Evolution — NEET Zoology MCQs with answers

Evolution is a Class 12 Zoology chapter in the NEET (UG) syllabus. NEET720 has 1,265 reviewed practice questions on it, each with a quick answer and a step-by-step explanation. The 8 questions below are free and fixed, so you can bookmark this page; the full chapter, plus mistake tracking and spaced revision, is in the app.

Topics covered

Genetic Drift and Gene Flow · Evolution Concepts · Origin of Life · Evidence for Evolution · Darwinism and Natural Selection · Hardy-Weinberg and Speciation · Human Evolution · Evidences for Evolution · Adaptations and Natural Selection · Mechanism of Evolution · Evolution mechanisms · Lamarckism vs Darwinism · Adaptive Radiation and Convergent Evolution · Hardy-Weinberg and Natural Selection · Types of Selection · Allopatric Speciation · Hardy-Weinberg and Migration · Speciation and Reproductive Isolation · Evolution of Life Forms · Natural Selection and Hardy-Weinberg · Convergent Evolution and Homology · Synthesis of Evolutionary Mechanisms · Fossil Evidence · Types of Natural Selection · Evolution · Hardy-Weinberg principle · Natural selection · Evidences of evolution · Adaptive radiation · Speciation · Evolutionary tempo · Theories of evolution · Population genetics and selection · Sexual selection · Speciation mechanisms · Species concept · Coevolution · Tempo of evolution · Social behaviour evolution · Molecular evolution

8 free Evolution practice questions with answers

Choose an answer in your head before opening it. Each explanation says why the correct option is right and, where relevant, why the tempting wrong option is wrong.

1. Question 1 · easy · Darwinism and Natural Selection

   Lamarck's theory of inheritance of acquired characters proposed that evolutionary change in a lineage results primarily from which of the following?

   • A.Random mutations in germ cells that are selected by the environment
   • B.Use and disuse of organs during an organism's lifetime, with the resulting change passed on to offspring
   • C.Differential survival and reproduction of individuals best suited to the environment
   • D.Recombination of alleles during meiosis in the parental generation
   Show answer and explanation

   Answer: B. Use and disuse of organs during an organism's lifetime, with the resulting change passed on to offspring

   Lamarck proposed that organs used more become stronger/larger and organs disused degenerate, and that such acquired changes are inherited by offspring — the theory of use and disuse coupled with inheritance of acquired characters.

   Jean-Baptiste Lamarck (1744-1829) explained adaptive change through two linked ideas: (1) use and disuse — organs that are used extensively become more developed, while unused organs degenerate, and (2) these acquired changes are transmitted to the next generation. Option B captures this correctly. Option A describes a more modern, mutation-and-selection framework not proposed by Lamarck. Option C describes Darwin's natural selection, which operates on pre-existing heritable variation rather than characters acquired during an individual's life. Option D is a genetics concept irrelevant to Lamarck's mechanism. Lamarckism is now scientifically rejected because changes to somatic tissues (e.g., muscle build from exercise) do not alter the DNA sequence of germ cells and therefore cannot be transmitted to offspring.

   Common mistake: Confusing Lamarck's mechanism with Darwin's differential survival/reproduction mechanism.

   Key point: Lamarckism = use/disuse of organs + inheritance of the acquired change; this is distinct from and predates Darwin's natural selection.

2. Question 2 · easy · Darwinism and Natural Selection

   Charles Darwin's ideas on evolution by natural selection were substantially shaped by his observations made during a five-year voyage aboard which ship?

   • A.HMS Challenger
   • B.HMS Endeavour
   • C.HMS Beagle
   • D.HMS Discovery
   Show answer and explanation

   Answer: C. HMS Beagle

   Darwin served as naturalist on HMS Beagle during its 1831-1836 survey voyage, observing varied life forms across South America, the Galapagos Islands, and other regions, which shaped his theory of natural selection.

