The Fossil Record
What are the remains or evidence of once-living organisms?
Fossil.
What is the preserved evidence of the activity of an organism?
Trace fossil.
What kind of rocks form from volcanic magma?
Igneous rocks.
What is a chart that divides Earth’s history into different time units?
Geologic time scale.
What occurs when the last individual organism of a species dies?
Extinction.
The fossil record is enormous, but is still_________.
incomplete.
What is a fossil copy of an organism in a rock?
Cast.
In a undisturbed rock formation, they know that the bottom layers are _______ and the top layer are _______.
Oldest; youngest.
What are the longest time units?
Eons.
What is an example of how environments can change slowly?
Plate tectonics.
What is made up of all the fossils ever discovered on Earth?
Fossil record.
What is the impression of an organism in a rock?
Mold.
What is a natural clocklike process in rocks, to learn a rock’s absolute age, or its age in years?
Radioactive decay.
What provide an easy way to mark time?
Fossils.
What can occur when environments change suddenly or slowly?
Extinction.
What provides evidence that species have changed over time?
Fossil record.
In what process does a fossil forms when a dead organism is compressed over time and pressure drives off the organism’s liquids and gases?
Carbonization.
____________ helps scientists determine the relative order in which species have appeared on earth over time.
Relative-age dating
Some times entire collections of fossils are found in ___________. (Five words)
A single layer of rock.
Who developed a theory about how species evolve from one another?
Charles Darwin.
What stays the same from day to day?
Characteristics.
What is the process called in which after an organism dies, its body could be buried under mud, sand, or other sediments in a stream or river. If minerals in the water replace the organism’s original material and harden into rock, a fossil forms?
Mineralization.
What is it called when a scientist determines the relative order in which rock layers were deposited?
Relative-age dating.
It seemed as if whole communities of _________ had suddenly disappeared.
Organisms
What is the change over time in populations of related organisms?
Biological evolution.