Specimen Prep - Evolution

Specimen Prep Guide: Evolution

Key Concepts (Recall & Understanding)

• Origin of Life: Understand the theories of the origin of life, including the theory of chemical evolution proposed by Oparin and Haldane.
• Evidences for Evolution: Know the evidences from paleontology, comparative anatomy (homologous and analogous organs), embryology, and molecular biology.
• Theories of Evolution: Understand Lamarckism, Darwinism (natural selection), and the modern synthetic theory of evolution.
• Hardy-Weinberg Principle: Know the principle and the factors that affect it (gene flow, genetic drift, mutation, natural selection).
• Human Evolution: Know the major stages of human evolution.

Application Corner

• Problem Type: Applying the Hardy-Weinberg principle to calculate allele and genotype frequencies in a population.
• Example: If the frequency of a recessive allele is 0.4, what is the frequency of the homozygous dominant genotype? (Answer: p² = (0.6)² = 0.36 or 36%).

Analytical Thinking

• Scenario: The peppered moth population in England changed from being predominantly light-colored to dark-colored after the industrial revolution. Explain this phenomenon.
• Analysis: This is an example of natural selection. The dark-colored moths were better camouflaged against the soot-covered trees and were less likely to be eaten by predators.
• Diagram Interpretation: Be able to interpret diagrams showing homologous and analogous structures.

Key Case Study

• Darwin's Finches: The finches on the Galapagos Islands are a classic example of adaptive radiation. They evolved from a common ancestor but adapted to different food sources on different islands, leading to the evolution of different beak shapes.

Assertion-Reason Practice

1. Assertion: Homologous organs suggest a common ancestry. Reason: They have a similar basic structure but perform different functions.

   • (a) Both Assertion and Reason are true and Reason is the correct explanation for Assertion.

2. Assertion: Genetic drift is more likely to occur in small populations. Reason: In a small population, random events can have a greater impact on allele frequencies.

   • (a) Both Assertion and Reason are true and Reason is the correct explanation for Assertion.

HOTS (Higher-Order Thinking Skills) Question

• How does the modern synthetic theory of evolution differ from Darwin's theory of natural selection?
  • Answer: The modern synthetic theory incorporates our understanding of genetics (mutations, recombination, genetic drift) into Darwin's theory of natural selection. It provides a more complete explanation of the sources of variation and the mechanisms of evolution.