A scientist studying rRNA nucleotide sequences of bacterial species is working on which concept?

The study of ribosomal RNA (rRNA) nucleotide sequences is crucial for understanding the evolutionary relationships among different bacterial species. rRNA genes are highly conserved across many organisms, making them excellent markers for phylogenetic studies. By comparing these sequences, scientists can infer how closely related different species are to one another and construct evolutionary trees that illustrate their relationships.

This approach leverages the fact that mutations in rRNA sequences occur at a relatively consistent rate over time, allowing for the estimation of divergence times among various bacterial lineages. Therefore, examining rRNA sequences is a foundational method in molecular phylogenetics and is particularly valuable for identifying and classifying bacteria based on their evolutionary history.

In contrast, gene expression focuses on the transcription and translation of genes into proteins, while proteomics deals with the study of the entire set of proteins produced by an organism. Metagenomics involves the analysis of genetic material obtained directly from environmental samples, which can encompass a wide variety of microbial community compositions but does not specifically center on rRNA sequences for determining relationships among individual bacterial species.