Deep Time Bio 181 Unit 2

cambrian explosion

resulted in a large increase in animal species, at this point all animals live in the ocean

250 mya

permian extinction occurs

4 billion years ago

1st life (prokaryotes), first land mosses, stromatolites

3 billion years ago

early photosynthesis=1st O2, cyanobacteria O2 mutates DNA

2.5 billion years ago

oxygen catastrophe, success eukaryotes(speciation)

1 billion years ago

earliest multicellular organisms (plants, animals, fungi)

.5 billion years ago

Cambrian explosion, colonization of land

450 mya

plants move to land (mosses) and then arthropods

no competition on land...

adaptation to land

400 mya

high competition in the water, ferns evolve, plants lead to more insects, tetropods evolve (4 legged fish)

300 mya

1st reptiles and conifers

permian extinction

caused 90% of land animals to die off plus many in the ocean, caused by a raise in atmospheric CO2 levels, massive volcanic activity, extinctions create open niches allowing for more speciation and diversification, mammals and reptiles and birds all evolved from different pops of dinosaurs

65 mya

Cretaceous extinction occurs

creatceous extinction

most dinosaurs go extinct (birds survive), birds and mammals expand into open niches

lilliput effect

reduction in size of animals during an extinction event