Chapter-1 Pg:- 7 and 8
Phylogenetic Trees: DNA sequences are used to construct phylogenetic trees, which represent evolutionary relationships among species. These trees show how different species are related through common ancestors.
Gene Comparisons: By comparing specific genes or entire genomes, scientists can determine the degree of genetic similarity and divergence among organisms.
DNA Barcoding: Short genetic sequences from a standardized region of the genome (e.g., the COI gene in animals, the rbcL gene in plants) are used as unique identifiers or "barcodes" to distinguish species.
Cryptic Species: DNA sequencing can reveal cryptic species, which are groups of organisms that are morphologically similar but genetically distinct.
Reclassification: Sequencing can clarify relationships where traditional morphological methods are inconclusive, leading to the reclassification of species, genera, and families.
Hybridization Events: It can identify instances of hybridization and introgression, providing a clearer picture of species boundaries and evolutionary history.
16S rRNA Sequencing: For bacteria and archaea, sequencing the 16S ribosomal RNA gene is a common method to identify and classify microorganisms.
Metagenomics: Sequencing entire microbial communities directly from environmental samples allows for the classification and study of unculturable microorganisms.