Life On Earth Do Now: Scientists estimate that there may be as many as 100,000,000 different species of organisms on Earth. Of these, about 1 x 107 have been identified. What % of species have not been identified?
Classifying Life • Biologists classify organisms in two major ways: • Morphology = the structures and characteristics of organisms • Phylogeny = the evolutionary history and relationships of organisms “phylo” = “type, kind, race, or tribe” “morph” = “form”
Morphological Classification Example • Mollusks are animals that have an organ called a mantle that makes a shell. • Organisms with one shell are called gastropods, organisms with a double shell are called bivalves. gastropod bivalve
Phylogenetic Classification Example • These bacteria are all unicellular prokaryotes. • The tree shown classifies the species according to DNA similarity • The more similar the DNA of two species is, the more recently they shared a common ancestor.
The Modern Classification Scheme • The picture at right shows the classification scheme used to group similar organisms together. • Notice how each group is made up of many of the smaller groups below it. • In other words, as you go down the picture, the groups are more specific and include less organisms
Hierarchy: An arrangement of items into groups “above,” “below,” or “at the same level as” other groups.
Hierarchy Example: Many Classes Make up One Phylum • The phylumchordata includes all animals that have backbones • There are many different classes of animals that have backbones, like class rodentia(rodents), class primates, etc. etc.
Taxonomy = The practice of classification • Taxonomy is the process or study of classification. • A biological taxonomist is a scientist who specializes in classifying organisms
Taxonomy Activity • Your group will receive 11 items classified in the family junkus. • Your job is to divide family junkus into several genera (genuses). • Each genus can then be divided into 1 or more “species” of organism
Things To Include in Your Report • Unique “scientific names” of each “species.” • Should be “latin.” • Each must be unique • Scientific names include genus and species. Example: “Pencilumreddus.” • A tree diagram showing the relationships of the genuses and species. • Answers to questions – complete independently!