Bio exam 1
Consider three populations of brown pelicans. Which population is most likely to experience changes in allele frequencies due to random chance? -10 birds, 1 with white phenotype and the others brown -100 birds, 20 white and 80 brown -50 birds, 25 white and 25 brown
10 birds, 1 with white phenotype and the others brown
Which of the following individuals would be considered the most evolutionarily 'fit'? -A mother who has three children and lives to 103. -A rock star who fathers three children, each with a different mother, and lives until 62. -A man who fathers seven children and dies at age 47. -A banker who is worth three billion dollars, has one child, and lives to 80.
A man who fathers seven children and dies at age 47.
What is a homology?
A similarity that is found in two or more species because they descend from a common ancestor.
When did life first appear on Earth?
About 3.8 billion years ago
How old is Earth?
About 4.6 billion years old
What mechanisms might result in reproductive isolation? -Geographic separation -Different mating times -Anatomical incompatibility -Different behaviors -All of the above
All of the above
The process of natural selection leads to... (check all that apply) -a higher frequency of traits that enhance reproductive success -adaptations -a higher frequency of traits that increase survival -evolution
All options
The white-tailed antelope squirrel (Ammospermophilus leucurus) and Harris's antelope squirrel (Ammospermophilus harrisii) are two closely-related species (last shared a common ancestor 3.6 million years ago) that live on either side of the Grand Canyon. What kind of speciation is likely at play for these rodents? -Allopatric speciation -Sympatric speciation -Adaptive radiation -Natural speciation
Allopatric speciation
What is an adaption?
An inherited characteristic of an organism to enhance survival and reproduction in specific environments
Biogeography
An island splits up and new species are created
An ancestral species of butterfly contains a gene for ultraviolet vision. A gene descended from the original UV gene is possessed by two modern species of butterfly, except that in one species, the gene is now responsible for infrared vision. The two modern genes -are the result of convergent evolution -cannot be located on the same chromosome -have the same function -are homologous
Are homologous
Speciation events... -Require a geographic separation between two populations -Can occur very rapidly -Are most likely when there is a lot of gene flow between two populations -All of the above
Can occur very rapidly
Whose theory centered on catastrophes causing extinction of species? -Aristotle -Cuvier -Hutton -Lamarck -Lyell
Cuvier
Did this example of natural selection (when the population of rats in our population of rats of mixed colors moves into a dark-colored habitat) increase or decrease the genetic diversity in our population? -Increase -Decrease -Neither
Decrease
Indicate what type of selection is occurring in the example here: During a warm year, it was discovered that finches with large beaks and those with small beaks were more successful than the ones with medium-sized beaks due to the food sources available. -directional selection -disruptive selection -stabilizing selection -balancing selection
Disruptive selection
Which is the best theory of how eukaryotic cells evolved from prokaryotic cells? -Eukaryotic cells evolved from prokaryotic cells that acquired intracellular prokaryotic symbionts. -Organelles of eukaryotic cells mutated from the RNA of prokaryotic cells. -Prokaryotic cells formed multicellular organisms which eventually fused to become eukaryotic. -Intracellular viruses of prokaryotes evolved to become membrane bound organelles of eukaryotic cells.
Eukaryotic cells evolved from prokaryotic cells that acquired intracellular prokaryotic symbionts.
Why was the study of islands instrumental in recognizing the mechanism of natural selection? -Evolution happens faster on islands. -On the mainland, there are too many species to observe. -Evolution is more obvious on islands, because species on islands are often separated from ancestors on the mainland or nearby islands and evolve independently -Because of the small area of islands, scientists can study the entire surface. Answer
Evolution is more obvious on islands, because species on islands are often separated from ancestors on the mainland or nearby islands and evolve independently
What is evolution?
Evolution is occurring in a population when there is a change in heritable characteristics from one generation to the next. Darwin used to summarize the process by which species accumulate differences from their ancestors as they adapt to different environments over time.
