PARAPHYLY Meaning and
Definition
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Paraphyly is a term used in the field of evolutionary biology and taxonomy to describe a situation where a group of organisms sharing a common ancestor is not considered as a proper taxonomic group. This occurs when some but not all descendants of a common ancestor are included in the classification. In other words, paraphyly is a situation where a taxonomic group does not encompass all the descendants that have evolved from a common ancestor.
The concept of paraphyly challenges the idea of creating exclusive and monophyletic taxonomic groups that include all descendants of a common ancestor. Instead, paraphyletic groups consist of only a subset of the descendants, excluding some closely related organisms.
This term is often used in the context of phylogenetic trees, which represent the evolutionary relationships between different organisms. The inclusion of paraphyletic groups in these trees is debated among taxonomists, as it can lead to confusion and inconsistency in classifying and labeling organisms.
Paraphyly can be contrasted with monophyly, which is a situation where all the descendants of a common ancestor are included in the taxonomic group. Another related term is polyphyly, which occurs when taxa are grouped together that do not share a common ancestor.
Etymology of PARAPHYLY
The word "paraphyly" is derived from two Greek roots: "para" meaning "beside" or "near" and "phylē" meaning "tribe" or "class". In the context of biological taxonomy, "paraphyly" refers to a situation where a group of organisms is classified together in a taxa (tribe or class) but excludes one or more descendants that should belong to that group according to their common evolutionary ancestry.
