Classification Notes

What is classification? Any ideas?

Classification is ordering into groups

Why do we classify organisms? Easier to find out information about them and identify them

Taxonomy Field of Biology that classifies and identifies organisms by looking at shared characteristics to determine relationships between species

Levels of Classification Kingdom (most general) Phylum Class Order Family Genus Species (most specific-can interbreed)

Kingdoms Eubacteria Archaebacteria Protista Plantae Fungi Animalia

Carolus Linnaeus (a.k.a. Carl von Linne) Developed the classification system we use today

Naming Organisms We use Latin for naming because it is “dead” language (meaning of the words do not change)

Binomial Nomenclature (“two-name”) naming system Uses the organisms genus name first and then its species name (ex. Homo sapien)

Introduction dichotomous key: tool that allows the user to determine the identity of items in the natural world "Dichotomous" means "divided into two parts". Therefore, dichotomous keys always give two choices in each step.

1. a. wings covered by an exoskeleton – go to step 2 b 1. a. wings covered by an exoskeleton – go to step 2 b. wings freely observed – Go to step 3 2. a. body has a round shape……….ladybug b. body has an elongated shape…grasshopper 3. a. wings point out from the side of the body ……….dragonfly b. wings point to the posterior of the body …….housefly

Phylogenetic Trees -show the evolutionary relationship between organisms -determined by the fossil record -determined by molecular/structural comparisons

Branches indicate the degree to which organisms are related Branches indicate the degree to which organisms are related. The closer the branches = more closely related.

***Physical similarities do not always indicate evolutionary relatedness ***Larger differences in DNA sequences, the more distantly related