Regarding Butterflies: Mimicry and the Evolutionary Path...

[cyb]

Herein lies a question that I have been wanting to ask an Evolutionary Scientist all my life;​

I have followed science for the longest time and have been awed by its beauty, complexity and relevance since childhood. Many questions have been answered eloquently and satisfactually by the scientific method.
Even quantum theory appears plausible, if a little vague. (It does skirt the precipice with mysticism quite uniquely though).

However one question remains unanswered to me and I would like to ask some of the fine, intelligent minds, that reside within the walls of the Nexus, if they could bring their knowledge and opinion to bear on this conundrum.

I have posted this elsewhere to no avail; Understanding the plant-animal dependencies - Philosophy - Welcome to the DMT-Nexus
so here it is again in the proper fora.
(and please...no talk of Religion in this thread...however tempting.)

I have a problem with Darwinian Evolution theory...​

In particular the mimics...

Take the eye spots of some butterflies (Owl Butterfly shown). Notice in the 'Pupil' there is a 'Specular Highlight'...
Specular highlights are a product of light refracting on a shiny surface...
A Specular Highlight has to be 'seen' using 'eyes' to be understood by a 'brain'.

How, then, could an evolutionary path, taking 100,000's of generations, actually 'see' this anomaly (-evolution has no eyes-) and then remember and carry forth this information over those generations (making tiny genetic corrections on each successive generation and arrive at a coherent end goal )?? :surprised

It almost appears that this mimicry is 'Designed' in one hit...!
Or coded to look like that.
What then, is doing the 'designing' or 'coding'??
How does this come about?? :?

Same question goes for the other Mimics...Leaf bud insects-Stick insects and the like...even 'camouflage' comes to mind.

If you are a new 'seedling' and can't post here...please start a thread and reference this topic/thread and discuss it in Open Discussion.

So...give it your best shot...!

​

 

[Parshvik Chintan]

i have no strong opinions either way, but this is what wikipedia has to say on the subject

The lepidopterist and writer Vladimir Nabokov argued that although natural selection might stabilize a "mimic" form, it would not be necessary to create it. It may be that much of insect mimicry, including the Viceroy/Monarch mimicry, results from similar self-organizing processes, and thus the tendency for convergence by chance would be high.

The most widely accepted model used to explain the evolution of mimicry in butterflies is the two-step hypothesis. In this model the first step involves mutation in modifier genes that regulate a complex cluster of linked genes associated with large changes in morphology. The second step consists of selections on genes with smaller phenotypic effects and this leading to increasing closeness of resemblance. This model is supported by empirical evidence that suggests that there are only a few single point mutations that cause large phenotypic effects while there are numerous others that produce smaller effects. Some regulatory elements are now known to be involved in a supergene that is involved in the development of butterfly color patterns. Computational simulations of population genetics have also supported this idea.

also this

 

[DeMenTed]

The way i believe evolution to work is that an array of mutations will happen and the most successful mutation is the one that will carry forward.

The butterfly might have mutated a lot of different patterns on its wings and the mutation that resembled an eye was the most successful for the butterfly, so that mutation breeded with other successful mutations and over time the lifelike eye mimicry design was the overall winner in the mutation battle.

I think that's how it works. If i'm wrong someone please correct me.

 

[cyb]

The butterfly might have mutated a lot of different patterns on its wings and the mutation that resembled an eye was the most successful for the butterfly, so that mutation bred with other successful mutations and over time the lifelike eye mimicry design was the overall winner in the mutation battle.

That explains evolution..But that doesn't explain the most important part of the boggling...that of 'observing' the 'Specular Highlight'...

 

[DeMenTed]

Maybe the design for eyes is entangled in the butterflies dna but appears on its wings rather than where it's eyes are?

All life on earth seems to come from one common ancestor so maybe all the possibilities are there but the dna is organised differently so the eye design is on its wing.

Maybe life can observe itself outwith conscioussness and can make immediate changes when it recognises advances in keeping its species alive?

Of course i have no real scientific ideas as to how the specular highlight got there but it does seem to be of intelligent design.

Maybe a higher intelligence controls life and we are merely pilots of these life vessels or something the possibilities are endless lol.

