Phylogeny Systematics Cladistics Modern Classification sorts organisms into groups shows relationships among them Phylogeny Systematics Cladistics
Classification and Diversity - tries to organize all living things into groups - show how they evolved from earlier life forms - show relationships to other present forms - changes with new information Early Systems Aristotle - by environment: land, water, air John Ray (1600s) - in related groups - short description for each species
Linnaeus Carolus Linnaeus – Swedish botanist, 1700s used physical appearance and structure 7 taxa: from broad to specific Kingdom – Phylum – Class – Order - Family – Genus – Species Binomial Nomenclature - two names for each Genus: group to which it belongs species: 1-2 word description Ex. Homo sapiens
Evidence for Classification Many forms: - physical appearance and structure (morphology) - other present organisms - fossils - molecules, especially DNA, RNA, proteins - embryology patterns Various organizing diagrams
Evidence for Evolutionary Relationships Physical appearance and structure Resemblance to other organisms
Fossils Embryo Development
Phylogeny and Systematics Taxonomy – sort and name organisms Phylogeny - Evolutionary history of a group of organisms - shows common ancestry Systematics - combines taxonomy with evolution - organized way to study diversity and relationships
Taxonomy – sorting and naming Species – individual type of organism Genus – group of related species Scientific Name = Genus & species Family – related genera Order – related families Class – related orders Phylum – related classes Kingdom – related phyla Domain – Three Domain System
Phylogeny – evolution history
Simplest relationships make the most likely phylogenetic trees
Phylogeny -compares structure Homologous – similar structure, with adaptations - shows common ancestry
Analogous structures Evolved in similar environments NOT shared ancestry
Cladistics Tries to show evolutionary relationships based on physical traits shared by different groups of organisms
Cladograms More shared traits = more closely related Derived character – more recent branch from evolutionary line Primitive character - older, shared by more groups
Molecular Systematics Compares molecules to find relationships
Ribosomal RNA Have shown that fungi are more closely related to humans than to green plants Student Mushroom Tulip Common ancestor Figure 15.9B
DNA – Compare genes and DNA sequences - many similar sequences = closely related
More shared genes = closer relationship Human Chimpanzee Gorilla Orangutan Common ancestor Figure 15.9C
Molecular Clocks Some regions of DNA or proteins Change at a fairly consistent rate Can date evolutionary events
Five- Kingdoms System Prokaryotes are in one Kingdom – Monera (Classification is a work in progress!) Prokaryotes are in one Kingdom – Monera Eukaryotes are grouped in separate kingdoms Animals, Plants, Fungi, Protists
Bacteria are divided into two kingdoms, based on their chemical nature Six-Kingdom System Bacteria are divided into two kingdoms, based on their chemical nature
Three Domain System One domain for all eukaryotes One domain for each of the two kinds of bacteria