Infrafamilies

Infrafamilies are a concept used in biology, particularly in zoology, to categorize groups of animals that are more closely related than a typical family but not as closely related as a subfamily. The term "infrafamily" is not a formally recognized rank in the standard Linnaean system of biological classification, which typically includes ranks like kingdom, phylum, class, order, family, genus, and species. Instead, it functions as an informal or supplementary grouping that can be useful when the traditional family-level distinctions do not adequately capture the evolutionary relationships within a larger group.

The use of infrafamilies often arises when a particular family is very diverse, containing numerous distinct lineages that warrant further subdivision. These subdivisions might be based on significant morphological, genetic, or behavioral differences that suggest a long period of separate evolutionary history. For instance, an order might contain several families, and one of these families might be so large and varied that scientists choose to group its members into several infrafamilies to better reflect their evolutionary divergence before proposing new, lower-level family ranks, which is a more formal and infrequent taxonomic change.

The primary purpose of identifying infrafamilies is to provide a more nuanced understanding of the evolutionary tree of life. By creating these intermediate groupings, researchers can highlight specific branches of evolution that are more complex than a simple family classification would suggest. This can aid in comparative studies across different lineages within a broader taxonomic group, allowing for more precise investigations into adaptation, speciation, and evolutionary processes. However, due to its informal status, the recognition and application of infrafamilies can vary among different scientific communities and research projects.