As you know, I have been inquiring about the missing prokaryotic mice. Essentially, why is it that evolution has been unable to use the bacterial cell plan to spawn an organism as structurally and behaviorally complex as a mouse? Let me remind you of two lessons derived from pondering the missing mouse.
First, since natural selection is a designer-mimic (the blind watchmaker), then, like all designers, it is limited by the material it is using to express its design. This should not be all that controversial to accept. For example, everyone would agree that natural selection is limited by the laws of physics. No problem there. But we can go further and ponder to what degree natural selection is limited by the raw material which composes life itself. This is a key point for teleologists to ponder, as a limitation is a constraint, and a constraint can be used by a designer as a form of guidance.
So here’s where the missing prokaryotic mice come in, as it would seem natural selection has run into the wall of constraint. The bacterial cell plan, with its remarkable ability to laterally exchange information, engage in cell-cell communication, and metabolically adapt to an immense range of environmental conditions, has been an astounding success when it comes to colonizing and terraforming. But when it comes to evolving something akin to a mouse, it has never come close.
The missing prokaryotic mice is even more strange when you consider the ubiquity of convergent evolution. Simon Conway Morris has gathered a mountain of evidence outlining the manner in which convergence permeates the evolutionary tree. In fact, this is one area of his thinking that Richard Dawkins applauds. Why? Because ubiquitous convergence helps to move natural selection closer to a law-like phenomenon. (a status lost with the loss of strict gradualism). But if natural selection is law-like, as seen from the ubiquitous nature of convergence, the lack of convergence between bacteria and eukaryotes is even more striking – we can find nice examples of convergence between bacteria and fungi, we don’t see much between bacteria and animals.
So the missing prokaryotic mice boil down to a huge lacuna in the landscape of convergence. And I propose this is explained, ultimately, by the fact that designers are limited by their design material – the bacterial cell plan cannot be tweaked and tinkered with to generate something like a mouse. And this leads us to the second lesson (as I briefly outlined before).
If the bacterial cell plan, so good at colonizing and terraforming, is insufficient for making something like a mouse, then in order to make something like a mouse, the cell plan first needs to be radically re-tooled. From the front-loading perspective, this means the origin of the eukaryotic cell must have been front-loaded by features of bacterial cell design.
Let’s then begin the process of investigating for clues that would help us assess this prediction.