Fossil Layers & Dating
Evidence of Extinction
Organisms Over Time
Comparing Skeletal Structures
Misc.
100
Which layer is the oldest?
Layer A
100
A sudden disappearance of many species in the fossil record suggests what event?
Mass extinction.
100
Are the oldest known fossils of simple or complex organisms?
Simple (single-celled bacteria and algae)
100
What does it mean when two species have similar bone structues?
They may share a common ancestor
100
TRUE OR FALSE: As the percentage of DNA shared between organisms increases they have more anatomical similarities.
TRUE
200
Which layer is the youngest?
Layer E
200
What is one sign in rock layers that a mass extinction occurred?
A layer with many fossils followed by a layer with no fossils followed by layers where the original fossils do not come back.
200
How does the fossil record show that organisms have become more complex over time?
Older fossils are simpler: newer ones have more advanced structures like eyes, limbs, and skulls
200
How can comparing the bones of different animals help scientists understand their evolutionary relationships?
By looking at similarities in bone structure, scientists can tell if species evolved from a common ancestor
200
Gorillas most likely share a common ancestor with which organism? Dogs or Humans.
DOUBLE JEOPARDY: Fill in the blank.
Humans and Gorillas are the only two animals with ________________________.
Humans.
Opposable thumbs!
300
If you find a fossil in a lower rock layer compared to another, is it older or younger?
Older
300
Name one possible cause of a mass extinction event.
Meteor impact, volcanic eruption, climate change, etc.
300
What type of organisms first appeared in the fossil record: single-celled or multi-celled?
Single-celled
300
Put them in order
300
Millions of years ago, this area was covered by ocean. Which rock layer shows this time period? #____
#5
400
How do scientists determine the relative age of fossils?
By examining their position in rock layers (deeper layers contain older fossils)
400
How does the fossil record help scientists identify past extinction events?
It shows a sudden loss of species in specific rock layers.
400
Why do older fossils often lack complex structures like bones?
Early life forms were soft-bodied and lacked hard parts like skeletons
400
What does it tell us when animals with different body structures have bones arranged in a similar way?
They may have evolved from a common ancestor and adapted over time to different evironments
400
Would sharks and whales be able to survive in this area 3,000 years ago? Why or why not?
No because there is evidence that the area 3,000 years ago was dry
500
Arrange these rock layers from oldest to youngest:
(a) layer with trilobite fossils
(b) layer with human artifacts
(c) layer with dinosaur fossils.
(a) Trilobites
(c) Dinosaurs
(b) Human Artifacts
500
What major extinction event is believed to have wiped out the dinosaurs?
DOUBLE JEOPARDY!! Double points if you name the specific event.
The Cretaceous-Paleogene (K-Pg) extinction, likely caused by an asteroid impact.
NOT ON YOUR SUMMATIVE!
500
What major evolutionary change occurred as organisms became more complex?
The development of vertebrae, allowing for larger body sizes and more advanced movement
500
Which two organisms are more likely to have a common ancestor and why?
A & B because they share common skeletal structures
500
Define homologous structures
Body parts in different species that have similar structure because they come from a common ancestor