Difference between “Intra Specific” and “Inter Specific Competition” – Explained!
In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species (intraspecific interactions), or of different species (interspecific interactions). There are diverse organisms that are present in the community and because of this; different relationships are developed between them. In interspecies competition, two species use the same limited resource. define a 3D space representing the organism's niche in relation to those variables. . Last modified June 1, posavski-obzor.info .
Each axis represents a different variable — for instance, if we were talking about a fish, we might use temperature, pH, and salinity as three of our axes.
On each axis, the fish would be able to survive only within a certain range of values. By seeing where the ranges on the different axes intersected, we could define a 3D space representing the organism's niche in relation to those variables.
But the niche of our fish species wouldn't be fully defined by just three axes. For instance, what about levels of dissolved nutrients in the water?
What about presence or levels of algae and other microorganisms? If you think about it, there are many different variables that define the conditions under which a fish can live. This is why we need an n-dimensional hyperspace with n referring to the many axes representing different variables in order to define a niche.
Intraspecific competition - Wikipedia
As we'll see, two organisms with exactly the same niche can't survive in the same habitat because they compete for exactly the same resources, so one will drive the other to extinction. However, species whose niches only partly overlap may be able to coexist. Also, over long periods of time, they may evolve to make use of more different, or less overlapping, sets of resources.
Competitive exclusion principle The competitive exclusion principle tells us that two species can't have exactly the same niche in a habitat and stably coexist. That's because species with identical niches also have identical needs, which means they would compete for precisely the same resources.
Niches & competition
A famous example of the competitive exclusion principle is shown in the figure below, which features two types of single-celled microorganisms, Paramecium aurelia and Paramecium caudatum. When grown individually in the lab, both species thrive.
But when they are grown in the same test tube habitat with a fixed amount of nutrients, both grow more poorly and P. Graphs a, b, and c all plot number of cells versus time in days.
In Graph aP. In graph bP. In graph cboth species are grown together. When grown separately, the two species both exhibit logistic growth and grow to a relatively high cell density. When the two species are grown together, P.
Image modified from " Community ecology: In nature, it's rarely the case that two species occupy exactly identical niches. However, the greater the extent to which two species' niches overlap, the stronger the competition between them will tend to be 2 2.
Resource partitioning Competitive exclusion may be avoided if one or both of the competing species evolves to use a different resource, occupy a different area of the habitat, or feed during a different time of day. The result of this kind of evolution is that two similar species use largely non-overlapping resources and thus have different niches.
This is called resource partitioning, and it helps the species coexist because there is less direct competition between them. The anole lizards found on the island of Puerto Rico are a good example of resource partitioning. In this group, natural selection has led to the evolution of different species that make use of different resources.
The figure below shows resource partitioning among 1 1 11 11 species of anole lizards. Sometimes these types of competition are referred to as symmetric scramble vs. Scramble and contest competition are two ends of a spectrum, of completely equal or completely unequal effects.
Apparent competition[ edit ] Apparent competition is actually an example of predation that alters the relative abundances of prey on the same trophic level. It occurs when two or more species in a habitat affect shared natural enemies in a higher trophic level.
Investigators sometimes mistakenly attribute the increase in abundance in the second species as evidence for resource competition between prey species.
It is "apparently" competition, but is in fact due to a shared predator, parasitoid, parasite, or pathogen. Consequences[ edit ] Many studies, including those cited previously, have shown major impacts on both individuals and populations from interspecific competition.
Documentation of these impacts has been found in species from every major branch of organism. The effects of interspecific competition can also reach communities and can even influence the evolution of species as they adapt to avoid competition.
This evolution may result in the exclusion of a species in the habitat, niche separationand local extinction. The changes of these species over time can also change communities as other species must adapt. Gause's law The competitive exclusion principle, also called " Gause's law "  which arose from mathematical analysis and simple competition models states that two species that use the same limiting resource in the same way in the same space and time cannot coexist and must diverge from each other over time in order for the two species to coexist.
One species will often exhibit an advantage in resource use. This superior competitor will out-compete the other with more efficient use of the limiting resource. As a result, the inferior competitor will suffer a decline in population over time. It will be excluded from the area and replaced by the superior competitor. A well-documented example of competitive exclusion was observed to occur between Dolly Varden charr Trout Salvelinus malma and white spotted char Trout S.
Both of these species were morphologically similar but the former species was found primarily at higher elevations than the latter. Although there was a zone of overlap, each species excluded the other from its dominant region by becoming better adapted to its habitat over time. In some such cases, each species gets displaced into an exclusive segment of the original habitat. Because each species suffers from competition, natural selection favors the avoidance of competition in such a way.
Niche differentiation Niche differentiation is a process by which competitive exclusion leads to differences in resource use. In the previous example, niche differentiation resulted in spatial displacement. In other cases it may result in other changes that also avoid competition. If competition avoidance is achievable, each species will occupy an edge of the niche and will become more specialized to that area thus minimizing competition.
Positive Interspecific Interactions
This phenomenon often results in the separation of species over time as they become more specialized to their edge of the niche, called niche differentiation. The species do not have to be in separate habitats however to avoid niche overlap. Some species adapt regionally to utilizing different resources than they ordinarily would in order to avoid competition.
There have been several well-documented cases in birds where species that are very similar change their habitat use where they overlap. For example, they may consume different food resources or use different nesting habitat or materials.
Difference between “Intra Specific” and “Inter Specific Competition” – Explained!
On the Galapagos Islandsfinch species have been observed to change dietary specializations in just a few generations in order to utilize limited resources and minimize competition. In some cases, third party species interfere to the detriment or benefit of the competing species. In a laboratory study, coexistence between two competing bacterial species was mediated by phage parasites.