This is meant as something challenging, fun, and educational.
I’m asking you to write your own answers before looking at other people’s.
Q1. There is no planning in evolution. How can a wing develop when you can’t fly with a half-developed wing?
Q2. The caterpillar of the Liphyra brassolis “Moth butterfly” has a glossy, horny shield on it’s back. It marches right into an ants nest. No matter what the ants do, they can’t stop it. It goes into the nursery and eats ant grubs. After several weeks, they shed their armor and turn into butterflies. But how can they get past the ant soldiers? It is covered in scales that are so slippery that the ants can’t get a proper grip on them. Those that do manage to bite get their jaws covered with a sort of fluff that they find intensely irritating. The murderous lodger goes free.
Evolution is a gradual process. How can the Moth butterfly evolve to such a specific attack and defense mechanism when it would have a success-rate of 0 if all it’s pieces weren’t in place?
To answer these questions requires a background in biochemistry, molecular biology, and genetics. In addition, the answers are not as straight forward or simple. My background in biology is only at the undergraduate level. I latter saw the light and switched to physics.
1.) Evolutionary changes are due to changes in the DNA or RNA sequence. It was believed, at one time, that gradual genotypic changes gave way to small changes in phenotypic expression. No so. Genetic engineering has taught that evolution can take very large steps.
You can state that a half winged appendage has no use for the organism. However, a half winged appendage can be advantageous for a particular set of environmental conditions. Secondly, evolution is molded by environmental feedback. It’s not random. Thus, you have to understand the underlying dynamo on how a particular phenotypic expression is observed in a natural habitat.
2.) See the above. There are general evolutionary mechanisms that evolve independently. For instance, many insects use formic acid as a defensive poison. The biochemical pathway for the formation of this simple carboxylic acid doesn’t take large amounts of change in the genetic code. Matter of fact, changing the structure of acids, like formic acid, can lead to very potent poisons that target specific organs of organism.
3.) The chicken. There’s an intermediate book on molecular genetics & biochemistry by Voet, I believe, that describes the reasoning behind this. It’s a bit involving but requires only a basic understanding on the Central Dogma of Molecular biology, and a little organic chemistry.
One factor that many don’t consider when taking genetics and evolution into account is what physics has to say on the matter. Since biology is governed by chemistry, and chemistry is governed by physics- it has fundamental insight in areas like evolution. It’s only recently, that areas like biophysics and physical biochemistry have had astonishing ramifications on the study of biology. Currently, the greatest advancements in these fields are being attacked using physics and the physical sciences.
Cus u gots arms and fins. Flying is like air-swimming.
Maybe when it began predation on the ants, they weren’t evolved enough to attack a squishy caterpillar. As their tactics / poison got better, the caterpillar evolved too.
Alternatively, the caterpillar’s characteristics might have been developed for some other purpose and later adapted to serve the ant lodging.
I’m thinking the key to these questions might be mutations. Evolution is not necessarily gradual. There are sudden leaps when a genetic mutation results in a new trait that is dramatically different and beneficial.
First, it might be advantageous to have a wing-like limb, but no flight. Eventually, a mutation produces a wing that can provide flight. This trait is very beneficial and is passed on. Or there could just be gradual development - from no flight, to being able to hop around and glide a few feet, to flying for a few minutes, to full flight.
The moth perishes every time it attempts to invade the ant nest…until a mutation provides it with the final piece of the puzzle for survival. Also, the moth could acquire the traits doing other things besides invading the nest. Traits like the shield of armor, slippery scales, and fluff could be useful for more than one task.
An “almost chicken” lays an egg. The egg hatches, and due to a mutation or the gradual process of evolution, a chicken emerges. So, the egg came first, laid by an animal who was almost a chicken, but not quite.
Q1. Birds lived in trees before they could fly. Bird flight evolved in a tree-down manner, think flying squirrel. All flying species, birds, bats, bugs, evolved flight independently.
Q2. Perhaps it started out as an ant defense and evolved into an ant attack.
Q3. Egg. A non chicken laid the first chicken egg.
I think there is ambiguity over whether we are investigating eggs in general or narrowly ‘chicken eggs’. There were creatures laying non-chicken eggs long before chickens were laying chicken eggs (to my knowledge). so if you had been on planet earth long enough ago you would have seen lots of eggs first and no chickens anywhere. But the question is somewhat different if its ‘chicken eggs’ that you are asking about…
how about co-emergent. the first chicken was in the first chicken egg.
a non-chicken laid it. but what it laid, (an egg with a chicken in it). is not ‘prior’ to the chicken that is in it. the chicken is in it. so they exist at the same time.
But the question is somewhat different if its ‘chicken eggs’ that you are asking about…
how about co-emergent. the first chicken was in the first chicken egg.
a non-chicken laid it. but what it laid, (an egg with a chicken in it). is not ‘prior’ to the chicken that is in it. the chicken is in it. so they exist at the same time.
hmm… But is a “chicken egg” a “chicken egg” because a chicken came out of the egg or because the egg came out of a chicken?
I suppose the reasonable thing to do when casting our attention back to the origins is to simply be more precise and say what exactly we mean by ‘chicken egg’ and in this way abandon the loose talk about ‘chicken eggs’ which are precise enough only for mundane talk concerning day to day affairs.
