actual final exam Flashcards
(149 cards)
earth as a 24 hr clock - when did oldest rocks, first fish, first plants, dinosaurs, ice age, and modern man happen?
oldesr rocks - 10:27 am
first fish - 11:53 pm
plants - 11:54 pm
dinosaur - 11:57 pm
ice age - 11:59.2 pm
modern man - 11:59.9 pm
what is taxonomy
the process of grouping species into higher and higher divisions based on similar characteristics
order of taxonomy
kingdom - phylum - class - order - family - genus - species
if a fossil is discovered that belongs to a known order, what is true?
then everything above that must exist (class, phylum, kingdom)
if an extinction wipes out up to a known order, what is true?
then everything below that must also be extinct (family, genus, species)
species higher up on the taxonomy are ___ _____ to large disturbances
more resistent
cambrian period and biodiversity
545 million years ago
an “explosion” of diversity in marine phyla
unknown exactly why, but likely some large geologic event that disrupted the environments in which the species were adapted
mass extinction
loss of more than 25% of the families in a kingdom can lead to
mass extinction
mass extinction events have removed 60-90% of the species that have ever
existed on Earth
hypotheses for mass extinction events
changes in plate tectonics (# of continents and climatic changes)
changes in ecosystems
volcanic causes (impact weather, climate, flood basalts)
meteorite impacts
impact of volcanic eroptions on climate and atmosphere
ozone reduction (Cl), global warming (CO2 and H2O), global cooling (blocking sunlight), acid rain (SO2)
flood basalt eruptions and extinction
linked to Permian extinction
85% of all marine species
70% of all terrestrial species
Cretaceous extinction
probably part of what killed the dinosaurs
meteorite extinctions
craters aren’t well preserved because of erosion
modern extinctions
initiated by humans
migration patterns, industry, hunting
extinction over the past 10,000 years
73% of large mammals
66% of large birds
(bc of the end of the ice age and humans)
insured loss by diff disasters
hurricane - 35%
thunderstorm/tornado/hail - 25%
flood - 18%
blizzard - 15%
earthquake - 3%
wildfire - 2%
windstorms 2%
early earth was most like which planet
venus - volcanic activity, CO2, and hotter temps
where did the CO2 from early earth go
80% in rocks, some dissolved, some are in living things
how do scientists know what past climates were?
examining changes in fossil composition - O2 isotipe ratio in shells
O2 isotopes
16O, 17O, 18O
16O is most common
evaporation from ocean favors lighter isotopes
16O and 17O are mostly on land and 18O is in the sea
lower 18O means warmer temps
what factors lead to changes in global climate
plate tectonics (land mass at the poles leads to ice sheets and colder climates)
N-S alignment of continents (more evaporation, more snow because blocks EW flow of warmer currents)
shorter term climate changes
melting of ice and rising ocean temps
el nino/la nina - cycles of warming/cooling in the pacific ocean
large volcanic eruptions - reflect incoming solar energy
human influence on climate change
burning fossil fuls, land clearing by burning
greenhouse gases
H2O, CO2, methane (CH4), nitrous oxide (N2O), (ozone O3)
water vapor responsible for __% of greenhouse effect
0.75