Topic 4- Evolution

Question 1

What is evoution

Answer 1

A gradual change in the inherited traits within a population over time
Pccurs due to natural selection

Question 2

Theory of natural selection (steps)

Answer 2

1. Genetic variation exists due to mutations
2. Selection pressures (e.g competition, disease) exist
3. Random mutation gives an organism a selective advantage
4. Organism is better adapted
5. Organisms reproduce, passing on its beneficial alleles
6. Frequency of advantageous alleles increase

Question 3

Why does competition between organisms in a habitat exist

Answer 3

The resources within a habitat required for survuvak are limited

Question 4

Examples of competition between organisms within a habitat

Answer 4

Food, shelter mates

With plants - light, water, minerals

Question 5

Describe how antibiotic resistance in bacteria can be used as an example to illustrate the process of evolution

Answer 5

1. Genetic variation exists due to mutations
2. Antibiotics act as a selection pressure
3. Mutations giv bacterium antibiotic-resistance
4. If an antibiotic is administered, the bacterium is better adapted and survuves, whilst other bacter are killed
5. Bacterium reproduces, passing on its resistant variant
6. Frequency of antibiotic-resistant allele increases

Question 6

Why is the development of antibiotic resistance in bacteriaa good study for evolution

Answer 6

Bactera reproduce ver rapidly, allowing first-hand observation of evolution

Question 7

How can the observation of fossils provide evidence of evolution

Answer 7

• oldr fossils contain simpler organisms. Newer fossils contain more complex organisms. Comparisons to fossils show that simple organisms evolved into more complex life forms

Question 8

Describe the role of darwin in the development of the theory of evolution by natural selection

Answer 8

• studied a variety of organisms whilst travelling around the world
• noted that traits can be passed from parents to offspring
• proposed idea of competition
• established theory of natural selection

Question 9

Describe the role of wallaxe in the development of the theory of evolution by natural selection

Answer 9

Propose the theory of natural selection (similar to Darwin’s)
Gathered greater evidence

Question 10

How has the theory of evolution by natural selection impacyed modern biology and society

Answer 10

Enables the classification of organisms

Highlights the importance of high genetic diversity in habitats

Question 11

What fossils have provided evidence for human evolution (2)

Answer 11

Ardi - 4.4 million years old

Lucy - 3.2 million years old

Question 12

What clues does ardi give scientists about human evolution

Answer 12

Shows phenotypic traits which shre similar characteristcsto both humans and apes
- ape like - long arms
Human like - structure of bones suggested she walked upright

Question 13

What does lucy give scientists about human evolution

Answer 13

Phenotypic traits which are more human like than ardi

• structire of bones suggest she was vetter adapted to walking and climbing
• however, brain sze closer to that of an ape

Question 14

How has the developmen of stone tools provided evidence for evolution

Answer 14

• Correlation between the development of more comple tools and an increase in brain size
• as brain size increased, advancements in tool use were made

Question 15

Describe the methods used by scientits to date tools

Answer 15

Carbon-14 dating — estimating the age of carbon-containing material that is found in tools
Statigraphy - using the ae of the layers of sediment surrounding the tool as an indication of the age of the tool

Question 16

What is a pentadactyl limb

Answer 16

A limb with 5 digits present in animals, reptiles and amphibians

Question 17

How does the pentadactyle limb provide evidence for evolutiom

Answer 17

The presence of the pentadactyl limb suggest all species which possess it have descended from a common ancestor