Exam 2 Study Guide Flashcards
What is radioactive decay?
Decay of unstable isotopes to stable Isotopes
What are isotopes?
Same number of protons, different number of neutrons
What is a half-life?
The amount of time it takes for half of the percent isotopes (unstable) to decay
How old is the earth?
4.65 billion years
What is the age of the earth based on?
Meteorites
How did the earth form?
Clumping together of material from the Big Bang
What are the different types of radioactive decay?
Alpha, beta, electron capture
What method is used to date younger events versus older events?
Younger is carbon 14 up to 70,000 years
Older stuff argon-argon, potassium-argon, uranium- thorium
What was the beagle in relation to Darwin?
Ship he sailed on
How did john jolly attempt to determine the age of the earth?
Salinity of the sea
How did lord kelvin attempt to calculate the age of the earth?
Cooling of the earth
What is Antoine Henri-Becquerel associated with?
First to note radioactive decay
Why are unstable isotopes useful for dating rocks?
Decay at a steady rate
According to young earthers, how old is the earth?
6017 years
Who calculated the age of the young earth?
Bishop ussher
What is catastrophism?
States that earth was created by a series of catastrophe allows for young earth physics has changed
What is the approximate age of the universe?
13-15 billion years old
What is a trace fossil?
Evidence that an organism was there. Ex. Coprolite, foot print, burrow, nest, track way
How was the moon formed?
A large mars size planet hit earth and splash debris into space which coalesced into the moon.
How did the universe form?
From a singularity that began expanding (Big Bang)
Compare and contrast relative dating and absolute dating
Relative dating puta things in a sequence.
Absolute(numerical) assign an age in numbers
What did Darwin’s finches and tortoises display that contributed to evolutionary theory?
A) finishes had variety of beaks types based on the environment in which they lived.
B) tortoises had a variety of shell and neck morphology based on the environment in which they lived; area with high shrubs had tortoises with long necks.
What are vestigial organs?
Organ that do not serve a purpose but may have at some point in the past. Ex. Appendix in humans, legs on a skinks, femur in whales
What drive evolution?
Mutation
What is natural selection?
Nature selects the strong most viable species survival of the fittest.
What was the tile of Darwin’s book and when was it published?
On the Origin of the Species 1859
What is homology?
Different species have similar or same traits. Ex. Radius and ulna in humans, bat, whales, horses.
Key components of natural selection.
A) all organisms exhibit variability
B) more offsprings than survive
C) individual most suited to their environment survive, those less suited fail to reproduce
D) the characteristic of the strongest are passed on
What is Speciation?
Origin of new species from two preexisting species and must produce viable offspring.
What is evolutionary convergence?
Evolution of similar forms in two or more biological groups
What is extinction?
Loss of a species
What is mass extinction?
Significant number of species die off in a short period of time.
What is cope’s rules?
Body size increase during evolution
What is dollo’s law?
Evolution does not reverse
What are the geological principles?
Super position, cross cutting, age of inclusion, biological succession, original horizontally, unconformity (gap in rock record)
What types of rocks can be dated?
Igneous
What are the three main eras?
Paleozoic, Mesozoic, and Cenozoic
How was the geologic time scales originally constructed?
Base on observation and relative age dating
How old must something be in order to be considered a fossil?
20,000 years
What are altered vs unaltered remains?
Altered remains: had been changed
Unaltered: no change to original material
What are types of unaltered fossils?
Freezing, tar impregnation, amber entombment
What are types of altered remains?
Replacement, recrystallization, permineralization
What types of fossils have been found in California?
Trilobites, sharks, plesiosaurs, mosasaurs, giant short faced bear, saber toothed cat, direr wolf, mammoths, hadrosaur
