Unit 3 Evolution Flashcards
Which of the following is NOT correct:
a) Darwin’s theory held that species can arise by evolution from other species, while Lamarck’s theory did not.
b) Darwin’s theory is a much better fit to Linnaean (hierarchical) taxonomy than was Lamarck’s theory.
c) Lamarck’s theory required that characteristics of individuals can change within their lifetimes, whereas Darwinian natural selection requires that populations include individuals with intrinsic, heritable differences.
d) Lamarck imagined (incorrectly) that life arose many times, and that each lineage increased in complexity over time.
e) Darwinian natural selection results in adaptation to the environment in which a species lives.
a) Darwin’s theory held that species can arise by evolution from other species, while Lamarck’s theory did not.
Which of the following conditions are required for natural selection to take place?
a) That individuals have differing traits that are heritable.
b) That there is use and disuse of parts
c) That there was a single origin of life on Earth
d) A and B are both required
a) That individuals have differing traits that are heritable.
Which of the following pairs of structures are homologous?
a) Bat wings; Human arms
b) Bat wings; Insect wings
c) Bat wings; Whale flippers
d) Both A and C
d) Both A and C
Consider two closely related species of animals, X and Y; X has wings, Y has vestigial wings. From this information, which of the following is most likely correct?
a) The most recent common ancestor of X and Y had wings
b) The most recent common ancestor of X and Y had vestigial wings
c) The most recent common ancestor of X and Y had both wings and vestigial wings
d) The most recent common ancestor of X and Y had no wings at all (i.e. the wings of X and vestigial wings of Y evolved separately)
a) The most recent common ancestor of X and Y had wings
Living whales are fully aquatic mammals that, unlike land mammals, lack hindlimbs. However, fossil skeletons of some extinct whales include bones of the upper and lower hind leg and some foot bones. Which of the following options best describes this situation?
a) The extinct whale’s hindlimbs arose through convergent evolution (convergent with land mammals)
b) These extinct whales are more closely related to land animals than they are to modern whales
c) These extinct whales must be the last common ancestors of living whales
d) These extinct whales must represent a different branch on the tree of life than modern whales
e) These extinct whales represent a transitional form between land mammals and modern whales
e) These extinct whales represent a transitional form between land mammals and modern whales
Which of the following can cause microevolution in a population?
a) Natural selection
b) Gene flow
c) Genetic drift
d) Both A and C
e) Any of A, B and C
e) Any of A, B and C
A population of a species has two alleles, “B” and “b”, at some locus. The population has 68 BB individuals, 20 bb individuals and 12 heterozygotes. What is the frequency of allele “B” in the population?
0.74
Consider a single locus where there is one dominant and one recessive allele. 9% of a population shows the homozygous recessive genotype (i.e. the frequency of this genotype is 0.09). What is the expected frequency of the dominant allele in this population, if we assume that the population is in Hardy-Weinberg equilibrium?
0.7
Consider a single locus where there is one dominant and one recessive allele. 9% of a population shows the homozygous recessive genotype (i.e. the frequency of this genotype is 0.09). What is the expected frequency of heterozygotes in this population, if we assume that the population is in Hardy-Weinberg equilibrium?
0.42
Which of the following is NOT an assumption of the Hardy-Weinberg principle?
a) Natural selection is not favouring any allele over the others at the locus in question
b) Random mating
c) The breeding population is very large
d) There is no ‘gene flow’ between this population and others
e) There are more heterozygotes than homozygotes in the population
e) There are more heterozygotes than homozygotes in the population
Consider an allele at a locus where there is no natural selection, in a very small population, in which its frequency is 0.5. Assume there are no mutations or gene flow. What is the theoretical probability that this allele will eventually go extinct?
0.5
Which of the following best describes conditions under which we would see a dramatic increase in the rate of genetic drift in a population of animals?
a) When migration suddenly stops between that population and all other populations of the species
b) When the rate of migration suddenly increases between the population and all other populations of the species
c) When the size of the population suddenly drops to just a few individuals for several generations
d) When the size of the population increases several-fold, due to excellent reproductive success throughout the population (rather than through migration)
e) When the whole population moves from one geographic region to another
c) When the size of the population suddenly drops to just a few individuals for several generations
Consider the case where a population of wild goats includes individuals with different lengths of horns, ranging from long, to short, and everything between. Horn size is heritable. Suppose there is disruptive selection acting on horn size. From the following options, which best describes the individuals that would have the lowest relative fitness on average?
a) Goats with long horns
b) Goats with short horns
c) Goats with mid-sized horns
d) Goats with either long or short horns (i.e. goats with mid-sized horns have the highest fitness)
c) Goats with mid-sized horns
Within the context of distinguishing biological species, and the evolution of species, which of the following reproductive barriers (= barriers to gene flow) is a pre-zygotic barrier?
a) Hybrid infertility (reduced hybrid fertility)
b) Mechanical isolation
c) Temporal isolation
d) A and C
e) B and C
e) B and C
A fish species is separated into two populations when the large lake it inhabits becomes divided into two separate lakes by falling water levels. Over several thousand years the two populations evolve independently of each other (with no gene flow between them). The two lakes then become connected again to form one large lake, and the fish mix throughout the lake. After this time the two populations interbreed quite often, but the offspring from the mixed matings are very susceptible to predators and disease, and never survive to reproductive age. Assuming we are following the biological species concept, which of the following pairs of terms best describes this scenario?
a) Allopatric speciation; Habitat isolation
b) Allopatric speciation; Hybrid inviability
c) Habitat isolation; Sympatric speciation
d) Habitat isolation; Hybrid inviability
b) Allopatric speciation; Hybrid inviability
After 100 years a scientist returns to the lake described in the previous question, and finds that interbreeding between the two populations is now very rare. They encounter each other often, and still breed at the same time of year. However, the courtship rituals of the males of the two populations are somewhat different, and females from Population 1 do not respond to the courtship rituals of the males of Population 2, and vice versa. Which of the following pairs of terms best describes this new development?
a) Behavioural isolation; Post-zygotic Barrier
b) Behavioural isolation; Reinforcement
c) Gametic isolation; Post-zygotic barrier
d) Gametic isolation; Reinforcement
b) Behavioural isolation; Reinforcement
Monophyletic, Paraphyletic, polyphyletic
Ancestor and all descendants
Ancestor and some, not all descendants
Group doesn’t include most recent common ancestor (2+ branches artificially branched together)
Which geological time began most recently?
Cretaceous
List periods and eras in order (older to newer)
Paleozoic, Mesozoic, Cenozoic
In between P & M; Permian and Cretaceous
T/F mass extinction events are usually caused by adaptive radiation
False
When two genes are parallel what does this mean
They arose through duplication of ancestral gene
What best describes where peptidoglycan is found
Surrounding the plasma membrane (cell membrane) of bacterium
