Living beings that share a habitat or ecosystem interact with each other in different ways, either for mutual benefit or for the benefit of one individual. Since resources are always limited, whether land, food, or water, it’s natural that there are forms of interrelationship in which species cooperate ( association ) or, conversely, fight ( competition ).
- It may be useful to you: Amensalism
The biological association
We’ll talk about association , then, although we can also talk about cooperation , when two animal individuals allow themselves to work together to mutually benefit, making better use of resources or providing each other with an opportunity they wouldn’t have had separately. This type of beneficial relationship can occur intraspecifically (between two members of the same species) or interspecifically (between two members of different species).
A good example of association is colonies , in which numerous individuals of the same species share a habitat, sometimes to the point of being physically fused. Thus, corals form colonies of identical individuals that cooperate to protect and feed each other; while bees do the same, but in a hierarchical manner and by sharing labor, to keep the whole group alive and protected.
Types of association
Interspecies biological associations can be of the following types, judging by the specific relationship between the associated individuals:
- Commensalism. Both individuals live together, and one benefits from the other (for example, from its waste) without causing any harm. For example, remoras attached to a shark , which feed on its hunting remains.
- Symbiosis. In symbiosis, both associated individuals mutually benefit, either by cooperating to provide sustenance or by defending each other from predators . For example, in lichen, a fungus and an alga join together to provide mutual protection and structure.
- Parasitism. In this case, the mutual association isn’t as beneficial to one of the two individuals, as the other feeds on it or at its expense, and can sometimes cause harm. For example, ticks that suck the blood of cattle.
- Tenancy. In this case, one of the two individuals seeks protection from the other, without causing harm or being harmed by it. For example, the clownfish that lives among the petals of anemones , without being harmed by them but safe from predators.
Biological competition
On the contrary, competition occurs when the presence of two individuals in the same habitat causes the other to experience a decrease in the satisfaction of its needs , whether for food , water, or territory. That is, competition consists of the struggle or effort on the part of the animals involved to obtain benefits for themselves, so it is a case contrary to association of any kind.
Again, this competition can occur between species or within the same species and plays a fundamental role in natural selection , vital to the theory of evolution.
The generational predominance of the fittest individuals (and their genetic material) over the less fit or those that fail in the competition will then force species in nature to compete with each other to adapt to the environment or, otherwise, become extinct.
The same thing happens within a species, as individuals will compete for access to resources and reproduction, which causes the most competent to reproduce more and better than the less fit.
Types of competition
There are three fundamental forms of competition, according to the mechanism by which they occur:
- Interference competition. This occurs when an individual or species interferes, that is, hinders the competition of another, through aggression or other methods, preventing it from accessing food or habitat.
- Exploitative competition. This occurs indirectly when the exploitation of a resource or living space leaves others out, depriving them of their basic needs but without any direct relationship with another individual or species.
- Overt competition. This is direct competition between two species or two individuals for survival, which may involve, for example, competition to hide from a predator, leaving the other exposed.
Differences between association and competition
- In association, both individuals or species cooperate and benefit to a greater or lesser extent, while in competition, only one of the two will benefit.
- Association allows for the development of colonies and complex modes of interaction, while competition pushes for survival or perish and instead drives the engine of selection and culling.
- Association encourages sharing of space and resources, while competition encourages fighting over them.
- Association allows for mutual survival, while competition leads to the extinction of one of the competitors.
