6.2 Variation and Evolution
Variation
Mutations cause new characteristics
Mutations occur continuously but most do not result in a new phenotype
Phenotype determined by interaction between genotype and environment
Evolution
Change in inherited characteristics over time
Continuous process
Due to natural selection
Can lead to formation of new species
New species formed when organisms can no longer interbreed to produce fertile offspring
Selective breeding
Breed organisms with desirable qualities
Genetic engineering
Involves modifying an organisms genome to give it desirable characteristics
Genes from other organisms can be added
Bacteria modified to produce insulin
Risks: loss of biodiversity, GM crops are expensive, long term health impacts unknown
Benefits: improve crop yield, produce materials for medicines, less waste
GM crops are resistant to disease, can produce better fruit and are frost resistant