Classification method of logically grouping organisms based on common characteristics Taxonomy does the actually grouping into the groups called TAXON (s – TAXA) with some kind of biological significance. EX: Things that fly, swim, walk, have feathers, etc.

Early Systems of Classification  Biologists use a system of classification to organize information about the diversity of living things.classification The History of Classification Organizing Life’s Diversity Section 1

How many different terms can you think of for trying to tell someone something is really good? WRITE ‘EM DOWN! Need for common terms of description and classification so that everyone knows what you are saing

Linnaeus’s System Organizing Life’s Diversity The History of Classification Section 1 He assigned two Latin names to each different species of organism This is their scientific name (binomial nomenclature) Homo sapiens (human) Ursus maritimus (polar bear) Alba rubrum (red oak) Ursus arctos (grizzly bear)

Taxonomic Categories Organizing Life’s Diversity nested nested  categories used by scientists are part of a nested -hierarchal system. nested  Each category is contained within another, and they are arranged from broadest to most specific. The History of Classification Section 1 Linked

Scientific names will always be in Latin. Latin is a dead language that will not evolve unlike other languages so it cannot change. Genus name first –Always CAPITALIZED Species name second –Never capitalized Can either be… –Italicized –Underlined

ORGANISM Felis domesticus Canis familiaris Haliaeetus leucocephalus Danaus plexippus English CatDagEagleButterfly Spanish GatoPerroÁguilaMariposa French ChatChienneL'aiglePapillion German KatzeHundAlderSchmetterling Picture

The Taxonomic order: DOMAIN KINGDOM PHYLUM CLASS ORDER FAMILY GENUS SPECIES

The Taxonomic order: From the biggest group to the smallest group or taxa Taxa Human Cat Dog Kingdom Animalia AnimaliaAnimalia PhylumChordataChordataChordata ClassMammaliaMammaliaMammalia OrderPrimateCarnivoraCarnivora FamilyHominoidaeFelidae Canidae GenusHomoFelisCanis speciessapienscatuslupus Which two organisms are more closely related and why?

Organizing Life’s Diversity  Phylogeny is the evolutionary history of a species.  The phylogenic species concept defines a species as a cluster of organisms that is distinct from other clusters and shows evidence of a pattern of ancestry and descent. Section 2  To classify a species, scientists construct patterns of descent by using characters. Concepts in Motion p497

Morphological Characters  Shared morphological characters suggest that species are related closely and evolved from a recent common ancestor. Organizing Life’s Diversity  Analogous characters are those that have the same function but different underlying construction. Section 2  Homologous characters might perform different functions, but show an anatomical similarity inherited from a common ancestor.

Birds and Dinosaurs Organizing Life’s Diversity  Compare birds and dinosaurs:  Hollow bones  Theropods have leg, wrist, hip, and shoulder structures similar to birds.  Some theropods may have had feathers. Modern Classification Section 2

Biochemical Characters concepts in motion p498 concepts in motion p498 Organizing Life’s Diversity  amino acids and nucleotides are used to determine evolutionary relationships among species  DNA and RNA analyses are powerful tools for reconstructing phylogenies Section 2

Organizing Life’s Diversity  The similar appearance of chromosomes among chimpanzees, gorillas, and orangutans suggests a shared ancestry. Modern Classification Section 2

Organizing Life’s Diversity Section 2  Cladistics reconstructs phylogenies based on shared characters.  ancestral character found within the entire line of descents  derived characters are present for one group line but not in common ancestor CladogramsCladograms (concepts in motion p496)  the closer the clades the more shared characters Kingdoms and Quiz (video p501)