Evolution is synonymous with natural selection True False
False
All of the following statements correctly describe some part of natural selection, EXCEPT: -Variation in a heritable trait is required for natural selection to take place -Fitness of an organism is directly equivalent to its survival ability -Traits that enhance survival and reproduction become more prevalent in future generations -Typically, more offspring are produced than can survive
Fitness of an organism is directly equivalent to its survival ability
A male elk mates with a female cow but no offspring is produced. What could this be an example of? -Geographic isolation -Mechanical isolation -Behavioral isolation -Hybrid breakdown -Gametic isolation
Gametic isolation
Who would most likely have said the following quote? "A cheetah moves into a gazelle habitat. Knowing that they will need to be faster to survive, a few of the gazelles struggle to run faster, becoming better adapted to their new environment. The offspring of these individuals are faster and better equipped to survive" -Charles Lyell -Alfred Wallace -Thomas Malthus -Jean-Baptiste Lamarck -Charles Darwin
Jean-Baptiste Lamarck
This passage is best matched with what evolutionary theorist? A fast predator moves into an Emu habitat. Knowing that they will need to be faster to survive, a few of the Emu struggle to run faster, becoming better adapted to their new environment. The offspring of these individuals are faster and better equipped to survive. -Aristotle -Cuvier -Darwin -Lyell -Lamarck
Lamarck
House sparrows were introduced to North America in 1852. Since that time the sparrows have evolved different characteristics in different locations. Sparrow populations in the north are larger-bodied than sparrow populations in the south. Larger-bodied birds can often survive lower temperatures than smaller-bodied birds can. Changes in house sparrows in the northern and southern population is: -Microevolution caused by natural selection: in the northern population, there is stronger selection for larger bodies due to the colder climate than in the southern population -Macroevolution caused by natural selection, since the northern and southern population do not interbreed -Microevolution not caused by natural selection, and most likely the result of random changes in allele and genotype frequencies -Macroevolution not caused by natural selection, and most likely the result of hybridization with other species
Microevolution caused by natural selection: in the northern population, there is stronger selection for larger bodies due to the colder climate than in the southern population
A strange thing happens to a population of brown rats. One of the new baby rats turns out to be white. This is the first time any rat in this population has ever been white. Which mechanism of evolution produced this new rat color? -Natural selection -Genetic drift -Mutation -Gene flow -Non-random mating
Mutation
Relationship between evolution and natural selection?
Natural selection is just one mechanism of evolution.
Your study partner tells you the following statement. Is it correct? "Since giraffes stretch their necks to obtain food, their own necks get longer during their lives and their offspring therefore inherit longer necks"
No. Changes in characteristics acquired during an individual's lifetime are due to changes in gene expression and are not passed on to offspring
How is natural selection different than artificial selection? -Unlike in artificial selection, the genes for the trait must be present in the population before natural selection can occur -In only artificial selection can traits influenced by multiple genes can be selected -Only in artificial selection, there is an end goal -All of the above
Only in artificial selection, there is an end goal
Which represents the correct order in which key steps for life would have appeared on Earth? -Protocells->organic molecules->organic polymers->self-replicating genetic material and metabolism -Organic molecules->organic polymers->protocells->self-replicating genetic material and complex metabolism -Organic molecules->organic polymers->self-replicating genetic material and complex metabolism->protocells
Organic molecules->organic polymers->protocells->self-replicating genetic material and complex metabolism
Two species of frog belonging to the same genus occasionally mate creating a zygote, but the offspring fail to develop and hatch. What is the mechanism keeping these two species separate? -Prezygotic barrier, gametic isolation -Postzygotic barrier, hybrid inviability -Prezygotic barrier, mechanical isolation -Postzygotic barrier, hybrid sterility -Prezygotic barrier, temporal isolation
Postzygotic barrier, hybrid inviability
Which is thought to be the first macromolecule found in protocells? -DNA -RNA -Proteins -Carbohydrates
RNA
What is a homoplasy
Similarity due to convergent evolution
The theory of natural selection contends that -Species and populations evolve, but individuals do not. -Species can evolve, but populations and individuals do not. -Populations can evolve, but species and individuals do not. -Populations and individuals can evolve, but species do not. -Species and individuals can evolve, but populations do no.
