BIO 141: Life over time and mass extinctions

Bacteria

no nucleus

membranes composed of unbranched fatty acids attached to glycerol by ester linkages

cell wall contains peptiddoglycan

unique rRNA

Archaea

no nucleus

membranes composed of branched hydrocarbon chains attached to glycerol by ether linkages

cell wall contains no peptidoglycan

unique rRNA

Eucarya

nucleus

membranes composed of unbranched fatty acids attached to glycerol by ester linkages

if cell wall present, contains no peptidoglycan

unique rRNA

t or f Bacteria and Eukarya have the same hydrocarbon chains

true

t or f bacteria and archaea can form a monophyletic group

false

formation of planet earth

4.6 billon years ago

first oceans and continents

4.4 billion years ago

first evidence of life

happened after first oceans and continents

rise of atmospheric oxygen

appeared after evidence of life

first eukaryote

appeared after oxygen

first animals

after eukaryote

first land plant

after animals

animals move to land

after land plant

evidence of dino

after animals move to land

permo-triassic mass extinction

after dino

first mammal

after mass extinction

opening of atlantic ocean

after mammal

extinction of dinos

after opening of atlantic ocean

rise of himalayan mountains

after extinction of dinos

first human

after mountains

extinction of wooly mammoths

after first humans

what is the driving factor that might have influenced the appearance of the first euukaryote

rise of atmospheric oxygen

t or f the opening of the alantic ocean is relatively new

true

precambrain era

spans from earth’s formation to the appearance of most animal groups

enviroment of precambrain

mostly unicellular

very little oxygen

cenozoic era

mammals and angiosperms (flowering plants) dominant terrestrial vertebrates and plants

mesozoic

dinos snf gymnsospens most dominant vertebrates and plants and ends with the extinction of dinosaurs betweeen the cretaceous and paleogene

Paleozioz era

appearance of most major anmal lineages

initial diversification of animlas, land plants and fungi

proterzoic econ

edicaran period

phaneroiz eon

cambrian

microfossils from ediacaran period

first animals included less than 1 mm sponges and corals

likely filter feeders

first macroscopic fossils during the ediacaran

including sponges, jellyfish, comb jellies, fossilized burrows, tracks and traces from unidentified animals

no shells, limbs, heads or feeding appendages

likely burrowing, floating or immobile filter feeders

what caused ediacaran fauna to go mostly extinct

cambrian explosion

cambrian explosion

the most spectacular diversification in the history of life which happened very quickly

what triggered the cambrian explosion

oxygen levels rose rapidly

evolution of predation

new niches beget more new niches

new genes and new bodies