Podcast
Questions and Answers
What is macroevolution concerned with?
What is macroevolution concerned with?
Which statement best defines the term 'proximate causes'?
Which statement best defines the term 'proximate causes'?
Which of the following contributed to the theory of evolution by emphasizing the inheritance of acquired traits?
Which of the following contributed to the theory of evolution by emphasizing the inheritance of acquired traits?
How did Aristotle contribute to the early understanding of evolution?
How did Aristotle contribute to the early understanding of evolution?
Signup and view all the answers
What key idea was put forth by Darwin during his research, even though he did not develop the theory of adaptation at that time?
What key idea was put forth by Darwin during his research, even though he did not develop the theory of adaptation at that time?
Signup and view all the answers
What is the significance of variability within a population in the context of natural selection?
What is the significance of variability within a population in the context of natural selection?
Signup and view all the answers
Which of the following best defines relative fitness?
Which of the following best defines relative fitness?
Signup and view all the answers
What role do mutations play in genetic diversity?
What role do mutations play in genetic diversity?
Signup and view all the answers
How do the concepts of genotype and phenotype relate in the context of natural selection?
How do the concepts of genotype and phenotype relate in the context of natural selection?
Signup and view all the answers
Which statement correctly describes Darwin's hypothesis about species divergence?
Which statement correctly describes Darwin's hypothesis about species divergence?
Signup and view all the answers
What effect does genetic drift have on a population's genetic variation?
What effect does genetic drift have on a population's genetic variation?
Signup and view all the answers
Which of the following accurately defines sexual selection?
Which of the following accurately defines sexual selection?
Signup and view all the answers
Why are most new mutations expected to go extinct in a population?
Why are most new mutations expected to go extinct in a population?
Signup and view all the answers
What impact does a mutation that alters the binding between MC1R and its activators have on coat color?
What impact does a mutation that alters the binding between MC1R and its activators have on coat color?
Signup and view all the answers
What is one significant disadvantage of sexual reproduction compared to asexual reproduction?
What is one significant disadvantage of sexual reproduction compared to asexual reproduction?
Signup and view all the answers
How does recombination in sexual populations benefit beneficial mutations?
How does recombination in sexual populations benefit beneficial mutations?
Signup and view all the answers
What characterizes heterozygote advantage in overdominance selection?
What characterizes heterozygote advantage in overdominance selection?
Signup and view all the answers
How does apostatic selection affect genetic diversity in a population?
How does apostatic selection affect genetic diversity in a population?
Signup and view all the answers
What statement about genetic drift is true?
What statement about genetic drift is true?
Signup and view all the answers
What is the idea behind frequency-dependent selection?
What is the idea behind frequency-dependent selection?
Signup and view all the answers
Which model suggests that male traits may not provide direct benefits but are preferred because of an intrinsic female preference?
Which model suggests that male traits may not provide direct benefits but are preferred because of an intrinsic female preference?
Signup and view all the answers
What mechanism could maintain polymorphism in a population according to negative frequency dependence selection?
What mechanism could maintain polymorphism in a population according to negative frequency dependence selection?
Signup and view all the answers
In the context of the good genes hypothesis, what do bright male ornaments signify to female mates?
In the context of the good genes hypothesis, what do bright male ornaments signify to female mates?
Signup and view all the answers
What is the primary advantage of sexual reproduction as suggested by the Red Queen hypothesis?
What is the primary advantage of sexual reproduction as suggested by the Red Queen hypothesis?
Signup and view all the answers
What is a key distinction between adaptation and speciation as discussed in the content?
What is a key distinction between adaptation and speciation as discussed in the content?
Signup and view all the answers
Which of the following best describes anisogamy?
Which of the following best describes anisogamy?
Signup and view all the answers
What role does male-male competition play in the context of sexual selection?
What role does male-male competition play in the context of sexual selection?
Signup and view all the answers
How does sexual reproduction help in the clearance of deleterious mutations?
How does sexual reproduction help in the clearance of deleterious mutations?
Signup and view all the answers
What scenario does disruptive selection in anisogamy lead to?
What scenario does disruptive selection in anisogamy lead to?
Signup and view all the answers
What distinction does sexual conflict highlight between males and females?
What distinction does sexual conflict highlight between males and females?
