Question

Discuss whether the phenomenon of reproductive isolation applies to bacteria, which reproduce asexually. How would a geneticist divide bacteria into separate species?

Short answer

Reproductive isolation does not apply to bacteria, as they reproduce asexually. Geneticists divide bacteria into different species based on both phenotypic and genotypic characteristics.

Step-by-step solution

Understanding the Concept of Reproductive Isolation

Reproductive isolation is an evolutionary mechanism that prevents members of different species from producing offspring together. This concept mainly applies to sexually reproducing organisms, where inherent barriers can include physical incompatibilities, behavioral differences, or time of day when they reproduce.

Reproduction Characteristics of Bacteria

Bacteria perform asexual reproduction, also known as 'binary fission', where a single organism duplicates its DNA and then divides into two equal parts. Since bacteria reproduce asexually, they do not need a mate to reproduce. Therefore, the classical idea of reproductive isolation does not hold true for bacteria.

Classification of Bacteria into Separate Species

Bacteria are typically classified based on phenotypic or genotypic characteristics rather than reproductive isolation. Phenotypic characteristics can include shape, structure, and metabolic activities, while genotypic characteristics are based upon genetic makeup. It is often the case that bacteria with similar phenotypic characteristics may have different genotypic characteristics and vice versa. Therefore, the classification of bacteria into separate species is essentially based upon a combination of both phenotypic and genotypic characteristics. The geneticist would use DNA sequences, such as the genes for ribosomal RNA, enzyme coding genes, and other noncoding regions to classify bacteria into different species.