chapter 18 classification. 18.1 finding order in diversity i.assigning scientific names □ common...

Chapter 18 Classification

18.1 Finding Order in DiversityI. Assigning Scientific Names

□Common names confusing=varies w/lang & location□Scientific name (latin) same worldwide

Puma Cougar Panther

Common names for a mountain lion:

The many names of Boletus edulis

France:

Cepe

United States:

King Bolete

Italy:Porcini

Germany:

Steinpilz

England:

Penny Bun

Sweden:

Stensopp

Poland:

Borowik

Finland:

Herkkutatti

Spanish:

Rodellón

□ Dichotomous key: guide to ID unknown org Uses paired statements with alternate choices

A. Binomial Nomenclature: 1. Linneaus (Swedish botanist) developed

2. 2-word naming system□ Genus species or Genus species□ Genus=type or group; species=unique description

B. Classifying species into larger groups1. Systematics: organizing life into meaningful groups

2. Taxa: biological groupings

This poison arrow frog's scientific name, Dendrobates azureus, means blue tree-walker!

The king vulture Sarcorhamphus papa has a scientific name that means "father or leader with a fleshy, curved beak."

II. Linnaean Classification SystemA. Uses 7 hierarchical, ordered ranks-taxa

1. Largest to smallest: Kingdom, phylum, class, order, family, genus, species

B. Problems with Traditional Classification1. Used visible similarities/differences (barnacles look like

limpets but are more like crabs)

2. Today: use evolutionary relationships

Limpet: gastropod molluskBarnacle: crustacea

Crab: Crustacea

18.2 Modern Evolutionary ClassificationI. Evolutionary Classification□Phylogeny: species grouped by evolutionary descent

A. Common Ancestors: taxa groupings show relationships1. Larger, more diverse taxa=more ancient common ancestor

B. Clades-a monophyletic group: single common ancestor and all descendants (living & extinct)

II. Cladogram Cladistic analysis shows specific traits branch from comm ancestor Links groups showing evolutionary relationships

A. Building Cladograms: branches (nodes) represent ancestral species splitting in 2

1. Each node=last point species above line shared com ancestor

2. Root of node=common ancestor of those more recent

B. Derived Characters: trait arising in most recent ancestor of lineage

C. Losing Traits: tetrapods (4 limbs) include reptiles; snake still reptile

D. Interpreting Cladogram: character positions reflects order they arose

E. Clade vs Traditional grps: evol. links more accurate=clades connects all species back to original ancestor (dinosaurs/ birds/reptile)

III.DNA in ClassficationA. Genes as Derived Characteristics

1. Gene homologies (similarities) determine evolutionry relationshps

2. Mutations=derived characteristisc

3. More recent commn ancestors = ↓ diffs in genes (more mutations

in common) =>closer related

B. New Evolutionary Trees1. DNA=more accurate evolutionary tree

2. American vulture looks like African vulture yet DNA & behavior more similar to stork (more recent comm ancestor)

3. Giant panda DNA more like bears; Red panda DNA more like racoons (Pandas now in different clades)

AfricanVulture

AmercanVulture

Stork

Giant Panda

RedPanda

Raccoons Red pandas Giant pandas Bears

Common Ancestor

18.3 Kingdoms (6) & Domains(3)I. Changing Ideas about Kingdoms

A. W/diversity of life: science moved from Linnaeus’s 2 kingdms to 5

B. Genetic data= bacteria Kingdom Monera divided into 2

C. Genome data=new taxonomic division: Domain (larger than kingdom); now have 3

□ “Protista”: so diverse, > than 1 comm ancestr=not true clade

II. The Tree of Life

A. Domain Bacteria

1. Kingdom Eubacteria

2. Characteristics:a) Unicellular

b) Prokaryotic

c) Thick Cell Wall□Peptidoglycan

d) Diverse (majority)

1. Kingdom Archaebacteria

2. Characteristics:a) Unicellular & anaerobic

b) Prokaryotic

c) Cell membranes contain unique lipids

d) Extreme Env’t

B. Domain Archaea

C. Domain Eukarya w/4 Kingdoms1. Kingdom Protista

a) Paraphyletic group (more than 1 com ancestor)

b) Plant-like, fungus-like, animal-like members

c) Now at least 5 clades

d) Most single celled

2. Kingdom Fungia) Feed on dead/decaying org.

b) Cell walls contain chitin

c) Digest externally

d) Most multicellular

3. Kingdom Plantaea) Autotrophic=Photosynthesisb) Cell Wall (cellulose)c) All plants are sister group to red algae (protist)

4. Kingdom Animaliaa) Multicellular/heterob) No Cell Wall/Motile