Organizing Life’s Diversity

Classification – the grouping of objects or information based on similarities. (ie. organizing your music collection)

(ie: organizing a grocery store)

Taxonomy – the branch of biology that groups and names organisms based on studies of their different characteristics.

Today’s phylogenetic classification uses a hierarchy of taxa to classify organisms. From largest to smallest(A mnemonic to help you remember) DomainDear KingdomKing PhylumPhillip Another way to help you ClassCame remember the order, sing the OrderOver groups to the tune of FamilyFor “Yankee Doodle.” GenusGreek SpeciesSalad

The phylogeny for a Bobcat is: Kingdom Animalia PhylumChordata ClassMammalia OrderCarnivora FamilyFelidae GenusLynx SpeicesLynx rufus

The 3 domains are: –Bacteria Prokaryotes Cell walls contain peptidoglycan Most abundant organism –Archaea Most ancient Most closely related to Eukaryotes Extremophiles (live in extreme environments) –Eukarya Have membrane-bound nucleus Have membrane-bound organelles

The six kingdoms of organisms are: –Eubacteria Domain Bacteria –ArchaeDomain Archae –Protists –Fungi –Plants Domain Eukarya –Animals

Phylogeny – Evolutionary history of a species. –Phylogentic species concept defines species as a cluster of organisms that is distinct from other clusters.

Cladistics – a type of classification system based on phylogeny (evolutionary history) Scientists use a cladogram or phylogenetic tree to diagram evolutionary relationships of traits

Phylogeny of Humans

Aristotle - developed the first accepted system of biological classification Two groups: Plants and Animals Carolus Linnaeus - developed classification system based on physical & structural similarities of organisms. –Still used today –Includes classification based on structural similarities & evolutionary relationships of species.

Binomial Nomenclature – Two word naming, developed by Linnaeus to identify species –First word = genus –Second word = species (ie. Homo sapiens = modern humans) Note: Scientific names are always written in italics or underlined

Evolutionary History Phylogeny describes the evolutionary history of a related group of species All organisms on Earth evolved from a single ancestor Life on earth began about 3.5 billion years ago; since that time, new species have emerged, lived and died out New species evolve from pre-existing species

Fossil Evidence Through fossil evidence, physical and molecular similarities between ancient species and modern species have been found. Physical and molecular similarities between diverse species has also been found.

Extinction Organisms try to survive in their environments through adaptation, however many species become extinct Extinction can occur because of environmental changes, human interference or as a result of failure to adapt to new conditions

Extinction Cont. Extinction is a natural and important part of evolution It is estimated that 999 of every 1,000 species that have ever lived on Earth have become extinct The average species survives between 2 and 10 million years Even the most highly adapted species become extinct.

Mass Extinctions There have been many mass extinctions during Earth’s history Mass extinction = when more than 50% of species were wiped out Mass extinctions make it possible for new species to develop Surviving species are able to diversify v=zX060c b5f7f7e6663&t=Pre historic-Animalshttp:// v=zX060c b5f7f7e6663&t=Pre historic-Animals