 

[daedaloops]

The butterfly might have mutated a lot of different patterns on its wings and the mutation that resembled an eye was the most successful for the butterfly, so that mutation bred with other successful mutations and over time the lifelike eye mimicry design was the overall winner in the mutation battle.

That explains evolution..But that doesn't explain the most important part of the boggling...that of 'observing' the 'Specular Highlight'...

Thanks for the thread I've been thinking about this on and off ever since you posted about it in the other thread, but I couldn't quite get my head around it. Like I know exactly what you mean you don't really care about mimicry itself you're just interested in the specular highlight phenomena. Instead of mimicking just the general form of things the specular part would require photons to reach some sort of "eye" of evolution, or so it feels like.

But actually, now that I read what demented said, couldn't it be attributed to the same thing as the rest of the mimicry? It could rise out of massive amounts of trial and error. Like, consider a butterfly millions of years ago that had just developed a blank circle on its wings, for whatever reason maybe some sort of random patterning process. Then the circle starts to mutate and it gets all these different mutations like a red square in the middle or a blue halo or any possible color/shape combination. Among those happens to also be the white specular shape, and the butterflies that are slightly mutated with that one have a slightly higher probability for survival than the rest. Therefore that mutation would kind of stick-on and stay, without needing any kind of an outside observer. This all would happen in a span of millions of years obviously, with incredibly small increments, and with alot of rejected (dead) pattern possibilities.

I think it's just really hard to grasp the concept of such a big timespan and such little changes having any effect, but I guess in the big picture even the smallest things have an effect. (speaking of butterflies and effects..) I for one have a really hard time understanding sometimes how such exquisite and beautiful creatures that we have on planet earth could have arisen out of pure randomness, they look like they were designed and engineered by a studio of cosmic professionals, but who knows maybe it's the same thing. Maybe randomness IS a designer, and we're looking at its artworks all the time but we've just gotten so used to it that they start to look like things and patterns. Maybe if a traveler from a non-random universe visited us they would be like "Oh gosh those guys are so random!". It's the curse and blessing of subjectivity. But enough rambling...

 

[Infundibulum]

Take the eye spots of some butterflies (Owl Butterfly shown). Notice in the 'Pupil' there is a 'Specular Highlight'...
Specular highlights are a product of light refracting on a shiny surface...
Something that has to be 'seen' using 'eyes' to be understood by a 'brain'.

I am not quite sure what you try to convey here. Why do you think that "Something that has to be 'seen' using 'eyes' to be understood by a 'brain'"?. The butterfly does not mimic the eye because the butterfly has seen its predator's eyes (or whatever the butterfly tries to mimic).

Even though I do not know how exactly this particular mimic arose in these butterflies, abrupt, gross changes are not infrequent in evolution. Lets say there are a few genes that control basic outlines of a given organ (for instance where your arms are going to start growing from and that you're going to have one in each side) and many genes that fine tune the process (like how many fingers, rotary constraints of the joints etc). If you happen to get a random disruption in one of the few key genes you might end up (having radical changes in just a single generation.

 

[cyb]

Like I know exactly what you mean you don't really care about mimicry itself you're just interested in the specular highlight phenomena. Instead of mimicking just the general form of things the specular part would require photons to reach some sort of "eye" of evolution, or so it feels like.

You got it...

But actually, now that I read what demented said, couldn't it be attributed to the same thing as the rest of the mimicry? It could rise out of massive amounts of trial and error..

honestly...I can't see that happening. (the highlight is quite clearly ...'specular')
I could totally go for the whole 'copying' a successful form scenario...but the photonic nature of specular highlights just upsets the whole apple cart...

they look like they were designed and engineered by a studio of cosmic professionals.

They absolutely do don't they...?

And don't get me started on some of the s**t that lives in the deep Ocean... :surprised

 

[cyb]

I am not quite sure what you try to convey here. Why do you think that "Something that has to be 'seen' using 'eyes' to be understood by a 'brain'"?. The butterfly does not mimic the eye because the butterfly has seen its predator's eyes (or whatever the butterfly tries to mimic).

