Exam 3 Flashcards
Relative Dating
Earths layers, the lower the strata the older it is, the higher strata the younger it is
one is older than the other but don’t know how old
Numerical Dating
Is related to putting a time (age) into how old the layers on Earth are in the sense of the lowest layer as the oldest and how old it is.
based on radioactive decay can tell how old something is.
Alpha Decay
basically lose 2 proton and 2 neutrons lose 4 atomic mas and lose 2 atomic number
Beta Decay
don’t change atomic mass increase 1 atomic number
Gamma Decay
Dangerous rays
doesn’t change atomic number, doesn’t change atomic mass, gamma rays the worst.
Atomic Number
The number of protons in the nucleus.
Atomic Mass
The sum of the number of protons and neutrons in the nucleus .
Radioactive half-life
The interval of time required for one-half of the atomic nuclei of a radioactive sample to decay.
Decay Series
Chain of radioactive decays where an unstable atom transforms into a series of different elements until it becomes a stable, non-radioactive atom.
Radiometric Dating
Method used to measuring the amount of radioactive elements they contain and calculating how long it took for those elements to decay.
Model Conversion Factor*
Reconstruct what the animal might have looked like, including how big it may have been, construct a small scale model of the animal, and then estimate the total weight of its bones, muscles and other tissues using a conversion equation
Density
Measure of how much mass is packed into a given amount of space; it tells us how heavy or light something feels for its size.
Metric Ton
Unit equal to 1,000 kg
U.S Ton
Unit equal to 2,000 pounds
Local extinction
The loss of an organism in a local area.
Global extinction
The loss of an organism from the planet.
Background extinction
The constant, low level loss of species from the planet.
Mass extinction
The loss of a significant portion of the organisms that had been alive during a fairly short time period.
Cyclic Mass Extinction
Mass extinctions that occur on a repeating regular basis.
Siberian Traps
similarity: both result of extensive volcanism, indicative of volcanic activity going on for a long time, associated Permian extinction, older
Area of an extensive lava.
Lava that covers 2 km thick almost a 1 million square miles that covers.
Deccan Traps
associated with the dinosaur extinction, extensive volcanism
Extensive volcanism, Located in India or where India was, 65 million years ago.
2,000 meters thick.
Covering 500,000 km2 (193,051square miles)
Antarctic Crater
Evidence of a bolide Crater in Antartica dates about 250 million years ago.
Chicxulub
massive crater buried under Mexico’s Yucatán Peninsula. It was created about 66 million years ago when a huge asteroid or comet hit Earth. This impact is believed to have caused the mass extinction of the dinosaurs by triggering massive fires, a “nuclear winter” from dust blocking sunlight, and drastic changes to the climate.
Shiva Bolide Crater
Crater right next to India, dates about 65 million years ago,
Topics related to readings:
The argument surrounding the collar vbone and the dinosaur-bird connection
Topics related to readings:
Mosaic evolution in the dinosaur/bird transition
Def: diff parts of the body evolve at diff rates, ex. Human lose body hair, brain got bigger, walking bipedally, 3 toe feet, happened earlier feathers happens a lot later, getting smaller in size, changes happened in time nothing happen at once.
Topics related to readings:
Melanosomes and the color of feathers
(melanosomes) cells have pigments, different shapes different colors
Topics related to readings:
Feathered dinosaurs and the role od feathers before flight.
- Homeothermic thermal regulation, to keep heat in the body, bigger feathers (melanosomes) cells have pigments, different shapes different colors, feathers for display, for intimidating other males, some dinosaurs flew (microraptor)
Topics related to readings:
The sequencew of devastating events following the bolide impact 65 million years ago. (look in the chapter)
The flash of the meteor coming into earth, earthquakes, volcanos started erupting, rain was glass and chunks of rock coming down, tornadoes, wildfires, extreme heat, tsunamis, no sunlight= no plants, no plants=no food for some animals
Topics related to readings:
The probability of extinction in relation to body size, aquatic habits, omnivorous diet, “cold-blooded” physiology, and generation time.
