Which of these statements is true about adaptive evolution? The ability to learn plays a key role in the process of adaptive evolution. Viruses play a key role in the process of adaptive evolution. Sudden changes in the somatic cells of organisms play a key role in the process of adaptive evolution ...

The correct answer is "Sudden changes in the somatic cells of organisms play a key role in the process of adaptive evolution". Adaption in evolution is caused by sudden gene mutations that affect an organism's offspring and give it - potentially - a better chance of survival. For example, a giraffe who passed on a mutated gene for a slightly longer neck to its offspring gave its offspring a better chance of reaching untouched food, and thus a survival advantage.