3.1 Describe the process of natural selection - NSC Life Sciences - Question 3 - 2020 - Paper 2
Question 3
3.1 Describe the process of natural selection.
- Organisms produce a large number of offspring.
- There is variation amongst the offspring.
- Some have favourable c... show full transcript
Worked Solution & Example Answer:3.1 Describe the process of natural selection - NSC Life Sciences - Question 3 - 2020 - Paper 2
Step 1
3.2.1 Name the family to which all the represented organisms belong.
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Answer
Hominidae
Step 2
3.2.2 Describe how cultural evidence is used to support the theory of human evolution.
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Answer
Cultural evidence such as tools, weapons, and language artifacts shows advancements in human development. It demonstrates the capabilities and adaptations of early humans, linking them to evolutionary changes.
Step 3
3.2.3 How long ago did the most recent common ancestor of H. erectus and H. heidelbergensis exist on Earth?
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The most recent common ancestor existed approximately 3 million years ago.
Step 4
3.2.4 Explain a possible reason why H. ergaster was placed between A. afarensis and H. heidelbergensis on the model.
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H. ergaster is considered a transitional species that exhibits characteristics of both A. afarensis and H. heidelbergensis, marking it as an evolutionary link in the human lineage.
Step 5
3.2.5 Explain how the fossils of organisms that existed from 4 mya to present time are used to support the 'Out of Africa' hypothesis.
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Fossils such as those of Australopithecus and Homo species, found predominantly in Africa, indicate that these lineages originated from Africa and migrated outwards. This supports the theory that modern humans also originated from Africa.
Step 6
3.3.1 Name:
(a) Reproductive isolating mechanism that occurs in long-tailed widowbirds.
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(a) Species-specific courtship behaviour
Step 7
3.3.1 Name:
(b) Independent variable in this investigation.
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Answer
(b) Length of the (male long-tailed widowbird's) tails
Step 8
3.3.2 Explain why 27 long-tailed widowbirds were used in the investigation instead of only 3.
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A larger sample size increases the reliability of the investigation and provides more accurate data.
Step 9
3.3.3 Explain why Group 3 was included in the investigation.
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Group 3 serves as a control group, allowing comparisons with the other groups, ensuring that the effect observed is solely due to tail length.
Step 10
3.3.4 Draw a bar graph to represent the results of this investigation.
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The bar graph should display three bars representing the average number of nests produced by each group, labelled accordingly.
Step 11
3.3.5 State a conclusion for this investigation.
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The longer the (male long-tailed widowbird's) tail, the higher the mating success; conversely, a shorter tail leads to lower mating success.
Step 12
3.4.1 Explain how continental drift could have affected the distribution of the common ancestor.
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Continental drift could have separated populations of the common ancestor by the ocean, leading to changes in environmental conditions and genetic divergence over time.
Step 13
3.4.2 Describe the speciation of the pottos and lemurs to become different species.
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The common ancestor became separated into two groups by the ocean. Each group experienced different environmental conditions, leading to adaptation and eventual speciation of the pottos and lemurs.
