• Genetic Variation
• Mutations
  • Mutations are random
  • The Lederberg experiment
• Causes of mutations
  • Reviewing DNA
  • Types of mutations
  • Case study: sickle cell anemia
• Gene flow
  • Gene flow: details
• Sex and genetic shuffling
  • Sex and genetic shuffling: details
• Development
  • Types of developmental change
  • Ontogeny and phylogeny
  • Developmental constraints
  • Understanding complexity
  • Hox genes

Mutations (1 of 2)

Mutation is a change in DNA, the hereditary material of life. An organism’s DNA affects how it looks, how it behaves, and its physiology—all aspects of its life. So a change in an organism’s DNA can cause changes in all aspects of its life.

Mutations are random.
Mutations can be beneficial, neutral, or harmful for the organism, but mutations do not “try” to supply what the organism “needs.” In this respect, mutations are random—whether a particular mutation happens or not is unrelated to how useful that mutation would be.

Not all mutations matter to evolution.
Since all cells in our body contain DNA, there are lots of places for mutations to occur; however, not all mutations matter for evolution. Somatic mutations occur in non-reproductive cells and won’t be passed onto offspring.

For example, the golden color on half of this Red Delicious apple was caused by a somatic mutation. The seeds of this apple do not carry the mutation.