The American Chemical Society's special issue of Accounts of Chemical Research is dedicated to chemical evolution. See our previous comments here and here. Now let's look at an article by Irene Chen and Martin Nowak that addresses the fundamental evolutionary step involved in making the transition from non-life to life ("From Prelife to Life: How Chemical Kinetics Become Evolutionary Dynamics"). The authors say that they are going to explain how longer RNA sequences arise from shorter ones and how the ability to replicate emerges.
OK, let's hear it.
Well, the article proposes a model based on prior origin-of-life research. Thus the authors assume that certain research questions are already answered. Many of their assumptions are, however, problem areas for RNA-world experiments.
The model on offer is based on chemical kinetics (reaction rates) giving rise to evolutionary dynamics (replication and competition). Essentially, the authors define "prelife" as a system that maintains chemical rules and "life" as a system that maintains biological rules. Prelife systems are subject to chemical equilibrium and reaction rates. Living systems are subject to environmental pressures and replication rates. Therefore, the point at which a chemical system can self-replicate is the point at which the system transitions from prelife to life. Here is how the authors define this distinction:
Implicit here is the assumption that biological and chemical systems operate differently. But the authors explicitly compare their model to a bottom-up approach to synthetic life. Usually when people take a "bottom-up" approach, they are assuming that biology is reducible to chemistry. Otherwise it is NOT a "bottom-up" approach, but is based on some other overarching parameter or driving force.
Here is a summary of the proposed model:
Goodness me, has there ever been anything easier to figure out? I don't know why I continue to torture myself by pointing out the following, but let's give it one last go.
ReplyDeleteOK, put yourself in the position of nature and say to humankind, "Humankind, I'm going to give you 70-plus years of love, great affection for life, treasured personal interactions, cherished family relationships, ambition and goal setting, positive attitudes about the outcome of all manner of things, and any other fixation you want to consider as making your life worth living. But don't get too excited buckos, because at the end of it I'm going to rip it all away, stomp on it, tear it to shreds, make it thoroughly profitless, turn it into a laughable joke, and otherwise - well - just kill it. What a pathetic and meaningless creature you really are!"
That's what nature is saying to all buckos - if you don't believe in eternal life. Come and let us reason together (I've read that before, somewhere)would you do to any individual what nature says it's going to do to you? OF COURSE NOT!! Unless, of course a horse, you are the most brutal of nihilists. Listen, please, listen: The threat of nature's lie is so demonstrably obvious as to need no explanation.
Pastor J, put this one in your box of apologetic bullets and fire it at will. You will find the atheist standing with their mouths glued wide open - with nothing more to say. They have no answer for this, the DSs (you can figure out that one) haven't even taken the time to think about it in this most reasonable and positively logical way. The beginning, middle and end of the story.