A mutation is a change in the sequence of an organism's DNA. Mutations can be caused by high-energy sources such as radiation or by chemicals in the environment.
Hummingbirds evolved from insect-eating ancestors. The genes that detect the savoury flavor of insects underwent changes, making hummingbirds more sensitive to sugars. These new sweet-sensing genes give hummingbirds a preference for high-calorie flower nectar.
Learn more about How has the presence of the sweet sensing gene increased in the hummingbird? here: https://brainly.com/question/14236000
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