Evolution of Earth Flashcards
Origin and History of Continents
Hot volcanic surface during the Hadean
Principle of Differentiation
First good evidence of plate-tectonics is in the Archean-Protozeroic boundary
Early continents accumulated Felsic Material
The stable interior of the current continents are called cratons they were formed in the Archean
What makes up a craton
The stable interior of current continents are called cratons –they were formed in the Archean
the crystalline core (the shield) and the platform made of sedimentary rocks covering the shield. A lot is added to the edges, which we call an orogen
Discovering of how life might have originated ***Possible test question check story in textbook
There are isolated ecosystems around hydrothermal vents in the ocean, where organisms survive off of chemosynthesis.
First evidence of life
The oldest fossils are from 3.5-3.8 GA
They were called Cyanobacteria
- They were prokayrotes (single cell)
Explain the Isua Formation
Is an Archean crustal belt in Greenland, it represents the most complete and largest belt of Archean crust in the world. It is date to 3.7-3.8 billion years old. It is the earthliest known stratigraphic part of earths history.
What do rocks from the Eoarchean lack
Fossils
How did Banded Iron Formations play into the development of life*** test question
iron remained in solution in the non-oxygenated environment of the earlier Archean Eon. In chemistry, this is known as a reducing environment. Once the environment was oxygenated, iron combined with free oxygen to form solid precipitates of iron oxide, such as the mineral hematite or magnetite. These precipitates accumulated into large mineral deposits with red chert known as banded-iron formations, which are dated at about 2 billion years.
Define GOE
Great Oxidation Event
Define Stomatolites
A fossil that forms as algal mats grow and capture sediment into mounds.
These first well-preserved fossils are photosynthetic microbial mats, called stromatolites, found in Australia.
Think “layered rock”
When did the first Eukaryotes appear
2 billion years ago,
Define Eukaryotes
A type of organism in with a cell or cells that contains a nucleus. The process of mitosis or splitting into identical daughter cells.
Define and explain the Ediacaran Biota
The instance or biome in the world that preserves the first multicellular life on earth
Explain the Cambrian Explosion
Part of the reason there is an explosion of life is because life can be preserved as in the Cambrian more organisms have shells. Small shelly fauna
Explain the Burgess Shale formation
massive site of preservation of soft bodied animals
very rare in the geologic record because
Life in the Paleozoic
Silurian and Devonian - age of the fishes
How did evolutionary advantages assist Coelacanth
a
Living Fossils part of Coelacanth
a
How would you classify the land in the Paleozoic
Microbial crust or Devoid of plants, thus their is no soil, this lasted until mid to late Ordovician.
Define exaptation’s
Definition of exaptation : a trait, feature, or structure of an organism or taxonomic group that takes on a function when none previously existed or that differs from its original function which had been derived by evolution. Like exoskeletons and rigid legs for support
What were the first organisms to move to land
Arthropods
Where did amphibians develop from
Bony Fish with lungs and strong limbs. First instance was in the Devonian
How do we divide marine life
Cambrian Fauna
Paleozoic Fauna
Modern Fauna
Explain the End Permian Mass Extinction (EPME)
3 Million cubic kilometers of basaltic lava flowed out of hot spots in Siberia and the burning of all the coal lead to a significant rise in C02. This reduced oceanic circulation which lead to lower oxygen levels, another bioproduct of CO2 was increased chemical weathering. This produced algal blooms which mass consumed C02 and produced anoxic or stratified oceans after the Alga died.
What are the time periods within the Mesozoic
Cretaceous
Jurassic
Triassic
What are two defining features of life within the Mesozoic
The late Triassic was the first time Dinosaurs’ came around.
Jurassic had the first flowers and Mammals
Two major groups of Dinosaurs
Ornithischian ---Bird hipped -------Stegosaurs: Mid Jurassic - late Cretaceous, -------Hadrosaurs: Late Cretaceous: -------Ceratopsians: Late Cretaceous -------Ankylosaurs: Saurischian -----lizard hipped --------Sauropods --------Theropods: Meat eaters, most major groups in Cretaceous
What is a defining feature of Ornithischian
All herbivores
Are all reptiles dinosaurs?
No
Explain and Define the Cretaceous-Paleogene Boundary
Line of evidence suggesting an asteroid impact occurred in the Yucatan, around 60% of all know animals became extinct. A deposit of 1cm of clay with a high iridium content marks the boundary of Cretaceous and Paleogene.
What are 3 lines of evidence for an asteroid impact
High iridium content clay
Shock patterns in grains of quartz
Glassy Beads
How many major extinction events were there
5
What time period did mammals become dominant
Cenozoic
when was the first evidence of plate tectonics
First good evidence of plate-tectonics is in the Archean-Protozeroic boundary
