What does evolution refer to in biological terms?

In biological terms, evolution refers to the change in heritable characteristics over generations. This process encompasses the gradual changes that populations of organisms undergo as they adapt to their environments and can result in the development of new species over long periods of time. These heritable characteristics, which can include physical traits, behaviors, or physiological processes, are influenced by natural selection, genetic drift, mutations, and gene flow.

This understanding of evolution is fundamental to the field of biology, as it explains the diversity of life on Earth and the relationships among different organisms. The emphasis is on changes that are passed down through reproduction, making it a slow and generational process.

The other options, while related to certain biological concepts, do not accurately define evolution. Immediate changes within an organism's lifetime pertain more to phenotypic plasticity rather than evolutionary change. Adaptation to climatic changes can be a result of evolutionary processes, but it does not encapsulate the broad scope of evolution itself. Lastly, genetic modification through technology refers to artificial manipulation of an organism's genome, which is not a natural evolutionary process but rather a form of biotechnology.