Untitled Flashcards Set

• Theory: something that explains the natural world that is well tested.

  • No “theory” of gravity, bc there's no explanation

  • No theory is safe in science, can always be retested and overturned.

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• Uniformitarianism: The idea that all scientific principles work the same everywhere, every time.

  • Physics works the same today as they did millions of years ago.

  • The dirt washes into the rivers and the mountains get smaller, ak

• Catastrophism: Uniformitarianism works, but sometimes there are things that happen fast and make huge changes

  • The Mediterranean Sea flooded into the Black Sea, and flooded an entire town.

  • Meteor wiped out the dinosaurs & nuclear winter

• Hypothesis: A guess that will be tested with the intention of becoming a theory.

  • “Every experiment demonstrates something, maybe not what was intended but something.”

  • A hypothesis must be falsifiable.

• We had the biggest mountains ever on campus apparently??

  • Near Buchanan Park??

• There is always uncertainty in science

  • In science there are often more questions raised from a test than answers.

  • The more people know the larger the boundary between knowledge and ignorance.

  • “All I know is that I know nothing”

• Simplicity in science is good.

  • Simple is more likely to be correct.

• Science is not democratic, it is one truth.

  • “In questions of science the authority of 1000 is not worth the humble reasoning of a single individual.”

• Consensus: When the majority of scientists agree on one thing.

  • Perspective is important: If there is dissent, look into why and compare to amount of consensus. (Anti-Climate change funded by oil).

• Disproving is the proof

  • We can't prove anything in the positive sense.

  • When you can't prove that you are wrong, you can expedite doubt.

  • “Scientists start by trying very hard to disprove what they hope is true. When they fail they have a good reason for believing.”

  • “You cannot prove that all swans are white by counting white swans, but you can prove that not all swans are white by counting just one black swan.”

• Malthusian: A theory proved wrong by a change in environmental impact.

• Human population consumes many resources.

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• Big Ideas:

  • Deep Time

    • Radiometric Dating (how do we know how old the Earth is)

    • Deep Space= Deep Time (Time Dilation)

  • Cycles and Spheres

    • Feedbacks

    • Environmental Unity

  • Plate Tectonics

  • Evolution

• Deep Time:

  • The Earth is old & the Universe is older.

    • Preservation of rocks tells us the age of the Earth.

• Radiometric Dating: the ratio of a parent product to a daughter product. (how long something takes to decay & become something else, rate is completely steady)

• Half-Life: The time it take for one half of a material to turn into its daughter material.

• How do we know how old the Universe is?

  • B/C light has a finite speed (299,792,458 m/s)

  • How long it takes the light to travel tells us the age.

• Lightyear: The distance light can travel in one year. 

• The Doppler Effect: The shift of frequency of a wave in relation to an observer due to relative motion of the wave source and observer

  • Ex: a siren lowering in pitch as it passes you, a color changing to higher frequency blue shifted light as it moves towards you.

  • A galaxy’s age can be estimated by its color shift. 

• Cycles: Transfer of material through Earth’s systems (water cycle, rock cycle, nutrient cycle, carbon cycle, etc).

  • Matter & Energy cycle between the Spheres if the Earth

    • Atmosphere

      • Consists of the gases that surround Earth.

    • Geosphere

      • Consists of the rock (solid and molten) and material derived from rock that make up Earth. 

    • Hydrosphere

      • Consists of all the water (both liquid and frozen) ON Earth’s surface AND underground.

    • Biosphere

      • Consists of all the living organisms that inhabit the Earth.

    • Cryosphere

      • Consists of all the frozen things BELOW the land AND ocean surface. 

  • Ex: carbon cycle

    • Dying plants release carbon, growing plants take carbon, the oceans take and push out carbon, weathering rocks take and push out carbon.

    • Carbon in the atmosphere is increasing because the cycle is not in a consistent flux.

• Milankovitch Cycles: Periodic changes in the shape of Earth’s orbit around the Sun

  • Cycles of atmospheric CH4 vs Insulation.

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• CO2 goes up due to plant emissions (as they decay) in the northern hemisphere.

• Humans interrupted the methane cycle by beginning to farm (plants grown release more emissions)

  • Keeps us from entering an ice age

• Positive Feedback: Self sustaining or run-away 

  • Ex: Earth grew bc of gravitational attraction of dust to each other. (More mass, stronger attraction, loop) 

  • Ex: Water vapor as a greenhouse gas (as the earth warms, more water vapor from the sea, loop)

  • Not necessarily good

• Negative Feedback: means self-limiting or stable

  • Ex: Water vapor heats the earth, causes more clouds, earth does not warm anymore

• Tipping Point: When 1 type of feedback becomes another.

