1.5.2 The Fossil Record

Question 1

coevolution

Answer 1

• the reciprocal evolution (change over time) of two or more interacting populations. An example is the colonization of land plants followed by the colonization of insects that fed on them.

Question 2

note

Answer 2

• The depth of fossils in geologic strata can provide the relative age of fossils.
• A changing array of fossils appears through time, yielding forms adapted to different environmental conditions.

Question 3

Precambrian era (4.5 billion years ago):

Answer 3

• The Earth is thought to be approximately 4.5
  billion years old.
• The oldest known fossils are those of prokaryotes and are well over 2 billion years old.
• The dominant organisms until the end of the Precambrian era (almost 570 million years ago) were bacteria and algae.

Question 4

Cambrian period (began approximately 500 million years ago)

Answer 4

• Most modern animal phyla had been established by the end of the Cambrian period.
• greatest period of evolutionary diversification occurred

Question 5

Ordovician (began approximately 440 million years ago)

Answer 5

• Plants originate; marine algae are abundant; other marine life, such as fish and corals, appear as ocean covers most of the continents.

Question 6

Silurian (began approximately 400 million years ago)

Answer 6

• First jawless fishes appear; plants and animals begin to colonize land.

Question 7

Devonian (began approximately 350 million years ago)

Answer 7

• The first insects and amphibians appear. Fishes with jaws first appear. Vascular plants diversify.

Question 8

Carboniferous (began approximately 290 million years ago)

Answer 8

• First reptiles appear; extensive forests exist on land.

Question 9

Permian (began approximately 250 million years ago):

Answer 9

• Reptiles radiate and become exceptionally abundant. Many organisms become extinct.

Question 10

Cretaceous (began approximately 66 million years ago)

Answer 10

• Dinosaurs become extinct at the end of this period. Flowering plants appear.

Question 11

fossil record represents most completely

Answer 11

• organisms that were abundant
• organisms that existed for long periods of time
• organisms that had hard shells or skeletons

Question 12

The oldest fossils known are

Answer 12

• bacteria

Question 13

The greatest period of evolutionary diversification occurred during the

Answer 13

• Cambrian period

Question 14

Which of the following is not an example of coevolution?

Answer 14

• the evolution of reptiles after the evolution of amphibians

Question 15

The fossil record represents most completely

Answer 15

• organisms that were abundant.
• organisms that existed for long periods of time.
• organisms that had hard shells or skeletons.

Question 16

Coevolution refers to the process by which

Answer 16

• the interaction between species affects the evolution of these species.
• most species have evolved