Multiple Choice
Which term describes the common ancestor that gave rise to the most evolutionarily recent derived characters in a phylogenetic tree?
106
views
1. Introduction to Biology
Natural Selection and Evolution
Multiple Choice
Which of the following is a situation in which directional selection may be observed?
A
A population of fish where rare color patterns are favored over common ones.
B
A population of birds maintains two distinct beak sizes, both favored by different food sources.
C
A population of rabbits with intermediate fur length survives better than those with very short or very long fur.
D
A population of moths becomes darker in color over time due to increased industrial pollution.
Verified step by step guidance1
Step 1: Understand the concept of directional selection. Directional selection occurs when one extreme phenotype is favored over others, leading to a shift in the population's traits over time. This is often observed in response to environmental changes.
Step 2: Analyze the given scenarios to identify which one demonstrates a shift toward an extreme phenotype. For example, consider how environmental factors might favor one specific trait over others.
Step 3: Evaluate the scenario involving moths. Increased industrial pollution can darken the environment, making darker moths less visible to predators. This would favor the darker phenotype, causing a shift in the population's coloration over time.
Step 4: Compare this scenario to the others provided. The other examples describe stabilizing selection (favoring intermediate traits) or disruptive selection (favoring multiple distinct traits), which are different from directional selection.
Step 5: Conclude that the correct answer is the scenario where a population of moths becomes darker in color over time due to increased industrial pollution, as it demonstrates a clear example of directional selection.
Related Videos
Related Practice
