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Niche construction


Niche construction is the process by which an organism alters its own (or another species) environment. These alterations can be a physical change to the organism’s environment or even encompass when an organism leaves one habitat for another. Although these alterations are often beneficial to the constructor they do not always increase chances of survival. The process of niche construction can be very broad but for an organism to be considered a niche constructor then the change must follow certain rules. When determining if an organism is undergoing niche construction that organism must satisfy the following three criteria: 1) the organism must significantly modify environmental conditions, 2) these modifications must influence selection pressures on a recipient organism, & 3) There must be an evolutionary response in at least one recipient population caused by the environmental modification.


Recently, some biologists have argued that niche construction is as important to evolution as natural selection. They believe that not only does an environment select for changes in a species but a species also can cause changes in their environment through niche construction. This intricate back-and-forth creates a feedback relationship between natural selection and niche-construction: when organisms affect their environment, that change can then cause a shift in what traits are being naturally selected for. 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, in conjunction with natural selection, shows that organisms inherit two legacies from their ancestors: genes and a modified environment. Together, these two evolutionary mechanisms determine a population's fitness and what adaptations those organisms develop in the continuation for their survival. A niche constructing organism may or may not be considered an ecosystem engineer. Ecosystem engineering is a more specific concept being precisely tied to structural changes brought about in the environment, while the former encompasses any kind of change.

Organisms can achieve environmental modification in a number of ways. Organisms can directly alter their environments (i.e. corals making coral reefs), disrupt an already fluctuating variable in the environment (stop or encourage), or even leave an environment entirely. Some examples of how species can undergo niche construction are as follows:

As creatures move into new niches, they can have a significant effect on the world around them.

An important consequence of niche construction is that it can affect the natural selection pressures put on the species doing the constructing. The common cuckoo bird is an excellent example of such a consequence. This species of bird parasitizes other birds by laying their eggs in the other species' nests. This had led to several adaptations among the cuckoos, one of which is a short incubation time for their eggs. The eggs need to hatch first so that the chick can push the other species' eggs out of the nest, ensuring it has no competition for the parents' attention. Another adaptation it has acquired is that the chick mimics the calls of multiple young chicks, so that the parents are bringing in food not just for one offspring, but a whole brood.


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