Can you just teach this course please? lol :)
Geology 105: Exam 1 Study Guide
1. What is Evolution?
Biological evolution is the cumulative changes that occur in a population over time. 2. There are multiple layers to evolution, what is a fact (observable and predictable)?
∙ Evolution is a fact (law) and a theory, therefore it observable and explains “why”. o Fact- defines it as descent with modification, meaning every generation is slightly different than the one before. Don't forget about the age old question of Who moved to the south to find opportunity and to take advantage of the chaos?
o Theory- says that all life on earth descended from single-celled organisms through evolution.
3. How does evolution work?
∙ Genetic variation: every generation has a varied genetic structure ∙ Certain traits are passed down to offspring
4. Why do changes happen?
Survival of the fittest, the best adaptive trait is received in order to survive. Factors that promote a new species or new characteristics:
∙ climate change
∙ extinction events (killing off most of the current life forms)
Ex. White and brown mice. If there are white, dark brown, and light brown baby mice move into an area that has darker soil, the mice will get darker (dark brown babies will survive) We also discuss several other topics like What are the longterm consequences of the 14th amend?
5. Why are some traits preserved?
Because they allow the organism to survive.
6. How does natural selection work vs. artificial selection?
Natural selection is when genes are naturally passed down from parents to offspring, usually the best genes are passed down in order to survive.
Artificial selection is selective breeding so only certain, desirable traits move forward 7. What factors increase diversity? (form new species & characteristics)
∙ Isolation- isolated communities tend to have lower diversity, however, isolating a population from other parts enables diversity between isolated populations
∙ Mutations, evolving
∙ Nutrition- do you get enough food?
∙ Climate change- how do you compete for food source?
∙ Predator evasion We also discuss several other topics like What are the two types of sites that can be occupied ions?
∙ Resistance to diseases
∙ Extinction events (killing off most of the current life forms)
8. What is natural selection?
When individuals in a population well-adapted to a particular set of environmental conditions have an advantage over those no as well-adapted, it allows the favorable trait to live on. If you want to learn more check out Why did the us declare war on germany in april 1917?
∙ You survive how your babies survive.
Ex. a baby born without teeth will not be able to eat seeds. In this environment, your babies are on top.
9. What effects which genetic material gets passed on? (have healthy babies)
∙ Ability to reach sexual maturity without getting eaten
∙ Enough food to make you healthy
∙ Ability to fight off a disease
∙ Body temperature
∙ Ability to attract a healthy mate
∙ Ability to reproduce
10. How do we know that some things are older than others?
Dates of fossils
11. What assumptions do we make?
We assume that the oldest rocks are at the bottom and the youngest are on the top. 12. What principles do we adhere to determine relative age?
∙ Principle of Original Horizontality: sedimentary rocks (rocks deposited by wind & water) were originally flat. Most deposited in water, not land, because over time land erodes away
∙ Principle of Superposition: oldest, undisturbed sedimentary rocks on the bottom ∙ Geologic time scale: (before numbers)
∙ Unconformity: missing time (thick line on columns indicating age) in sediments. A period of non-deposition/erosion (at a specific location, the rocks were not preserved at that time) If you want to learn more check out What is biological anthropology?
∙ Principle of Cross Cutting Relationships: a feature that cuts another feature is the younger of the two
∙ Faunal succession: an established succession of fossils found throughout the world ∙ Stratigraphic columns: tell us the sequence We also discuss several other topics like How are business trends impacting careers?
∙ Index fossils: used to characterize a time (if find in one place & somewhere else ???? same age)
o Short lived
o Abundant in fossil record
o Widely distributed
13. What is the difference between relative & absolute age?
∙ Relative Dating: which is older than which, based on fundamental assumption that the oldest, undisturbed rocks are on the bottom
∙ Absolute dating: radiometric dating of isotopes gives us approximate number of years since the X was deposited
14. Combine to determine types of rocks.
15. How do we determine absolute age of rocks?
Radioactivity/radiometric decay (half-lives)
16. What types of rocks do we use? Why?
Fossils? We can determine how old the fossil is through radioactivity. 17. What is the geologic time scale?
∙ A scale found before there were numbers/dates
∙ Whenever you don’t see certain fossils anymore it means the end of that time ∙ Find group of fossils & other things- put them in time frame
∙ Different group of fossils means a different time period
o However, sitting on top of each other means it was changing over time 18. Know the major dates/names up to the Cambrian.
o First fishes
o First chordates
o Sudden diversification of metazoan families
o First vascular land plants
o First amphibians
o Jawed fishes diversify
∙ Carboniferous: Pennsylvanian, Mississippian
o first reptiles
o soale trees
o seed ferns
o Major extinctions
o Reptiles diversify
o First mammals
o First dinosaurs
o First birds
o Dinosaurs diversify
o Extinction of dinosaurs
o First primates
o First flowering plants
o Mammals diversify
o Evolution of humans
19. What is radioactivity?
Particles emitted from the nuclei as a result of instability.
20. How does it work?
∙ Beta Decay: a neutron is turned into a proton & an electron. The electron is still then emitted.
∙ Gamma Decay: The nucleus falls down to a lower energy state & in the process emits a high energy proton known as a gamma particle. MOST DANGEROUS.
∙ length of time it takes to lose half of the starting amount
∙ time it takes for half the parent atom to turn into the daughter atom ∙ Example: you are trying to determine the age of an ashfall with some dinosaur bones. When you measure the radioactive element you find that you have 2100
daughter elements & 300 parent elements. The half-life of the unstable isotope is 75 million years. How old are the dinosaur bones?
