Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account

theory of biogenesis

states that only living organisms can produce other living organisms.

Cambrian explosion

rapid diversification of most major animal groups during the Paleozoic era.

endosymbiont theory

explains that eukaryotic cells may have evolved from prokaryotic cells.


a large division of Earth's geologic time scale that is further divided into one or more periods.


preserved evidence of an organism, often found in sedimentary rock, that provides evidence of past life.

geologic time scale

model showing major geological and biological events in Earth's history.


amount of time required for half of a radioactive isotope to decay.

K-T boundary

layer of iridium-rich material between rocks of the Cretaceous period and rocks of the Paleogene period that provides evidence of a meteorite impact.

law of superposition

states that the oldest layers of rock are found at the bottom and the youngest layers of rock are found at the top of a formation if the rock layers have not been disturbed.


scientist who studies fossils.


subdivision of an era on the geologic time scale.

plate tectonics

geologic theory that Earth's surface is broken into several huge plates that move slowly on a partially molten rock layer.

radiometric dating

method used to determine the age of rocks using the rate of decay of radioactive isotopes.

relative dating

method used to determine the age of rocks by comparing the rocks with younger and older rock layers.

spontaneous generation

idea that life arises from nonliving things.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording