Evidence for Evolution

Question 1

Main evidence of evolution

Answer 1

1. Comparisons of existing animals and plants
2. Fossilised remains of animals / plants million years ago
3. DNA of existing animals / plants
4. Geographical distribution of species

Question 2

Pattern of Divergent Evolution

Answer 2

• One ancestral species becomes two or more new species
• Species live in different environments, with different selection pressures.
• Evidence: homologous structure

Question 3

What is homologous structure?

Answer 3

They have same Origin but different function.

Question 4

Pattern of convergent evolution

Answer 4

• Two or more unrelated species evolve to become more similar to each other.
• Species live in similar environments, with the same selection pressures. But they can NEVER merge to become one species.
  -Evidence: Analogous structure
  -E.g. Vertebrate forelimbs

Question 5

Evidence of convergent evolution

Answer 5

Analogous structures

Question 6

Evidence of divergent evolution

Answer 6

homologous structure

Question 7

What is analogous structure?

Answer 7

have different structure and origin but the same function.

Question 8

What is analogous structure?

Answer 8

• The ability to fly, evolved independently

Question 9

What are bird wings supported by？

Answer 9

Bones

Question 10

What are bee wings supported by?

Answer 10

Strong fibres

Question 11

Difference between homologous and analogous

Answer 11

H: Same structure and Origin, different function.
A: different structure, same function

Question 12

Evidence from fossils

Answer 12

Rock layers reveals differences in the fossils contained each year, oldest rock / fossils at the bottom, youngest at the top.

Question 13

What is the sequence of fossils

Answer 13

• Plant fossils appear before animal fossils
• Plants on land appear before animals on land
• Plant suitable for insect pollination appear before insect pollinators

Question 14

Evidence from DNA - DNA sequence

Answer 14

DNA sequence from two species are very similar, then they are closely related.

Question 15

Evidence from anatomy

Answer 15

Similarities and differences in the body structures of different species

Question 16

What is geographical distutribution

Answer 16

Broad groupings of organisms that had already evolved before the breakup of the supercontinent

Question 17

What are anatomical changes?

Answer 17

Placental development, weight gain, abdominal extension, breast enlargement,posture changes.