classification

amount of species identified so far

1.5 million

amount of species still undiscovered

2-100 million

why are so many species still undiscovered?

they live in isolated environments, or are incredibly small

why should we classify

to give uniform names to an organism

taxonomy

science of classifying living organisms

aristotle

first to classify living things

aristotle’s classification

animals-where they lived

plants-shrubs, herbs, or trees based on size and structure

carolus linnaeus

used comparative anatomy

linnaeus’ system of classification

7 levels called taxon (taxa)

largest to smallest taxa

kingdom, phylum, class, order, family, genus, species

linnaeus’ system originally had ____ kingdoms, ____ and _____

2, animalia, plantae

as we become more specific in classification, numbers of organisms ______

decreases

the more closely related, the more _____ classified the organisms should be

similarly

linnaeus’ binomial nomenclature system

two-part scientific name, written in italics with first word capitalized (genus), second word lowercase (species）

language of linnaeus’ binomial nomenclature system

latin

classification of man

kingdom animalia, phylum chordata, class mammalia, order primates, family hominidae, genus homo, species sapiens

phylogeny

grouping organisms by evolutionary descent by comparing biochemistry and embryology

biochemistry

compares mutations in dna or amino acid sequences, shows how long species have evolved separately, different molecular clocks tick at different rates

molecular clock

the average rate at which a species' genome mutates, used to measure their evolutionary divergance

mitochondrial dna

mutates fast, use for closely related species

ribosomal rna

mutates slowly, use for distantly related species

embryology

compares development to determine similarities that may not exist in adult stage

cladistics

study of evolutionary classification showing the relationships of organisms based on common ancestors

derived characteristics

new trait that evolved

cladogram

diagram like a family tree

outgroup

determines the new characters being studied

clade

a group of organisms sharing a common ancestor

node

a point where two groups branch off

clades include ___ ___, and all ____

common ancestor, descendents

cladogram misconceptions

cladograms are like a tree, not a ladder, there is no levels of advancement

kingdoms

linnaeus began with two kingdoms, protista for microorganisms added in 1969, fungi for mushrooms, yeast, and molds added in 1969

moneran kingdom

added for bacteria b/c of missing nucleus and other organelles in 1969, now separated into two kingdoms

archaebacteria and eubacteria kingdoms

once joined as moneran kingdom

domains

three systems that are one level above kingdoms used in modern classification

kingdom eubacteria

domain bacteria, unicellular, prokaryotic, cell walls made of peptidoglycan, auto or heterotrophic, variety of bacteria in variety of climates

kingdom archaebacteria

domain archaea, unicellular, prokaryotic, auto or heterotrophic, live in extreme environments; usually without oxygen, cell walls w/o peptidoglycan, cell membranes made of lipids not found in other organisms

kindgom protista

domain eukarya—all organisms that have a nucleus, not plants, animals, or fungi, great variety, unicellular (most) or multicellular, auto or heterotrophic

kingdom fungi

domain eukarya, heterotrophs, usually feeds off dead or decaying organic matter by digesting externally and absorbing nutrients, multi (most) or unicellular, cell walls of chitin

kingdom plantae

domain eukarya, photosynthetic autotrophs, multicellular, cell walls of cellulose, include cone-bearing and flowering plants, mosses and ferns, most don’t move

kingdom animalia

domain eukarya, heterotrophic, multicellular, no cell walls, most move