Transcript Chapter 18 Classificationx

Chapter 18 Classification
18.1 Finding Order in Diversity
I. Assigning Scientific Names
□ Common names confusing=varies w/lang & location
□ Scientific name (latin) same worldwide
The many names of Boletus
edulis
France:
Cepe
Puma
Cougar
Panther
German
y:
Steinpilz
United
States:
King
Bolete
Italy:
Porcini
England
:
Penny
Bun
Sweden
:
Stensop
p
Common names for a mountain lion:
Poland:
Borowik
Finland:
Herkkut
atti
Spanish:
Rodelló
n
□ 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
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."
B. Classifying species into larger groups
1. Systematics: organizing life into meaningful groups
2. Taxa: biological groupings
II.
Linnaean Classification System
A. Uses 7 hierarchical, ordered ranks-taxa
1. Largest to smallest: Kingdom, phylum, class, order,
family, genus, species
B. Problems with Traditional Classification
1. Used visible similarities/differences (barnacles look like
limpets but are more like crabs)
2. Today: use evolutionary relationships
Barnacle: crustacea
Crab: Crustacea
Limpet:
gastropod mollusk
18.2 Modern Evolutionary Classification
I. Evolutionary Classification
□ Phylogeny: species grouped by evolutionary descent
A. Common Ancestors: taxa groupings show relationships
1.
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.
2.
Each node=last point species above line shared com ancestor
Root of node=common ancestor of those more recent
B.
C.
D.
E.
Derived Characters: trait arising in most recent ancestor of lineage
Losing Traits: tetrapods (4 limbs) include reptiles; snake still reptile
Interpreting Cladogram: character positions reflects order they arose
Clade vs Traditional grps: evol. links more accurate=clades connects
all species back to original ancestor (dinosaurs/ birds/reptile)
III.DNA in Classfication
A. 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 Trees
1. 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)
African
Vulture
Amercan
Vulture
Giant Panda
Raccoons
Stork
Red pandas
Giant pandas
Common Ancestor
Bears
Red
Panda
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)
B.
Domain Archaea
1. Kingdom Archaebacteria
2. Characteristics:
a)
b)
c)
d)
Unicellular & anaerobic
Prokaryotic
Cell membranes contain unique lipids
Extreme Env’t
C.
Domain Eukarya w/4 Kingdoms
1. Kingdom Protista
a)
b)
c)
d)
Paraphyletic group (more than 1 com ancestor)
Plant-like, fungus-like, animal-like members
Now at least 5 clades
Most single celled
2. Kingdom Fungi
a)
b)
c)
d)
Feed on dead/decaying org.
Cell walls contain chitin
Digest externally
Most multicellular
3. Kingdom Plantae
a) Autotrophic=Photosynthesis
b) Cell Wall (cellulose)
c) All plants are sister group to red algae (protist)
4. Kingdom Animalia
a) Multicellular/hetero
b) No Cell Wall/Motile