Doesn't darwinian theory fall apart on ontological grounds?

Or...what if Viceroys also are unpalatable ? What if Monarchs are heading toward Viceroy, or maybe both are approaching a common point , and Monarchs are moving faster toward it than Viceroy ?

But viceroys are not unpalatable, that's the whole thing. Monarchs are unpalatable in part from their pre-pupation diet, which is exclusively milkweed. Viceroys do not feed on milkweed and they are not unpalatable.

Their respective appearances are an example of convergent evolution, and since looking like a monarch is advantageous it clearly stands to reason that the viceroy is doing most of the convergence.

... and in fact that is one of the competing theories ... that is, if Viceroys and Monarchs are equally unpalatable, then it may be evolutionarily valuable for them to mimic each other such that "once biting, twice shy" applies both ways (if a predator makes the mistake of eating a Viceroy, no Monarchs get eaten and vice versa) ...

depends on who's doing the tasting, eh, Paul ?
What's your expertize in this area ?

When I was in high school I did a lot of volunteering at a local chapter of the Audubon Society, and there was an entomologist there who taught me a great deal about monarch and viceroy butterflies. I used to find monarch eggs on milkweed plants and grow them all the way through the larval and pupal stage, then release them when they emerged from the chrysalis. (This, by the way, is a GREAT project to do with kids). To this day I can still easily tell a male from a female monarch (there is a dot mid-stripe on the males' wings), and I can tell a viceroy from a monarch (viceroys have an orthogonal stripe).

I don't think creatures are capable of slef-interest in the same way, even though in some ways the same principle, namely deception, is involved.

... and in fact that is one of the competing theories ... that is, if Viceroys and Monarchs are equally unpalatable, then it may be evolutionarily valuable for them to mimic each other such that "once biting, twice shy" applies both ways (if a predator makes the mistake of eating a Viceroy, no Monarchs get eaten and vice versa) ...

but what did they TASTE like ?
and what do viceroys taste like ?

some testing showed that Redwing Blackbirds liked Viceroy even LESS than Monarch.

Nonetheless, the take home message for evolutionary biology is that selection acts on function and not on sequence, i.e. whether it's the structure of a gene product or if it's simply the amount of the same gene product, it's this end effect that matters in the end however it's achieved.

and what if Viceroys are NOT moving toward Monarch ?

... if that turns out to be the case, then neither of the mimicry theories would be applicable to the case of Viceroys and Monarchs ... and in fact, there is evidence that in some localized regions the Viceroy is moving toward the Queen ... and that's an interesting thing to ponder ... in some regions, the Viceroy appears to be mimicking the Monarch; in other regions it appears to be mimicking the Queen ... could the Viceroy have evolved a high degree of genetic coloration plasticity relative to other butterflies? - that is, could the Viceroy have evolved a genetic "talent" for mimicry? (now we're really speculating! ) ...

Then it's not a deceptive at all; it's clear warning from either species involved. If anything, it's Queens, perhaps being less distasteful, that have the supposed direction to go in, toward Viceroy.

How do you know it is not Queen moving toward Viceroy ? You still have the Viceroy "pegged". Is ti now The USUAL suspect or something ?

Biased Gene Conversion shows this is inaccurate

... yes, that's exactly what my last sentence speculated ... if it looks like the Monarch in one region but diverges to look like the Queen in another, it is not unreasonable to hypothesize that the Viceroy is "the usual suspect" ...

Bed Time Stories from Science.

Not at all. The development and dispersion of polymorphisms by whatever mechanism, and changes in population gene frequencies due to drift, founder effects, etc, (and this INCLUDES biased gene conversion), are all NONSELECTIVE causes of population gene frequency change. Selection acts on the phenotype, whether the novel underlying gene sequence got there because of a GC vs AT bias or a point mutation or whatever.

But who SAYS selection acts only on phenotype ? And on WHAT BASIS ?

Also, are you dismissing things that can be observed as possible phenotype ?

Are you also limiting selection to the individual ?

Because the lion that's about to eat you doesn't know your genotype. It only knows how fast you run. Because the ice age doesn't know your genotype -- it only knows that more furry babies will survive.

What kind of question is it to ask whether selection only acts on phenotype?

Selection by definition is differential survival or fecundity

, and these are in themselves PHENOTYPES. It is a phenotype of humans that we drown in the ocean, and it's a phenotype of fish that they die on land.

Furthermore, this is about mechanism. Even viruses that integrate into a host genome do not select via targeted alteration of host germline DNA.

I'm not quite sure what you're asking. Any phenotype is subject to selection.

Gene regulation is a phenotype -- that's where it gets sticky. But again the physiology produced by gene regulation is what favors survival or not, i.e. what is subject to selection.

Yes!! (Individual being defined inclusively, because ability to produce viable offspring that survive to reproduction is critical to this)

EVOLUTION is a population phenomenon. Allele frequencies change in populations. This is evolution. Selection may lead to significant and rapid changes in a population in few generations, but the UNIT of natural selection is the procreation (or not) of an individual genotype, as determined by how the resultant phenotype favors survival and reproduction.

In order for there to be a FREQUENCY, there has to be a numerator and a denominator. The denominator is the total population. The numerator is a big group of individuals.