Mechanism (biology)

Mechanism (biology)

In biology, and in science in general, a mechanism is a complex object (system) or, more generally, a process that produces a regular phenomenon. For example, natural selection is one of the mechanisms of biological evolution, other being genetic drift, biased mutation, and gene flow; competition, predation, host-parasite interactions, etc. are mechanisms of community structuring; and membrane depolarization is the mechanism of transmission of neural signals.

Accordingly, descriptions of mechanisms are a part of an answer to a question about why some object or process occurred. In other words, descriptions of mechanisms occur in explanations of biological facts. Thus, mechanism refers back from the object or process, along some chain of causation. No description of mechanism is ever complete. For example, the mechanism of sunlight might include the rotation of the earth, the Earth's orbit, the sun, nuclear reactions, heat, temperature, radiation emission, electromagnetic theory about the propagation of light, formation of the solar system, etc. Compare this to the function of the object or process, which looks forward along some chain of causation to a goal or evolutionary success.