I hadn’t realised that the Biologic Instute had a diary/blog.
February’s article is by Ann Gauger, although it consists largely of quotations from Douglas Axe, and is called Natural Selection’s Reach.
What continues to astonish me about ID proponents is just how ignorant they are of evolutionary theory. Ann Gauger starts by setting out to address a reader’s query:
A reader wrote us recently to ask why natural selection can’t extract enough information from the fitness landscape to explain complex features.
Well, obviously I dispute the premise of the question, but assuming that the reader and Gauger share the view that natural selection’s “reach” is too limited to “explain complex features”, let’s see how Gauger explains her stance. She starts by rightly saying that:
It all depends on what you think the fitness landscape looks like
and then lets Axe go on to explain further. Unfortunately, Axe appears to think it looks like this:
with complex features situated on the high distant peaks, and natural selection only able to move a step at a time, and only upwards.
If this were actually a realistic model of the fitness landscape, of course, natural selection would be doomed. But what Axe has presented is, at most, a two-dimensional map. This would be what the landscape would look like if organisms could only vary along two dimensions, say, size and colour. When the population had optimised its size and colour, it would be stuck on the top of one of those little mud ridges, with nowhere to go but down.
Does Axe really think that there are only two dimensions to the fitness landscape of biological organisms? Or has it simply not occurred to him to extend his metaphor to the harder-to-envisage realm of multidimensional fitness space?
The “limited reach” of natural selection is not the problem – yes, populations generally can only “move” over the fitness landscape step by tiny step. But that doesn’t matter if the landscape consists of many ramps along many dimensions, and the more dimensions there are, the more ramped routes there will be, thus vastly increasing the accessibility of those distant peaks.
Gauger concludes her piece:
What is the mutational reach of natural selection in general? It’s very short. For bacteria, our work suggests the reach is only a few mutations at a time. That’s not enough to get a genuinely new function for a protein, let alone a new pathway made up of a handful of proteins, or a metabolism made up of hundreds of proteins. For larger multicellular organisms like us, with slower generation times and smaller populations, the problem gets worse. Much worse.
So unless someone paved a highway to Mt. Whitney that went uphill every step of the way, Darwin’s engine would never get out of Death Valley. But a paved highway isn’t evolution, it’s design.
Nope. A route that goes uphill (or at least not drastically downhill – drift helps too) every step of the way is highly probable in a multidimensional fitness landscape, and a multidimensional fitness landscape doesn’t have to be designed. You just need an environment in which there are lots of resources that are exploitable by the kinds of variation possible to biological organisms. And given that we know (and both Axe and Gauger must know, being biologists) that similar phenotypes have similar genotypes, the landscape is not only full of climbing ramps, but is also “paved” – smoothed by the similarities between the phenotypic consequence of similar genotypes.
Honestly, it’s not that I’m “skeptical” of ID – I have just yet to read a pro-ID article, even by the academics in the field, that doesn’t make rookie errors about evolutionary science. Oh, except for Todd Wood, and he relies on faith, not science, for his belief.