Question

Select the odd option in the context of convergent evolution.

• A. Eyes of Octopus and Mammals
• B. Flippers of Penguins and Dolphins
• C. Flying Squirrel and Flying Phalanger
• D. Thorns of Bougainvillea and Tendrils of Cucurbita

Hint:

Homology = Same origin, different function (Divergent). Analogy = Different origin, same function (Convergent). Thorns and tendrils both come from axillary buds $\rightarrow$ Homologous $\rightarrow$ Divergent!

Answer 1

The Correct Option is D

Concept: Evolutionary biology distinguishes structures based on their anatomical origins and functional adaptations:
• Convergent Evolution Analogous Organs: Different structural lineages evolve similar functional adaptations independently because they share a comparable ecological niche or selective pressure. They have different origins but similar functions.
• Divergent Evolution Homologous Organs: Structures share a common embryonic/anatomical origin but have diverged over generations to perform completely distinct functions in response to different requirements.

Step 1: Assess Option (A).
The eyes of an octopus (mollusk) and a mammal (vertebrate) have completely different retinal architectures and embryonic origins. However, they perform the exact same function of vision. They are analogous structures representing convergent evolution.

Step 2: Assess Option (B).
Flippers of penguins (birds) and dolphins (mammals) possess distinct internal structural layouts reflecting their distinct evolutionary groups. However, both structures are modified for swimming. They are analogous structures representing convergent evolution.

Step 3: Assess Option (C).
The flying squirrel (placental mammal) and flying phalanger (marsupial mammal) belong to completely separated mammalian lineages. They have evolved matching gliding adaptations independently due to convergent evolution in parallel ecosystems.

Step 4: Assess Option (D).
Thorns of Bougainvillea and tendrils of Cucurbita both arise from the exact same anatomical position: the axillary bud. Because they share a common structural origin but serve different functions (protection vs. climbing support), they are homologous organs arising from divergent evolution. This makes Option (D) the odd one out.