  • Ex: Energy consumption:

    • Negative feedback now

    • Burning fossil fuels burns into the atmosphere, warms the earth, makes the earth warmer, less need to burn fossil fuels

    • Tipping point: Earth will eventually be so warm that we need AC to stay alive, burn more fossil fuels, the Earth will warm, more AC needed, loop.

• Plate Tectonics: Plates shift the continents as new crust is created, sea floor carries continents along.

  • Alfred Wegner observed that you could fit Africa & South America together.

  • Believed the continents had moved

  • Found that the rocks in Africa and SA were the same across the Atlantic Ocean

  • Looked at fossils in Africa and SA, they were the same too. Also connected india & Antarctica & Australia with the same fossils.

  • Looked at glacial deposits, same too across continents.

    • This showed him what the Earth used to look like.

  • He hypothesized “Continental Drift”, but had no “Theory” because he didn't know why it happened. So, he never got credit.

• Evolution:

  • Explains life

  • C,H,O,S,N, (and maybe P) (Think chosen)

    • Carbon, hydrogen, oxygen, sulfur, nitrogen (and maybe phosphorus)

  • Building Blocks of Life:

    • Free hydrogen (H2)

    • Free oxygen (O2)

    • Water (H2O)

    • Hydrogen Sulfide (H2S)

    • Carbon Dioxide (CO2)

    • Ammonia (NH3)

    • Methane (CH4)

    • Hydrogen Cyanide (HCN)

  • What is the Origin of Life?

    • Many theories.

    • Amino acids in “Primordial Soup”.

    • Deep sea volcanic vents

    • An experiment by Miller and Urey got close, by creating RNA.

  • Biodiversity: Variety of living things

  • Charles Darwin’s Theory of Evolution:

    • Evolution, or change over time, is the process by which modern organisms have descended from ancient organisms.

    • Looking at fossils, he wondered where these organisms went? 

    • Hypothesis: Species may have came from different island from an OG ancestor, but differing environments favored different characteristics, so different species thrived in different environments. The species breed and change over time.

  • The first theory of evolution came from Lamarck, who though humanity wanted to achieve perfection through breeding.

  • Charles Darwin finished his book before Alfred Russel Wallace could finish his theory

  • Artificial Selection: 

    • Mutations: (natural variation) make differences among a species

    • Artificial Selection: Human select and breed variations they find useful (dog breeds)

  • Natural Selection: Members of a species that are able to thrive in an environment will breed with others like them and create a species that can survive their environment.

  • Survival of the Fittest: Some individuals are better suited for their environment.

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• If a difference (Mutation) between parent and offspring is advantageous, they may survive better and pass that difference (mutation) onto kids who will be more advantageous

  • Some mutations are good, some are bad (birth defects)

• Mutations are random, but natural selection is not.

  • Advantageous mutations will slowly but surely prevail in a species

• Evolution stops when they get it rights

  • Sharks are the same b/c they are apex predators, perfect for their environment

  • Quick reproducers and matures can adapt better to quickly changing environments

• Sexual Selection:

  • Traits with no true advantage that may be attractive to random individuals. B/c the trait is attractive, it helps increase reproduction. 

    • Passes on that trait, and the attraction to that trait.

• Descent

  • Descent with Modification: Each living organism has descended, with changes, from other species over time

  • Common Descent: Derived from Common Ancestors

• The Fossil Record:

  • Layers show changes within species and from species to species (Oldest at bottom youngest at top)

• Geographic Distribution of Living Things: 

  • Similar environments have similar types of organisms (often not related)

• Convergent Evolution: 

  • the process where unrelated species independently evolve similar traits or adaptations due to similar environmental pressures.

• Homologous Structures: 

  • Similar physical features in organisms that share a common ancestor, but the features serve completely different functions.

• Analogous:

  •  features of different species that are similar in function but not necessarily in structure and which do not derive from a common ancestral feature

• Vestigial Organs: 

  • Serve no modern useful function, but did in the past (appendix, wisdom teeth)

• Lost organs: 

  • Organs that do not appear on closely related species who do not need them

• Speciation:

  • How new species appear. When a group within a species separates from other members of its species and develops its own unique characteristics. (Due to Isolation)

• Isolation:

  • Geographic Isolation: Species occur in different areas, which often are separated by a barrier (river, mountain range)

  • Ecological Isolation: Species occur in the same area, but they occupy different habitats and rarely encounter each other.

  • Temporal Isolation: Species reproduce at different seasons or at different times of day

• Extinction occurs when environmental changes are too rapid