Using Game Theory to Understand the Paradox of Biodiversity
https://phys.org/news/2018-08-tackling-great-paradox-biodiversity-game.html
This blog focuses on research currently being conducted by biodiversity scientists at the Champalimaud Centre for the Unknown, in Lisbon, Portugal. These researchers are seeking to rationalize the paradox of biodiversity sustainability using classical models of Game Theory. The longtime question these scientists desire to comprehend is how the various species on earth manage to stay alive and coexist with one another, given the comparatively limited amount of resources available. The authors explain how this situation is called the “Plankton Paradox,” given the original question scientists had about how there are hundreds of different kinds of plankton species that all are sustained by the same 10 resources. However, none of the species ever go extinct or have difficulties maintaining the size of their individual species. This paradox can be applied to all different types of organisms that compete for life resources. At first, scientists tried to rationalize this logical inconsistency by claiming that every species maintains just one other species, and that is how food chains are formed. However, the article explains that this one-to-one ratio does not model what occurs in real life. Therefore, the scientists in Portugal discovered a means of using game theory to explain this environmental phenomenon that best justifies why this paradox occurs.
The researchers claim that these occurrences in the Plankton Paradox and, generally, in nature can clearly be reflected by the Hawk-Dove Game illustrated in lecture. The Nash Equilibrium when fighting for a resource to live is for one species to serve as the Hawk and use their aggressive tendencies and one to be the dove with passive actions. As shown in class, both the hawk and the dove end up with a portion of the resource. Therefore, despite the fact that in this Nash Equilibrium the hawk would end up with more than the dove, the conclusion of this game is that the species manage to coexist. The researchers explain that this simple model can prove why there is stability in the amount of species in the ecosystem and why the Plankton Paradox occurs. They claim that this game can be expanded to include many different types of species that all fight for the same resources to survive. They argue that species have this ability to coexist, rather than the desire to completely dominate the other by both playing hawk. As shown by the Nash Equilibrium, if one plays hawk and one plays dove, then neither can be better off. Therefore, species do not drive each other to extinction and there can be an ecosystem with biodiversity where resources are shared. The Hawk-Dove game can be applied to any species in nature where there are competitive resources. The animals, dependent on their needs and physical skills, choose to play the Hawk or the Dove, yet they manage to both live by choosing the option where there is no better response. Because of this mutually beneficial agreement in the Nash Equilibrium, the species can share the resources and, in the long-term, can maintain a steady growth rate to their populations. To conclude, the researchers plan to continue to search into this field using the foundations of Game Theory, as they believe that this model of rationalization can serve as the true answer to the Plankton Paradox, and can be expanded to explain concepts in extinction and biodiversity sustainability.