What is the process that darwin described as "descent with modification?

The process that Darwin described as "descent with modification" is the process of evolution.

"Descent with modification" is one of the fundamental ideas behind Darwin's theory of evolution. According to Darwin, the characteristics of an organism are inherited. Offspring with inherited characteristics which allows them to compete best with the limited resources in the environment will survive. Organisms will pass the traits providing an advantage to survive and reproduce to the next generations. Over time and generations, the traits providing reproductive advantage will become common among the polpulation. This will lead to change in populations over generations in a process called the "descent with modification".

c.more precipitation,but only when emission levels.

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.