Agenda 12/7 and 12/8 Classification history notes Phylogenetic tree activity Homework: Phylogenetics video and notes Turn in: Video Notes IA FINAL DRAFT DUE 12/19

Taxonomy Classification originated with Carolus Linnaeus in the 18th century. Based on structural (outward and inward) similarities Hierarchal scheme, the largest most inclusive grouping is the kingdom level The most specific grouping is the species level Point out that Linnaeus had the kingdom as the highest or largest grouping. The domain concept is recent. Relate to the students that at first there were just two kingdoms. The addition of the third kingdom, Protista occurred 1866. The addition of the fourth kingdom Monera occurred in 1938. The addition of the fifth kingdom, Fungi occurred in 1969. Finally, in 1977 the Monerans were split into the Bacteria and Archeabacteria.

Taxonomy Taxonomy is the classification of organisms based on shared characteristics. Historically, these were visible characteristics like anatomy and behavior Under the three-domain system of taxonomy, which was established in 1990 and reflects the evolutionary history of life as currently understood, the organisms found in kingdom Monera have been divided into two domains, Archaea and Bacteria (with Eukarya as the third domain). The term "moneran" is the informal name of members of this group and is still sometimes used (as is the term "prokaryote") to denote a member of either domain.

Domains- A Recent Development Carl Woese proposed three domains based the rRNA sequencing 1. Eukarya 2. Archaea 3. Bacteria Organisms are grouped from species to domain, the groupings are increasingly more inclusive. The taxonomic groups from broad to narrow are domain, kingdom, phylum, class, order, family, genus, and species. Point out that Archaea was thought to be very ancient but many are beginning to believe that is not the case because of rRNA evidence. The graphic indicates that Eukarya and Archaea had a more recent common ancestor than Bacteria and Eukarya. Also mention that Archaea often live in some very extreme environments. Some species can tolerate very high temperatures, others high salinity, and others low pH.

Scientific Naming of Organisms Latin is used – why? Species is the most specific level Bi-nomial nomenclature

How has classification changed through time? DNA and molecular evidence used exclusively now Mostly done with computers Scientific, bi-nomial naming still used Why is DNA preferred over anatomical features?