Okay, that’s cool. What does that mean to our discussion in this context? I would guess there are maybe a few options here (feel free to add or subtract from this list):
- Given that you are a microbiologist and I am not, we should defer to your expertise and evaluation of the relevant evidence
- Given that you’ve published scientific papers, you know the rigor that goes into them and don’t see the same thing here with bacterial flagellum
- You, like @Leyton, see yourself as a neutral arbiter of truth in these gaps of evolutionary theory and like consider your approach to be superior to that of anything in either that BioLogos article I shared or the scientific literature
And thus what you want is:
Okay fine. Here’s a nice paper closing some of the “evolutionary gap” for bacterial flagellum. It doesn’t explain everything, but it’s a piece of the puzzle.
How did the Campylobacter- type motor evolve from a simpler ancestral motor? During our previous work, we discovered that each accessory protein is essential, posing a conundrum: how could proteins have been added stepwise to form this (naively “irreducibly complex”) motor? To identify a possible incremental evolutionary pathway, we determined a phylogeny of ε-proteobacterial and related motors, used different accessory protein occurrences to identify and determine structures of the likely descendants of evolutionarily intermediate motors found in Wolinella succinogenes , Arcobacter butzleri , and Bdellovibrio bacteriovorus. W. succinogenes is a cattle rumen commensal12,13 while A. butzleri is a human gastrointestinal pathogen12,14, similar environments to C. jejuni . The more distantly related B. bacteriovorus can be found in a number of habitats including sewage and the human gut15. Subsequent to imaging the motor structures we related their structure to mechanical output using swimming speed assays. Our results enable us to propose a model for how the Campylobacter- type motor evolved by inferring a possible scenario for the order of protein recruitment events, and the selective benefits at each step.
Or another interesting review paper in microbiology from 2020:
Over the last decade, new single-molecule and in vivo biophysical methods have allowed investigation of the stability of this and other large protein complexes, working in their natural environment inside live cells. This has revealed that in the bacterial flagellar motor, protein molecules in both the rotor and stator exchange with freely circulating pools of spares on a timescale of minutes, even while motors are continuously rotating. This constant exchange has allowed the evolution of modified components allowing bacteria to keep swimming as the viscosity or the ion composition of the outside environment changes.
Or another highlighting some other features of motor evolution,
Complementing our imaging with bioinformatics analysis, we find a correlation between the motor’s stator system and its structural elaboration. Motors with a single H±driven stator have only the core periplasmic P- and L-rings; those with dual H±driven stators have an elaborated P-ring; and motors with Na+ or Na+/H±driven stators have both their P- and L-rings embellished. Our results suggest an evolution of structural elaboration that may have enabled pathogenic bacteria to colonize higher-viscosity environments in animal hosts.
Or another discussing other aspects of the evolution of these nanomachines:
Bacterial flagella have evolved as highly versatile nanomachines that enable bacteria to navigate and survive diverse environments such as the mucous of the mammalian gut. Over the last decade, cryo-ET has enabled direct visualization of conservation and adaptation of the bacterial flagellum to niche environments. Cryo-EM and X-ray crystallography have led to near-atomic views of purified flagellar proteins and subcomplexes, such as the MS ring, C ring, and stator complexes. By combining these techniques, it is becoming feasible to establish nearly complete models of the flagellar motor, such as the one shown in Figure 3. High-resolution views of the intact flagellar motor not only significantly enhance our understanding of flagellar structure and assembly but also provide the basis to address fundamental questions about bacterial flagella: How does proton motive force drive the flagellar assembly and rotation? How does the flagellum switch its rotational direction? And how has the flagellum evolved as a highly diverse nanomachine?
But nah yeah, evolutionists have no scientific arguments. Many people think their approach is superior, which is probably just an argument from incredulity a lot of the time. Such “contrarian” thinkers, superior to the deceived evolutionists, are the ones who are doing real science with real standards of evidence.