Misconception: "Selective breeding creates new genes in an organism."
Reality: Selective breeding does not create any new genes or alleles. It only selects from variation that already exists in the population. The alleles for the desired trait were already present โ selective breeding just increases their frequency. New alleles can only arise through mutation, not through breeding choices.
Misconception: "Selective breeding and genetic engineering are the same thing."
Reality: They are very different processes. Selective breeding works within a species (or closely related species) and takes many generations โ it increases the frequency of alleles that already exist. Genetic engineering directly cuts and inserts specific genes, can move genes between unrelated species, and can achieve results in a single generation. Genetic engineering is far more precise but also more controversial.
Misconception: "Selectively bred animals are always healthier because humans chose the best traits."
Reality: Selective breeding can cause serious health problems. Breeders select for traits humans find desirable (appearance, productivity) rather than what is best for the animal. Flat-faced (brachycephalic) dog breeds such as bulldogs and pugs were selected for their short snouts but now suffer from breathing difficulties, skin infections, and eye problems as a direct consequence of those bred-in features.
This common misconceptions covers Common Misconceptions within Selective Breeding for GCSE Biology. Artificial selection and selective breeding techniques It is section 6 of 11 in this topic. Use this common misconceptions to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Selective Breeding
What is selective breeding?
Explain how selective breeding has been used to develop modern wheat varieties with higher yields.