The coevolution It occurs in those situations in which two or more species are affected by a reciprocal evolution, that is, they go through an evolution jointly.
The notion is completely related to the dependence that exists between species to the extent that, in all cases, there is a need for some means that another species produces or transforms.
The coevolution theory was contributed by biologist Paul Ehrlich, who advanced the seminal idea that the interactions of plants and herbivores shape the evolutionary history of species as an engine for the generation of diversity.
The work was part of a much larger investigation that is the search for the origin of biodiversity, and Ehrlich set up experimental facilities, determining that there are patterns in population dynamics and genetic structure, as well as in the factors that regulate them.
The elementary conditions for the coevolution process to occur formally are four:
- Two species must show variation in certain characteristics that influence how the interaction between them develops;
- There must be a consistent relationship between those characters and the adequacy;
- Those characters must be inheritable;
- The interaction between the two species must be reciprocal, of high specificity and produced simultaneously in evolutionary time.
There are times when coevolution manifests itself in really surprising ways, like morphological adjustments between different species, physical transformations that are used exclusively to fulfill some function of another species.
The Evolutionary process then, it becomes an action circumscribed to a time and to a space, and the question of evolution as survival now comes to be understood in community and in relation to other species, generally based on defense mechanisms.
The ways in which coevolution occurs lead to a classification into different types:
- Diffuse. Evolution occurs in response to a character of several species, and not a single one. There is no genetic correlation.
- Co-speciation. The interactions between the species generate a reciprocal speciation, in which one controls the movement of gametes of the other.
- Gene by gene. Coevolution is driven by changes in the major genes, and for each one that causes resistance there is a corresponding one of virulence.
- Mixed process. Evolution is reciprocal, and adaptation causes the population of the other species to be reproductively isolated.
- Geographic mosaic. Interactions have different outcomes depending on the demographic structure of the population, so the interaction may co-evolve in some populations and not in others. The evolutionary pattern can cause a species to coevolve with several simultaneously.
Examples of coevolution processes
- The pilot fish is protected by the shark, while cleaning their teeth, mouth and eyes.
- The species of acacia plants from Central America, with hollow spines and pores at the base of its leaves that secrete nectar, where some ants nest that drink it.
- The hummingbirds of America that coevolved with plant families such as those of the orchids.
- The bat Mexican long-nosed feeds on the nectar of the saguaro cactus, changing its morphology based on it.
- The plant of the genus Passiflora generates anti-herbivory defenses with toxin production, which is a successful strategy against most insects. Some of them outgrow it, and the poison makes them unpleasant to predators, so they repel them.
- The cycle between hares American and the trees, whereby the hares need to feed on them so as not to starve, but they produce progressively higher concentrations of resin: the hare population declines and the cycle begins anew.
- The moth collect pollen from a flower, and then deposits it ensuring food for the larva: the plant benefits when the remaining ovules are transformed into seeds.
- The hunting process between the Cheetah and the impala made a kind of competition take place between the two, increasing speed according to evolution.
- The orchid mantis It is an insect that resembled the flower to protect itself from its predators.
- The butterfly nymphalid viceroy has coevolved with blue jays, since they repel birds because they are toxic: mimicry gives security to the butterfly.