Niche construction

Niche construction is the process by which an organism alters its own (or another species') local environment. These alterations can be a physical change to the organism’s environment or encompass when an organism actively moves from one habitat to another to experience a different environment. Examples of niche construction include the building of nests and burrows by animals, and the creation of shade, influencing of wind speed, and alternation of nutrient cycling by plants. Although these alterations are often beneficial to the constructor, they are not always (for example, when organisms dump detritus, they can degrade their own environments). For niche construction to affect evolution it must satisfy three criteria: 1) the organism must significantly modify environmental conditions, 2) these modifications must influence one or more selection pressures on a recipient organism, and 3) there must be an evolutionary response in at least one recipient population caused by the environmental modification. The first two criteria alone provide evidence of niche construction. Recently, some biologists have argued that niche construction is an evolutionary process that works in conjunction with natural selection. Evolution entails networks of feedbacks in which previously selected organisms drive environmental changes, and organism-modified environments subsequently select for changes in organisms. The complementary match between an organism and its environment results from the two processes of natural selection and niche construction. The effect of niche construction is especially pronounced in situations where environmental alterations persist for several generations, introducing the evolutionary role of ecological inheritance. This theory emphasizes that organisms inherit two legacies from their ancestors: genes and a modified environment. A niche constructing organism may or may not be considered an ecosystem engineer. Ecosystem engineering is a related but non-evolutionary concept referring to structural changes brought about in the environment by organisms.