Evolution Review
Adaptation
Extinct
Mimicry
Selective advantage
Variation
Artificial selection
Natural selection
Selective pressure
Catastrophism
Descent with modification
Evolution
Inheritance of acquired characteristics
Paleontology
Survival of the fittest
Uniformitarianism
Analogous structures
Biogeography
Embryology
Fossil record
Homologous structures
Fossil
Vestigial structures
Lamarck
Darwin
Wallace
Lyell
Linnaeus
Cuvier
Bottleneck effect
Directional selection
Disruptive selection
Founder effect
Gene flow
Genetic drift
Non-random mating
Stabilizing selection
Allopatric speciation
Post-zygotic isolating mechanism
Pre-zygotic isolating mechanism
Speciation
Sympatric speciation
Radiometric dating
Multiple Choice
1. Which best describes selective advantage?
a) a characteristic that reduces and organism’s chance of survival
b) the process by which populations change biologically over time as organisms pass their traits to their offspring.
c) the process by which individuals change biologically over time as organisms pass their traits to offspring.
d) a characteristic that improves and organism’s chance of survival
e) environmental conditions that select for certain characteristics of individuals and select against characteristics that are not adaptive.
2. Which best describes selective pressure?
a) a characteristic that reduces and organism’s chance of survival
b) the process by which populations change biologically over time as organisms pass their traits to offspring.
c) the process by which individuals change biologically over time as organisms pass their traits to offspring
d) a characteristic that improves an organism’s chance of survival
e) environmental conditions that select for certain characteristics of individuals and select against other characteristics that are not adaptive.
3. Which of the following is an example of mimicry?
a) a toxic chemical excreted by a stinging nettle plant
b) a syrphid fly that looks like a wasp
c) the migration of arctic geese
d) the venom of a rattlesnake
e) the courtship display of the red-winged blackbird
4. Which of the following is an example of natural selection?
a) the speed of a racing greyhound dog
b) the long fur of a Persian cat
c) the high oil content of some types of corn syrup
d) antibiotic-resistant bacteria
e) crops modified to be pest resistant
5. What is an end product of natural selection?
a) mutation
b) adaptation
c) monoculture (all the same)
d) environmental change
e) artificial selection
6. Based on the peppered moths example, what do you expect occurs in moths that rest on birch trees (light-coloured bark) in a polluted environmental that darkens tree trunks?
a) fewer light-coloured moths
b) fewer dark-coloured moths
c) the number of dark and light coloured moths stays the same
d) there will be an increase in the numbers of light-coloured and dark-coloured moths
e) the number of medium-coloured moths increases.
7. What is the source of NEW alleles in a species?
a) selective pressure
b) natural selection
c) mutation
d) adaptation
e) selective advantage
8. Which of the following sources of evidence of evolution is used to establish genetic relationships between organisms?
a) the fossil record
b) transitional fossils
c) biogeography
d) embryology
e) DNA
9. How do vestigial structures provide evidence for evolution?
a) they show direction of change
b) they show shared ancestry
c) they show genetic relationships
d) they show how new structures evolve
e) they show geographical relationships
10. Lamarck and Darwin proposed different explanations for how characteristics are passed from parent to offspring, but their theories had some similarities. Which of the following points are true?
a) The men disagreed that there was a line of descent in organisms.
b) Both believed that organisms adapt to their environments.
c) Both believed in catastrophism and the idea that if a body part were not used, it would simply disappear over time.
d) Both believed that characteristics were acquired in each generation.
e) Both believed that giraffes acquired their long necks by stretching to reach leaves high in trees.
11. Which of the following is the best example of the founder effect?
a) a population explosion of mosquitos occurs after a storm
b) a moth carries pollen from one plant population to another and cross-fertilization occurs
c) an earthquake forms a canyon that splits apart a population of toads, and this leads to speciation.
d) ten birds of the same species colonize a newly formed volcanic island, and this leads to a new species of bird.
e) ten male and sebem female seagulls of an original population of 500 survive a devastating tornado. This leads to changes in the population.