   Darwin's five-year voyage on HMS Beagle exposed him to the geographic distribution and variation of species, most famously the finches of the Galapagos Islands, fossil remains of extinct giant mammals resembling living species, and geological evidence of gradual change. These observations formed the empirical basis for 'On the Origin of Species' (1859). HMS Endeavour was Captain Cook's ship on an earlier, unrelated 18th-century voyage. HMS Challenger conducted the pioneering oceanographic expedition of 1872-76, decades after Darwin's voyage. HMS Discovery is a generic ship name used in various expeditions unrelated to Darwin.

   Common mistake: Mixing up HMS Beagle with other famous exploration ships.

   Key point: Darwin's key observations were made on the HMS Beagle voyage (1831-1836).

3. Question 3 · medium · Darwinism and Natural Selection

   On the Galapagos Islands, Darwin observed several species of finches whose beak shapes and sizes differed markedly and correlated closely with their feeding habits (seed-crushing, insect-probing, etc.), despite the finches sharing a common ancestor. This phenomenon, where a single ancestral species diversifies into many forms adapted to different ecological niches within a relatively confined geographic area, is best described as an example of:

   • A.Convergent evolution
   • B.Genetic drift
   • C.Industrial melanism
   • D.Adaptive radiation
   Show answer and explanation

   Answer: D. Adaptive radiation

   The diversification of a single ancestral finch species into multiple beak forms suited to different food sources within the isolated Galapagos archipelago is the textbook example of adaptive radiation.

   Adaptive radiation is the evolution of different species from a common ancestor, each adapted to a distinct niche/habitat within a given geographical area, starting from one point and radiating to other areas. Darwin's finches (also called Galapagos finches) illustrate this: an ancestral seed-eating finch population colonized the islands and, in the absence of competitors, diversified into forms with beaks specialized for cracking seeds, probing for insects, or feeding on cactus flowers. Option A, convergent evolution, describes the opposite pattern — unrelated species independently evolving similar structures because they face similar environments (e.g., the placental wolf and Tasmanian marsupial wolf having similar body forms despite different ancestry) — not diversification from one ancestor. Option C, industrial melanism, refers to the shift toward darker Biston betularia moths in polluted areas, an unrelated example of natural selection acting on an existing character, not radiation into many forms. Option D, genetic drift, is random change in allele frequency, especially in small populations, and does not by itself explain adaptive, niche-correlated diversification.

   Common mistake: Confusing adaptive radiation (one ancestor, many places/niches, same region) with convergent evolution (different ancestors, similar form, due to similar environments).

   Key point: Adaptive radiation = one ancestor diversifying into many species within one geographic region, each fitted to a different niche (classic example: Darwin's Galapagos finches).

4. Question 4 · medium · Darwinism and Natural Selection

   Darwin noted that all organisms have the capacity to reproduce in a geometric (exponential) progression, yet population sizes in nature generally remain fairly stable over time. Which conclusion did he draw from this observation, and what did he term it?

   • A.Most offspring fail to survive and reproduce because resources are limited, a condition he called the 'struggle for existence'
   • B.Population sizes are actively regulated by a hereditary mechanism that Darwin called 'genetic homeostasis'
   • C.Organisms deliberately limit their own reproduction to avoid overcrowding, a behaviour Darwin termed 'reproductive restraint'
   • D.Exponential reproduction is balanced entirely by seasonal migration, which Darwin termed 'range equilibrium'
   Show answer and explanation

   Answer: A. Most offspring fail to survive and reproduce because resources are limited, a condition he called the 'struggle for existence'

   Darwin reasoned that because reproductive potential vastly exceeds the resources available (food, space), most individuals produced do not survive to reproduce — a competitive struggle he called the 'struggle for existence,' a foundational premise of natural selection.

   Darwin observed (following ideas from Malthus) that organisms can, in principle, increase in numbers geometrically if all offspring survived and reproduced. Yet natural populations tend to stay roughly constant because food, space, and other resources are limited. He concluded that this mismatch forces a 'struggle for existence' among individuals for the limited resources, and only some individuals survive and reproduce. This struggle for existence, combined with heritable variation, sets up differential survival and reproduction — the essence of natural selection. Options B, C and D fabricate mechanisms/terms Darwin did not propose; population regulation via deliberate self-restraint or migration equilibrium are anachronistic or incorrect group-selection-style ideas not part of Darwin's argument.