Species and populations evolve, but individuals do not.
What is true regarding species and populations? -Species usually contain multiple populations -Species are groups of similar sexually reproducing individuals, and populations are groups of similar asexual individuals -In order to be considered the same species, individuals must interact, but this is not required to be in the same population -Individuals from two populations cannot interbreed, but individuals from two species can
Species usually contain multiple populations
Two populations of wildflower live on the same grassland. One flowers in spring, and the other flowers in summer. What is the mechanism of reproductive isolation? -Temporal isolation -Mechanical isolation -Behavioral isolation -Gametic isolation
Temporal isolation
Antibiotic resistance in bacteria is often cited as a case of directional selection. What is the process by which antibiotic resistant strains of bacteria are produced? -The antibiotic causes mutations in the bacteria, making them more resistant. -Bacteria become resistant to the antibiotic after repeated exposures by building up defenses. -Bacteria are given resistance genes via biotechnology. -The bacteria that were the most resistant to the antibiotic were the ones that survived exposure.
The bacteria that were the most resistant to the antibiotic were the ones that survived exposure.
Imagine that our rat population which now has dark and light-colored individuals and moves to a new habitat that is in a rocky environment that is also a dark color. What might happen to the two rat color alleles over time? -The frequency of the light colored allele increases because those light individuals reproduce better than dark individuals -The frequency of the dark colored allele increases because light-colored allele mutated into a dark one to match the surroundings -The frequency of the dark colored allele increases because light-colored individuals have a greater mortality rate than dark-colored individuals -The frequency of light and dark color alleles remains the same because coloration would not influence reproductive success
The frequency of the dark colored alllele increases because light-colored individuals have a greater mortality rate than dark-colored individuals
Cheetahs (Acinonyx jubatus) are extremely fast predators, running at speeds of up to 120km/h for shorts bursts. This speed greatly increases their success in catching prey. Several adaptations allow cheetahs such fast speeds, including a thin and light body, as well as tight binding of the tibia and the fibula restrict rotation about the lower leg, thus stabilizing the animal throughout the sprint. Given that high running speed enhances predatory success rate, why are those adaptations not found in all predatory cats? -Species that don't have those traits have not had long enough to evolve, but given enough time they will also gain these beneficial adaptations -Most species don't have as much training as cheetahs do, therefore individuals do not develop all the necessary traits to catch fast-moving prey -The genetic material for tight binding of the tibia and fibula may not have appeared in other lineages of predatory cats -All of the above
The genetic material for tight binding of the tibia and fibula may not have appeared in other lineages of predatory cats
What is microevolution
The process of evolution on a small scale related to changes in the allele and genotype frequency in a population over time.
Which of these is a statement that Darwin would have rejected? -Environmental change can play a role in evolution -The smallest entity that can evolve is an individual organism -Inherited variation in a population is necessary for natural selection to operate -Natural populations exhibit variation in nature -The characteristics that promote survival & reproduction in a population may change over time
The smallest entity that can evolve is an individual organism
What was Darwin's/Wallace's contribution to evolutionary theory? -They were the first to postulate that individuals donate traits to their offspring. -They were the first to recognize that species change over time. -They were the first to explain how species can change without individuals changing. -They were the first to describe how individuals adapt to their environment.
They were the first to explain how species can change without individuals changing.
A population of bats has one gene for ear length with two alleles: long ears (L) and short ears (l). The allele frequency for the L allele is 0.5, and frequency for each of the three genotypes is 0.33. This population is evolving. True False
True
Convergent evolution can present a challenge when classifying organisms. True False
True
For a given gene, there is usually variation in nucleotide sequences between individuals in a population. True of False
True
What is convergent evolution?
Two species from two different lineages show similar characteristics because they occupy similar environments (countershading on penguins and killer whales)
What is stabilizing selection?
acts against both extreme phenotypes and favors intermediate variants. This mode of selection reduces variation and tends to maintain the status quo for a particular phenotypic character. For example, the birth weights of most human babies lie in the range of 3-4 kg (6.6-8.8 pounds). Babies who are much smaller suffer considerably higher rates of mortality; babies who are much larger show a slight increase in mortality.
