IB Biology Sub-topic A4.1 Definitions
This page contains our IB Biology definitions for sub-topic A4.1. By learning each one of these definitions, you will fully cover the content for IB Biology 'Evolution & speciation'.
adaptation
Characteristics that make an individual suited to its environment and way of life
adaptive radiation
The divergence in function of homologous structures over time
analogous structure
A different structure found in different organisms for the same function
evolution
A change in heritable characteristics of a species over time
homologous structure
A similar structure found in different organisms for different functions, suggesting a common ancestor from which it originated
melanism
The dark variation of light insects
selective breeding
The artificial selection and mating of organisms such as horses and cows to express desired characteristics
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