What Is Symbiosis?
Symbiosis is defined as the close association between two or more interacting organisms, usually of different species. The relationship is usually classified as belonging to one of three types: mutualism (benefiting both partners), parasitism (one partner, the parasite, benefits, at the expense of the host), or commensalism (one partner benefits while the other is unaffected). Changes in the physical environment such as the amount of sunlight or salinity, or the temperature, and in the biological community, such as the presence or absence of other organisms and how they interact with the symbiotic pair, may change the nature of the symbiotic relationship from one type to another. Like organisms, symbiotic relationships are responsive to the environment and can change over time.
Symbiosis was first defined in 1879 by Anton de Bary as “the living together of differently named organisms”. This definition includes mutualistic as well as parasitic relationships. A mutualism is a relationship in which both partners benefit by their association. Parasitism affords benefits to only one partner, with the other partner being either unaffected or detrimentally affected by the association. When using the term symbiosis a mutualism is usually implied. Our limited knowledge of the dynamics of real world symbioses, however, may make a distinction between mutualism and parasitism difficult at best. Although other definitions of symbiosis as purely mutualistic have been proposed, most biologists prefer to use de Bary’s definition simply because our incomplete understanding of these types of relationships does not allow the clear cut categorization of symbiotic relationships as either mutualistic or parasitic. Some prefer to use the term mutualistic symbiosis to describe relat
Three-course sequence SYMBIOSIS I (IBMS 1100) , II (IBMS 1200), & III (IBMS 1300) integrates material from 3 introductory biology courses (Cell/Molecular, Structure/Function of Plants & Animals, Population Biology/Ecology/Evolution) with 2 courses from math (Calculus I & Probability & Statistics) plus several components from other math courses. The Symbiosis initiative has been funded for $1.
