Which of the following describes vicariance? a. Small populations coalesce into one large population. b. A population is fragmented into isolated subpopulations. c. Individuals colonize a novel habitat. d. Individuals disperse and found a new population.

Verified step by step guidance

1. Step 1: Understand the term 'vicariance'. Vicariance is a process in biogeography where a population is split into two or more isolated ranges by a geographical change or barrier such as mountain formation, river change, or climate change.
2. Step 2: Look at option a. 'Small populations coalesce into one large population.' This is not vicariance because it describes the merging of populations, not the splitting of one population into isolated groups.
3. Step 3: Look at option b. 'A population is fragmented into isolated subpopulations.' This is the definition of vicariance. A single population is split into two or more isolated groups by a geographical barrier.
4. Step 4: Look at option c. 'Individuals colonize a novel habitat.' This is not vicariance because it describes the expansion of a population into a new area, not the splitting of a population.
5. Step 5: Look at option d. 'Individuals disperse and found a new population.' This is not vicariance because it describes the founding of a new population, not the splitting of an existing population.

Key Concepts

Vicariance

Vicariance is a biogeographical concept that refers to the process by which a population is divided into smaller, isolated subpopulations due to geographical barriers, such as mountains or rivers. This fragmentation can lead to speciation as the isolated groups evolve independently over time.

Population Fragmentation

Population fragmentation occurs when a once-continuous population is split into smaller, isolated groups. This can result from environmental changes, human activities, or natural events, and it can significantly impact genetic diversity and the long-term survival of species.

Speciation

Speciation is the evolutionary process through which new biological species arise. It often occurs when populations become isolated, either through vicariance or dispersal, leading to genetic divergence and the eventual inability to interbreed, thus forming distinct species.