According to geneticist Michael Denton, the break between the non-living and the living world `represents the most dramatic and fundamental of all the discontinuities of nature. Between a living cell and the most highly ordered non-biological systems, such as a crystal or a snowflake, there is a chasm as vast and absolute as it is possible to conceive." Even the tiniest of bacterial cells, weighing less than a trillionth of a gram, is `a veritable microminiaturized factory containing thousands of exquisitely designed pieces of intricate molecular machinery, made up altogether of 100 thousand million atoms, far more complicated than any machine built by man and absolutely without parallel in the non-living world'.
Thus the simplest cells available to us for study have nothing "primitive" about them... no vestiges of truly primitive structures are discernible.
God's Undertaker: Has Science Buried God? by John C. Lennox