Biology- Classification

1. Classification

a. Groups based on evolutionary relationships

2. Phylogeny

b. Evolutionary history of species or group

c. Systematics- classifying relationships

3. Binomial Nomenclature

d. Species- basic unit of classification

e. Classification system by Carolus Linaeus

i. 2 part name

f. Genus + Specific Epithet

ii. i.e. Homo Sapiens

g. Rules

iii. Latin

iv. Genus species

v. Both names italicized or underlines

vi. Genus can be abbreviated

1. H. sapiens

vii. The genus is unique, species name not necessarily

4. Hierarchical system of classification

h. Species

i. Hierarchy

viii. Fig 26.3

ix. Taxon (pl- taxa)

2. Grouping of organisms at any level

x. Each level is more inclusive than the one below it

5. Phylogenic tree

j. Branching diagram

xi. To represent evolutionary history of a group

3. Patterns of descent

k. Allows hypotheses aout evolutionary relationships to be made

l. Should be depicted as a series of dichotomies

xii. 2 way branch points

m. Components

xiii. Branching point= node(where they split)

4. Divergence of 2 evolutionary lineages from a common ancestor

xiv. Sister taxa

5. Groups of organisms that share an immediate common ancestor

xv. Rooted tree

6. Has 1 branch point(usually to the lect)

a. Represents most recent common ancestor of all taxa on tree

xvi. Basal taxon

7. Lineage that diverges early in history of group

8. Lies on a branch that originates near common ancestor

xvii. Polytomy

9. Branch point where more than 2 decendant groups emerge

xviii. Extant species(not extinct)

10. At tips of branches

xix. Fig 26.4,...