Signup and view all the answers
What is the primary factor that pleiotropy influences in the evolution of traits?
What is the primary factor that pleiotropy influences in the evolution of traits?
Signup and view all the answers
Which type of isolation occurs when mating songs between species are incompatible?
Which type of isolation occurs when mating songs between species are incompatible?
Signup and view all the answers
Which mechanism requires groups within a population to utilize different resources in order to drive reproductive isolation?
Which mechanism requires groups within a population to utilize different resources in order to drive reproductive isolation?
Signup and view all the answers
What is considered a key feature distinguishing peripatric speciation from allopatric speciation?
What is considered a key feature distinguishing peripatric speciation from allopatric speciation?
Signup and view all the answers
Which statement accurately describes the process of adaptive radiation?
Which statement accurately describes the process of adaptive radiation?
Signup and view all the answers
What role does negative frequency-dependent selection play in host-pathogen interactions?
What role does negative frequency-dependent selection play in host-pathogen interactions?
Signup and view all the answers
Which of the following statements accurately describes positive frequency-dependent selection?
Which of the following statements accurately describes positive frequency-dependent selection?
Signup and view all the answers
How does Fisher's theorem relate to sex ratios in populations?
How does Fisher's theorem relate to sex ratios in populations?
Signup and view all the answers
What is the primary characteristic of Batesian mimicry?
What is the primary characteristic of Batesian mimicry?
Signup and view all the answers
In what context is density dependence most relevant?
In what context is density dependence most relevant?
Signup and view all the answers
Study Notes
Phylogenetic Trees
- Phylogenetic trees illustrate common ancestry, aiding treatment development.
Evolution of Drug Resistance
- Bacterial mutations lead to antibiotic resistance.
Evolution
- Evolution explains living things' diversity using DNA sequences, proteins, biochemical pathways, embryological development, anatomy, behavior, life histories, species interactions, and fossils.
Time Scales of Evolutionary Changes
- Microevolution occurs at the population level over short time scales.
- Macroevolution occurs at the species level over long time scales.
Proximate vs. Ultimate Causes
- Proximate causes are immediate mechanisms underlying a behavior.
- Ultimate causes are past conditions leading to encoded DNA information.
What is Evolution?
- Evolution is descent with modification (Darwin).
- Biological evolution is inherited change in organism groups across generations.
Early Evolutionary Biologists
- Early farmers practiced artificial selection, choosing cows for higher milk production.
- Aristotle was a great naturalist and zoologist.
- Classified species based on observation.
- Used comparative anatomy.
- Noted correlations in anatomy.
- Believed species were fixed, permanent, unalterable, and eternal.
- Al-Jahiz (781-868/9 AD) understood survival of the fittest and interconnected organisms, including food chains.
- Linnaeus developed binomial nomenclature and classified species.
- Lamarck proposed a theory of species change.
- Species evolved gradually toward increased complexity along a single lineage.
- Changes occurred due to environmental pressures.
Darwin's Voyage
- Darwin didn't develop his adaptation theory during his voyage.
- Tortoise and finch variations were pointed out by the vice governor, not noticed by Darwin initially.
- Observed organism appearances, not mechanisms.
- Two tortoise adaptations existed in different habitats/diets (southern/dome shell). Correlated, but not proven causal relationships.
Darwin vs. Lamarck
- Darwin proposed that species diverge from a common ancestor with natural selection as the driving force.
Darwin and Wallace
- One main obstacle to Darwin's theory was the model of inheritance, where parental fluids blended in offspring. Mendel's views, opposed to blending idea of inheritance, proposed traits transmitted directly from parents to offspring.
Natural Selection
- Darwin's Logic:
- Fact 1: Species have high fertility, leading to exponential population growth.
- Fact 2: Populations remain stable, with minor fluctuations.
- Fact 3: Natural resources are limited.
- Inference 1: A struggle for existence occurs, with only some offspring surviving.
- Inference 2: Survival is not random; inherits traits from survivors.
- Fact 4: Variation in individuals in a population.
- Fact 5: Much of this variation is heritable.
- Inference 3: Natural selection leads to gradual population change and evolution.
Evidence for Evolution
- All life descended from a few common ancestors.
- Species sharing a common ancestor resemble each other.
- Species evolve from pre-existing species, not creation or spontaneous generation.
