Evolutionary Mechanisms & Population Genetics

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A population of frogs is separated by a newly formed river, preventing them from interbreeding. Over time, the two groups develop distinct mating calls. Which evolutionary mechanism is primarily responsible for this divergence?

Temporal isolation
Genetic drift
Geographic isolation leading to allopatric speciation (correct)
Stabilizing selection

A species of plant typically flowers in early spring. Due to climate change, some plants now flower in late autumn. What type of reproductive barrier is most likely occurring in this plant population?

Mechanical Isolation
Habitat Isolation
Temporal Isolation (correct)
Geographic Isolation

A scientist discovers a new species of beetle on an isolated island. Genetic analysis reveals that the beetle population has significantly less genetic diversity than mainland beetle populations. Which evolutionary phenomenon likely explains this reduced diversity?

Stabilizing Selection
The founder effect (correct)
Gene flow
Natural selection

In a population of butterflies, larger wingspans are favored because they allow for better flight and predator evasion. Over several generations, the average wingspan increases. What type of selection is most likely occurring?

Directional selection (D) Signup and view all the answers

A population of birds is in Hardy-Weinberg equilibrium. Which of the following scenarios would disrupt this equilibrium?

A new group of birds immigrates into the population, introducing new alleles. (D) Signup and view all the answers

Which of the following scenarios best illustrates Darwin's concept of 'fitness' in the context of natural selection?

A desert plant that can store large amounts of water and successfully reproduces in dry conditions. (A) Signup and view all the answers

How did Darwin's observations of Galapagos finches contribute to his theory of evolution by natural selection?

They showcased adaptive radiation and the role of environmental pressures in shaping beak morphology. (C) Signup and view all the answers

A population of insects is exposed to a new insecticide. Initially, most of the insects are susceptible, but over several generations, the population becomes increasingly resistant. Which of the following best explains this phenomenon?

Insects with pre-existing resistance alleles survive and reproduce, increasing the frequency of resistance in the population. (B) Signup and view all the answers

Which of the following is an example of a vestigial structure and what does it suggest about the evolutionary history of the organism?

The appendix in humans, suggesting a past reliance on a plant-based diet. (B) Signup and view all the answers

How does artificial selection differ from natural selection?

Artificial selection is driven by human preferences, while natural selection is driven by environmental pressures. (C) Signup and view all the answers

Why is the concept of a 'gene pool' important in the study of evolution?

It reflects the genetic diversity within a population and the potential for evolutionary change. (A) Signup and view all the answers

Which of the following scenarios best explains the process of 'founder effect'?

A small group of individuals colonizes a new habitat, resulting in reduced genetic diversity. (D) Signup and view all the answers

Which of the following is most directly related to the study of biogeography?

Mapping the distribution of species across different geographic regions. (A) Signup and view all the answers

Half-life

The time it takes for half of a substance to break down.

Mutation

A random change in genetic material that can be harmful or beneficial.