Studied by 7 peoplenode
decision points
contingency
the notion that future events are dependent on passed ones but not determined or predicted
Teleology
the belief that some process unfolds toward a predetermined goal, divinely ordained or just destined
Scale
how big/how small
Big Bang time
13.7 bya
big bang
small infinitely dense then rapidly expands, still expanding today
10^43 seconds
Planck time, universe is smaller than Planck length, nothing before this, gravity appears
10^-35
inflation begins, energy and matter are interchangeable, e = mc^2, gravity, strong nuclear force, quark soup
10^-6
temp fell to 1 trillion K, quarks stable enough to bond
1 second- 2 minutes
1 electron per proton, 1 billion K, nuclei formed
380,000 years after big bang
temp fell to around 3,000 K, threshold, end of radiation era, neutral atoms with electron orbits, gravity
Hubble constant
rate of universe expansion seen through red shift
cosmic background radiation
radiation left over from the big bang
makeup of universe after big bang
about 75% hydrogen, 25% helium, similar today
Lord Brahma
hindu origin story, creator of universe
contingency in big bang
tiny imbalance of matter and antimatter, slightly more matter, that's why we're here. Proof is CBR unevenly distributed.
200 million years after Big Bang
"Dark Age" universe cools and expands, matter clumps
at 200 million years after Big Bang
stars and galaxies begin to form. hydrogen and helium
Milky Way age
13 billion years
Msolar system distance from center of galaxy
26,000 light years
Nebular Hypothesis
swirling massive clouds of dust, gravity pulls into center, sun ignited and remaining stuff is planets
Earth special
wwater, tectonic activity, size, distance from sun, MOON
Theia
4.5 bya earth and companion planet collided, became molten, became earth and moon
moon benefits
slow down earth's spin, regulates tides, keeps axis stable
Hadeon Era
4.6-4.0 bya, after theia, lots of asteroids, crust began to harden, cooled to 3000 degrees, black sphere with cracks of lava, red sky, rained for millions of years to make oceans
both shape history
contingent and deterministic events
Anthropic Principle
we live on an Earth designed for life
Strong Anthropic Principle
The circumstances in our universe have made the emergence of life inevitable, perhaps because the universe way designed that way
Weak Anthropic Principle
The universe just happens to be this was, and if it were any different we wouldn't observe it
what is life
organized cellular structure, reproduces, store info (genetics), metabolism, composed of organic things
steps of life emergence
building blocks: amino acids, sugars, lipids form 2. come together to make macromolecules 3. molecular selection, symmetrical efficient bonds (RNA/DNA) 4. Replication
Complex adaptive systems
interact and adapt with their environments to survive, determinism and contingency
Life made of?
lipids, carbohydrates, proteins, nucleic acids
RNA world hypothesis
RNA formed first (genes first), primordial soup and acted like proteins and replicated
Iron-sulfide world hypothesis
metabolism came first
Panspermia
life originiated somewhere else and was delivered to Earth through meteors
3.5 bya
first life: prokaryotes
2.5 bya
Great Oxygenation Event, photosynthesis in cyanobacteria, contingent event
1.9 bya
first Eukaryotic cell, one prokaryote absorbed another, "Last Common Ancestor"
Dark matter
matter that does not give off electromagnetic radiation, 90% of universe
sun/solar system age
4.56 billion years old, will live for 4-5 billion more years
T Tauri Wind
100,000 years after sun's formation, blasted away remaining gas and dust in inner orbits and young earth atmosphere
evidence for early earth
seismograph, relative dating, radiometric dating, meteorites
Uniformitarianism
geologic processes happened over huge periods of time, deep time
Archean Era
3.8 bya, continental crust, seas, carbon dioxide atmosphere, Pangaea, age of bacteria
synestias
impact-generates hybrid between planet and disk
cladogram
shows the evolutionary relationships among a group of organisms, how long ago that had a common ancestor
natural selection
determines how evolution functions
struggle for existence
scarcity of food, competition among species
allopatric speciation
populations get separated and eventually grow into separate populations with different features and genetics, evolution happens quicker in small group
Bottleneck events
The Great Oxygenation Event, Snowball Earth
Snowball Earth
700 mya, during breakup of Rodenia, produced massive ice age
Ediacaran Era time
560-540mya
Ediacaran importance
first multicellular life
Path dependency
the idea that certain possibilities are made more or less likely because of the historical path taken
Path dependency examples
bilateral symmetry, varnanimalcula
540 mya
Cambrian explosion, marin life
50 mya
all animal groups that live now were there
Arthropods
segmentation, same body plan, trilobites
niche
particular way of living for an organism that seems to have been adapted or sculpted by evolutionary processes
taxonomy
biological classification
acquired traits
occur in a life time, a buff guy won't have a buff kid
Phanerozoic Eon
last 600 ma, all of Earth's history
Carboniferous Period
300 mya, highest oxygen concentration, dinosaurs came about
Random walk
a stochastic or random process describing a path consisting of random steps through some mathematical space (integers), memory of previous steps
Just because there is a trend...
