Evolution Chapter 8.2

Question 1

What is a fossil record?

Answer 1

Shows history of life on earth and organisms in sedimentary rock (fossils)

Question 2

Evidence from fossil record (three points)

Answer 2

1. Fossils found in higher layers of sedimentary rock are similar to species presently alive
2. Fossils appear in chronological order in rock layers (ancestors on bottom)
3. Not all organisms appear in the fossil record at the same time

Question 3

What is Evolutionary Timeline?

Answer 3

• Very slow at first
• Cambrian explosion ~ 500mya
• Multiple mass extinctions

Question 4

What are transitional fossils?

Answer 4

• States between an ancestral form and that of its descendants (link past and present)

Question 5

What is a Tiktaalik roseae?

Answer 5

• Transition between fish and land-dwelling animals

Question 6

What is Archaeopteryx?

Answer 6

• Transitional stage between reptiles (dinosaurs) and birds

- Species had characteristics of both reptiles and birds

Question 7

What is Pakicetus and Ambuloceties?

Answer 7

Transition between land mammals and whales and dolphins

Question 8

What is biogeography?

Answer 8

• Study of past and present geographical distribution of organisms
• Species evolve in one location then spread to others

Question 9

Evidence of biogeography (four points)

Answer 9

1. Geographically close environments are more likely to be populated by related species than those of the same environment but in a different continent
2. Animals found on islands resemble animals found on closest continent (animals on islands evolved from mainland migrants
3. Fossils of the same species can be found on the coastline of neighboring continents (because of Gondwana)
4. Closely related species are never found in same location or habitat

Question 10

What is a vestigial structure?

Answer 10

• Structure that is a reduced version that once was used in an ancestor
• Not used but still present

Question 11

What are homologous structures?

Answer 11

• Similar structure and origin but different function

- Can be similar in function, structure

Question 12

Difference between homologous and analogous structures?

Answer 12

• Evolved independently

- Perform similar functions but do not have a common evolutionary origin

Question 13

What is embryology?

Answer 13

Study of pre-birth stages of development

Question 14

Evidence of Embryology?

Answer 14

Embryos of related species show similar stages of embryonic development

Question 15

Evidence in DNA?

Answer 15

Similar patterns in DNA among different species and groups inherited from a common ancestor