   Common mistake: Assuming population stability implies organisms deliberately regulate their own numbers, rather than being limited by resource-driven mortality.

   Key point: Geometric reproductive potential + limited resources = struggle for existence, a core premise underlying natural selection.

5. Question 5 · medium · Darwinism and Natural Selection

   Arrange the following steps in the correct logical sequence of Darwin's theory of natural selection, from the starting premise to the ultimate evolutionary outcome: (i) Individuals best suited to the environment survive and reproduce more successfully ('survival of the fittest') (ii) Heritable variation exists among individuals of a population (iii) More individuals are produced than the environment can support, leading to a struggle for existence (iv) Favourable heritable traits accumulate in the population over generations, gradually changing its characteristics

   • A.(ii) → (iii) → (i) → (iv)
   • B.(iii) → (ii) → (i) → (iv)
   • C.(i) → (ii) → (iii) → (iv)
   • D.(ii) → (i) → (iii) → (iv)
   Show answer and explanation

   Answer: B. (iii) → (ii) → (i) → (iv)

   The correct Darwinian logic is: overproduction creates a struggle for existence (iii) among a population that already shows heritable variation (ii); the fittest variants survive and reproduce preferentially (i); and this differential reproduction gradually shifts the population's characteristics over generations (iv).

   Darwin's argument can be reconstructed as: populations reproduce in excess of what resources can support, creating competition/struggle for existence (iii). Within any population, individuals already show heritable variation (ii) — some variants are better suited to prevailing conditions. Given the struggle for existence, those individuals whose variations make them better suited ('fittest') survive and reproduce more successfully (i). Because the advantageous variations are heritable, they accumulate in the population across generations, gradually altering it (iv). Note that all four premises (overproduction, struggle, variation, differential survival/reproduction) interact, but the standard textbook presentation orders struggle for existence and variation as the setup, survival of the fittest as the selective step, and gradual change as the outcome. Options A, C and D scramble this causal order, placing outcomes before their necessary premises.

   Common mistake: Placing 'survival of the fittest' as the very first step instead of recognizing it depends on prior overproduction and variation.

   Key point: Order: overproduction/struggle → pre-existing heritable variation → differential survival/reproduction of the fit → gradual population change.

6. Question 6 · medium · Darwinism and Natural Selection

   A researcher studying an isolated island population of finches finds that individuals with deep, strong beaks feed efficiently on hard seeds, while individuals with slender, pointed beaks feed efficiently on soft insects. Over many generations, the population splits into two forms, each specialized to one food type. This scenario is most directly analogous to which observation that influenced Darwin's thinking?

   • A.The uniform body plan of cockroaches across different habitats
   • B.The correlation between Galapagos finch beak shape and feeding habit, illustrating adaptive divergence from a common ancestor
   • C.The similarity in wing structure between birds and bats despite different ancestry
   • D.The presence of vestigial hind limb bones in whales
   Show answer and explanation

   Answer: B. The correlation between Galapagos finch beak shape and feeding habit, illustrating adaptive divergence from a common ancestor

   The scenario mirrors Darwin's Galapagos finch observations, where distinct beak forms correlated tightly with feeding habits, illustrating how a single ancestral population diversifies (adaptive radiation) into forms suited to different food resources.

   This is a direct application of the finch example: differing beak morphology tracks differing diet within one lineage occupying one region, i.e., adaptive radiation/divergence driven by natural selection favouring beak shapes matched to available food. Option A describes uniformity, the opposite of the diversification described. Option C describes convergent evolution (analogous structures in unrelated lineages), which is a different phenomenon from the divergence of one ancestral finch population. Option D is an unrelated vestigial-organ example (evidence for evolution generally, but not an example of adaptive divergence by feeding niche). Correct reasoning selects B because both the scenario and Darwin's finches show a single ancestral stock diversifying to exploit different food resources via distinguishable beak morphology.

