Evolution
- Evolution can be defined as:
A change in the inherited characteristics of a population over time
- Evolution occurs by a process known as natural selection
- During natural selection individuals with phenotypes that are best suited to their environment are more likely to survive and pass on their features to their offspring
- The theory of evolution by natural selection states that all species of living things have evolved from simple life forms that first developed more than three billion years ago
- Natural selection can lead to the development of new species by a process known as speciation
- Speciation is said to have occurred when two populations have phenotypes that are so different that they can no longer breed together to produce fertile offspring
Evolution diagram
The theory of evolution states that all living things have evolved from simple life forms
Examiner Tip
Remember that the term evolution refers to changes in species over time, while natural selection is the mechanism by which this change has taken place.
