Q: What is macroevolution?
A: The pattern of evolution over large time scales.
Q: Cambrian explosion
A: sudden appearance of fossils resembling modern phyla in the Cambrian period (535 to 525 million years ago)
Q: What are stromatolites?
A: Layered rocks that form when certain prokaryotes bind think films of sediment together.
1. Conditions on early Earth made the origin of life possible
2. The fossil record documents the history of life
3. Key events in life’s history include the origins of single-celled and multicelled organisms and the colonization of land
4. Oldest known fossils are stromatolites, structures of many layers of bacteria and sediment
5. Chemical and physical processes on early Earth may have produced very simple cells through a sequence of stages:
Major continental plates:
The arrows indicate direction of movement. The reddish-orange dots represent zones of violent tectonic activity.
Earth formed about 4.6 billion years ago, along with the rest of the solar system. Earth’s early atmosphere likely contained water vapor and chemicals released by volcanic eruptions (nitrogen, nitrogen oxides, carbon dioxide, methane, ammonia, hydrogen, hydrogen sulfide). Protobionts exhibit simple reproduction and metabolism and maintain an internal chemical environment. The geologic record is divided into the Archaean, the Proterozoic, and the Phanerozoic eons. The oldest known fossils of multicellular eukaryotes are of small algae that lived about 1.2 billion years ago. first plants were terrestrial, so oxygen atmosphere must develop to produce protective ozone layer. Continental Drift.
At three points in time, the land masses of Earth have formed a supercontinent: 1.1 billion, 600 million, and 250 million years ago. Mammals underwent an adaptive radiation after the extinction of terrestrial dinosaurs. The Hawaiian Islands are one of the world’s great showcases of adaptive radiation
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