Understanding biological evolution — ESL vocabulary lesson

This ESL lesson plan introduces learners to the topic of biological evolution, focusing on building foundational vocabulary and conversational skills in English.

Designed for beginner to intermediate learners, the plan covers essential terms like evolution, natural selection, and adaptation, alongside useful phrases to explain concepts, give examples, and ask questions.

Through engaging activities, relatable examples, and structured dialogues, students will develop confidence in discussing evolution while improving their English fluency.

The lesson incorporates visuals, role-plays, and active practice to make complex scientific ideas accessible and relevant, encouraging curiosity and critical thinking in a supportive learning environment.

Basic vocabulary

Start with foundational terms that are essential for understanding and discussing biological evolution. Each term is explained briefly to ensure clarity.

• Evolution: The process by which living things change over time, leading to new species.
• Natural selection: The way nature favors traits that help organisms survive and reproduce.
• Adaptation: A trait that helps an organism survive in its environment.
• Species: A group of organisms that can interbreed and produce fertile offspring.
• Gene: A unit of heredity that carries traits from parents to offspring.
• Mutation: A random change in an organism’s genes that can lead to new traits.
• Fossil: Remains or traces of ancient organisms preserved in rock.
• Trait: A characteristic or feature of an organism, like color or size.
• Environment: The surroundings where an organism lives, including climate and food sources.
• Survival of the fittest: The idea that organisms best suited to their environment are more likely to survive and reproduce.

Vocabulary for extension

• Biodiversity: The variety of life forms, including different species, in an ecosystem or on Earth.
• Speciation: The process by which new species form, often due to isolation or environmental changes.
• Genetic drift: Random changes in gene frequencies in a population, especially in small groups.
• Extinction: The complete disappearance of a species from Earth.
• Common ancestor: An organism from which two or more species evolved.
• Variation: Differences in traits among individuals in a population, often due to genes or mutations.
• Evolutionary tree: A diagram showing how species are related through common ancestors.
• Naturalist: A scientist who studies nature, like Charles Darwin, who developed the theory of evolution.
• Selection pressure: Environmental factors that influence which traits help organisms survive.
• Homologous structures: Body parts in different species that have similar structures but different functions, showing shared ancestry.

Teaching tips

Introduce 2-3 terms at a time, using visuals (e.g., pictures of fossils or animals) or simple examples (e.g., “A polar bear’s white fur is an adaptation to snowy environments”). Encourage learners to repeat and use each term in a sentence.

Useful phrases

These phrases help learners express ideas, ask questions, and explain concepts related to evolution. They are simple and versatile for conversations.

• Explaining concepts
  • “Evolution is how species change over time.”
  • “Natural selection means the strongest or best-adapted organisms survive.”
  • “An adaptation helps an organism live better in its environment.”
  • “Mutations can create new traits in a species.”
• Giving examples
  • “For example, birds with stronger beaks can eat tougher seeds.”
  • “A fossil shows us what animals looked like long ago.”
  • “Giraffes have long necks because of natural selection.”
• Asking questions
  • “What is an example of an adaptation?”
  • “How does natural selection work?”
  • “Why do species change over time?”
• Expressing opinions or curiosity
  • “I think evolution is interesting because it explains diversity.”
  • “I’m curious about how fossils help us understand evolution.”
  • “It’s amazing how mutations can lead to new species.”

Teaching tips

Practice these phrases in pairs or small groups. Have learners role-play as students or teachers, using the phrases to explain or ask about evolution.

Example conversations

These sample dialogues demonstrate how to use the vocabulary and phrases in natural conversations. They are designed for beginners and can be adapted for different proficiency levels.

Conversation 1: Explaining evolution

Teacher: Can you tell me what evolution is?
Student: Evolution is how living things change over time. For example, dinosaurs became birds.
Teacher: That’s a good start! Can you explain why species change?
Student: Yes, because of natural selection. The environment favors organisms with better traits, like stronger animals surviving.
Teacher: Great! Can you give an example of an adaptation?
Student: Sure, a camel’s hump is an adaptation. It stores fat to help the camel survive in the desert. Teaching tip: After reading, have learners practice this dialogue, swapping roles. Encourage them to replace examples (e.g., camel’s hump) with their own.

Conversation 2: Discussing fossils

Friend 1: I saw a fossil in a museum. What does it tell us about evolution?
Friend 2: Fossils show us what ancient animals or plants were like. They help us see how species changed over time.
Friend 1: Like how?
Friend 2: For example, a fossil of a dinosaur with feathers shows that birds evolved from dinosaurs.
Friend 1: That’s cool! So fossils are like evidence for evolution?
Friend 2: Yes, exactly! They’re proof of how life changed.

Conversation 3: Asking questions

Student: How does natural selection work?
Teacher: Natural selection is when organisms with helpful traits survive and reproduce more. For example, a fast deer escapes predators and passes its speed to its babies.
Student: So, the environment chooses the best traits?
Teacher: Yes, the environment decides which traits are useful. That’s why adaptations happen.
Student: I’m curious—can mutations change a species a lot?
Teacher: Yes, mutations can create new traits. Over time, those changes can lead to a new species.

Teaching tips

Encourage learners to write five questions about evolution and practice answering them using the vocabulary and phrases. You can also ask learners to create their own dialogue using a different topic, like natural selection or mutations, incorporating at least three vocabulary words.

Teaching strategies

To effectively teach someone to discuss evolution in English:

• Start simple: Begin with one concept (e.g., natural selection) and build from there. Use relatable examples, like animals they know.
• Use visuals and stories: Show pictures of adaptations (e.g., a chameleon’s color-changing skin) or tell stories about how species evolved (e.g., Darwin’s finches).
• Practice actively: Have learners explain concepts in their own words or debate simple questions, like “Why do some species go extinct?”
• Correct gently: If they misuse a term (e.g., saying “evolution” instead of “adaptation”), clarify with an example rather than just correcting.
• Encourage questions: Prompt them to ask “why” or “how” to deepen understanding and practice English.
• Repeat and review: Revisit vocabulary and phrases in different contexts (e.g., a written summary or a group discussion) to reinforce learning.

Practice activity: “Evolution in action” role-play

• Step 1: Divide learners into pairs. Assign each pair an animal (e.g., polar bear, cheetah, or cactus).
• Step 2: Ask them to discuss how their animal evolved to survive in its environment, using at least five vocabulary words and three phrases.
• Example output: “The polar bear’s white fur is an adaptation to blend into snow. Natural selection favored bears with lighter fur because they could hide from predators. This trait helped the species survive in its cold environment.”
• Step 3: Have pairs present their discussion to the group, encouraging others to ask questions using the phrases (e.g., “What is an example of an adaptation?”).

Additional tips for learners

• Listen and learn: Watch simple videos about evolution (e.g., on YouTube, like Crash Course Biology) to hear the vocabulary in context.
• Write it down: Keep a notebook of new words and phrases, and write a short paragraph about evolution weekly.
• Talk regularly: Practice discussing evolution with friends or teachers to build confidence.
• Use real examples: Connect evolution to animals or plants they see daily to make it relatable.