Does Evolution Explain Tiger Stripes?

[archer75]

He's unwilling to listen because you don't have an answer. You have guess work with no proof that it actually occurred.

The OP asked this question:

How do evolutionists explain this?

Not "what exactly happened, and prove it, down to the finest detail." But "How do evolutionists explain this?" More than one person on the thread has offered information in response to this question, and the OP does not seem to be interested in that information, although he requested it.

 

[sfs]

Yes all those people know nothing.

Right -- all of those Nobel Prize winners and distinguished scientists with their inventions and discoveries and stuff know nothing about science, but you know better because, uh, . . . how exactly do you know anything about science?

 

[LutheranGuy123]

Can I give the actual answer? A guy named Alan Turing (SUPER famous for his work in mathematics and code breaking) published a single paper in the field of biochemistry. He proposed a mathematical model suggesting that a homogeneous* mix of particles can arrange itself into stripe patterns through "random" changes. I put quotes around it because the changes aren't truly random. They follow basic mathematical principles.

Assume two proteins "A" and "B" depend on each other for rate of production. If you want a tangible, real-world example, FGF and Shh* do this to form the "stripes" that are the ridges on the roof of your mouth. Now if A is present, it causes a cell to produce more of itself, but also to produce a bit of B. As A goes up, the production of A goes up relatively quickly, but production of B goes up relatively slowly. Also, B diffuses* better than A and as B goes up, production of A goes down. What ends up happening is A concentrates into peaks while B spreads out and suppresses A around those peaks. Because B can only diffuse so far from its source, multiple peaks form. Depending on the exact relationship (how well does B suppress A, how well does A spread, etc.) this can form stripes, spots, rings, and all kinds of patterns.

We've seen these "random" patterns form in real time by watching what's called the Belousov–Zhabotinsky reaction. You can search this on YouTube to find a lot of videos on it and Wikipedia to read about it if you know more chemistry than me. You start with a well-mixed solution, then peaks randomly form in the mix and spread into rings. You can then stir the mixture really well to get it back to the starting point, and the rings will reform in different spots.

Unlike FGF and Shh, we have not identified the exact proteins involved in tiger stripes. But we do have precedent to show that these patterns can easily form through random processes.

Definitions:

homogeneous - evenly-distributed throughout. At least two substances are mixed, and at any one location the ratio of substances is the same at any other.

FGF and Shh - Fibroblast Growth Factor and Sonic Hedgehog protein. Yes, that's its real name and scientists refer to it as such.

diffuses - spreads itself evenly. If you put a drop of color in water, you will have clear spots and a dot of deep color. Over time the random movement of particles causes the entire sample to be a light color. No portion is darker or lighter because the sample has become homogeneous. If more color is constantly added, as is happening with the proteins, this point will never be reached.

 

[sfs]

Can I give the actual answer?

That's the answer to what the mechanistic basis for tiger stripes is; the actual question was about the evolution of tiger stripes. (And until somebody does the work to test it, it's a hypothetical answer.)

 

[LutheranGuy123]

The question wasn't what the mechanism was, it was how can something so complex evolve randomly. And my reply was that it isn't very complex and is also very random.

 

[UpandDown]

I have to assume "genetics" are relevant because it seems genes "control" or "cause" the visible patterning. And genes, they tell me, are passed from generation to generation, which makes them relevant to evolution.

I certainly didn't mean to pretend to expertise on evolution or markings on cat fur, let alone tiger fur. But if you're asking how something might have come about, seems that knowing what it is at more than one level (genotype, phenotype?) might help in formulating and answering the question.

When you say WHY in this way, I'm not sure whst you're asking. Why and how would seem to be answered together when one is speaking of a process without any human motivation. Or if you mean "what was the tiger's coat's intention..." then I don't think anyone can give you an answer unless you learn to talk to tigers / their coats and get them to talk back.

Anyway, it seems there's some cool stuff about this online, but it all seems to mentions genes in some way, so I won't post any links.

Seems to me your original post has successfully said in advance you won't accept any answer, since the post asks about evolution and that has to do with genes. So I'll be interested to see where the thread goes. Interesting question.

First, let's DEFINE the type of "EVOLUTION" you speak of. If you mean Micro Evolution where we see variations in the same kind of animals, YES, That's a fact. If you mean Darwinian Evolution were a Dinosaur can change into a BIRD, NO. That's a fairy tale.

