What makes the origins of the eukaryotic cell cycle particularly resistant to evolutionary explanations is that a wide gulf exists between the mechanism of cell division by eukaryotes and that employed by prokaryotic cells — both in terms of the protein components involved, as well as the underlying logic. There is essentially nothing in common between the two systems.

Various components of the mitotic cell division apparatus are indispensable for the system to work. This makes the eukaryotic cell division irreducibly complex, rendering it resistant to explanations in terms of blind, evolutionary processes.

My new paper is out now in the journal BIO-Complexity, regarding the origins of the eukaryotic cell division cycle.

Have you ever wondered how our fingers and toes form during embryonic development? Our digits are, in fact, sculpted from a paddle-like structure in the embryo through the process of apoptosis — that is, programmed cell death. During early development, the hands and feet begin as solid, webbed structures. Through carefully controlled apoptosis, the tissue between them is eliminated, facilitating the separation of the digits.

The spindle assembly checkpoint pathway is an elegantly engineered surveillance system for protecting the cell from the adverse consequences of improper kinetochore-microtubule attachment.

In a recent article, I discussed the astounding role of motor proteins in eukaryotic cell division. But this is just one of many incredible engineered features associated with mitosis. In this and a subsequent article, I will provide an overview of the elegant molecular mechanisms that underlie the spindle assembly checkpoint and discuss the implications of its dysfunction.