Question

1. discuss type of animals on either side of the wallace line - provide specific terminology. where were islands once attached. 4 marks t
2. circle whether each of the following is an example of stabilizing, directional, or disruptive selection. (7 a marks)

a population has only very large and very small snails | stabilizing | directional | disruptive
a population of ducks lays eggs of the intermediate weight | stabilizing | directional | disruptive
most individuals in a population of hummingbirds have long beaks | stabilizing | directional | disruptive
a population shifts from being primarily black moths to being primarily flecked moths | stabilizing | directional | disruptive
in different parts of africa, the colour pattern of the butterfly papilio dardanus is dramatically different. | stabilizing | directional | disru ptive
a population has only medium - sized spiders | stabilizing | directional | disruptive
a population shifts from being primarily black moths to being primarily flecked moths | stabilizing | directional | disruptive

Explanation:

Question 8 (Selection Types)

1. "A population has only very large and very small snails"

• Explanation: Disruptive selection favors extreme phenotypes (large or small) over intermediate ones, leading to two distinct groups.
• Answer: disruptive

2. "A population of ducks lays eggs of the intermediate weight"

• Explanation: Stabilizing selection favors intermediate phenotypes (medium - sized eggs) and reduces extreme ones (very large or very small eggs).
• Answer: stabilizing

3. "Most individuals in a population of hummingbirds have long beaks"

• Explanation: Directional selection shifts the population towards one extreme phenotype (long beaks, away from short or medium beaks).
• Answer: directional

4. "A population shifts from being primarily black moths to being primarily flecked moths"

• Explanation: Directional selection occurs when the population shifts towards a new phenotype (flecked moths) from the original (black moths).
• Answer: directional

5. "In different parts of Africa, the colour pattern of the butterfly Papilio dardanus is dramatically different"

• Explanation: Disruptive selection (or diversifying selection) can lead to different phenotypes in different environments, favoring extreme or distinct traits in different regions.
• Answer: disruptive

6. "A population has only medium - sized spiders"

• Explanation: Stabilizing selection favors the intermediate phenotype (medium - sized spiders) and eliminates extreme sizes (very large or very small).
• Answer: stabilizing

7. "A population shifts from being primarily black moths to being primarily flecked moths" (repeated)

• Explanation: Same as the 4th question, directional selection as the population shifts to a new phenotype.
• Answer: directional

Question 7 (Wallace Line)

The Wallace Line separates Asian and Australian fauna.

• West of Wallace Line: Animals are of Asian origin (e.g., tigers, monkeys, Asian elephants) because these islands were once attached to the Asian mainland (Sundaland: includes Borneo, Sumatra, Java, and the Malay Peninsula).
• East of Wallace Line: Animals are of Australian origin (e.g., kangaroos, possums, monotremes) as these islands were once near Australia (Sahul: Australia, New Guinea, and nearby islands).
• Islands once attached: West: Islands like Borneo, Sumatra, Java were attached to Asia (Sundaland). East: Islands near Australia (e.g., New Guinea - related islands) were attached to Australia (Sahul).

Final Answers (Question 8)

1. disruptive
2. stabilizing
3. directional
4. directional
5. disruptive
6. stabilizing
7. directional

(For Question 7, the key points are the fauna types on each side and the attached landmasses: West - Asian fauna, attached to Asia (Sundaland); East - Australian fauna, attached to Australia (Sahul).)

Answer:

The Wallace Line separates Asian and Australian fauna.

• West of Wallace Line: Animals are of Asian origin (e.g., tigers, monkeys, Asian elephants) because these islands were once attached to the Asian mainland (Sundaland: includes Borneo, Sumatra, Java, and the Malay Peninsula).
• East of Wallace Line: Animals are of Australian origin (e.g., kangaroos, possums, monotremes) as these islands were once near Australia (Sahul: Australia, New Guinea, and nearby islands).
• Islands once attached: West: Islands like Borneo, Sumatra, Java were attached to Asia (Sundaland). East: Islands near Australia (e.g., New Guinea - related islands) were attached to Australia (Sahul).

Final Answers (Question 8)

1. disruptive
2. stabilizing
3. directional
4. directional
5. disruptive
6. stabilizing
7. directional

(For Question 7, the key points are the fauna types on each side and the attached landmasses: West - Asian fauna, attached to Asia (Sundaland); East - Australian fauna, attached to Australia (Sahul).)