The taxon cycle is the predicted, progressive ecological and evolutionary changes in the descendants of founding populations. Taking the case of insular biotas, the figure can be used to conceptualize and predict species types (a, b, c, d, e, f, g, h) based on their fundamental capacities to evolve, immigrate, and persist.

The table below has species types (Column X) and the possible traits (Column Y) associated with each type.

Which one of the following options represents all correct matches between Column X and Column Y?

Correct option is A

Correct Answer

Option (1): P (i), Q (ii), R (iii), S (iv)

Explanation:

Species type c represents late-stage island endemics that are ecologically naïve, fitting trait (i). Type d lies at the high evolution end and represents an unlikely type because long persistence is needed to evolve on isolated islands, matching (ii). Type e corresponds to species with poor dispersal ability, unlikely to reach remote islands, matching (iii). Type b represents early colonizers with strong dispersal ability or “supertramps,” matching (iv).

Information Booster

•         The taxon cycle describes how species transition from widespread, highly dispersive colonizers to localized, specialized endemics over time.

•         Island environments strongly filter species based on dispersal ability, persistence, and evolutionary potential.

•         This framework is particularly valuable for understanding patterns in island biogeography and conservation biology.