Question

Compare and contrast the Biological and Phylogenetic Species Concepts, discussing advantages and disadvantages of both.

Answer 1

The biological species concept states that a species is a group of populations whose members have the potential to interbreed in nature and produce viable fertile offspring, they do not breed successfully with other populations. In contrast, phylogenetic species concept states that a species is an irreducible group whose members are descended from a common ancestor and who all possess a combination of certain defining, or derived traits.

Advantages of biological species concept-

This is a species concept based on a mechanism. Either individual can or cannot produce viable offspring, although failure may be down to individuals. The issue of potential interbreeding arises when members of populations are separated but are brought into contact in a lab, or by chance mechanisms.

Disadvantages: Many living species have never been observed mating and then those offspring mating and raising viable. Fossils certainly can’t mate any longer, although we have to classify them. Some living organisms, e.g. bacteria don’t have sex but can swap genetic material among themselves.

Advantages of phylogenetic concept-

Recognizes the role of history in generating species explicitly and can be reasonably objective. Can use nearly any sort(s) of data.

Disadvantages- Detailed evolutionary histories have been described for relatively few groups of organisms, so biologists are not yet able to apply the phylogenetic species concept to all forms of life.