- Metabolism: warm blood require a lot of energy, produce a lot of internal heat, those that don’t produce internal heat don’t need a lot of food and don’t spend a lot of
- Aquatic: can be in environment that doesn’t change the temperature a lot, moderate were able to survive
- Omnivorous: eat plants and animals, the more things you can eat the better when there isn’t one thing you can eat the other,
- Body size: the bigger you are the more food you need, small live of scraps, small things can survive underground can hide, bigger things can’t hide.
Topics related to readings:
Peramorphosis and the evolution of mammals after the bolide impact
- Peramorposis: increase in some characteristic over evolutionary time, dinosaur were smalls and then got bigger.
- Paedomorphosis: example birds from a large ancestor got smaller and smaller.
- Relate it to hox genes: controls the genes that some characteristics grow and other don’t.
- Mammals when dinosaurs were around they were small and once dinosaurs got extinct then they started to get bigger, there was less competitions, getting bigger was an advantage.
Describe the differences in the model conversion and key measurements methods of determining dinosaur weights.
Describe the possible roles that the supercontinent Pangea, the Siberian traps, and the Antarctic bolide crater had in the end Permian extinction.
Pangea: The supercontinent Pangea formed during this time, combining most of Earth’s land into one giant landmass. This caused drastic changes in climate, reduced coastal habitats, and created dry, harsh interiors, making survival difficult for many species.
Siberian Traps: Massive volcanic eruptions in Siberia released huge amounts of lava, ash, and greenhouse gases like carbon dioxide and methane. This likely caused global warming, ocean acidification, and a lack of oxygen in the seas, killing many marine and land species.
Antarctic Bolide Crater: A large impact event, like the one that formed a crater in Antarctica, might have added to the disaster by causing earthquakes, wildfires, and more environmental damage, further stressing life on Earth.
Together, these events created a perfect storm of environmental crises that wiped out most of Earth’s species.
Describe the possible roles that the Chicxulub bolide crater, the postulated Shiva bolide crater, and the Deccan traps had in the end Cretaceous extinction.
Chicxulub Bolide Crater: A massive asteroid hit Earth in what is now Mexico, creating the Chicxulub crater. This impact released huge amounts of dust and gases into the atmosphere, blocking sunlight, causing fires, and triggering a “nuclear winter,” which led to rapid cooling and disrupted ecosystems.
Postulated Shiva Bolide Crater: Another possible impact, the Shiva crater in India, might have added to the chaos with similar effects, including fires, earthquakes, and atmospheric changes, although its role is less certain.
Deccan Traps: At the same time, massive volcanic eruptions in India created the Deccan Traps, releasing huge amounts of lava, carbon dioxide, and sulfur gases. These gases caused climate change, ocean acidification, and further stress on life.
These events likely worked together, creating a chain reaction of environmental disasters that made it impossible for many species, including the dinosaurs, to survive.
Describe a possible cause for cyclic mass extinctions.
A possible cause for cyclic mass extinctions is changes in Earth’s environment caused by regular cosmic events.
For example, as our solar system moves through the galaxy, it might pass through regions with more comets or denser interstellar clouds, increasing impacts on Earth or blocking sunlight. These events could disrupt ecosystems and trigger extinction cycles over millions of years.
Determine the changes in atomic mass and atomic number given the type of radioactive decay.
Calculate the speed of a dinosaur given data from its footprints.
Leg length = Footprint Length x 5.0
Relative Stride Length = Stride Length/ Leg length
Dimensionless speed = (Relative Stride Length – 0.8) / 1.25
Speed = Dimensionless speed x √ (leg length x 9.8 m/s2)
Calculate the weight of a dinosaur given specific information from a model of the dinosaur.
Weight = Density x Volume x model conversion factor
Calculate the age of a fossil given the proportion of radioactive material present in the sample.
Time = (the half-life of the element/0.693) x ln [(daughter/parent) + 1]
