofsson said he was always interested in mathematics but wanted his field to have a connection to the real world.

“Probability is fun, but people have a poor intuition for it,” he said. For example, in a random group with as few as 23 people, there is a better than 50-50 chance that two people will share the same birthday. This can be computed using the laws of probability and can also be verified empirically, for example, by examining rosters of sports teams. Other than the natural sciences, probability can also be applied to finance, economics, engineering, psychology, sociology, and other fields that rely upon statistical analysis.

Biology and probability
In the area of biology, he looks at probability involving cell populations. Lately, Olofsson has studied prions, which he describes as “little bundles” of proteins in cells. These proteins have not folded correctly but instead have aggregated together to cause disease, such as mad cow disease that is not linked to bacteria or a virus. Using probability, he and his collaborators can mathematically model how prions grow in mother cells along with the likelihood of disease being transferred to daughter cells.

Olofsson also is completing work on a grant, funded by the National Institutes of Health and guiding work of biology students directed by Trinity biologist Kevin Livingstone, to study speciation, which explores mathematical explanations for ways in which evolution might work to produce new species. Applying probability theory, researchers can examine how one species, through mutation, selection, and reproduction, may eventually divide into two new species. The math required to solve such problems is not necessarily very complex but does require some creativity, Olofsson said.

In addition to research papers, he has written a textbook that was recently published in a second edition and a general audience book that is scheduled to be translated into Chinese. Olofsson also has written articles that expose flaws in mathematical arguments previously published by proponents of intelligent design, including a satirical piece titled “The Coulter Hoax” in Skeptical Inquirer. “There was no math in that article, but it was fun to write.” 

Courses Taught

  • Probability

  • Stochastic Processes

  • Probability Models in the Life Sciences

  • Statistical Methods

Selected Publications
A discrete time branching process model of yeast prion curves. With Suzanne Sindi. Mathematical Population Studies, 2013

A stochastic model for the development of Bateson-Dobzhansky-Muller incompatibilities incorporating protein interaction networks. With Garner Cochran, Andrius Dagilis, Karen MacPherson, Kerry Seitz (students), and Kevin Livingstone. Mathematical Biosciences, 2012

Modeling and estimating bacterial lag phase. With Xin Ma (student). Mathematical Biosciences, 2011

Budding yeast, branching processes, and generalized Fibonacci numbers. With Ryan Daileda. Mathematics Magazine, 2011

Modeling growth and telomere dynamics in S. cerevisiae. With Alison A. Bertuch. Journal of Theoretical Biology, 2010

A stochastic model of cell cycle desynchronization. With Thomas O. McDonald (student). Mathematical Biosciences, 2010

Size-biased branching population measures and the multi-type x log x condition. Bernoulli, 2009


Susie P. Gonzalez is director of public and media relations in Trinity’s Office of University Communications. She can be reached at