Question

What is a challenge that can make it difficult to apply the Phylogenetic Species Concept?

		Understanding whether the environmental requirements of the organisms overlap.
		Determining whether the organisms recognize each other as potential mates.
		Testing whether or not the organisms can reproduce and produce viable offspring.
		Polymorphism leading to different forms in a population.

Answer 1

Paleontologists can find the fossil evidence of the ancestors of today's species, but they cannot observe whether those fossil organisms could reproduce with each other.

The phylogenetic species concept is an attempt to define species by their relationships to other species. Instead of trying to determine the reproductive boundaries of populations, scientists using the phylogenetic species concept attempt to uncover their genealogical relationships.

Key to the phylogenetic species concept is the idea that species must be "diagnosable." In other words, members of the species should share a combination of characteristics that other species lack.

Thus, because the phylogenetic species concept does not identify species based on the reproductive boundaries between them, it may have the effect of identifying populations connected by gene flow as different species. So determining whether the organisms recognize each other as potential mates.