Which of the following statements regarding the definition of species is FALSE?

• A. The phylogenetic species concept identifies species based on shared evolutionary history.
• B. All species concepts agree that gene flow between populations is always impossible.
• C. The biological species concept defines a species as a group of organisms that can interbreed and produce fertile offspring.
• D. The morphological species concept relies on physical characteristics to distinguish species.

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the different species concepts mentioned in the problem. The biological species concept defines species as groups of organisms that can interbreed and produce fertile offspring. This concept emphasizes reproductive isolation as a key factor.
2. Step 2: Examine the morphological species concept. This concept relies on physical characteristics, such as shape, size, and structure, to distinguish species. It is often used when reproductive data is unavailable.
3. Step 3: Review the phylogenetic species concept. This concept identifies species based on shared evolutionary history and genetic similarities, often using phylogenetic trees to trace lineage relationships.
4. Step 4: Analyze the statement 'All species concepts agree that gene flow between populations is always impossible.' This statement is false because gene flow can occur between populations in certain species concepts, such as the biological species concept, where populations may interbreed under certain conditions.
5. Step 5: Conclude that the false statement is the one regarding gene flow being always impossible, as it contradicts the principles of some species concepts, particularly the biological species concept.