Which of the following is the best example of gene flow?

• A. A small population of humans colonizes a newly formed island.
• B. Genes are shuffled by the crossing over of chromosomes during meiosis.
• C. An earthquake results in the formation of a canyon, splitting a population of toads apart.
• D. A fire drastically reduces the size of a white-tailed deer population. The remaining individuals spread out throughout the remaining forest.
• E. Wind blows pollen from one population of plants to another and cross-fertilization occurs.

Answer: (E)

Verified step by step guidance

1. Understand the concept of gene flow: Gene flow is the transfer of genetic material from one population to another. It occurs when individuals from different populations interbreed, leading to the exchange of genes.
2. Analyze each option to determine if it involves the transfer of genetic material between populations: For example, colonization of a new island by humans does not necessarily involve gene flow unless there is interbreeding with another population.
3. Consider the role of natural events: Events like earthquakes or fires may affect population size or distribution but do not inherently involve gene flow unless they lead to interbreeding between previously separated populations.
4. Focus on the option involving pollen: Wind blowing pollen from one population of plants to another is a classic example of gene flow, as it involves the transfer of genetic material (pollen) between plant populations, leading to cross-fertilization.
5. Conclude that the best example of gene flow is the option where wind facilitates the movement of pollen between plant populations, resulting in genetic exchange through cross-fertilization.