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Describe natural selection and punctuated equilibrium - NSC Life Sciences - Question 4 - 2019 - Paper 2
Question 4
Describe natural selection and punctuated equilibrium. Also state THREE ways in which natural selection differs from artificial selection.
Worked Solution & Example Answer:Describe natural selection and punctuated equilibrium - NSC Life Sciences - Question 4 - 2019 - Paper 2
Step 1
Describe natural selection
Answer
Natural selection is a fundamental mechanism of evolution. It involves the following key concepts:
- Variation among Offspring: Organisms produce a large number of offspring, and there is variation among them.
- Survival of the Fittest: Some individuals possess favorable characteristics that enhance their survival in changing environmental conditions, while those with unfavorable traits are less likely to survive.
- Reproduction: Organisms that survive tend to reproduce, passing their favorable traits to the next generation through their alleles.
- Population Changes: Over generations, the allele frequency in the population shifts, leading to a higher proportion of individuals with beneficial characteristics.
Step 2
Describe punctuated equilibrium
Answer
Punctuated equilibrium is a theory that explains the pace of evolution. Its main points are:
- Evolution Speed: It highlights that evolution does not occur gradually but in bursts of significant change, which occur during relatively short periods.
- Long Periods of Stasis: Between these bursts of evolutionary activity, species remain largely unchanged for long durations.
- Rapid Changes: Rapid changes occur due to environmental factors or significant mutations that enhance survival.
Step 3
State THREE ways in which natural selection differs from artificial selection
Answer
- Selection Process: In natural selection, the environment selects which traits are advantageous, whereas in artificial selection, humans select desired traits based on preferences.
- Population Characteristics: Natural selection leads to an evolutionary advantage and improves survival of a population, while artificial selection may not necessarily enhance survival in natural contexts.
- Randomness: Natural selection is a random process driven by environmental factors, while artificial selection is deliberate and oriented towards achieving specific goals.