How It Works: Selective Breeding Over Generations
Part of Selective Breeding — GCSE Biology
This how it works covers How It Works: Selective Breeding Over Generations within Selective Breeding for GCSE Biology. Artificial selection and selective breeding techniques It is section 4 of 11 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 4 of 11
Practice
28 questions
Recall
20 flashcards
How It Works: Selective Breeding Over Generations
Selective breeding — also called artificial selection — is the deliberate choice by humans of which individuals in a population are allowed to reproduce. Unlike natural selection, where the environment determines which organisms survive and breed, in selective breeding it is human judgement that decides which traits are desirable.
The process works because the traits humans want are encoded in alleles. By choosing parents that both carry alleles for the desired trait, breeders increase the probability that offspring will inherit those alleles and express the characteristic. The key steps are:
- Identify the desired characteristic — for example, high grain yield in wheat, or calm temperament in dogs.
- Select individuals that most strongly show that characteristic and use them as breeding parents.
- Breed the selected parents together and examine the offspring.
- Select the best offspring and use them for the next round of breeding.
- Repeat over many generations — the alleles for the desired trait become more common in the population with each cycle.
This process can produce dramatic results over tens to hundreds of generations — all modern dog breeds, from Chihuahuas to Great Danes, were derived from the wolf through thousands of years of selective breeding.