Lecture 1: Phylogeny & Tree of Life

Homology

when two groups are similar due to a shared ancestor

Analogy

when two groups (can be closely or NOT closely related) are similar due to convergent evolution (similar environmental pressures & evolution/natural selection -> resulting in similar adaptations)

What is the hierarchy of taxonomic groups? (from largest to smallest)

Domain

Kingdom

Phylum

Class

Order

Family

Genu

Species

Shared ancestral character

when a trait originates from ancestor

Shared derived trait

when a trait is unique to a subgroup OR is evolved from a recent ancestor

Intraspecific variation

diversity among multiple groups

Interspecific variation

diversity within one group

Clade

a group that contains an ancestor & ALL of its descendants

Lineage

a line or ancestry or descent from a common ancestor; does NOT show ALL descendants

Horizontal gene transfer

exchanging DNA from two individuals

Similar species

have recent common ancestors

Disimilar species

have common ancestors dated further back in history

Phylogeny

evolutionary history of a species/group of related species

Sister taxa

share an immediate common ancestor

Tree of Life

-represents a hypothesis about evolutionary relationships & shared ancestry

-does NOT tell OR when how much genetic variation occurred

-shows patterns of descent

Cladistics

grouping organisms by common descent

character

can be BOTH ancestral & derived

Outgroup

species or group of species that is closely related to the ingroup (group of species you are studying)

Ingroup

group of species you are studying

Binomial Nomenclature (Two-part names for species

Genus/Genra: first part, which the species belongs to; italicized & 1st letter capitalized

Epiphet: second part; unique for each species within a genus; italicized

5-kingdoms

Monera (Prokaryotes), Protista, Plantae, Fungi, Animalia

3-domain system

Bacteria, Archaea, Eukarya

What are the 3 ways of Horizontal Gene Transfer?

Transformation, Transduction, Conjugation