2100 + 300 = 2400
2400/2 = 1200
1200/2 = 600
600/2 = 300
Dive by 2 three times. 3 x 75,000,000
o 225 million years
Formation of the Universe & Earth
21. What is the Big Bang?
It flung the basis for everything in the universe out. Scientists theorize that all matter in the universe was once crammed into a tiny area that then exploded all the matter into space
∙ Hydrogen (H)
∙ Some Helium (He)
22. What evidence is there for it?
One line of evidence that scientists give is that everything in the universe looks slightly red in the telescope because everything is moving away from everything else
∙ This glow should be visible as microwaves, part of the electromagnetic spectrum 23. How do we know how old it is?
The oldest earth mineral (Zircon) is about 4.375 billion years old, give or take about 6 million years
24. What did it create?
Hydrogen (H) & Helium (He)
25. How did we get planets?
A star explodes and dies because the elements get too big to get into each other, so the star collapses on itself. It isn’t stable so it blows up because there is too much energy in such a small space. The elements these stars create also explode and are flung into space, creating new planets.
26. How did we get the elements?
The stars create them after dying (due to lots of heat through fiction & compaction). When they are flung out into space many new elements are formed.
27. How did the Earth form?
∙ Giant dust clouds (without all possible elements formed) begin to spin & condense, the center forms a new sun and the elements in the clouds form clumps (from gravity), each clump attracts more material, therefore planetesimals (little planets) form.
∙ It was molten due to the heat from all of the asteroids that hit it and because it was ductile its spin made it round
28. Why is it different than Jupiter/Saturn (outer Jovian planets)?
∙ They don’t have a liquid outer core like Earth does because we have enough latent heat (heat left over) to have liquid. The weight of the Earth creates tons of pressure at the solid, inner core, keeping it at a solid state
∙ The warmer atoms rise because of low pressure
∙ Cooler atoms sink, become more dense, high pressure
29. How did the interior form?
The earth then cooled enough for Iron (Fe) & Nickel (Ni) core to sink 30. How did the moon form, how do we know?
While the Earth was a molten blob (from something massive) a giant, moon-sized piece of earth comes off and created the moon. We know because it got hit about 4.7 billion years ago (while our whole universe was forming), the age of the moon is the same age as the asteroids.
31. What created the magnetic field?
The solid, Iron (Fe) core surrounded by liquid, Iron (Fe) core interacts with the electrical field of sun to generate a magnetic field
32. Why were the planets molten?
They were molten due to the heat from the asteroids.
33. How can we tell it was molten and asteroids weren’t?
We know they were molten because the planets are round, whereas the asteroids (that didn’t melt) are lumpy.
34. Why is the magnetic field important?
∙ The magnetic field protects us from the solar wind by deflecting elements from the sun
o Blocks the sun’s radiation
∙ It also allows us to navigate
35. Where did the atmosphere and ocean come from?
∙ The atmosphere forms due to a build-up of primary gases: Carbon Dioxide (CO2), Water (H20), Chlorine (Cl), Hydrogen (H), & Nitrogen (N) spewed out from volcanoes while the earth cooled
∙ For the oceans to form, the earth has to cool enough for water to precipitate out of the atmosphere
36. What does the interior of the Earth look like?
∙ Crust: felsic or mafic
▪ Oceanic crust: mafic
▪ Continental crust: felsic
∙ Mantle: ultra-mafic
o Outer: liquid iron
o Inner: solid iron
37. How is plate tectonics tied to the formation of the Earth?
Because they form continents and they move together.
38. How does plate tectonics affect the atmosphere?
At convergent boundaries mountains form, which allow carbon dioxide to be released from the atmosphere. At subduction zones the old, cold lithosphere sinks, the subducting plate adds water to the mantle, causing it to melt (low density), then it rises to the surface & creates volcanoes (which release gases).
Therefore, plate tectonics don’t allow as much CO2 build up on Earth
39. How did we get continental crust and ocean crust?
Plate boundaries. Oceanic crust is denser than continental crust because it is mafic and made up of Iron. Decompression melting of the mantle = mafic lava and oceanic crust.
Continental crust formed due to convergent boundaries? Rocks form and pile up due to felsic magma from volcanoes? Makes it less dense? Volcanoes and mountains make continents.
Water from subduction zones goes into the mantel (it is trapped in the sediments that dive down with the rest of the oceanic lithosphere) and the same water comes back out of the composite/stratovolcanoes at subduction zones to keep the water volume on the surface of the earth to stay.
40. How is the early earth different and similar to today?
∙ CO2/H20 atmosphere
o also ammonia & methane
∙ Hot ???? speed = lots of volcanoes
∙ Mostly ocean
∙ Land looks like barren eroding wasteland (basalt)
∙ Lots of volcanoes
∙ O2 atmosphere
∙ Now have continents and land
∙ Living things: plants, animals, people
41. What are they?
An element is defined by the number of protons
42. What makes them up?
Protons, neutrons, and electrons
43. What is an isotope?
Changing the mass (neutrons) of an element makes it a different form of the element (still the same element though)
44. How are density, temperature, pressure, and elemental spazzing related?
When elements are compressed they generate heat, so the hot elements in the center push to the outside of the clump of elements. Heat gets hot enough to cause super speed & fusion cascades into a massive nuclear ball. If it is spazzing than it is less dense (because heat is rising)
45. What is the difference between fusion & elemental bonding?
Fusion: two elements slam into each other & combine their nucleus’s
In elemental bonding:
∙ Ionic bond: one atom gains electrons the other loses electrons
∙ Covalent bond: sharing of electron pairs
∙ Metallic bond: sharing of electrons between metals
**These are just answers to the questions asked on the Study Guide. Not everything from all of the lectures and PowerPoints are covered on this review, but they are definitely in my previous notes and the PowerPoint slides on OAKS (: