A group of UA scientists has developed a mathematical theory that has allowed them to predict Darwinism in beetles, and they believe that in the future it may help lead them to a cure for cancer.
Jim Cushing, Thomas Vincent and Rosalyn Rael are using a mathematical modeling theory to explain some historical observations of evolution that were considered anomalies for more than half a century.
The team studied evolutionary game theory, which is an application of the mathematical theory of games to biological contexts, such as finding possible cures for cancer.
They wanted to know if their model of evolutionary game theory could explain or predict the instance where similar beetles coexisted. They realized that the straightforward answer was no, thus they introduced a new concept.
The new concept was coined the Boxer Effect, which means the most intense competition is between species that are extremely similar, the team explained.
“”It’s sort of like mathematical Darwinism,”” said Vincent, co-author of the study and professor emeritus in aerospace and mechanical engineering. “”In other words, taking his ideas and such and putting them into a mathematical setting which allows us to predict the outcome of evolution.””
Vincent said one of the most interesting applications of evolutionary game theory is the study of cancer and viewing it as an evolutionary process. Species are always subject to invasion by another species. With this theory, scientists can explain when a species can invade and when it can’t invade, Vincent said.
“”In cancer, why is it that cancer cells can invade healthy cells? It is a question of being able to model that and saying why you would be vulnerable and why wouldn’t you be vulnerable to invasion,”” Vincent said. “”And how could we change things so that they couldn’t invade; or even after invasion how could we change the course of evolution.””
Vincent, who has been retired for seven years, said Rael had contacted him regarding her interest in evolutionary game theory for her graduate project in the applied mathematics program at the UA. The connection to Cushing came from Vincent’s knowledge of the mathematician’s previous work regarding modeling flour beetles.
Prior to this project, Cushing had a long collaboration with other researchers for almost 20 years – which was affectionately called the “”Beetle Team.””
Cushing said he wanted to revisit the past observations of flour beetles and factor them into evolutionary game theory.
The whole idea behind the team’s study goes back to the 1960s and builds upon the work of Thomas Park at the University of Chicago.
His experimental expertise was with flour beetles, and his main claim to fame was that he offered experimental evidence of various principles concerning competition between species, Cushing said.
Park performed experiments with 32 generations of flour beetle. He would place two species of flour beetle into a confined place and observe the outcome.
Many scientists thought Park’s experiments were conducted in support of the belief in “”survival of the fittest”” – and most cases lived up to the assumption that if two of these species of beetles lived together in a uniform habitat, one of them should go extinct, Cushing said. However, there was one instance where neither one of the species was killed off. “”This instance is never mentioned in the textbooks,”” Cushing said. “”This was very unusual, because those beetles are not supposed to coexist.””
Cushing said the most important observation that Park wrote was that something had changed in the beetles; certain phenotypes, or observable traits of the beetles, had changed during the course of the experiment.
“”We picked up on that and said maybe something evolutionary had happened during this one treatment that had caused it to be different from all the others,”” Cushing said.
“”We wanted to see if we could duplicate that kind of occurrence and more importantly under what conditions?”” Cushing explained. “”The question is: what are the key mechanisms that cause such a thing to happen versus the normal thing to happen?””
When the team added the Boxer Effect principle into the model, Cushing said, “”It was like ‘Bingo!’ The model could predict the evolution from exclusion to coexistence.””
“”Ants and elephants is one thing, but two similar species of ants trying to do the same thing are going to feel the most pressure,”” Cushing said. “”We took issue with that and said, ‘There comes a point when you get so close that any closer will decrease competition because I can’t tell you from my own species.'””
The team hopes to continue their work with the evolutionary game theory in a broader scope of ecosystems and eventually tie it back into how cancer cells interact with the human body.
“”That is the real key to getting this theory into use,”” Vincent said. “”To tackle some real life problems.””
