Lesson 2 PowerPoint_ Artificial Selection-amended
Items in this lesson
Why do all of these dogs look different?
Essential Question
How can humans selectively alter the traits of organisms?
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Key Vocabulary
1.
Artificial Breeding
2.
Selective Breeding
3.
Genetic Engineering
The controlled reproduction of plants or animals by humans to produce offspring with desirable traits, such as higher yield, better quality, or disease resistance.
A method of artificial breeding in which humans choose parents with specific desirable characteristics and mate them over several generations to enhance those traits in the offspring.
A scientific process in which the DNA of an organism is directly modified by adding, removing, or altering genes to produce specific desired characteristics more precisely and quickly than traditional breeding methods
Independent Practice: Scenario Analysis
A scientist crosses two types of wheat: one that produces high yield but is easily affected by pests, and another that has low yield but strong pest resistance. After several generations of selective breeding, a new wheat variety is developed that has both high yield and good pest resistance.
Questions:
What process is being used in this scenario?
What traits are being selected for?
How does this show artificial selection in action?
Artificial Selection
Adaptations show how Earth's species match their environments through evolution by natural selection.
Darwin bred domestic pigeons and found that humans influence traits through artificial selection.
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Perform the LAB: Developing Dogs
Selective Breeding
Selective breeding occurs when humans breed organisms with desired traits for food or companionship.
Humans, instead of nature, select traits in organisms, changing them like natural selection does.
Selective breeding has produced cows with more milk, dogs of different sizes, and unique roses.
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(br)Richard Bailey/Corbis Documentary/Getty Images
Three-Dimensional Thinking
Can traits of organisms always be predicted with selective breeding? Explain how multiple causes can influence the traits of an organism.
Revisit your claim about how humans can influence traits of organisms. Review the evidence you collected. Explain how your evidence supports your claim.
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Complete the Lesson Review.
Exit Ticket
What is artificial selection
in your own words?
2. Why might farmers use artificial selection when breeding crops or livestock?
3. Do you think artificial selection is always beneficial? Why or why not?
4. What could happen to a population if only certain traits are repeatedly selected?
5. In one or two sentences: How does artificial selection show the influence humans have on evolution?
Exit Ticket You might say………..
Artificial selection is when is when humans choose which plants or animals to reproduce in order to get desired trait like bigger fruits.
Farmers use artificial selection to produce crops and animals with useful traits, such as higher yield, better taste, disease resistance, or faster growth.
Artificial selection is not always beneficial. While it can improve certain traits, it can also reduce genetic diversity and sometimes lead to health problems in plants or animals.
Exit Ticket You might say………..
4. If only certain traits are repeatedly selected, the population can become less genetically diverse and more specialized for those traits. Over time, this can make the population more vulnerable to diseases or environmental changes because other traits have been reduced or lost.
5.. Artificial selection shows that humans can guide evolution by choosing which organisms reproduce based on desired traits. This demonstrates that selective pressures—whether natural or human-driven—can shape how species change over generations.
Link to National Identity
Date farming is not just agriculture—it represents history, sustainability, and survival in harsh environments..
2. Falconry (national pride and tradition)
The falcon, especially species like the Saker Falcon, is the national bird of the UAE and a major cultural symbol.
Falcons are selectively bred in farms for traits like speed, strength, and hunting ability.
Breeding programs also help increase populations and protect endangered species.
SDG 15 – Life on Land
How it connects to artificial selection:
Artificial selection can reduce genetic diversity in plants and animals, which may harm ecosystems and biodiversity if not balanced with conservation efforts.
So what have we learnt today!
Definition:
Artificial selection is when humans choose which plants or animals reproduce to promote desirable traits.
Key Idea:
Humans act as the “selective pressure,” shaping how species change over generations.
How it works:
Variation exists within a species
Humans select individuals with desired traits
Those individuals reproduce
Traits become more common over time
Examples:
Dog breeds (size, behavior, appearance)
Maize bred for larger, sweeter kernels
Date palm in the UAE for better fruit quality
So what have we learnt today!
Advantages:
Increased food production
Improved quality (taste, size, yield)
Disease-resistant crops
Disadvantages:
Reduced genetic diversity
Higher risk from diseases/environmental change
Ethical concerns (animal welfare, overbreeding)
Link to UAE Identity:
Selective breeding of Date palm and falcons reflects heritage, survival in desert environments, and modern innovation.
One-line summary:
Artificial selection is human-controlled evolution used to enhance useful traits, but it must be balanced to protect biodiversity.
