Identify the correct sequence of taxonomic categories

To identify the correct sequence of taxonomic categories, let us look at the taxonomic hierarchy used in biological classification.

Organisms are classified in a hierarchical system, moving from the most specific group to the most general group. The standard taxonomic hierarchy (from lowest/most specific to highest/most general) is:
Species ⇒ Genus ⇒ Family ⇒ Order ⇒ Class ⇒ Phylum (or Division for plants) ⇒ Kingdom ⇒ Domain

Let us evaluate the given option "species – genus – order – phylum" in the context of this hierarchy:
1. Species is the lowest, most specific category.
2. Genus is the next category, comprising one or more closely related species.
3. Order is a higher category that groups related families (which in turn group related genera).
4. Phylum is an even higher category that groups related classes (which group related orders).

Therefore, the sequence "species – genus – order – phylum" represents a correct ascending order (from lowest to highest) of taxonomic categories.

The correct answer is species – genus – order – phylum.