Polyfyletisistä

Polyfyletisistä refers to a concept in taxonomy and phylogenetics where a group of organisms is incorrectly assembled because it does not include all descendants of their most recent common ancestor. This is in contrast to a monophyletic group, which includes an ancestor and all of its descendants, and a paraphyletic group, which includes an ancestor and some, but not all, of its descendants. Polyphyletic groups are considered artificial groupings because they are formed based on convergent evolution, where unrelated organisms evolve similar traits independently due to similar environmental pressures or lifestyles. For example, grouping together all flying animals like birds, bats, and insects based solely on the ability to fly would be a polyphyletic classification. Their common ancestor did not possess the trait of flight, and the ability evolved separately in each lineage. Identifying and avoiding polyphyletic groups is a fundamental goal in constructing accurate evolutionary trees and understanding the true relationships between species. The study of genetics and molecular data has been instrumental in correcting many previously polyphyletic classifications by providing a more objective measure of evolutionary relatedness.