First, God created a perfect world, all life was programed by GOD. That program is what we call DNA, Genetics. There is a CODE in all living things that determine everything about that life form. SIZE, SHAPE, COLOR, Arms, Claws, Hair, Hair color, etc.
After the fall of man, everything started falling apart. We get things called Mutations in the gene pool which not only damages DNA Code, but removes some of it.
Also, if you breed two short haired wolves you get short haired baby wolf. If you bread a long hair wolf with a short hair wolf you get a medium hair wolf. That's the basic idea.
Stripes on Tiger and other animals can CHANGE and be ALTERED through breading. You might have one Tiger that experienced a MUTATION in the STRIPE Gene code which makes irregular stripes. If that tiger breads with another Tiger it's a chance the babies will have that mutation also.

However, a genetic MUTATION within the same kind of animal does NOT equate to Darwinian evolution where a Tiger could change into a Fish for example. It's simply genetics changes within the same kind of animal but that animal will NEVER change into a totally different KIND of animal. The Bible says they will PRODUCE AFTER THEIR OWN KIND.

Don't forget, we live in a fallen world 6,000 years after the fall of man. So God's origenal DESIGN has been altered by genetics. But only to the point that the DNA allows for those changes. Tigers are still Tigers.

Stripes on Tigers don't translate to Dinosaurs being able to change into Birds or fish into people. It's nonsense. It's simple genetics and change within the same kind over time.

You can't argue just because stripes on a Tiger look odd to you that PROVES Darwinian Evolution. That's simply illogical and a logical fallacy. And an uneducated assumption.

 

[archer75]

[QUOTE="UpandDown, post: 70912258, member: 392095"


You can't argue just because stripes on a Tiger look odd to you that PROVES Darwinian Evolution. That's simply illogical and a logical fallacy. And an uneducated assumption.[/QUOTE]

Indeed, one can't claim that the irregularity of tiger stripes is a proof for Darwinian evolution. And I have never made such a claim.

I am curious, though, which kind of logical fallacy it would be if one did say "I see irregular striped on a tiger, therefore, Darwinian evolution is proven."

 

[LutheranGuy123]

First, let's DEFINE the type of "EVOLUTION" you speak of. If you mean Micro Evolution where we see variations in the same kind of animals, YES, That's a fact. If you mean Darwinian Evolution were a Dinosaur can change into a BIRD, NO.

Literally zero scientists believe in dinosaurs becoming birds. First of all birds are still considered dinosaurs, so the idea itself is meaningless, but Darwinian evolution doesn't involve anything "becoming" anything else. It involves the idea (which has been observed in nature) that two separated populations of organisms will accumulate mutations independently of each other until they are distinguishable enough to be called different species. For example, to say that modern dogs descended from modern wolves is false. Both modern wolves and modern dogs descended from an ancient wolf that probably looked similar to modern wolves. Nobody can say for certain where we should start calling the modern wolf and the ancient wolf a different species, so scientists call the ancient wolf an ancestor to both modern species.

As another example, look at the shiba inu and the doberman. Neither of them look like wolves, and we don't know of any "in-between" breeds that are alive today (we have hybrids, but those came after the established breeds existed) so sometime a few hundred years ago there was a breed of dog that looked like a bit of both. Either that or a wolf gave birth to a doberman and a shiba separately.

You don't have to believe that the majority of modern species exist from a single ancestral species, but it would be a complete denial of science as we know it to say that one organism can't change significantly over time and even split into two groups that can't breed anymore. Also biology as we know it kind of breaks if we don't at least assume evolution to be true. So if it isn't true, then God made life in a way that acts exactly like if it were true.

 

[-57]

I do expect certain freaks of nature. Wouldn't surprise me to find a blonde woman with a few random black hairs, or a black woman with a few random red hairs. Or whatever. Fine. But striping? Look at a tiger. THOUSANDS of hairs perfectly arranged to form one stripe, then THOUSANDS forming a primary-color section, then THOUSANDS to form the next stripe. This evolved? Really? Evolution appears to be a pretty good artist, then.

Sure you can find scientists providing explanations - but they seem to be telling us what we already know, that's there some chemical or genetic process involved. That's still not telling us WHY it would evolve. If it were just a few random stripes - again - fine. I already attested to freaks of nature. But perfectly striped, OVER EVERY INCH OF ITS BODY? Hard to believe it's not design.

How do evolutionists explain this? They can talk about 'selective advantage' all they want but I doubt it would provide a convincing explanation of how PERFECTLY regular striping 'evolved'.

How about a peacock?

 

[-57]

ROM 1:20 For since the creation of the world God's invisible qualities--his eternal power and divine nature--have been clearly seen, being understood from what has been made, so that men are without excuse

The South American false-eyed frog is an interesting creature. Generally about 3 inches[7.62 cm] long, it is brown, black, blue, gray, and white! Drops of each color are on its skin, and it can suddenly change from one of these colors to the others, simply by masking out certain color spots.

The change-color effect that this frog regularly produces is totally amazing, and completely unexplainable by any kind of evolutionary theory.

The frog will be sitting in the jungle minding its own business, when an enemy, such as a snake or rat, will come along.