12. What aspect of a population is most critical for determining a species?
a) similar appearance
b) the ability to mate in captivity
c) the ability to eat the same food in the same ecological niche
d) similar behaviours
e) the ability to interbreed in nature
13. Which of the following is an example of a post-zygotic isolating mechanism?
a) species use different mating songs
b) hybrids of two species are sterile
c) species feed at different times of day
d) species have different breeding times
e) species pheromones are used by species to communicate
14. A human population has an unusually high percentage of individuals with a particular genetic disease. The most likely explanation for this is
a) gene flow
b) gradualism
c) natural selection
d) genetic drift
e) punctuated equilibrium
15. How does inbreeding affect genetic variation within a population?
a) variation decreases
b) variation increases
c) variation does not change
d) variation increases, then decreases
e) variation decreases, then increases
16. Allopatric speciation, but no sympatric speciation, requires which of the following?
a) reproductive isolation
b) geographical isolation
c) spontaneous differences in males and females
d) prior hybridization
e) rapid rate of mutation
17. What is gene flow?
a) reproductive success
b) the colonization of an area by a few individuals of a population that can lead to a new species
c) when individuals preferentially mate with individuals with a particular phenotype
d) the movement of alleles between populations
e) a severe reduction of a population that can lead to changes in populations
Short Answer Questions
1. Most eagles in a certain population have talons that are 20 cm long end very sharp. Some eagles, however, have talons that are slightly longer or slightly shorted than average. Explain why this variation within a population is important to the process of natural selection.
- need variation within a species in order for natural selection to occur
2. Explain the following observations from a scientific research study done on finches on the Galapagos Islands:
- during a drought in 1977, a large percentage of finches died of starvation on the Galapagos island Daphne Major.
- those that died must have preferred a seed that does not grow during a drought
- the 90 bird survivors in 1978 had a beak depth from about 9.4 mm to about 10.2 mm, which was greater than the beak depth of the finches that did not survive.
- “survival of the fittest” , the seed/food that was available must have been larger and only those with the larger beaks could eat, survive and therefore reproduce
3. During rainy years on the Galapagos Islands, small seed become abundant. Only bird with small beaks can eat small seeds effectively. If the rain persists for several years, what do you expect to occur due to natural selection?
- the number of birds with large beaks will decrease
4. Identify whether each of the following examples demonstrates artificial selection. Explain why or why not.
a) breeders select for speed in racing greyhound dogs - yes, choosing those with the fastest times to then breed
b) a person breeds long-furred Persian cats - yes, choosing to made only those with long hair
c) a farmer increases the variability in the fat content of different plant species - pressure exerted by the farmer
d) over time, plants develop chemical defences to keep herbivores away - no, this is natural not artificial
e) crops are selectively bred to be pest-resistant. – yes, choosing to breed this particular trait
5. You are hiking and your observant friend points out a green-colour leaf-eating insect that is resting on some plant leaves. What kind of adaptation is the insect exhibiting/- mimicry (form of structural adaptation)
6. Explain how scientists can use DNA to determine the evolutionary relationships between two organisms.
- all organisms are made of the same DNA nucleotides, we can compare codons to look for “spelling mistakes”, these mistakes can tell us how closely related two organisms are
7, What is the significance of a vestigial structure as evidence of evolution? - proves a common ancestry, a structure could have been useful in an ancestor but is no longer useful in an organism that descended from that ancestor
8. Lamark proposed an incorrect inheritance mechanism for how evolution can occur, but his ideas were instrumental for Darwin’s future work. Which aspect of Lamarck’s work did Darwin build upon? - both Darwin and Lamarck agreed that organisms adapt to their environment. However, Lamarck thought organisms could pass on acquired characteristics whereas Darwin believed in natural selection
9. RedIsland and Blue Island are hypothetical islands 500 km off the coast of South America. RedIsland is volcanic in origin and is only 5 million years old. Blue Island separated from South American more than 80 million years ago. Predict the origins of the animals on both islands, and explain how they may be similar to or different from animals of South America. – Blue island likely has much different species than Red island. Red island is newer but also has a much different habitat (volcanic) which would allow for different adaptations than on blue island. Both islands would have organisms that could be linked to those of South America.
