Evolution of Sex: PCB4674

Questions and Answers

What is one possible benefit of sex in evolutionary terms?

Increased genetic diversity through recombination (correct)

Reduced genetic mutations during reproduction

Complete elimination of genetic diseases

Guaranteed offspring survival

Which mechanism is primarily responsible for maintaining genetic diversity around a selected locus?

Drift stabilizing small populations

Gene flow minimizing allele frequency differences

Natural selection favoring heterozygosity (correct)

Linkage disequilibrium limiting diversity

What does Muller’s ratchet describe in evolutionary biology?

The complete fixation of advantageous alleles in a population

The gradual increase of genetic diversity in large populations

The rapid adaptation of sexual species to changing environments

Irreversible accumulation of deleterious mutations in asexual populations (correct)

How does the Red Queen effect relate to sexual reproduction?

It emphasizes the need for constant adaptation to co-evolving threats Signup and view all the answers

Which of the following is an example of a reproductive isolating mechanism?

Variability in mating calls among species Signup and view all the answers

Which reproductive strategy involves the formation of new species without geographical separation?

Sympatric speciation Signup and view all the answers

What is the primary function of sexual reproduction according to evolutionary processes?

To facilitate genetic variation and adapt to environmental changes Signup and view all the answers

What is an expected outcome of linkage disequilibrium in a population?

Reduction in genetic variation near selected sites Signup and view all the answers

What is the role of non-Bt refuges in managing pest resistance to Bt crops?

They encourage the mating of susceptible pests. Signup and view all the answers

How does the breeding of resistant pests with susceptible ones affect the resistance alleles?

It allows beneficial recessive alleles to remain at low frequency. Signup and view all the answers

What is a direct effect of human-altered selection pressure on wild populations?

Altered behavior and morphology of animals. Signup and view all the answers

Why is knowledge of evolutionary biology essential in pest management?

It allows for the prediction of outcomes from selective pressures. Signup and view all the answers

How do Bt crops exert selective pressure on pest populations?

By favoring the reproduction of resistant individuals. Signup and view all the answers

What is a consequence of breeding resistant individuals exclusively among themselves?

It decreases the effectiveness of Bt crops over time. Signup and view all the answers

What legal requirement has emerged to mitigate the impact of Bt crops on pest populations?

Mandatory planting of non-Bt refuges. Signup and view all the answers

Which of the following scenarios best represents sympatric speciation?

A species develops new mating behaviors that arise from local resource use. Signup and view all the answers

What does game theory examine in the context of natural selection?

The interactions of different strategies and their outcomes Signup and view all the answers

What characterizes an evolutionary stable strategy (ESS)?

It cannot be displaced by any alternative strategy in the population Signup and view all the answers

How is frequency-dependent selection different from other forms of natural selection?

It favors strategies based on their frequency in the population Signup and view all the answers

Which statement accurately describes the relationship between brain anatomy and body part function?

More complex functions correspond to larger brain areas devoted to those functions Signup and view all the answers

In which scenarios would natural selection prefer certain mating behaviors, based on the content provided?

When fitness outcomes of behaviors vary based on circumstances Signup and view all the answers

Which factor is least likely to be a result of facial tissues and forelimb development in burrowing animals?

Larger body size relative to other species Signup and view all the answers

What can be inferred about the mating strategies of side blotched lizards?

The effectiveness of their strategies can change based on population dynamics Signup and view all the answers

Why is touch and manipulation emphasized in human brain anatomy?

They are necessary for complex tasks and tool use Signup and view all the answers

Study Notes

Polymorphism and Genetic Diversity

Analyzing levels of polymorphism at synonymous and non-synonymous sites helps understand genetic variation.
Reduced genetic diversity around selected loci often indicates linkage disequilibrium.

Mechanisms of Reproduction

Mechanisms of reproduction exhibit extensive diversity across species.
Examples include:
- Populus tremuloides - Trembling aspen known for its clonal reproduction.
- Acropora palmata - Elkhorn coral, which reproduces through external fertilization.
- Cnemidophorus neomexicanus - New Mexico whiptail lizard, showcases complex asexual reproduction.
- Ariolimax columbianus - Banana slug, noted for unique reproductive strategies.

Sex and Genetic Recombination

Sexual reproduction serves dual purposes: reproduction and genetic recombination.
Recombination affects evolutionary dynamics by generating genetic diversity.

Evolutionary Dynamics and Costs of Sex

Two-fold cost of sex reflects the reproductive disadvantage of sexual reproduction compared to asexual reproduction.
Müller’s ratchet describes the accumulation of deleterious mutations in asexual populations over time.

Red Queen Effect

The Red Queen effect highlights the benefits of sexual reproduction as a mechanism to keep pace with evolving pathogens and parasites.

Pest Management via Bt Crops

Breeding resistant pests in Bt fields can lead to the persistence of a recessive allele, which is maintained at low frequencies due to fitness costs.
Non-Bt refuge areas near Bt crops ensure that susceptible pests survive, promoting genetic diversity and delaying resistance.

Human Impact on Natural Selection

Human activities, such as hunting and fishing, have profound effects on animal behavior, morphology, and life history traits.
Knowledge of evolutionary biology aids in managing outcomes in agriculture, disease control, and wildlife conservation.

Game Theory in Evolution

Game theory provides insights into the interactions of various adaptive strategies within animal groups.
Evolutionarily Stable Strategy (ESS) describes behaviors that resist invasion by alternative strategies and are maintained by natural selection.

Case Study: Side-blotched Lizards

Side-blotched lizards exhibit three distinct mating strategies, showcasing game theory dynamics in natural selection.

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Description

Explore the mechanisms of reproduction in Populus tremuloides and the concepts of polymorphism at synonymous and non-synonymous sites. This quiz delves into genetic diversity and linkage disequilibrium in evolutionary biology. Test your understanding of these critical concepts in reproductive evolution.