Final answer:
Carl Woese was a microbiologist who revolutionized the field by discovering that life evolved along three lineages, not five kingdoms. He introduced the domains Bacteria, Archaea, and Eukarya based on genetic relationships and constructed a phylogenetic tree using ribosomal RNA gene sequencing.
Step-by-step explanation:
Carl Woese's Contributions to Microbiology
Carl Woese was an American microbiologist who made a pivotal contribution to the field of microbiology with his research in the early 1970s. Woese challenged the traditional five kingdom paradigm by introducing a new taxonomic framework based on genetic relationships. Instead of classifying organisms into five kingdoms, he proposed that life evolved along three lineages, now recognized as domains: Bacteria, Archaea, and Eukarya.
Using comparative sequencing of ribosomal RNA genes that are universally distributed and conserved, Woese was able to construct a phylogenetic tree that acknowledged the distinction between two types of prokaryotes—Bacteria and Archaea. Prior to his work, these two types were grouped under a single category due to their similar morphology. Woese identified that despite their similar appearance, their genetic makeup exhibited tremendous diversity, thereby justifying their division into separate domains.
His discovery of the domain Archaea was particularly groundbreaking, as many of these microorganisms, known as extremophiles, survive in harsh environments. Woese's innovative method of using genetic information over morphological traits to classify organisms revolutionized microbiology and our understanding of life's evolutionary history.