The geologic record is a standard time scale dividing Earth’s history into the Hadean, Archaean, Proterozoic, and Phanerozoic eons.
The Phanerozoic encompasses most of the time that animals have existed on Earth.
The Phanerozoic is divided into three eras: the Paleozoic, Mesozoic, and Cenozoic.
Massextinction is the result of disruptive global environmental changes
In each of the five mass extinction events, more than 50% of Earth’s species became extinct
The Permian extinction defines the boundary between the Paleozoic and Mesozoic. It caused the extinction of about 96% of marine animal species.
According to the theory of platetectonics, Earth’s crust is composed of plates floating on Earth’s mantle.
RNA molecules called ribozymes have been found to catalyze many different reactions
Microfossils are fossilized forms of microscopic life
Life evolved into three monophyletic domains including Eubacteria, Archaea, and Eukaryotes.
The Miller-Urey experiment found within a week that methane gas converted into other simple carbon compounds. Concluded that key molecules of earth could have formed on early Earth.
Microfossils are fossilized forms of microscopic life
Stromatolites are mats of cyanobacterial cells that trap mineral deposits
Scientists estimate that the current rate of extinction is 100 to 1,000 times the typical background rate.
Extinction rates tend to increase when global temperatures increase
According to the theory of platetectonics, Earth’s crust is composed of plates floating on Earth’s mantle
Compartmentalization of cells enabled the advent of eukaryotes
Multicellularity leads to cell specialization
Sexual reproduction allows greater genetic diversity
The first genetic material was probably RNA
Chloroplasts are derived from cyanobacteria
Mitochondria and chloroplasts entered early eukaryotic cells by endosymbiosis
The trigger for global glaciations was the drop in atmospheric carbondioxide.
In order for the first cells to develop, a phospholipid-like molecule would be necessary so it can protect and concentrate the necessary molecules.
The Miller-Urey experiment showed that essential biological molecules associated with living organisms could be generated in an “abiotic” environment and conditions in the “primitive Earth environment” could have generated complex molecules.
Phosphorous increases the productivity of photosynthetic organisms and carbon fixation, thats why a mass release of phosphorous a potential explanation for glaciations.
Mitochondria and chloroplasts provides evidence for their endosymbiotic origins because the mitochondria and chloroplasts have their own DNA.
Chloroplasts are likely descendents of photosynthetic bacteria and likely have an endosymbiotic origin.
Hadean Earth was not a hospitable environment for early life to evolve because of extremely hot/cold temperatures, volcanic eruptions and asteroid impacts.
The Cretaceous separates the Mesozoic from the Cenozoic.