Lecture 2 - The Story of Life

Prokaryotes

Archaea and Bacteria, single celled, no nucleus, no organelles

Date of the oldest fossil:

3.5-3.7 billion years ago

Eukaryotes

True nucleus w/ membrane and nucleoli, organelles, lots of variety

Evolution of Photosynthesis

1) Blue-green algae evolves to photosynthesize

2) Releases oxygen

3) By 2.5 billion yrs ago oxygen is building

4) Builds ozone layer to protect organisms from radiation and led

Earliest Eukaryote fossil

2.2 billion years ago

Endosymbiosis Theory

Eukaryotes evolved from a symbiotic/mutualistic relationship between two prokaryotes.

Date of earliest animal fossil

560 mya

What and when was the Cambrian Explosion?

Start of the Paleozoic, produced most groups of aquatic animals. 541 mya

When and what first colonized land?

400-450 mya, plants and insects

Beginning of the Mesozoic

252 mya

Cretaceous mass extinction

End of the Mesozoic

66 mya

Permian mass extinction

Characteristics of Dinosaurs

Reptiles with an upright stance

What/When is the Asteroid Hypothesis?

Asteroid impact marked the end of the crataceous/mesozoic 66mya and wiped out all non-avian dinosaurs

Evidence for the Asteroid Hypothesis

1) Dinosaurs suddenly disappear from the fossil record

2) Thin layer of clay w/ high iridium across the globe

3) The impact crater on the Yucatan Peninsula

4) Sudden Ocean acidification

5) Shocked quartz grains

What were mammals like during the cretaceous?

Small, “mouse-sized”

Evidence that birds are dinosaurs

Both had feathers

Wishbone

Similar social behavior

S-shaped neck

Same feet

Hollow bones

Oldest Flowering Plant fossil

132 mya

What caused the success of Flowering Plants?

Their relationship with pollinators allowed new species to evolve

What are the 3 Domanins?

Bacteria, Archaea, Eukarya

What are the 4 kingdoms of Eukarya?

Protists, Plants, Fungi, Animals