Evolution

Question 1

Homologous Structures:

Answer 1

• Same structure
• Different function
• From common ancestor

Question 2

Analogous Structure:

Answer 2

• Same function
• Different structure
• Not inherited from common ancestor

Question 3

Vestigial Structure:

Answer 3

• Homologous to related species, however has no function today

Question 4

Conditions for Fossilisation:

Answer 4

1) Specimen must be quickly covered in sediment
- prevents bacterial action

2- Specimen must be left undisturbed for > thousands of years

3) Must have hard parts to preserve

Question 5

Divergent Evolution:

Answer 5

When lineages become more distant over time, but still contain similar homologous structures due to common ancestor

Question 6

Index Fossil Requirements:

Answer 6

1) Be common
2) Be widespread
3) Have existed for a short period of time

Question 7

Primate Characteristics:

Answer 7

• Opposable thumbs
• Forward facing eyes
• Large brain
• Social
• Flexible shoulders
• Flattened fingernails
• Acute vision

Question 8

Characteristics of Hominoids:

Answer 8

• Lack tail
• Broad, flat ribcage
• Arms longer than legs

Question 9

Characteristic of Hominins:

Answer 9

Bipedal

Question 10

Trends in Hominin Anatomy:

Answer 10

• Larger Cranium
• Flatter Face
• Lighter Jaw
• Smaller Teeth
• Larger Heel Bone

Question 11

Order of species

Answer 11

Mammals - Primates - Hominoids - Hominins

Question 12

How can you determine if a species is extinct in an area?

Answer 12

• No Fossils present
• No DNA present
• No Sightings
• No Nests/Homes

Question 13

Reasons for lack of DNA evidence supporting inbreeding in fossils

Answer 13

• DNA degenerates too quick
• Low chance of interbred fossil being found

Question 14

Why is mitochondrial DNA useful?

Answer 14

• Inherited from only the mother
• No crossing over/recombination/non-disjunction
• Known mutation rate

Question 15

Purpose of larger brain case

Answer 15

• accommodates larger brain
• allows more complex thought processes + ability to adapt

Question 16

What feature allows scientists to determine a skeleton was suited to climb trees?

Answer 16

• Longer upper limbs
• Prehensile toe

Question 17

Benefits of a projecting nose

Answer 17

• Greater sense of smell

Question 18

Species with legs around same length as arms are able to do what?

Answer 18

• Knuckle walk

Question 19

Effects of Bipedalism on Behaviour

Answer 19

• Freed hands for toolmaking
• Allows reach to higher food
• Raising head to scan for predators

Question 20

Explain why fossilised remains may not give scientists a more detailed understanding of relatedness between species

Answer 20

• incomplete fossil record
• limited fossils
• only small parts of fossil are found, making it hard to compare
• morphological differences
• non-linear evolution

Question 21

Trace Evidence

Answer 21

Provides evidence an organism lived in the area
- Indirect evidence of life
- e.g. footprints, scratches, moulds, casts

Question 22

Explain how faunal succession provides record of evidence for evolution

Answer 22

• Illustrates a chronological order
• Higher strata = younger and more complex
• Lower strata = older and less complex