Which of the following processes is primarily responsible for moving sand down the beach, thereby influencing the distribution of organisms and habitats over time?

• A. Genetic drift
• B. Longshore drift
• C. Mutation
• D. Natural selection

Answer: (B)

Verified step by step guidance

1. Understand the context of the problem: The question is asking about a physical process that moves sand along the beach, which impacts the distribution of organisms and habitats. This is not a biological process like genetic drift, mutation, or natural selection.
2. Recognize that the term 'longshore drift' refers to a geological process. It involves the movement of sand and sediment along the coastline due to the action of waves hitting the shore at an angle.
3. Clarify why genetic drift, mutation, and natural selection are not relevant here: These are biological processes that affect populations of organisms at the genetic level, not physical processes that move sand.
4. Explain how longshore drift works: Waves approach the shore at an angle, carrying sand and sediment with them. As the waves retreat, they move the sand back down the beach in a zigzag pattern, gradually transporting it along the coastline.
5. Conclude that longshore drift is the correct answer because it is the physical process responsible for redistributing sand along the beach, which in turn influences the habitats and organisms in the area over time.