Chapter 17- Geologic Time

How many periods of time are there?

12

How did the change of species over time get proven?

by comparing old fossils (deeper layers of rock) with younger fossils

What were some clues from living organisms that led to the theory that species changed overtime?

• embryonic- similar structures, development, and proteins

• homologous structures and vestigial organs, DNA

Details about the Paleozoic Era

• life explodes

• worlds climate became very seasonal, probably causing dramatic extinction

• iridium layer

• late Paleozoic extinction was the greatest of at least 5 mass extinctions

Details about the Mesozoic Era

• Dinosaurs lasted 160-235 million years ago

• break up of Pangea occured

How old is the earth?

4.6 billion years old

how long have humans been around the earth?

roughy 200,000 years

Who proposed evidence about continental drift?

Alfred Wegener in 1915. Correlations of mountains with nearly identical rocks and rocks

What is a divergent plate boundary?

when two plates move AWAY from each other

What is a convergent plate boundary?

when two plates move TOWARDS each other

What is a transform plate boundary?

when two plates slide PAST each other

What are the geologic periods?

Cambrian, Ordovician, Silurian, Devonian, Carboniferous (divided into Mississippian and Pennsylvanian), Permian, Triassic, Jurassic, Cretaceous, Paleogene, Neogene, and Quaternary

What is a homologous structure?

similar body parts in different species that share a common evolutionary origin but may have different functions

what does the endosymbiotic theory explain?

how eukaryotic cells (cells with a nucleus) likely evolved from prokaryotic cells (cells without a nucleus)