It's not the butterfly that would be the 'Something' in this sentence...it's 'what' drove the evolution forward with the highlight as an extra layer.
There are plenty of butterfly spots out there with just a pupil but only a select few with the highlight.

As a designer...it is my 'job', if you like, to observe what it in front of my 'eyes' and record what I 'see'...Thats fine...

But I don't design butterflies from scratch....So what/who/if etc. is Designing...?

 

[Vodsel]

Well, first of all, keep in mind that the fact you happen to see a pattern that strongly evokes for you the behavior of directed light upon a reflecting eye surface does not necessarily imply that pattern was designed (or it has evolved) to specifically mimic the reflection of light upon a eye surface. You can find many eye-shaped patterns in nature that have no reproduction of a light flare whatsoever, and other patterns that mimic an eye but show details that do not match its reflective properties at all, and even mimicry patterns that are obviously imperfect and do not seem to become more accurate through time. You can find many shapes that might be interpreted in many different ways depending on who's looking at them, human or not.

In any case, patterns like the ones in Owl Butterflies appear much faster than you might think, requiring relatively few changes in the corresponding regulatory genes. So they don't seem to be a long, perfectionist work of art where every hundred of generations adds yet another accurate spot to the "light-reflective" pattern, but a quite rapid one, where some of the patterns have details that depict closely for us a realistic perception of a reptile eye and others simply do not.

I'm leaving a paper attached about it, it was published in Nature magazine in 1996.

 

[Infundibulum]

I am not quite sure what you try to convey here. Why do you think that "Something that has to be 'seen' using 'eyes' to be understood by a 'brain'"?. The butterfly does not mimic the eye because the butterfly has seen its predator's eyes (or whatever the butterfly tries to mimic).

It's not the butterfly that would be the 'Something' in this sentence...it's 'what' drove the evolution forward with the highlight as an extra layer.
There are plenty of butterfly spots out there with just a pupil but only a select few with the highlight.

As a designer...it is my 'job', if you like, to observe what it in front of my 'eyes' and record what I 'see'...Thats fine...

But I don't design butterflies from scratch....So what/who/if etc. is Designing...?

Thanks for the explanation, yet I still do not see what you find so extraordinary in your given example. If a few select butterflies have the highlight, then that's a result of better, or let's say more adapted mimicry. I do not see why that is so mind-boggling.

As one can imagine, the butterfly likely evolved the eye mimicry to avoid predators. If that eye makes the butterfly look like a bird of prey to a bird that would normally eat the butterfly but would be scared of a bird of prey, then it's all good for the butterfly.

But then, mimicry is an arms-race among the involved species; sooner or later if birds want to successfully hunt down the eye-mimicking butterflies, they'll have to evolve or learn to tell apart the mimicry. The latter puts an evolutionary constrain in the butterfly which means "advance your mimicry or perish", which drives the highlight in the eye to become a fixed trait in the population. As said above, the highlight is a colour play to make the eye mimicry more convincing, that's all. Another butterfly with an eye in another ecosystem could had evolved an eylid to make the mimicry more convincing.

Mind you, evolution is pretty amazing as it is, I just do not see how your example (at least in the way you present it) qualifies as an outstanding something or challenging the evolutionary theory as we know it.

 

[cyb]

Mind you, evolution is pretty amazing as it is

Agreed...but I won't be able to fully jump on board the EvoTrain until I can resolve the conundrum.

Even a bug that looks just like a leaf bud appears like it just 'appeared' one day.
It just looks like 'Something' decided that it was better to look like a leaf bud to hide the insect from a bird or whatever.

Growing a tiny 'lump' on its head and then having that 'lump' morph over countless generations to form a pretty convincing bud seems...off somehow...

the highlight is a colour play to make the eye mimicry more convincing

Yes it is... but how on earth does 'Evo' 'know' that it is more convincing?

I'm leaving a paper attached about it, it was published in Nature magazine in 1996.

