Well, let’s start with the development from embryo to full-grown human. The mother lightens herself on the embryo by nurturing it, and after it’s become a baby so does the father (assuming a traditional parenting situation); in fact, after that so do other people, school teachers for instance. And of course during all this time there is the sun:
“If Nietzsche’s language is puzzling, his basic hypothesis is fairly straightforward. It is one later taken up and developed by the French Nietzschean Georges Bataille: namely, that the dynamic force of nature (that which propels growth, sexuality, procreation, struggle, and death) and of culture (production, form-giving, creativity, and play) is the superabundance of energy in the biosphere and the compulsion to expend it. As Bataille puts it, ‘it is not necessity but its contrary, “luxury,” that presents living matter and mankind with their fundamental problems.’ For both Bataille and Nietzsche, the source and archetype of this expenditure is the sun and its prodigality”. (Cox, Nietzsche: Naturalism and Interpretation, pp. 230-31.)
And as for the development from amoeba to ape, radiation—the sun’s, for example—causes genetic mutations that may prove heritable. 
That’s simply the counterpart to the singularity before the Big Bang idea… As I’ve explained to you before, I don’t think either singularity has ever been or will ever be actual; they’re limits, after all. As I’ve said many times, the Big Bang is the beginning that never began and the Big Chill is the ending that will never end. The universe or the whole is an actual singularity—a singular self-lightening that lightens itself into many self-lightenings, including into space-light: