Question

biologists are studying two populations of lizards, one from the northern end of the lizards territory and one from the southern end. dna analysis shows that the northern and southern populations are part of the same lineage, with little differentiation between them. the researchers had expected the two lizard populations to form two distinct lineages because the two ends of the territory had been separated by a river (which had subsequently dried up). however, unbeknownst to the researchers, the northern and southern lizards had failed to generate much reproductive isolation while they had been separated. hence, the two populations started interbreeding once the river was no longer a barrier. this example illustrates that reproductive isolation plays an important role in the biological species concept. reproductive isolation does not play an important role in the lineage species concept. reproductive isolation plays an important role in the lineage species concept. the biological species concept is superior to the lineage concept. the lineage species concept is superior to the biological concept.

Explanation:

The example shows that despite a physical separation (river), the two lizard populations didn't develop much reproductive isolation and could interbreed once the barrier was removed. This implies that in the context of lineage (as they are part of the same lineage), reproductive isolation didn't prevent them from being considered part of the same lineage. So, reproductive isolation does not play a crucial role in the lineage species concept.

Answer:

reproductive isolation does not play an important role in the lineage species concept.