Vodsel...cheers for the pdf...I shall read it when time permits :thumb_up:

These are of interest too:

Reflections in art

When artists depict a mirror in a painting, it necessarily lacks the most obvious property of a mirror: as we move around the painting of the mirror, the reflections we see in it do not change. And yet representations of mirrors and other reflecting surfaces ...

www.ncbi.nlm.nih.gov

http://www.annualreviews.org/doi/full/10.1146/annurev.ecolsys.38.091206.095745

Reflections are not uncommon in natural scenes but until the development of mirrors, reflecting surfaces were limited to just a few materials such as still water, glassy minerals, and, of course, eyes. The highlights from eyes are salient enough to be incorporated into the eyespots often seen in animal mimicry. Snakes, frogs, fish, and most notably moths and butterflies often evolve eyespots to disorient predators. In many cases, these eyespots incorporate a white highlight (Fig. 1). Here we get a free insight into the visual system of the predators for the species that use highlights. True reflections from a curved surface move as the observer moves, but of course, the pigment on the mimicked highlight cannot. Any visual system that interpreted reflections based on the rules of optics would immediately notice that the mimicked highlight was not optically correct and that would be it for the prey. Clearly, the fake highlight does work or it would not have survived eons of selection pressure. For the predator, the mimicked highlight must be conveying the additional realism of a reflection, and its immobility must not be breaking any of the rules for reflections actually implemented in the predator's visual system. Of course, the highlight also fools us — if we move our heads, the white spot does not lose its reflective quality.

 

[spinCycle]

Let's also remember that there are many examples in nature of extraordinarily bad design that still gets by because it is not so terrible as to actually prevent the individual from reproducing or actually has benificail side effects.

The structure of our backs, for example, which really isn't up to snuff for a lifetime of heavy upright use. Sickle Cell Anemia which provides protection from malaria but kills when expressed as a dominant trait. Hell, even our mouths and wisdom teeth are an example of pretty bad 'design'.

If you want to explain exquisite design through a designer you sort of need to explain all of the bad design out there too.

 

[Infundibulum]

the highlight is a colour play to make the eye mimicry more convincing

Yes it is... but how on earth does 'Evo' 'know' that it is more convincing?

Easy; it doesn't, as evolution is not deterministic. This maybe is the single most important thing to comprehend if you want to understand evolutionary theory.

You have to realise that all of these butterflies with eyes on their wings have by default slightly different-looking eyes, with some being more and other being less convincing mimicries. The individuals with less convincing mimicry will be eaten and their traits will be lost; those with more convincing mimicry will pass on their genes and the more convincing mimicry will prevail.

 

[cyb]

as evolution is not deterministic.

I agree...but where I come unglued is in the 'photonic' nature of specular highlights...
I just can't make my intellect agree that it is a 'random' mutation that works well...when light reflection only exists to an observer.

 

[spinCycle]

as evolution is not deterministic.

I agree...but where I come unglued is in the 'photonic' nature of specular highlights...
I just can't make my intellect agree that it is a 'random' mutation that works well...when light reflection only exists to an observer.

The predator is the observer.

 

[Infundibulum]

as evolution is not deterministic.

I agree...but where I come unglued is in the 'photonic' nature of specular highlights...
I just can't make my intellect agree that it is a 'random' mutation that works well...when light reflection only exists to an observer.

The predator is the observer.

Exactly.

And it is not a random mutation that works well....It is a random mutation (and series therein) that happened to work much better than hundreds of others mutations. It is the eye of the predator that got fooled by this particular variant of modified mimicry that allowed said mimicry to persist and dominate in the population.

 

[DeMenTed]

^^^^ nailed it!!

 

[cyb]

The predator is the observer.

This then makes it worse....
A predator 'observing' (with eyes) ... then kickstarts an evolutionary trait that, over a short eon, results in a form that resists being eaten?
I would have to suppose, then, that that was was one hell of a genius predator and architect of the Evo process...

It is the eye of the predator that got fooled by this particular variant of modified mimicry that allowed said mimicry to persist and dominate in the population.]

Is that just 'One' eye? Or an eons worth of different eyes all observing an extremely gradual change, whilst changing (minutely) themselves?

 

[DeMenTed]

The predator isn't the genius, the predator is being fooled. The predator didn't kickstart anything either. evolution is always at play and one of it's characteristics foolded the predator allowing that form to flourish.