Components of Natural Selection
- Inheritance: Offspring inherit traits.
- Differential reproductive success: Traits that help individuals survive and reproduce are more frequent.
- Variation: Individuals vary.
- Genotype: Genetic constitution of an organism.
- Phenotype: Physical manifestation of an organism (or part of it) influenced by genotypes.
Genetic Diversity
- Independent assortment of chromosomes during meiosis.
- Crossing over: Exchange of chromosome parts during meiosis.
- Mutation: Changes in DNA or chromosomes, occurring randomly.
Variation Due to Mutation
- Mutations introduce new variation.
- Occur randomly, independently of selection needs.
- Natural selection acts on existing genetic variation.
Natural Selection and Genotype/Phenotype
- Natural selection acts on phenotypes, not genotypes.
- Understand interplay between genotypes, phenotypes, and fitness.
Levels of Selection
- Selection acts on genes, cells, individuals, populations, etc. (e.g., selfish genes, transposons).
Fitness
- Fitness is the ability to survive and reproduce.
- Viability: Probability of survival to reproductive age.
- Fertility: Average number of offspring that survive.
- Absolute fitness: Average offspring number of a genotype.
- Relative fitness: Average offspring number relative to other genotypes in a population.
Coat Colors (Oldfield Mouse)
- Coat colour is a phenotype influenced by interactions of MC1R, Alpha melanocyte stimulating hormone, and Agouti signal protein.
- Mutations change receptor/activator binding, impacting color polymorphism.
- Coat color influences predator vulnerability and fitness.
Types of Selection
- Frequency-Independent Selection: Directional selection (recessive, codominant, dominant alleles).
- Overdominance: Heterozygote advantage, balancing selection. Underdominance: Heterozygote disadvantage.
- Frequency-Dependent Selection: Positive (trait fitness rises with frequency) and negative (trait fitness rises with decreasing frequency) selection.
Sexual Selection
- Sexual selection improves mating success at the cost of other success factors.
- Males and females differ in interests, leading to sexual conflict.
- Darwin proposed intrasexual (male-male competition) and intersexual (female choice) selection mechanisms.
Sex and Asexual Reproduction
- Advantages of sex include recombination, generating novel genotypes.
- Advantages of asexuality include rapid population increase.
- Disadvantages of sex include reduced relatedness and risks of disease transmission.
The Red Queen Hypothesis
- Sex is advantageous due to faster adaptation – "arms race" against parasites.
Speciation
- Biological species concept: Species have limited or no genetic exchange.
- Speciation is the formation of new species, separated by reproductive isolation. Prezygotic and postzygotic barriers can cause reproductive isolation.
- Allopatric speciation: Physical barriers isolate populations.
- Peripatric speciation: Small population moves to new territory.
- Parapatric speciation: Populations spread into adjacent, but not connected, territories.
- Sympatric speciation: Reproductive isolation without a physical barrier.
- Adaptive radiation: Rapid diversification into ecological niches.
Genome Evolution
- Genome changes include single base pair changes, insertions, deletions, chromosome rearrangements, gene duplications, and horizontal gene transfer.
- Single nucleotide polymorphisms (SNPs) can be synonymous (no change in protein sequence) or non-synonymous (change in protein sequence).
- Gene duplication and loss are contributors to evolution.
Domestication
- Domestication is the process of incorporating wild species into human society for control and breeding.
- This involves a mutualistic co-evolution between humans and domesticates.
- Plant and animal domestication were critical developments in human history.
- Homelands of agriculture were few, with early farmers achieving demographic advantages.
- Domestication can result in changes like smaller brains, reduced senses, and different coat colors.
Population Differentiation and Phylogeography
- Population differentiation: Variation exists between spatially distinct populations.
- Gene flow: Movement of individuals between populations affects gene frequencies.
- FST: Measure of population subdivision (0=no subdivision, 1=all populations different).
- Metapopulation structure: Series of subdivided populations connected by migration.
- Effective population size (Ne): Number of individuals contributing to the next generation (influences diversity).
- Selective sweeps: Linked genes change frequency with selection targets.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on macroevolution, natural selection, and the contributions of early scientists like Darwin and Aristotle. This quiz covers key concepts such as genetic diversity, mutations, and relative fitness. Challenge yourself and explore the complexities of evolutionary theory.
