Vocabulary: Ecology •  Ecosystem •  Community •  Population •  Abiotic/Biotic Factors •  Producers •  Consumers •  Decomposers •  Trophic (levels,

structure) •  Biodiversity

•  Biomass •  Primary Production •  Net Primary Production •  Photosynthesis •  Cellular Respiration

Carbon cycle •  Pools (reservoirs) •  Fluxes •  Sinks vs. sources •  Food chains •  Food webs

1.  Interpret phylogenetic trees. 2.  Use phylogeny to explain that evolution is NOT a

linear progression from primitive to advanced species.

3.  Describe interspecific interactions that define and organize community structures

4.  Predict the nature and direction of selective pressures acting on those interactions

Objectives, 11/06/08:

•  Clades = nested groups –  branches can “rotate”

•  order is changed, but relationship is maintained

•  Nodes - points in time when populations became reproductively isolated

•  Based on body plan (morphology)

•  Based on molecular information (RNA and/or DNA)

Similarities? Differences?

Linnaeus, mid 1700’s

•  2 Kingdoms

Plants Animals

don’t move move

autotrophic heterotrophic

Whittaker, 1969 •  5 Kingdoms •  Based on nutrition

Fungi

Plants

Animals

Protists

Monera

Fungi

Plants

Animals

Protists

Monera

PROKARYOTES

EUKARYOTES

Woese, 1977 •  generate “tree of life”

•  chemical basis for relatedness (SSU RNA from ribosomes)

•  Observations: –  ALL organisms have

ribosomes (inference?)

–  rRNA sequences change over time due to random mutation. (more time more opportunity for mutation)

Woese Hypothesis: •  If organisms are descended from common

ancestor, then rRNA sequences will be more similar in closely related organisms, less similar in more distantly related organisms.

Bacteria

Achaea

Eukarya

PROKARYOTES

EUKARYOTES

3 Domains

Woese’s Conclusions: •  3 major groups (= Domains):

–  Bacteria –  Archaea –  Eukarya

•  Prokaryotes are DIVERSE! (think: Kingdom-level differences btw plants,

animals, fungi)

•  Whittaker’s “Kingdoms” do not reflect phylogeny of organisms –  Monera obsolete

Ecology is the study of interactions between organisms and environment

Interspecific Interactions:

Species 1 Species 2

Mutualism

Predation, Parasitism

Competition

Commensalism

Effect is +/-/0 depending on its impact on fitness for the species

Competition

•  Species overlap in resource requirements and resource is limiting

•  Selection will favor traits that reduce competition

CQ

Commensalism •  Examples:

–  Seed dispersal by “Hitchhikers” –  Kirtland’s Warbler, Jack pine