does not mean its destined
Evolution trends
greater size, complexity because it was the only way to go
stochastic
random, unpredictable
Big 5 extinctions
End-ordovician, devonian, permian, triassic, cretaceous
Importance of extinctions
Leads to new opportunities for the survivors, new niches, rapid genetic evolution, bottleneck effects
extinctions causes
climate change, change in sea level, plate tectonics
1st extinction
end ordovician, 425 mya, led to colonization of land, planets first, first land animal (arthropods)
2nd extinction
end Devonian, synapses diversified, pelycosaurs, therapsids (mammal-like reptiles)
3rd extinction
permian, only synapses to survive were mammals, biggest, caused by global warming and volcanoes, no more large vertebrates
Triassic
After permian, new body plans, dinosaurs rose, bipedalism, Cambrian explosion like
4th extinction
50 mya, maybe asteroid, higher CO2, killed off Dinosaur competitiors
Jurassic
age of dinosaurs, mammals are small foragers, flight evolved
5th extinction
65 million years ago, huge asteroid impact, changed earth completely, ended Dinos, sunlight blocked for year
Catastrophism
geological changes have taken shape through sudden and dramatic catastrophes, such as major volcanic events, floods, and earthquakes. Explains why the fossil record has sudden extinctions.
punctuated equilibrium
Pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change
large scales vs. small
large: more stochastic, small: more deterministic
true symbiosis
one or both partners can no longer survive without the other
mammals first appeared
triassic
Gaia
Living organisms constitutes a single earth-wide system, Huge self regulating superorganism, keeping earth's conditions good for life
patter of species
migration, innovation, growth, overexploitation, decline, stabilization
Kt Boundary
Time of mass extinction of dinosaurs
Lucy
bipedal hominine, 3.2 mya, 40% fossil
mammal
milk, three middle ear bones, neocortex in the brain
Morganucodon
First true mammal, protected brain, strong jaw, faster digestion and metabolism, replacing teeth, more upright posture, flexible
Therian mammal
primates, placentals, marsupials
KT event name
K/Pg event
Micocene
23 mya, diversification of carnivores, temp drop
last common ancestor of humans and chimps date
6-7 mya
amount of DNA shared with chimps
98.4%
contingent event in human and chimps
human ancestor had mutation where two chromosomes fused
East African Rift Valley
birthplace of humanity, 6-4.5 mya
advantages of bipedalism
Free hands, heat regulation, efficient over distance, see further
Australopithecus anamensis
4.2 - 3.8 mya The oldest species of australopithecine from East Africa and a likely ancestor to A. afarensis.
Australopithecines
walked upright, primitive stone tools, ate meat without first, omnivore, bipedal
what separates human
internal life, recognize thoughts and feelings of others, others have internal life
Note
Flashcard