Neither darwin, nor Teilhard de Chardin, has an answer for that, based on strict evolution.
Read some of the newer writings by Behe and others.
They are far more rigorous than anything Teilhard de Chardin wrote and are a far better refutation of spontaneous life (implying a Creator).
Teilhard's idea of that is that there is little to be found of the first examples of a new evolutionary branch or of the beginning of it all. Life being what it is, eats everything around it. The beginnings, therefore, can never be known. We can see only what it is now, and a few remains of things that were, ever scarcer as they were closer to the beginning. It is speculation that we engage in, trying to find out how it happened when there is nothing left for scientists to work with, no samples, no facts. Life doesn't spontaneously appear to organize itself out of plain atoms now because conditions aren't right, not to say that someone might not find the right conditions in the lab one day and therefore become an IDer in his own right. Conditions were right once, that is the assumption, but it is speculation. We cannot know.