Waves
Index fossils
Fossil records and Earth's history
Relative dating
Comparative anatomy and evolution
100

This is the definition of a wave

A disturbance that transports energy
100

This is the definition of a fossil

The preserved remains or traces of a once living organism

100

This is the fossil record

The totality of fossils on Earth

100

This is the definition of relative dating

The science of determining the relative age of rock layers and fossils within those rock layers based on the comparative positions of those rock layers.

100

This is the definition of the theory of evolution

Explains how populations of living things have changed through time.
200

This is a transverse wave

particles of the medium move perpendicular to the direction that the energy of the waves travel

200

This is the definition of an index fossil

Helps scientists date unknown or less studied fossils and rock layers

200

This is how we use the fossil record

It shows the physical attributes of an organism, such as size, shape and body structure, have have small changes over long periods of time

200

This is the principle of original horizontality

Horizontality, sediment is deposited horizontally or in “flat rows” due to gravity.

200

This is an evolutionary tree

A branched diagram that shows the relationships between species.

300

This is a longitudinal wave

the particles of the medium vibrate back and forth parallel to the direction that the energy of the waves travel

300

These are the characteristics of an index fossil

Widely distributed and lived for a relatively short time period

300

These are limitations of the fossil record

Does not include every fossil, fossilization is rare and there are gaps on the record

300

This is the law of superposition

Sedimentary rock layers are laid down on top of each other, lower or deeper layers are always older than higher or shallower layers.

300

This is the definition of homologies

Similar characteristics due to relatedness.

400

These are wave behaviors

Absorption, reflection, refraction, diffraction

400

This is how we use index fossils to date fossils

When an unknown fossil is found in the same layer as an index fossil, scientists can infer that the unknown fossil is from the same period as the index fossil

400

This is the geological time scale and it's units

A system we use to measure and describe the history of Earth, the units are eons, eras and periods

400

This is the cross cutting relationship

A fault through rock layers must be younger than the layers through which it cuts.

400

This is the definition of an embryo

The early stages of development of a species (or simply life)

500

These are wave properties

Amplitude (A), Wavelength (λ), Frequency (f), Wave Speed (v), Period (T=1/f)

500

This is how we use index fossils to date rocks

Index fossils are also helpful in dating the age of rock layers and “matching” layers of rocks in different locations.

500

This is how the number and length of time periods are determined

based on important events in Earth’s history.

500

This is the intrusive relationship

An igneous intrusion is younger than the rock layers through which it “intrudes” or cuts.

500

These are the homologous structures of a tetrapod limb

The humerus, radius, ulna and CMP