All of the following statements correctly describe some part of natural selection, EXCEPT: a. Variation in a heritable trait is required for natural selection to take place b. Fitness of an organism is directly equivalent to its survival ability c. Traits that enhance survival and reproduction become more prevalent in future generations d. Typically, more offspring are produced than can survive
b
The textbook discusses how the conversion of quality habitat into farmland has greatly depleted the greater prairie chicken populations and, as a result, their genetic diversity. Which of the following occurred in this example? -founder effect -mutation -natural selection -gene flow -bottleneck effect
bottleneck effect
Why hasn't natural selection led to gills in dolphins and manatees? -Because their gills have atrophied over time due to water pressure they are exposed to as they dive -Because there is no genetic variation in wild dolphin and manatee populations -Because dolphins and manatees are closely related to land mammals and their ancestors had lungs, not gills
c
Two species with a recent common ancestor should have... (check all that apply) a. no morphological similarities b. few biochemical similarities c. several homologous structures d. similar embryonic development
c & d
What is directional selection
common when a population's environment changes or when members of a population migrate to a new (and different) habitat. For instance, an increase in the relative abundance of large seeds over small seeds led to an increase in beak depth in a population of Galápagos finches
Due to less snowfall in an area, white mice are eaten by predators more than dark mice. This should lead to... -directional selection -disruptive selection -stabilizing selection -balancing selection
directional selection
Which of the following is likely to evolve over time through natural selection? a. A female tick that competes with others for access to food b. A genetically-diverse population of ticks in an environment that has limited resources c. A group of coral polyps (building blocks of a coral colony) which all arose through mitosis of one coral larva d. A population of birds which vary in their ability to camouflage in their environment e. Two of the above
e (b and d)
Sea stars are broadcast spawners: They release their gametes into the water without courtship. Which of these reproductive isolation mechanisms is most likely affecting sea stars? -behavioral isolation or mechanical isolation -gametic isolation or temporal isolation -habitat isolation
gametic isolation or temporal isolation
A few individuals from a neighboring set of burrows immigrates to a population of naked mole rats. This is likely to _______________ the genetic diversity of the receiving population? -increase -decrease
increase
A few individuals from a neighboring set of burrows immigrates to a population of naked mole rats. This is likely to ________________ the genetic similarity of the two populations? -increase -decrease
increase
A population of spiders is exposed to a short burst of radiation, which results in some individuals developing mutations like enlarged mouth appendages and enlarged eyes. The radiation also affects reproductive organs, and all mutants are sterile. Is this radiation likely to lead to evolutionary change in this population of spiders? -yes -no
no
Natural selection... -can lead to microevolution but not macroevolution -occurs to an individual during its lifetime -occurs in populations over generations -is the only mechanism of evolution
occurs in populations over generations
What is disruptive selection?
occurs when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes. One example is a population of black-bellied seedcracker finches in Cameroon whose members display two distinctly different beak sizes. Small-billed birds feed mainly on soft seeds, whereas large-billed birds specialize in cracking hard seeds. It appears that birds with intermediate-sized bills are relatively inefficient at cracking both types of seeds and thus have lower relative fitness.
Darwin/Wallace's theory of natural selection was novel in that it was the first to... -suggest that species change over time -acknowledge that species can go extinct -suggest that large changes in species can occur gradually over long periods of time -suggest that species change over time due to variation in rates of survival and reproduction between individuals
suggest that species change over time due to variation in rates of survival and reproduction between individuals
The Hardy-Weinberg equation will NOT accurately predict offspring genotype frequencies in a population IF... -you attempt to determine the genotype frequencies for the heterozygotes. -the individuals in the population prefer particular types of mates. -no individuals are eaten by predators. -you don't put a ring on it.
the individuals in the population prefer particular types of mates.
Which of the following is necessary for natural selection to occur? -variation in traits between individuals of different species. -variation in traits that are due to differences in gene expression between individuals in a population. -variation in heritable traits between individuals in a population. -a change in the environment.
variation in heritable traits between individuals in a population
