Exam #4 Flashcards
Explain the difference between a hypothesis and a theory.
A hypothesis is a proposed explanation for a set of phenomena based on experience, observations, and logic.
A theory is a broad explanation for a wide range of phenomena, they are concise, coherent, systematic, and broadly applicable.
Explain the importance/qualifications of BIOSTRATIGRAPHY, and give examples.
Qualifications: wide geographic range, short stratographic range.
Biostratigraphy uses fossils to date rocks; helps determine ages of sedimentary rock structures.
Examples: Conodonts, Ammonoid Cephalopods
What factors contributed to MESOZOIC SEA LEVEL FLUCTUATIONS?
The rate of sea floor spreading as well as the lack of continental glaciations throughout the Mesozoic contributed to a general increase in sea level.
Describe the CLIMATE OF THE MESOZOIC.
Greenhouse climate (warm and wet)
Explain the differences between DIVERSITY vs DISPARITY
DIVERSITY refers to the taxonomic richness; the phanerozoic trend is generally up.
DISPARITY refers to variations in anatomy
Describe LAGERSTATTEN and provide an example.
LAGERSTATTEN is a fossil deposit rich in well preserved and well varied fossils. The most famous example is the KONZENTRAT-LAGERSTATTEN in Germany.
Describe the orogenic events that contributed to the geology of Utah.
Sonoma Orogeny - Permian/Triassic; results in the accretion of Paleozoic island arc terrains in Western N America
Nevadan - Jurrasic; uplift in California, Nevada, Western Utah and Idaho causing major depositional changes on the eastern side of the new mountain ranges (Sierra Nevada). Sediment from eroded mountains is deposited forming thick sequences of siliciclastic strata in Utah, Colorado and Wyoming.
Sevier - Jurrasic/Cretaceous; produced a zone of eastward-directed thrust faults and folds (and deformed rock strata) throughout southeastern California, southern Nevada, western Utah and western Wyoming.
Laramide - Cretaceous/Paleogene; produced structures in Utah, western Colorado, and Wyoming. (Includes the Uinta Mountain uplift).
Describe the difference between PROKARYOTES and EUKARYOTES
EUKAROYOTIC CELLS have a nucleus, membrane-enclosed organelles and carbohydrates that serve as receptors while Prokaryotes do not.
Describe the trends of reef-building organisms during the Mesozoic.
Cnidarians, Proiferans, Stromatoperoids flourished on the seafloor.
Describe the differences of BENTHIC MARINE COMMUNITIES during the Paleozoic and Mesozoic.
Dominated by trilobites, brachiopods, and bryozoans throughout the Paleozoic, Mollusks were generally rare.
Mesozoic oceans were populated by a rich and diverse fauna of fish, reptiles, and a variety of cephalopod mollusks including the ammonites and the belemnites
Describe the formation of SALT DOMES and the geologic features associated.
SALT DOMES form with the formation of an ocean basin; the water is cut off and sedimentation begins to take place. Due to it’s buoyancy, salt rises. A salt dome consists of a core of salt and an envelope of surrounding strata. In some areas, the core may contain “cap rock” and “sheath” in addition to salt.
Describe/give examples of HOMOLOGOUS STRUCTURES
A homologous structure is an example of an organ or bone that appears in different animals, underlining anatomical commonalities demonstrating descent from a common ancestor. A dolphin’s flipper, bird’s wing, cat’s leg, and the human arm are considered homologous structures.
Describe/give examples of CONVERGENT EVOLUTION
convergent evolution is the process whereby organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. Example: Crocodile and phidosaurus. Ostrich and Orithnominus.
Describe/give examples of CO EVOLUTION
Coevolution is when two different species evolve in a coordinated fashion. Example: Angiosperms (flowering plants) and insects.
List/Describe the major mass extinction events and potential causes.
end-ordivician, late devonian, end-permian, end-triassic, end-cretaceous. Possible causes: possible decline in sulinian levels may be a factor in Triassic mass extinction, eruption of a super volcano or prolonged episodes of volcanism (correlates to major volcanism in India end cretaceous) - gases impact atmosphere and marine chemistry. Formation/deformation of super continents (causes changes is eustatic sea level changes and removal of habitat). Asteroid impacts. Inability of animals to reproduce due to increased temps.