So present two answers, one each for the two possible definitions of ‘chicken egg’.
As long as we have to sharply demarcate along the line of descent between “chickens” and “non-chickens” then we have to say that the (chicken-producing) egg came first. However, this is not exactly helpful for any practical purpose.
Flying isn’t a necessary survival skill for birds. For example, chickens. Maybe half wings aid comparative advantage in some other way. Maybe they don’t but the effect was too insignificant to doom the variant species.
I would assume its ancestors had a different food source and the gradual evolution aided their survival in that context. They discovered the ant thing later.
In any case, I’m not sure the theory that evolution is gradual is necessarily true. Genetic mutation is indeed rare, especially ones that promote rather than hinder survival. And population growth takes a long time. But any genetic mutation can produce profound differences between parent and offspring.
1.) Evolutionary changes are due to changes in the DNA or RNA sequence. It was believed, at one time, that gradual genotypic changes gave way to small changes in phenotypic expression. No so. Genetic engineering has taught that evolution can take very large steps.
You can state that a half winged appendage has no use for the organism. However, a half winged appendage can be advantageous for a particular set of environmental conditions. Secondly, evolution is molded by environmental feedback. It’s not random. Thus, you have to understand the underlying dynamo on how a particular phenotypic expression is observed in a natural habitat. " - czelaya
I’d also add, questions like this assume their conclusion. They view the wing as a ‘final result’ of sorts and then use that status to argue it couldn’t have evolved. To an extent, this assume a designer and an ultimate purpose to the trait in question. The wing isn’t a final result, it’s one stage, the current stage of development the species who have it, have reached. It may evolve further to greater efficiencies in flying, or may change altogether with all birds eventually becoming flightless depending on what goes down in the future.
They also argue, as you say, that a half wing somehow isn’t useful, which ignores two crucial points. One, it only has to have a use in as much as it confers an advantage in certain circumstances, and that advantage could be entirely unrelated to flying. Two, it may confer no advantage whatsoever, but so long as it doesn’t hinder surival may still be passed on as a trait indefinitely until environmental pressures force a situation where one group has an advantage over another.
“In any case, I’m not sure the theory that evolution is gradual is necessarily true. Genetic mutation is indeed rare, especially ones that promote rather than hinder survival. And population growth takes a long time. But any genetic mutation can produce profound differences between parent and offspring.” - meambobbo
I think some of the more recent research shows that when genes are expressed is as important as which genes are expressed, and apparently the noncoding section of DNA has some role in this. Discovery Channel even touched on it a while ago with one of their dinosaur specials where they showed how it might be possible to reverse engineer modern birds to have dinosaur like traits. Introduce a certain protein at the right time and instead of feathers, bird fetuses start to develop scales. I haven’t read any of the books on this yet, but the implications are enormous. To a very large extent the DNA of our ancestors may still be within us, without much change.
Wings: Lots of varieties. Depends on the critter. Most flyers probably started as gliders. Creatures that gained an advantage by using their half-developed wings over those that didn’t have them. The critters that developed wings survived, whereas the others either didn’t or were forced to choose some other form of transportation. No planning is required. The ability to fly is a tactical advantage in hunting and defense.
The species in question owes it’s success to the ants, one of the more successful species on the planet. The advantages were developed over time, and I’m sure the ants have developed over time as well. Sort of an arms race. A superior attack leads to a superior defense, a superior defense leads to a superior attack. Those that don’t adapt are dinner.
Chicken or Egg? It depends.
If you’re talking omelets, then eggs come first. If you’re talking cheese cake, then chicken comes first. If eating both chicken and eggs at the same time, then you’d start the chicken first because of the cooking time.
A species is determined by it’s DNA, which is the product of two parents. The first “chicken” was the product of two “non-chickens”. Within this first “chicken” egg were the DNA necessary to produce the first “chicken”. So the egg came first.
The egg exists because it’s observable. Ah, but does the chicken exist or is it in that state of existence and non-existence until it is observed? [i.e., Schrodinger’s cat]
“Q1. There is no planning in evolution. How can a wing develop when you can’t fly with a half-developed wing?”
See question number 2, in particular the last two statements.
"Q2. The caterpillar of the Liphyra brassolis “Moth butterfly” has a glossy, horny shield on it’s back. It marches right into an ants nest. No matter what the ants do, they can’t stop it. It goes into the nursery and eats ant grubs. After several weeks, they shed their armor and turn into butterflies. But how can they get past the ant soldiers? It is covered in scales that are so slippery that the ants can’t get a proper grip on them. Those that do manage to bite get their jaws covered with a sort of fluff that they find intensely irritating. The murderous lodger goes free.
Evolution is a gradual process. How can the Moth butterfly evolve to such a specific attack and defense mechanism when it would have a success-rate of 0 if all it’s pieces weren’t in place?"
Because the half-formed mechanism could be utilized for the same strategy but with less effect, or utilized for a different strategy for survival, or the mechanism had no impact on the organism, until a mutation made it viable.
“Q3. What came first: the chicken or the egg?”
This question has so many ways of being interpreted, but the chicken egg came first. The thing that laid the chicken egg was not a chicken, but a mutation transformed the thing in the egg into a chicken.