The correct order of the four taxonomic levels from least inclusive to most inclusive is: species, genus, family, order.
To explain:
- Species is the most specific taxonomic rank. It refers to a group of individuals that can breed together and produce fertile offspring.
- Genus is a higher classification that groups together species that are closely related. For example, the genus Felis includes species like domestic cats and wildcats.
- Family is a broader classification that includes one or more genera (plural of genus). For instance, the family Felidae encompasses all the members of the cat family, including lions and tigers.
- Order is an even more inclusive category that comprises families. For instance, the order Carnivora includes families like Felidae (cats) and Canidae (dogs).
This hierarchy helps in organizing and understanding biological diversity.