unit 1.3 Flashcards
universe
13.8 BYA
data used: watching starts in our universe, farther stars=fast speed=expanding universe. Rate of expansion of our universe
Earth
4.5 BYA
data used:radioactive dating of oldest rocks, leave a distinct signal.
Early modern planet
- Earth temperature was a lot higher than it is now
- Meteoroids were very common-planet still forming-vacuuming to form planet
- More geologically active-volcanoes, underwater rifts
life began as
RNA molecules that can self-replicate
common elements in pre-biotic atmosphere made
basic building blocks of life-amino acids
RNA to DNA
ongoing research
Origin of Life
3.5 or 3.8 BYA,
data used: looked at oldest fossils, compared to colonial bacteria, same shapes. First living organisms: probably single cell bacteria.
- Escaped Genes Hypothesis
- Reduction Hypothesis
- Relics of RNA world hypothesis
- Escaped Genes Hypothesis- Viruses represent a portion of a once living organism escaped or separated (remnant of a once living cell)
- Reduction Hypothesis- Step by Step evolution. Viruses started as life on earth step by step slowly into viruses.
- Relics of RNA world hypothesis- Separate origin of life. Were a separate origin of life but never went beyond virus. Never connect to us.
Emergent Properties,
Synergy- another word for emergent properties- where we take a bunch of different elements and put them together to do something brand new that we originally couldn’t do. Same with cells, buildup of cells, become more efficient.
Origin of Photosynthesis
3.2 BYA,
data used: rust(red) bands, Iron oxide-formed by oxidation reaction, no oxygen in atmosphere, oxygen came from first photosynthesizes.
Eukaryotic cells
2BYA
very little fossil evidence
Early eukaryotic cells were a
fusion of archea and bacteria
endosymbiosis
-engulfed mitochondria nd chloroplast evidence: -double membrane -have similar genome to bacteria -mitochondria genes similar to protobacteria -chloroplast similar to cyanobacteria
Great Oxygenation Event
2.5 BYA data used: relative dating of fossils Origin of Eukaryotes Origin of Multicellularity Origin of Complex Animals
What are the advantages of being multicellular? Why is data difficult to determine
Advantages: Division of labor, response to gradients, economy of scale.
Date difficult to determine because multicellularity has evolved multiple times
What organisms are used as models for the origin of multicellularity?
Volvocine Algae-have multiple species of single cells, colonial cells, multicellular cells
Slime molds-single species diff. Stages- single celled-> colony-> multicellular
Cambrian explosion,
-dramatic rapid origin of these complex organisms
igneous, sedimentary, metamorphic
Igneous-formed from molten lava-magma
Sedimentary-formed from bits and pieces from many diff. types of other material. Weathered, sediment material
Metamorphic- were either once igneous or sedimentary but were changed dramatically through heat and pressure
direct dating rock applies to what kind of rock
igneous
- Estimate of original radioactivity
- We need a sample of a similar rock with unknown age, and measure radioactivity
- Known half-life
Fossil and where are they found
Fossil-preserved eminent of a living organism; bones, droppings, track. Can be found in sedimentary rock and metamorphic rock.
Stratigraphy, Relative Dating, How does this resolve the seeming paradox of dating fossils?
It helps us escape the “catch 22” of fossils dating, helps us get an accurate and not precise date.
Accuracy, Precision Are fossil dates accurate? Precise?
Accuracy- falls within that range. Precision-how sure are you
Fossil dates are accurate but not precise
Where did all life originate? What are the closest relatives of plants?
Life originates in the ocean. Closest relatives of plants are cyanobacteria, aquatic ancestors.
Which group’s diversification is most closely associated with the diversification of angiosperms?
insects
