Evolutionary convergence

The evolutionary convergence is the evolutionary mechanism which explains the morphological resemblances , sometimes Comportement ales, existing between Espèce S subjected to the same environmental constraints. More generally, this term also applies to the evolution of other adaptive systems as can the being of the human groups or the Civilization S.

Convergent evolution in biology

In Biology of the evolution, convergence or Homoplasie is the presence at two Espèce S, of character S similar S, of the same adaptation, but which was not inherited a common ancestor. It results from two evolutions independent in the same type of Environnement. It should not thus be confused with the Synapomorphie which indicates, on the contrary, a similarity due to a common ancestor.

Evolutionary convergence is interpreted as the result of an evolution towards the same evolutionary answer within two tax subjected to the same adaptive problem ] that it is about a Pression of natural selection or sexual.

In certain cases, the differences between two convergent species can be rather weak at first sight, and lead to errors of phylogenetic Classification. Thus, it is only in 1693, that the naturalist John Ray establishes that the Cétacé S belong well to the class of the Mammifère S, in spite of a strong resemblance to the Poisson S, due to convergent evolutions having carried out in both cases to a adaptation to the aquatic environment.

Some examples of convergent natures related to the adapation

One of the independent sources of convergent adaptations is related to the place occupied by the species in their Food chain. With the bottom of the chain, the végétaliens develop a very specific Digestive system enabling them to digest the vegetable fibers. The weak heating contribution of their food obliges them to spend more time eating. The Prédateur S have a sensory acuity increased which enables them to detect their Proie S. Of the very different ecosystems can thus nevertheless generate the same techniques of hunting, with the mounting, the race…

Convergent morphologies

The Hydrodynamic form and the Nageoire S appeared in multiples Taxon S in a completely independent way: obviously at the Poisson S and the Ichtyosaure S (of the watery Dinosaur S now disappeared) but also at the Bird X penguins like in two different orders among the Mammalian S: the Cetacea which are related with the Dromadaire and the Sirénien S which are related with the elephant. This similar morphological evolution is related to the fact that the force of trail exerted by water on a body moving is decreased for profiles in form of Ogive. Since all these species are subjected to this same constraint Hydromécanique they have, each one on their side, evolved to a adaptive solution very similar to the problem of the aquatic life.

In addition to the example illustrated above, one can quote many other examples of evolutionary convergence:

At the Hippopotame S and the Crocodile S, the Yeux and the Narine S is positioned on the top of the Crâne what allows them to see and to breathe at the time their displacements under water surface. This morphological feature is not inherited a common ancestor but evolved/moved independently at these Reptile S and these Mammifère S.
the comparison of the marsupial of Oceania with the Mammifère S Placentaire S of the rest of the world reveals cases of convergent evolution typical: one finds thus a “marsupial wolf”, very similar to the Canidé S like the wolf, or the “marsupial Souris S” whose morphology strongly evokes that of the Souris, etc

At the Insect S, an good example of convergent evolution is provided by the morphological resemblance between the mantispe and the Mante nun.

Behavioral convergences

There are also resemblances in the behavior Grégaire of the benches, the herds, the clouds and the flights.

One can extend the principle of evolutionary convergence to the study of the animal companies. The colonies of social insects and rats moles have a similar mode of organization called Eusocialité, which includes/understands a queen, reproducers and workmen sterile.

Convergent evolution in the human society

Technological convergences in the human history

Some Technologie S were invented independently by several Civilization S without one being able to show that they had been transmitted by former civilizations. It is the case of the writing independently appeared in civilizations sumérienne towards 3000 front J. - C., Chinese towards 1300 front J. - C. and précolombienne towards 650 front J. - C. One can also quote the case of the mathematical and the astronomy which were invented independently by civilizations Eurasia and civilizations précolombien born.

See too

Imitation

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