Classification species is not considered a group because a species is the most basic and fundamental unit of biological classification. It is the smallest unit that can be classified and represents a specific type of organism that shares common characteristics and can interbreed to produce fertile offspring. While species can be grouped together into higher taxonomic categories such as genus, family, order, class, phylum, and kingdom, species themselves are not considered groups in the same way that these higher taxonomic categories are. Instead, species are considered individual entities within these larger groupings, each representing a distinct type of organism with its own unique characteristics and evolutionary history.
