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