Chapter 22-24: Geologic Time Flashcards
describe the general theory of how the Earth was created
That it was formed at the same time as the rest of the solar system 4.6 billion years ago
How old is the Earth? How is this age determined?
4.2+ billion years ago, geologist have used radiometric dating on zicron traces (a mineral in granite) in Australia
prokaryotes vs. eukaryotes
- single cell
- multiple cells containing a nuleus
How did the Earth’s crust form
cooling of the uppermost mantle,
Describe the Precambrian atmosphere and how oxygen got into the atmosphere
hydrogen and helium likely dominated the atmosphere but being so light, they could not stay in the atmosphere because earth’s gravity is not strong enough. Some of the earliest organisms, cynobacteria, used photosynthesis to create food and therefore let off oxygen as as byproduct. billions of this bacteria produced the oxygen in the atmosphere
How did early life come to be
3.9-2.5 billion years ago life likely started to form. The Earth’s atmosphere likely contained carbon dioxide, nitrogen, water vapor, methane and ammonia. Around this time as well, earth had may lightning storms making it very warm. making the perfect environment for primordial soup. in which the life may have begun. This environment would have created the amino acids necessary for life to begin
transgression
sea level rises and shoreline moves further inland
regression
sea level falls and coastline moves seaward
what was life like in the middle to late Paleozoic
MIDDLE PALEOZOIC
- predominately dominated by sea creatures
- plants emerged on land
- vascular tissue spreading water allowed earth planets
- seed ferns allowed a more thorough colonization
LATE PALEOZOIC
- fish and sharks
- plants invaded the land
- swampy lands were breeding ground for insects
How did life move to land
the development of vascular tissue in plants allowed water and nutrients to circulate through the plant so it could survive outside the water. Seed ferns developed and allowed plants to make their own food and truly live on the land, they reproduced off of seeds so they could spread out on the land colonizing it
Major events during the Mesozoic
- break up of Pangaea
- active tectonics in West North America
- sand covered america, then a shallow sea
- mammals and bugs evolve
- cycad plants
- dinosaurs
- flying creatures
- Permian mass extinction
Major events in the Cenozoic Era
- ice ages
- volcanic in west north america
- India and Asia collided
- primates
- homo sapiens
