Free Evolution MCQs with Answers

11. Which of the following is NOT part of Darwin's theory of natural selection?

• A. Overproduction of offspring
• B. Struggle for existence
• C. Inheritance of characters acquired during life
• D. Survival of the fittest

Explanation: Inheritance of acquired characters is Lamarck's proposal, not Darwin's, and it is the standard distractor in this question. Darwin's argument runs from overproduction to a struggle for existence, and among the naturally varying individuals in that struggle the better adapted survive and reproduce. Darwin did in fact accept some inheritance of acquired characters personally, but it forms no part of the mechanism named after him.

12. Darwin's observations on the beaks of finches, which shaped his theory, were made on the

• A. Galapagos Islands
• B. Hawaiian Islands
• C. Canary Islands
• D. Maldive Islands

Explanation: During the voyage of HMS Beagle Darwin found that each island of the Galapagos group carried finches whose beaks matched the food available there, from heavy seed crushers to fine insect probes. He later realised they had descended from one mainland ancestor and diverged, which is the classic example of adaptive radiation. The other island groups have famous endemic species but were not visited by the Beagle.

13. Darwin presented his theory of evolution in the book

• A. Philosophie Zoologique
• B. The Origin of Species
• C. Systema Naturae
• D. Principles of Geology

Explanation: The Origin of Species was published in 1859 and set out both the evidence for common descent and natural selection as its mechanism. Philosophie Zoologique is Lamarck's book of 1809, which makes it the tempting wrong answer in a question about evolution. Systema Naturae is Linnaeus's classification and Principles of Geology is Lyell's work, which influenced Darwin by arguing that the earth is very old.

14. The increase of the dark form of the peppered moth in industrial England is a direct example of

• A. genetic drift
• B. artificial selection
• C. inheritance of an acquired character
• D. natural selection

Explanation: Soot darkened the tree trunks, so pale moths became conspicuous to birds while the dark variant was camouflaged, and the frequency of the dark form rose within a few decades. The variation already existed as a mutation and the environment merely decided which form survived to breed. It is not artificial selection because no human chose the breeders, and the moths did not darken through exposure to soot.

15. The main gap in Darwin's original theory was that he could not explain

• A. why more offspring are produced than can survive
• B. how variations arise and how they are passed on
• C. the struggle for existence between individuals
• D. the geographical distribution of related species

Explanation: Darwin had no knowledge of genes, so although he built his whole argument on heritable variation he could not say where variation came from or why it was not blended away in each generation. Mendel's work, rediscovered in 1900, supplied particulate inheritance and mutation supplied the source, and the combination became neo Darwinism. Overproduction, struggle and distribution were all matters Darwin documented well.

16. Neo Darwinism explains the raw material of evolution as arising from

• A. mutation and genetic recombination
• B. use and disuse of organs
• C. the needs felt by the organism
• D. the direct action of the environment on the gametes

Explanation: The modern synthesis keeps Darwin's natural selection and adds genetics: mutation creates new alleles and sexual reproduction shuffles them by recombination, producing the variation selection acts on. Selection then changes allele frequencies in the population, which is what evolution now formally means. Use and disuse and organism felt need are Lamarckian ideas that the synthesis explicitly excludes.

17. The presence of pharyngeal (gill) pouches in the embryos of fish, birds and humans alike is evidence drawn from

• A. comparative anatomy of adults
• B. palaeontology
• C. biogeography
• D. comparative embryology

Explanation: Early vertebrate embryos resemble one another far more than the adults do, and structures such as pharyngeal pouches and a post anal tail appear even in species that never use them, because development follows an inherited common programme. In humans the pouches go on to form parts of the ear, tonsil and parathyroid rather than gills. Adult anatomy, fossils and distribution are separate lines of evidence.

18. The production of high yielding varieties of wheat by repeatedly breeding from the best plants is an example of

• A. natural selection
• B. genetic drift
• C. artificial selection
• D. adaptive radiation

Explanation: Here a human being, not the environment, decides which individuals reproduce, and the chosen character is one that suits us rather than one that improves survival in the wild. Darwin opened The Origin of Species with exactly this comparison, arguing that if breeders can reshape a species in a few generations then nature can do far more over geological time. Drift is change by chance, with no selection of any kind.

19. Adaptive radiation is best illustrated by

• A. the two colour forms of the peppered moth
• B. the reduced human appendix
• C. Darwin's finches evolving different beak shapes from one ancestral species
• D. the similarity of cytochrome c in humans and chimpanzees

Explanation: Adaptive radiation is the spread of one ancestral species into many descendant species, each adapted to a different niche, which is exactly what happened when finches colonised the separate Galapagos islands. The peppered moth is a change in the frequency of two forms within a single species, not the origin of new ones. The appendix illustrates vestigial structures and cytochrome c illustrates molecular homology.

20. The spread of antibiotic resistant bacteria in hospitals is best explained by

• A. bacteria learning to resist the drug during exposure
• B. the antibiotic causing the resistance mutation to occur
• C. each bacterium passing on resistance it acquired in its own lifetime
• D. survival and multiplication of resistant mutants already present in the population

Explanation: Resistance mutations arise at random before the drug is ever met, and the antibiotic then kills the sensitive majority, leaving the rare resistant cells to multiply without competition. Because bacteria divide every twenty minutes, natural selection is visible within days, which is why this is the standard modern demonstration of Darwin's mechanism. The other three options are all Lamarckian readings of the same observation.