Instantly, that frog will jump and turn around, so that its back is now facing the intruder. In that same instance, the frog changed its colors!

Now the enemy sees a big head, nose, mouth, and two black and blues eyes!

All this looks so real—with even a black pupil with a blue iris around it. Yet the frog cannot see any of this, for the very highly intelligently designed markings are on its back!

The normal sitting position of this frog is head high and back low. But when the predator comes, he quickly turns around, so his back faces the predator! In addition, the frog puts his head low to the ground and his hind parts high. In this position, to the enemy viewing him, he appears to be a large rat’s head! In just the right location is that face and eyes staring at you!

The frog’s hind legs are tucked away together underneath his eyes—and they look like a large mouth! As he moves his hind legs, the mouth appears to move! The part of the frog’s body that once was a tadpole’s snail—now looks like a perfectly formed nose, and it is just at the right location!

To the side of the fake face, there appear long claws! These are the frog’s toes! As the frog tucks his legs to the sides of his body, he purposely lifts up two toes from each hind foot—and curls them out, so they will look like a couple of weird hooks. And the frog does all this in one second

At this, the predator leaves, feeling quite defeated. But that which it left behind is a tasty, defenseless, weak frog which can turn around quickly, but cannot hop away very fast.

The frog will never see that face on itself, so it did not put the face there. Someone very intelligent put that face there! And the face was put there by being programmed into its genes.

Well, there it is. And it is truly incredible.

How could that small, ignorant frog, with hardly enough brains to cover your little fingernail do that?

Could that frog possibly be intelligent enough to draw a portrait on the ground beneath it? No, it could not. Could it do it in living color? No!

Then how could it do it on its own back?

There is no human being in the world smart enough—unaided and without mirrors—to draw anything worthwhile on his own back. How then could a frog do it?

It cannot see its back, just as you cannot see yours. The task is an impossible one. And, to make matters more impossible, it does it without hands! Could you, unaided by devices or others, accurately draw a picture on your back? No. Could you do it simply by making colors to emerge on the skin? A thousand times, No.

"Portrait frog"! This is the motion-picture frog! And the entire process occurs on its back, where it will never see what is happening! And it would not have the brains to design or prepare this full-color, action pantomime even if it could see it.

Someone will comment that frogs learn this by watching the backs of other frogs. But the picture is only formed amid the desperate crisis of encountering an enemy about to leap upon it. Only the enemy sees the picture; at no other time is the picture formed.

All scientists will agree that this frog does not do these things because of intelligence, but as a result of coding within its DNA. How did that coding get there? It requires intelligence to produce a code. Random codes are meaningless and designs never arise though random activity. They require intelligent planning. Genetic codes within living creatures are the most complicated of humans to devise and fabricate.

The facts are clear. God made that frog, and He made all other living creatures also. Only His careful thought could produce and implant those codes and the physical systems they call for.

There can be no other answer (article copied from the web)

 

[sfs]

First, let's DEFINE the type of "EVOLUTION" you speak of. If you mean Micro Evolution where we see variations in the same kind of animals, YES, That's a fact.

But the whole point of the thread is that microevolution of traits like tiger stripes isn't a fact, and isn't possible. Perhaps you should save your response for some other thread.

 

[sfs]

The question wasn't what the mechanism was, it was how can something so complex evolve randomly. And my reply was that it isn't very complex and is also very random.

Sure, it's a good point that the mechanism of something like stripes is a lot less complex than the original post suggested (i.e. every hair follicle doesn't require individual handling). I still think it pretty unlikely that the evolution of tiger stripes involved evolution of a new set of morphogens, receptors and regulatory connections between them and with the production of melanin; there are simpler ways of evolving stripes.

 

[LutheranGuy123]

Sure, it's a good point that the mechanism of something like stripes is a lot less complex than the original post suggested (i.e. every hair follicle doesn't require individual handling). I still think it pretty unlikely that the evolution of tiger stripes involved evolution of a new set of morphogens, receptors and regulatory connections between them and with the production of melanin; there are simpler ways of evolving stripes.

It actually would just need one new protein, likely a derivative of an existing pigment. It would involve a gene being duplicated and then in later generations changed slightly through a mutation. It would be a coincidence that it formed stripes. It would be the one out of millions of ancient panthers that was lucky enough to get that good gene, but that gene would make it such an effective hunter that it and its offspring had a much easier time surviving and reproducing.

Just an interesting tidbit, the vast majority of snake venoms are incredibly similar to snake salivary enzymes, and also are easily digested without harming the snake. Or any other idiot who drinks venom, for that matter. Therefore scientists believe that a predatory snake that was non-venomous was born with a mutant copy of that gene that happened to produce a toxic substance. This made it a great hunter, and it and its offspring are MUCH more likely to survive and reproduce. So eventually the non-venomous lineage died out.

