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The flipper forelimbs of marine mammals (cetaceans, pinnipeds, and sirenians) are a classic example of convergent evolution. There is widespread convergence at the gene level. [ 6 ] Distinct substitutions in common genes created various aquatic adaptations, most of which also constitute parallel evolution because the substitutions in question ...
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy.
Carcinisation (American English: carcinization) is a form of convergent evolution in which non-crab crustaceans evolve a crab-like body plan. The term was introduced into evolutionary biology by L. A. Borradaile, who described it as "the many attempts of Nature to evolve a crab". [2]
The evolution of the digestive system has formed a significant influence in mammal evolution. With the emergence of mammals, the digestive system was modified in a variety of ways depending on the animal's diet. For example, cats and most carnivores have simple large intestines, while the horse as a herbivore has a voluminous large intestine. [127]
In this regard, these saber-toothed mammals can be viewed as examples of convergent evolution. [6] This convergence is remarkable due not only to the development of elongated canines, but also a suite of other characteristics, such as a wide gape and bulky forelimbs, which is so consistent that it has been termed the "saber-tooth suite." [7]
This convergent evolution leads to species independently sharing a trait that is different from the trait inferred to have been present in their common ancestor. [ 21 ] [ 22 ] [ 23 ] Parallel homoplasy – derived trait present in two groups or species without a common ancestor due to convergent evolution .
However, the criteria for defining convergent as opposed to parallel evolution are unclear in practice, so that arbitrary diagnosis is common. When two species share a trait, evolution is defined as parallel if the ancestors are known to have shared that similarity; if not, it is defined as convergent.
The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly / ˈ p ɒ l ɪ ˌ f aɪ l i /. [2] It is contrasted with monophyly and paraphyly.