Complex sentence: In 1999 Botting declared himself to be an atheist, like Richard Dawkins (for whose brand of genetic theory he has been an staunch advocate) a disciple of J.B.S. Haldane.
Split into simpler sentences: In 1999 Botting declared himself to be an atheist. Like Richard Dawkins, for whose brand of genetic theory Botting has been an staunch advocate, he considers himself a disciple of J.B.S. Haldane.