Micro v. Macro

In the first half of the 20^th century, scientists used the terms "microevolution" and "macroevolution" as a quantitative rather than qualitative distinction. They referred to the same thing, evolution, but over different timescales, the first being over periods much less than would (generally) permit speciation ¹. We need to stress it was not a qualitative distinction; all the mechanisms of evolution: natural selection, mutation, genetic drift, etc. are seen in both types.

Since then, among scientists, the terms have fallen out of favor.

On the other hand, many creationists, with the notable exception of theistic evolutionists, ² co-opted the terms, and then morphed the distinction between microevolution and macroevolution to a qualitative level. In fact, they simply assert that macroevolution, i.e. speciation, doesn't occur. Yes there are small adaptations, but no new species result. They accept a type of biological Zeno's paradox, where even an infinite number of micro-evolutionary baby steps will not bridge the finite gap between species B and its alleged ancestor, species A.

They are, of course, scientifically wrong. Not all speciations take millions of years. We have seen it in real time.

But that is not what I want to talk about. I want to talk about the logical and theological problems of accepting microevolution but not macroevolution. Microevolution, as defined by and accepted by most creationists, even YECs, refers to the rather obvious adaptations we see everywhere. They are so obvious, nobody can reasonably deny them. Check out the video for a rather dramatic example.


 


So, the question for micro-only advocates is this: are these non-speciation adaptations under God's direct control, or does he allow the secondary process of microevolution to work on its own? Did God actively create antibiotic resistance in the bacteria in the video, i.e. the mutations were illusions, or was he a passive observer in the same sense, say, that he doesn't actively move the planets in their orbits, but allows gravity to do the dirty work?

I suppose that if you believe that God actively changed the bacteria to be resistant then at least you can be self-consistent. But that actually violates the premise of this post, because you would be denying not just macro but also microevolution.

Now if you concede that God does allow (we agree he always has to allow) the secondary means of microevolution to function, the next question is: what prevents the process from leading, over time, to a new species? Because micro and macro have the same mechanisms. There is no natural barrier that says: okay stop already, you've adapted far enough, any more would result in a new species. You would have to, at that point, invoke direct action from God, to prevent further changes from microevolution, which you allow, from adding coherently (in, say, an isolated population) until you arrived at a new species. You would, it seems to me, require that God actively intervenes in the evolutionary process to prevent something (speciation) from resulting.

Congratulations, you are a theistic evolutionist. Because that is exactly what we claim--that God intervenes, when it pleases him, in an otherwise natural (i.e. secondary means) process. The only difference is that you claim (or rather it logically follows from your acceptance of microevolution) that God intervenes to prevent speciation, while I claim that God intervened (when needed) to permit it, in order to create the diversity of life he desired.

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¹ Our working definition of a species is grouping of animals that can produce fertile offspring within the group, but no fertile offspring (mostly no offspring at all) with other groups. There is some debate about the definition of a species, but this is good enough for our purposes.

² Many of whom (theistic evolutionists), in spite of all the aspersions cast on the sincerity and legitimacy of our faith, are still creationists in the sense that was sufficient and acceptable for the early church, although not the modern North American anti-science evangelical community. That is, we (some of us) affirm that God created the universe ex-nihilo, that Adam was historic, that man is exceptional among the species and was made in God's image, and that God is sovereign over creation. The argument is over secondary means. Theistic evolutionists believe that God used the secondary means accordant with what we observe in his creation, while non-theistic-evolutionary creationists believe that God's means are at odds with what we observe, or that mainstream scientists are conspiring to misrepresent the book of nature.