Polüfülogeneesia

Polüfülogeneesia refers to a grouping of organisms in a phylogenetic classification that includes species from different evolutionary lineages. This type of classification is considered artificial because it does not reflect true evolutionary relationships, as the shared characteristics used to group them are not due to common ancestry. Instead, these similarities are often the result of convergent evolution, where unrelated organisms independently evolve similar traits due to similar environmental pressures or ecological roles.

For example, a polüfülogenetic group might include birds and bats. Both have wings and the ability to fly, but their wings are structurally different and evolved independently. Birds evolved wings from their forelimbs over millions of years, while bat wings are formed by a membrane stretched between elongated fingers and their body. Therefore, grouping them solely based on flight would be polüfülogenetic.

In contrast, monophyletic groups, also known as clades, include all descendants of a common ancestor. Paraphyletic groups include a common ancestor and some, but not all, of its descendants. The goal of modern phylogenetic classification is to create exclusively monophyletic groups, as these accurately represent the evolutionary history and relatedness of life on Earth. Identifying and avoiding polüfülogenetic groupings is a key principle in constructing accurate evolutionary trees and understanding biodiversity.