Irreducible Complexity

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.

These molecular motors are absolutely indispensable to successful cell division in eukaryotes and thus constitute an irreducibly complex system. It therefore points forcefully and unequivocally to conscious intent.

Last week, I wrote an article highlighting the irreducible complexity of the DNA replisome. A reader asked me whether the complexity of the DNA replisome could in fact be used as an argument against intelligent design.

The DNA replisome is one of the most remarkable molecular machines, involving a complex of different proteins, each of which is very specifically crafted to fulfill its role in the process of replicating the genome in preparation for cell division.

Danaher’s critiques of irreducible complexity are poorly informed and based on misunderstandings of intelligent design and what its key defenders argue.

We are all familiar with thermostats — devices we use to regulate temperature, typically in central heating and air conditioning systems, as well as ovens, refrigerators, and water heaters. But did you know that our bodies also contain their own thermostat, which is responsible for maintaining our body temperature at the optimal level?

I recently read a paper from 2007 by two plant geneticists, Wolf-Ekkehard Lönnig and Heinz-Albert Becker, from the Max-Planck-Institute for Plant Breeding Research in Cologne, Germany. The paper presents a review of carnivorous plants, which, by employing “enormously different and ingenious trap mechanisms,” ensnare and digest insects.

The development of an egg cell and its activation in response to encountering a sperm cell exhibit exquisite design, being contingent upon multiple mutually dependent processes, all of which are needed for successful reproduction. When considered in conjunction with the incredible engineering features of the sperm cell and the seminal fluid, it would seem to put the thesis of design almost beyond question.