Responses to Environmental Changes-4 4.Evolutionary responses involve adaptation of a population over a long period of time. Evolutionary responses require many generations Example:sugar maples which grow in Canada are more resistant to winter injury than populations in the southern United States.This difference has a genetic basisResponses to Environmental Changes Responses to Environmental Changes – 4 4. Evolutionary responses involve adaptation of a population over a long period of time. • Evolutionary responses require many generations. • Example: sugar maples which grow in Canada are more resistant to winter injury than populations in the southern United States. This difference has a genetic basis