 

[sfs]

It actually would just need one new protein, likely a derivative of an existing pigment.

Sorry, but I don't see how a novel developmental pattern based on the Turing mechanism, could occur with a single gene duplication. What you described requires at least two morphogens and a pigmentation protein, plus regulatory elements, plus very likely membrane-bound receptors to mediate messages from the morphogens.

 

[LutheranGuy123]

Sorry, but I don't see how a novel developmental pattern based on the Turing mechanism, could occur with a single gene duplication. What you described requires at least two morphogens and a pigmentation protein, plus regulatory elements, plus very likely membrane-bound receptors to mediate messages from the morphogens.

Well the original protein would be either the black pigment or the orange pigment. It would be duplicated, and then after many generations one copy is mutated. The regulatory mechanism would likely be interference between the two, not a third protein. Also the morphogen proteins wouldn't be regulating the colors, they would be the thing that tells the tiger fetus where to grow skin and where to grow brain tissue, so they would have been around for thousands of generations already. The skin cells are all identical at the start, and the stripes come after they all start producing both proteins.

 

[Queller]

Evolution seems to be about randomness that gradually confers a selective advantage. A birthmark would seem to be a good example of a random freak of nature. Unsurprisingly it doesn’t typically persist, as it confers no selective advantage. If a blonde women (or a white tiger) were born with a single black hair, I would likewise NOT expect this trait to persist, speaking from an evolutionary standpoint.

So I guess we’re to believe something much more random than a birthmark? Thousands of hairs striping the ENTIRE body - just happened one day? (And yes, the stripes do cover the entire body, much as you tried to deny it).

Or perhaps you think it happened gradually – but camaflouge needn’t be so perfectly ubiquitous (and so amazingly full of symmetry) to be effective (i.e. to confer a selective advantage). I guess all the IMPERFECTLY camaflouged/striped tigers died out?

Exactly. The ones with less "perfect" camouflage lost out in the competition with the more "perfect" ones.

This is hard to believe, as such a level of perfection would hardly seem necessary for survival.

Why is it hard to believe that this camouflaged person:

might be more effective at hunting prey than this camouflaged person:

?

I mean, aren’t there plenty of non-striped animals that survive? Does an animal need to be striped, and perfectly so, to survive?

(Yawn). Yes, the genes we have right now are very good at what they do. And?

Pancreas are made of cells, and yes, I actually DO have cells growing all over my face. And?

Do you have pancreatic cells growing all over your face?

 

[Meowzltov]

Sure you can find scientists providing explanations - but they seem to be telling us what we already know, that's there some chemical or genetic process involved. That's still not telling us WHY it would evolve.

You just haven't listened. Tiger stripes have evolved because it is camouflage. It helps to hide them in the grass while they stalk their prey.

 

[loveofourlord]

Evolution seems to be about randomness that gradually confers a selective advantage. A birthmark would seem to be a good example of a random freak of nature. Unsurprisingly it doesn’t typically persist, as it confers no selective advantage. If a blonde women (or a white tiger) were born with a single black hair, I would likewise NOT expect this trait to persist, speaking from an evolutionary standpoint.


So I guess we’re to believe something much more random than a birthmark? Thousands of hairs striping the ENTIRE body - just happened one day? (And yes, the stripes do cover the entire body, much as you tried to deny it).


Or perhaps you think it happened gradually – but camaflouge needn’t be so perfectly ubiquitous (and so amazingly full of symmetry) to be effective (i.e. to confer a selective advantage). I guess all the IMPERFECTLY camaflouged/striped tigers died out? This is hard to believe, as such a level of perfection would hardly seem necessary for survival. I mean, aren’t there plenty of non-striped animals that survive? Does an animal need to be striped, and perfectly so, to survive?


(Yawn). Yes, the genes we have right now are very good at what they do. And?


Pancreas are made of cells, and yes, I actually DO have cells growing all over my face. And?

Well your flaw is assuming tigers evolved as they are from something like a lion or such, could be something simular to the king cheatah, or other things, a mutation that changes how spots form so they become stripes rather then spots, mutations arn't always gradients.

 

[archer75]

Well your flaw is assuming tigers evolved as they are from something like a lion or such, could be something simular to the king cheatah, or other things, a mutation that changes how spots form so they become stripes rather then spots, mutations arn't always gradients.

I guess the OP isn't coming back at this point, but I think then the objection might be "okay so how did all the hairs line up to make spots..." and so on.

 

[loveofourlord]

I guess the OP isn't coming back at this point, but I think then the objection might be "okay so how did all the hairs line up to make spots..." and so on.

yeah, these kind of arguments always make my head hurt.