How does the work of Peter and Rosemary Grant illustrate natural selection?

Similarly one may ask, what did Peter and Rosemary Grant do?

Peter and Rosemary Grant have seen evolution happen over the course of just two years. The Grants study the evolution of Darwin's finches on the Galapagos Islands. The major factor influencing survival of the medium ground finch is the weather, and thus the availability of food.

Similarly, which of the four factors that affect evolution apply to the finches that the grants study? The four factors that affect evolution are mutations, natural selection, genetic drift and the gene flow, In the case, if the ground finches that Grants studied, we can observe the working of the natural selection.

Also to know, what was the brief goal of the grants studies?

Every year since then, the Grants have returned to the Galapagos to study the finches in their habitat for months at a time. The Grants' goal was to determine how each of the 14 species of finches evolved from the ancestral one, which likely flew in from the South American mainland.

Who was the very first biologist that studied the Galapagos finches?

Charles Darwin