Why can we assume that the synthetic theory of evolution mainly develops in line with the ideas laid down by C. Darwin?

The synthetic theory of evolution revealed the deep mechanisms of the evolutionary process, accumulated many new facts and evidence of the evolution of living organisms, combined the data of many biological sciences. Nevertheless, the synthetic theory of evolution (or neo-Darwinism) is in line with the ideas and directions that were laid down by C. Darwin. The combination of Darwinism with ecology and genetics in the 1920s set the stage for a synthetic theory of evolution. Darwin’s doctrine is the basis, the backbone of modern theory, it gave impetus to the further development of evolution as a science.