Podcast
Questions and Answers
What best explains the variation in male and female mallard ducks' coloration?
What best explains the variation in male and female mallard ducks' coloration?
- Stabilizing selection
- Directional selection
- Disruptive selection (correct)
- Divergent evolution
Which factor is necessary to maintain allelic frequencies in a Hardy-Weinberg population model?
Which factor is necessary to maintain allelic frequencies in a Hardy-Weinberg population model?
- Natural selection
- Frequent mutation
- Random mating (correct)
- Genetic drift
What term describes barriers to successful interbreeding between species within the same community?
What term describes barriers to successful interbreeding between species within the same community?
- Adaptive radiation
- Geographic isolation
- Reproductive isolation (correct)
- Sexual dependency
The similarity in the underlying anatomy of bat wings and human arms suggests they are examples of what?
The similarity in the underlying anatomy of bat wings and human arms suggests they are examples of what?
In a population at Hardy-Weinberg equilibrium, if the frequency of a recessive allele is 0.4, what percentage of the population is heterozygous for that allele?
In a population at Hardy-Weinberg equilibrium, if the frequency of a recessive allele is 0.4, what percentage of the population is heterozygous for that allele?
According to the Hardy-Weinberg equation, how is the dominant trait represented?
According to the Hardy-Weinberg equation, how is the dominant trait represented?
The differences in sparrow songs among sympatric species of sparrows illustrate which concept?
The differences in sparrow songs among sympatric species of sparrows illustrate which concept?
Which of the following is an evolutionary process not based on random factors?
Which of the following is an evolutionary process not based on random factors?
Which of the following is not a sexually selected trait?
Which of the following is not a sexually selected trait?
Which of the following is not a requirement for natural selection to occur?
Which of the following is not a requirement for natural selection to occur?
Why can Hardy-Weinberg equilibrium occur only in large populations?
Why can Hardy-Weinberg equilibrium occur only in large populations?
What are the frequencies of the p and q alleles in a population of frogs consisting of 9 percent with speckles (the recessive condition) and 91 percent without speckles?
What are the frequencies of the p and q alleles in a population of frogs consisting of 9 percent with speckles (the recessive condition) and 91 percent without speckles?
Frequency-dependent selection is one way in which multiple alleles are preserved in a population. What is a false statement about it?
Frequency-dependent selection is one way in which multiple alleles are preserved in a population. What is a false statement about it?
Which of the following provides no evidence for evolution?
Which of the following provides no evidence for evolution?
Why do we assume that oxygen was not present in the original atmosphere?
Why do we assume that oxygen was not present in the original atmosphere?
Flashcards
Natural selection
Natural selection
A process that occurs when individuals with certain traits are more likely to survive and reproduce in a particular environment. It's driven by the interaction between organisms and their environment.
Genetic drift
Genetic drift
A change in the allele frequencies of a population due to random chance events. It's more pronounced in smaller populations.
Sexually selected trait
Sexually selected trait
A trait that increases an individual's chances of attracting mates and successfully reproducing.
Adaptation
Adaptation
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Differential reproductive success
Differential reproductive success
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Hardy-Weinberg equilibrium
Hardy-Weinberg equilibrium
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Frequency-dependent selection
Frequency-dependent selection
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Vestigial characters
Vestigial characters
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Reproductive Isolation
Reproductive Isolation
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Homologous Structures
Homologous Structures
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Heterozygous Frequency
Heterozygous Frequency
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Behavioral Isolation
Behavioral Isolation
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Dominant Trait Frequency
Dominant Trait Frequency
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Study Notes
Evolutionary Processes & Principles
- Non-random evolutionary processes: Natural selection, gene flow.
- Random evolutionary processes: Mutation, genetic drift, bottlenecks.
- Sexual selection traits: Male baboon canine teeth, peacock tail feathers, male/female size dimorphism in many species.
- Adaptations: Can be shaped by genetic drift, affect fitness if altered, can be deleterious, do not guarantee mating success.
- Requirements for natural selection: Variation between individuals, heritable trait, differences in reproductive success. Sexual reproduction is not a requirement for natural selection but is for reproduction of the trait itself.
Hardy-Weinberg Equilibrium
- Large populations & equilibrium: Genetic drift is stronger in small populations. Random mating is more likely in large populations.
- Conditions for Hardy-Weinberg equilibrium:
- No mutations
- Random mating
- No gene flow
- No genetic drift
- No natural selection
- Frequency of alleles (p and q) in equilibrium: Ex. 9% speckles (recessive) , 91% no speckles (dominant) determines p & q values.
Other Evolutionary Concepts
- Frequency-dependent selection: Preserves multiple alleles. Crucial during speciation
- Evidence for evolution: Vestigial characters, Darwin's finches, homologous characters, embryology.
- Absence of oxygen in early atmosphere: Inorganic molecules could form without oxygen.
- Random evolutionary processes example: earthquake separating a population, a mutation that changes characteristics, a new environment that causes a population’s home range to shift.
Selection Types
- Disruptive selection: Not the one highlighted in the selected text.
- Directional selection: Not the one highlighted in the selected text.
- Stabilizing selection: Not the one highlighted in the selected text.
Maintaining Allelic Frequencies
- Hardy-Weinberg equilibrium & alleles: Requires random mating; Natural selection and genetic drift disrupt equilibrium
- Reproductive isolation: Prevents interbreeding between species in the same community, a key concept in speciation.
Evolutionary Structures
- Homologous structures: Bat wings and human arms, similar underlying anatomy despite different functions, evidence of shared ancestry.
- Analogous structures: Not in the text.
Hardy-Weinberg Calculations
- Heterozygous individuals: Using the Hardy-Weinberg equation, the percentage of the population that is heterozygous for a certain allele can be determined.
- Allele Frequency Calculation Using the frequencies, p and q, you can find the frequency of heterozygous genotypes in populations.
- Hardy-Weinberg equation Variables:
- p represents the frequency of the dominant allele.
- q represents the frequency of the recessive allele.
- p2 represents the frequency of homozygous dominant individuals.
- q2 represents the frequency of homozygous recessive individuals.
- 2pq represents the frequency of heterozygous individuals.
- p + q = 1
Isolation Mechanisms
- Behavioral isolation: Examples include differences in courtship rituals between species, like sparrow songs.
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Description
Explore the essential concepts of evolutionary processes and the Hardy-Weinberg equilibrium. This quiz covers both non-random and random evolutionary processes, adaptations, and the key requirements for natural selection. Test your understanding of genetic principles and the conditions that maintain genetic equilibrium in populations.
