On the Galapagos Islands, Darwin found several finch species with different beak shapes that appeared to descend from a single species on the South American mainland.
Correct Answer
True
True. Darwin saw that the island finches were closely related to one mainland species and suspected they had all been modified from a common ancestor, an early clue toward natural selection.
Category: Darwin and Natural Selection
Question 2
Darwin explained how traits are inherited by applying Mendel's laws in On the Origin of Species.
Correct Answer
False
False. Darwin published in 1859 without knowing Mendel's work, which went largely unnoticed until it was rediscovered in the early 1900s. Natural selection and genetics were joined later in the modern synthesis.
Category: Darwin and Natural Selection
Question 3
Natural selection can produce evolutionary change only in traits that are heritable.
Correct Answer
True
True. Selection changes a population only when the favored differences are passed on through genes. A difference caused only by the environment, such as height affected by diet, does not shift the next generation.
Category: Darwin and Natural Selection
Question 4
The advantage a trait gives an organism stays the same no matter how environmental conditions change.
Correct Answer
False
False. Whether a trait is helpful depends on the current environment, so a trait that is favored under one set of conditions can become neutral or harmful when conditions change.
Category: Darwin and Natural Selection
Question 5
In population genetics, evolution is defined as a change in the allele frequencies of a population over time.
Correct Answer
True
True. Population geneticists measure evolution by tracking how the proportions of alleles in a gene pool shift from generation to generation.
Category: Population Genetics
Question 6
Genetic drift affects only selectively neutral alleles.
Correct Answer
False
False. Drift is the effect of chance on which alleles are passed on, and it acts on every allele, including those that selection favors or disfavors. Its effect is strongest in small populations.
Category: Mechanisms of Evolution
Question 7
Genetic drift would not occur in an infinitely large population.
Correct Answer
True
True. Drift arises because each generation's alleles are a random sample of the parents' alleles. As population size grows, chance sampling errors shrink, and in an infinite population they would disappear.
Category: Mechanisms of Evolution
Question 8
Harmful mutations usually spread quickly through a population because of natural selection.
Correct Answer
False
False. Natural selection removes harmful mutations, so they generally persist only at very low frequencies. Selection spreads beneficial mutations, not harmful ones.
Category: Mechanisms of Evolution
Question 9
Gene flow can occur through the movement of gametes, such as wind-blown pollen, as well as through the migration of individuals.
Correct Answer
True
True. Gene flow is the movement of alleles into or out of a population, and in plants it often happens when pollen or seeds travel between populations.
Category: Mechanisms of Evolution
Question 10
Eohippus, an early ancestor of modern horses, was larger than horses living today.
Correct Answer
False
False. Eohippus was small, about the size of a dog, with several toes on each foot. Later species in the lineage were larger and walked on a single hoofed toe.
Category: Evidence of Evolution
Question 11
Fossils with features intermediate between an older ancestral form and its later descendants are called transitional fossils.
Correct Answer
True
True. Transitional fossils show anatomy partway between earlier and later forms, and the horse and whale lineages have especially good series of them.
Category: Evidence of Evolution
Question 12
The tail structure seen in early human embryos remains present at birth.
Correct Answer
False
False. Human and other great ape embryos have a tail structure that is lost before birth. Its brief appearance during development is part of the embryological evidence for shared ancestry.
Category: Evidence of Evolution
Question 13
The large number of marsupial species in Australia reflects the continent's long isolation from other landmasses.
Correct Answer
True
True. Australia separated from other continents long ago, and its marsupials diversified there in isolation, a classic biogeographic pattern explained by evolution and plate movement.
Category: Evidence of Evolution
Question 14
The biological species concept works best for organisms that reproduce asexually.
Correct Answer
False
False. The biological species concept is based on interbreeding, so it applies to sexually reproducing organisms. Asexual organisms do not interbreed, so the definition does not fit them.
Category: Speciation
Question 15
Prezygotic barriers, such as differences in mating season, prevent fertilization between members of different species.
Correct Answer
True
True. Prezygotic barriers act before a zygote can form, through differences in timing, mating sites, courtship behavior, pheromones or physiology.
Category: Speciation
Question 16
Polyploidy is common in animals but rare in plants.
Correct Answer
False
False. The reverse is true: polyploidy is common in plants, and many plant species trace back to a polyploid origin, while it is rare in animals because most chromosome abnormalities are lethal to them.
Category: Speciation
Question 17
Cultivated wheat is an allopolyploid, formed from hybrids of different parent species.
Correct Answer
True
True. An allopolyploid carries chromosome sets from two or more species. Wheat, cotton and tobacco are well-known crop examples.
Category: Speciation
Question 18
The theory of evolution explains how the first living cells arose from nonliving chemicals.
Correct Answer
False
False. Evolution explains how populations change and species diversify once self-copying life exists. How the first cells arose is a separate question that evolutionary theory does not address.
Category: Misconceptions About Evolution
Question 19
Exposure to an antibiotic causes bacteria to produce the mutations that make them resistant.
Correct Answer
False
False. Resistance alleles are already present at low frequency before the drug is used. The antibiotic kills susceptible bacteria, so the resistant ones that already existed survive and increase.
Category: Misconceptions About Evolution
Question 20
Intelligent design is not considered a scientific explanation because it relies on causes that cannot be tested.
Correct Answer
True
True. Science addresses only testable, natural explanations. Ideas that depend on untestable, nonmaterial causes cannot generate research or be checked against evidence, so they fall outside science.
Category: Misconceptions About Evolution