Analogous organs are body parts that look and work alike and do the SAME function, but they are built differently and come from DIFFERENT ancestors. They are the result of convergent evolution, where unrelated groups living in a similar habitat evolve similar features. Memory hook: "Analogous = Alike in Action, different in Anatomy." Classic NCERT pairs: wings of butterfly and bird, flippers of penguin and dolphin, eye of octopus and mammal, sweet potato (root) and potato (stem).
Bird and butterfly come from different ancestors, yet both evolved wings for flight. Same function built from different structures makes them analogous organs, the result of convergent evolution.
Your doubts, answered
Do analogous organs have the same function or the same structure?
Same FUNCTION, but different internal structure. A butterfly wing and a bird wing both help in flight (same job), but their anatomy is totally different - the bird wing has bones (humerus, radius, ulna) while the insect wing does not. Because the function is the same but the build is different, they are analogous. This is the exact opposite of homologous organs, which share the same structure but do different jobs.
Why are flippers of penguins and dolphins analogous and not homologous?
A penguin is a BIRD and a dolphin is a MAMMAL - two unrelated groups. Their flippers look similar and both help in swimming, but they did not come from a shared swimming ancestor. Each group independently evolved a flipper because both live in water (similar habitat). Same function + different ancestry = analogous = convergent evolution. NEET repeatedly puts 'flippers of penguins and dolphins are homologous' as a WRONG statement to trap you.
Is convergent evolution an evidence of common ancestry?
No. Convergent evolution produces analogous organs, which show that similar needs can produce similar-looking features in UNRELATED lineages. So analogy does NOT prove common ancestry. It is homology (divergent evolution) that indicates common ancestry. ReNEET 2026 asked exactly this: convergent evolution of bird and butterfly wings is NOT direct evidence of common descent.
Why are sweet potato and potato an example of analogy?
Sweet potato is a modified ROOT and potato is a modified STEM - different structural origins. But both are swollen underground food-storage organs doing the same function. Same function from different structures means they are analogous, and analogy is the product of convergent evolution. NEET 2025 asked this and the answer was 'Analogy, convergent'.
Is the eye of octopus and eye of man homologous or analogous?
Analogous. Octopus (a mollusc) and man (a mammal) are unrelated groups whose eyes evolved separately but ended up looking similar and doing the same job of seeing. So the octopus eye and mammal eye are analogous (convergent evolution), NOT homologous. NEET 2018 used this as the odd one out in a list of divergent (homologous) examples.
⚠️ The NEET trap ✗ Flippers of penguins and dolphins are homologous organs. ✓ They are ANALOGOUS organs - penguin is a bird, dolphin is a mammal, so they are unrelated; the flipper evolved independently for swimming (convergent evolution). 🧠 If the two animals are from DIFFERENT groups but the parts do the SAME job, think ANALOGY, never homology.
Real NEET questions
2016
Analogous structures are a result of:
A · Divergent evolution
B · Convergent evolution ✓
C · Shared ancestry
D · Stabilizing selection
Solution: Analogous structures are anatomically dissimilar structures that perform the same function and look alike because different, unrelated lineages independently evolved similar features for the same role - this is convergent evolution (e.g. wings of butterfly and bird). Divergent evolution and shared ancestry give homologous structures instead.
2020 / 2024
Flippers of Penguins and Dolphins are examples of:
A · Industrial melanism
B · Natural selection
C · Adaptive radiation
D · Convergent evolution ✓
Solution: A penguin is a bird and a dolphin is a mammal. Their flippers are anatomically different structures that perform the same function (swimming), so they are analogous, not homologous. Analogous structures result from convergent evolution, where different structures evolve toward the same function because of a similar aquatic habitat.
2025
Sweet potato and potato represent a certain type of evolution. Select the correct combination of terms to explain the evolution.
A · Homology, convergent
B · Analogy, divergent
C · Analogy, convergent ✓
D · Homology, divergent
Solution: Sweet potato is a root modification while potato is a stem modification, yet both are swollen food-storage structures doing the same function despite different anatomical origins. Structures that look and function alike but arise from different ancestral structures are analogous, and analogy is the product of convergent evolution. Hence: Analogy, convergent.
Solved Evolution NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Convergent evolution is when unrelated groups of organisms living in a similar habitat independently evolve similar-looking features for the same function, producing analogous organs.
Give the main NCERT examples of analogous organs.
Wings of butterfly and bird, flippers of penguin and dolphin, eye of octopus and mammal, and sweet potato (root) and potato (stem). These are the exact pairs NEET repeats.
Do analogous organs indicate common ancestry?
No. Analogous organs indicate similar habitat and function, not shared ancestry. Only homologous organs (from divergent evolution) point to common ancestry.
What is the opposite of analogy?
Homology. Homologous organs have the same basic structure but different functions and arise by divergent evolution from a common ancestor, which is exactly opposite to analogy.
Why is convergent evolution important for NEET?
Almost every year NEET asks you to classify a given pair (flippers, wings, sweet potato-potato, octopus eye) as analogous/convergent or homologous/divergent, and to know that convergent evolution is not evidence of common ancestry.