10. In the Hawaiian Islands, there are thousands of species of plant and animals that are found nowhere else on Earth. How would you explain this phenomenon, and what is the name of this process? - = this is called speciation. The organisms have evolved significantly from those that originally inhabited the island. Hawaii is also far from any sort of mainland so it would be less prone to gene flow.
11. In order for species to remain distinct, they must remain reproductively isolated. Describe a pre-zygotic and post-zygotic isolating mechanism.
Prezygotic:
- behavioural
- habitat
- temporal
- mechanical
- gametic
Post-zygotic
- hybrid breakdown
- hybrid sterilization
- hybrid inviability
12. Explain how the following situations are isolating mechanisms that keep species separate.
a) species of fireflies use distinctive patterns of flashes - a pre-zygotic behavioural mechanism only those of the same species are attracted to the flashes
b) two species of grasses flower at different times of year, yet they live in the same environment – pre-zygotic temporal mechanism prevents them from pollinating due to timing
c) the crossing of two species produces a fertile hybrid offspring. The offspring of that fertile hybrid are weak and infertile.
- post-zygotic hybrid breakdown, even though the hybrid was fertile, the offspring are weak and infertile so it can not continue to become a new species
13. Why do geographical barriers, such as a river, prevent gene flow in some species but not in others? - only prevents gene flow in those that can not swim/cross rivers
14. How can a bird’s call be a barrier to speciation? What type of isolating mechanism is this? - this is a pre-zygotic behavioural isolating mechanism. The bird’s call will only be identified and will only attract those belonging to the same species
15. Male bighorn sheep battle for females by running at each other and butting their heads together. In some cases, the bighorn sheep can be hurt badly enough that they do not survive. Hypothesize how this behaviour may have evolved, even though it means that some individual males may not live as long as they could. – only males who are strong/healthy will survive and reproduce (only those that could win the fight), those that die in the fight were not as ‘fit’
16. Identify each of the following as one of the five mechanisms (gene flow, non-random mating, genetic drift, natural selection, mutations)
a) organisms become adapted to their environment– natural selection
b) the lack of genetic variability among cheetahs is contributed to this - genetic drift (bottleneck)
c) this often results in two adjacent populations having similar genetic variation due to immigration and emigration - gene flow
d) the movement of humans all over the world can influence this– gene flow
e) the original species that were blow over to the Galapagos Islands from South American are an example this. – genetic drift (founders effect)
17. Identify each of the following as pre-zygotic or post=zygotic isolating mechanisms
a) preferred times during the day for matingpre-zygotic
b) species specific mating dancespre-zygotic
c) habitat isolationpre-zygotic
d) unsuccessful offspring post-zygotic
e) adult birds with unique mating songs that they learn as young birdspre-zygotic
18. In Canada, individual grizzly bears and populations of grizzly bears are being isolated as human populations expand their use of land that was previously used by bears.
a) if the grizzly bear were to become extinct, what might some of the economic, political, and social implications be for Canada?
- answer vary
b) how might wildlife corridors help the situation? (Wildlife corridors are routes designed to help animals cross busy highways safely in Canada’s mountain parks) - allows gene flow between populations of grizzlies, allows movement for food/habitat
19. Today, individual giant pandas and populations of giant pandas are being isolated in many small reserves in China. What are the genetic implications of having so many small reserves rather than one large reserve?
- small reserves encourage inbreeding which leads to a decrease in diversity homozygous alleles disease/abnormalities