The organisms of the Galapagos islands have become famous for people studying their processes of speciation. Which statement best describes how speciation most likely occurs on islands like the Galapagos?

• A. Speciation likely occurs through vicariance as the organisms that reached the islands split off from mainland populations.
• B. Speciation likely occurs through dispersal as groups of organisms reach new islands and adapt to local conditions.
• C. Speciation likely occurs through sympatric speciation as organisms diverge in different ecological niches.
• D. Speciation likely occurs through hybridization as new organisms interact with resident organisms on islands.

Answer: (B)

Verified step by step guidance

1. Understand the concept of speciation: Speciation is the evolutionary process by which populations evolve to become distinct species. It often involves the separation of populations and the development of reproductive isolation.
2. Identify the types of speciation: There are several types of speciation, including allopatric (geographic isolation), sympatric (same geographic area but different ecological niches), and peripatric (small population isolated at the edge of a larger population).
3. Consider the geographic context of islands: Islands like the Galapagos are isolated from the mainland, which makes allopatric speciation through dispersal a likely mechanism. Organisms that reach the islands are geographically separated from their original populations.
4. Evaluate the role of adaptation: Once isolated, the organisms that reach new islands may adapt to the unique local conditions, leading to divergence from their original populations. This adaptation can result in the formation of new species.
5. Conclude with the most likely scenario: Given the isolation and unique environments of islands, speciation through dispersal and subsequent adaptation to local conditions is a common and likely scenario for the Galapagos islands.