   Common mistake: Selecting any example involving birds/adaptation without checking whether it involves divergence from a common ancestor within one region versus convergence between unrelated lineages.

   Key point: Beak-shape-feeding correlation in an isolated population diversifying from one ancestor = adaptive radiation, the same pattern Darwin observed in Galapagos finches.

7. Question 7 · medium · Darwinism and Natural Selection

   In the Darwinian sense used in evolutionary biology, the term 'fitness' of an organism most precisely refers to:

   • A.Its physical strength and muscular power relative to other individuals
   • B.Its overall body size compared to other members of the species
   • C.Its ability to migrate long distances in search of resources
   • D.Its relative capacity to survive and produce fertile, viable offspring compared to other individuals in the population
   Show answer and explanation

   Answer: D. Its relative capacity to survive and produce fertile, viable offspring compared to other individuals in the population

   In evolutionary biology, 'fitness' is a measure of an organism's relative reproductive success — its capacity to survive and pass on genes to viable, fertile offspring — not a measure of physical strength or size.

   Darwinian fitness is not synonymous with everyday notions of physical strength or size; it is a relative measure of how successfully an individual's genotype contributes offspring to the next generation compared with other genotypes in the same population. An organism could be physically weak yet highly fit if it reliably produces many surviving, fertile offspring, and conversely a physically powerful individual with low reproductive output has low fitness. Option A wrongly equates fitness with muscular strength. Option C picks one possible survival behaviour but is not the defining feature of fitness. Option D wrongly assumes larger body size necessarily confers higher fitness, which is not generally true and is not the definition.

   Common mistake: Equating biological 'fitness' with athletic fitness or physical strength.

   Key point: Fitness = relative reproductive success (survival + fertile viable offspring), not physical strength or size.

8. Question 8 · medium · Darwinism and Natural Selection

   Consider the following statements about Lamarck's theory of evolution: I. Lamarck proposed that a blacksmith's muscular arms, developed through repeated hammering, would be inherited by his children. II. Lamarck's theory is consistent with modern molecular genetics, which shows that environmentally induced changes in body cells are copied into sperm and egg DNA. III. Lamarck's explanation for snakes lacking limbs was that their ancestors gradually stopped using limbs, and this disuse-induced limb loss was inherited over generations. IV. Lamarck's proposal was later experimentally validated by Darwin's finch studies on the Galapagos Islands. How many of the above statements are correct?

   • A.One
   • B.Two
   • C.Three
   • D.Four
   Show answer and explanation

   Answer: B. Two

   Statements I and III correctly describe Lamarck's use/disuse examples (blacksmith's arms, limbless snakes); statements II and IV are false — modern genetics refutes rather than confirms Lamarckism, and Darwin's finch studies are unrelated to validating Lamarck.

   Statement I is a classic illustrative example historically associated with Lamarckian reasoning: repeated use of the arm muscles would supposedly be inherited by offspring — true as a description of Lamarck's claim (though the underlying mechanism is false biology, the statement about what Lamarck claimed is accurate). Statement II is false: modern molecular genetics shows the opposite — somatic (body cell) changes are NOT copied into germline DNA, which is precisely why Lamarckism is rejected today. Statement III is a correct restatement of Lamarck's disuse argument applied to limbless snakes — ancestors' limbs supposedly became reduced from disuse and this reduction was inherited. Statement IV is false: Darwin's finch observations support Darwinian natural selection acting on pre-existing variation, and were never framework for validating Lamarck's acquired-character mechanism; in fact, natural selection and Lamarckism are competing, not complementary, explanations. Therefore exactly two statements (I and III) are correct.

   Common mistake: Assuming any statement that 'sounds' like textbook content about Lamarck or Darwin must be true without checking factual accuracy of claims about genetics or supporting evidence.

   Key point: Lamarck's own claims (blacksmith's arms, limbless snakes from disuse) are correctly stated in I and III; modern genetics refutes, not confirms, his mechanism, and Darwin's finches support Darwinism, not Lamarckism.

Questions about Evolution for NEET

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