Selective Breeding

What Is Selective Breeding?

Selective breeding (also known as artificial selection) is when humans intentionally breed plants or animals with desired characteristics.

💡 Key Concept: It’s used to produce organisms with useful or attractive traits – and it’s been used for thousands of years in farming and domestication.

The Process of Selective Breeding

1️ Choose individuals with the desired trait (e.g. high milk yield).
2️ Breed them together.
3️ From the offspring, select the ones that show the desired trait best.
4️ Repeat this process for many generations until the trait is common.

Examples of Selective Breeding

Organism	Desired Trait
Cows	Produce more milk or meat.
Crops	Resistant to disease or produce bigger fruits.
Dogs	Friendly temperament or strong sense of smell.
Flowers	Larger blooms or specific colours.

Advantages of Selective Breeding

✔ Improves yield in crops and animals.
✔ Produces resistant or better-adapted organisms.
✔ Enhances desired traits (e.g. taste, size, colour).

Disadvantages and Risks

❌ Reduces gene pool (less genetic variation).
❌ Increases risk of inherited diseases.
❌ Organisms may be less able to adapt to changes in the environment (e.g. climate, disease).

💡 This is called inbreeding, and it can lead to genetic disorders in both animals and plants.

Selective Breeding vs Natural Selection

Selective Breeding	Natural Selection
Chosen by humans	Driven by environment
Faster changes	Slower process
May reduce variation	Increases survival

Questions

What is selective breeding?
Give one example of a trait that might be selected in animals.
What is one risk of selective breeding?
Why can selective breeding lead to disease?
How is selective breeding different from natural selection?

Summary

Selective breeding is used to enhance useful traits in animals and plants.
It can improve productivity but can also lead to reduced genetic diversity and inbreeding problems.
It differs from natural selection, which is not controlled by humans.