Science does in fact have an answer to the oft-repeated conundrum, Which came first, the chicken or the egg? This of course means that you should never let anyone offer this as a riddle ever again without correcting them.
The Egg
In nature, organisms evolve through small changes in their DNA. This is because DNA copying during reproduction is never 100% accurate, and these minor mistakes in copying are the fuel for natural selection. Beneficial mutations that allow an organism to better pass on its DNA are naturally selected by various environmental pressures (sexual, predatory, etc.), and can eventually become dominant in a population of organisms, resulting in new species.
In an animal like a chicken, DNA from a male sperm cell and a female ovum (egg) meet and combine to form a zygote: the first cell of a new baby chicken. This first cell divides innumerable times to form all of the cells of the complete animal. In any animal, every cell contains exactly the same DNA, and that DNA comes from the zygote.
From zygote to hatchling, the first chicken (or what we would consider a chicken) would have to be produced from mutations resulting from non-chicken parents. All new species arise this way, through small mutations in the DNA that are eventually realized in the new offspring. But two completely different animals did not suddenly plop out a chicken; the parents of the first true chicken would be genetically very similar to the newborn, yet not quite modern chickens. The first chicken would pass on its genetic material and, through the pressures of natural selection, the mutations that gave rise to the first chicken would permeate a community, creating a population of “true” chickens.
Chickens evolved from non-chickens through small changes caused by the mixing of male and female DNA or by mutations to the DNA. These changes and mutations only have an effect at the point where a new zygote is created. That is, two non-chickens mated and the DNA in their new zygote contained the necessary mutation(s) to the embryonic body plan to make the first true chicken. That one zygote cell then divided and formed a biologically modern chicken.
Prior to that first true chicken zygote, there were only non-chickens. The zygote cell is the only place where DNA mutations could produce a new animal, and the zygote cell is housed in the egg. So, the egg must have come first.
[Excerpted with editing from How Stuff Works]
There is no such thing as a first chicken.
There is if it lives in the White House. :>
Nice try, but it is making an omelet of the evolutionary biology perspective. (Which I am interested in as a student of astrobiology.)
True, hens (the species) evolved out of non-hens. But similarly, the hen egg as a trait evolved out of earlier egg traits. Bird eggs can be calcified, while I believe their non-avian dinosaur ancestors made do without that. And so on until you hit sexuality, since we are discussing fertilized eggs.
But that is another question altogether. Abstracting away, we get into cellular division as procreation and so on. (The specific root of sexuality is not well understood, I believe.)
To sum up, a chicken-and-egg situation, or what the early evolutionary biologist Muller termed “interlocking complexity” of traits, is a prediction and hence test of evolution, the article got that right. Such interlocking evolves from a previous system without it.
Hence the abstract answer is that it is inconsequential whether the chicken or egg was first. The previous functional system made do without any of them. As an example, a chicken-and-egg problem is “DNA-and-protein” because the modern cellular machinery uses proteins to fabricate DNA and DNA to fabricate proteins. The original system was RNA, which can function both as hereditary material and enzymes.*
Another interesting thing with these kind of systems are that they constitute a bottleneck for pathways.You can understand the resolution of the bottleneck from a fairly limited set of pathways. In the case of considering processes at large, it is only evolution of interlocked traits from non-interlocked traits that gives the answer. It is as good a test of evolution as finding the proverbial precambrian rabbit would be.
* I am fibbing a bit, since it is believed that proteins came before DNA. Turns out you need protein enzymes to make DNA, it is energetically costly and RNA can’t swing it. But that is contingency, not proof-of-principle that one or other of the component systems needs to be “first”.
Um, that was just a silly exercise in using big scientific words and hand-waving. Of course the “true” chicken mutated inside its egg… so the egg must have come first? Puh-leez.
The real question is — When did the chicken’s ancestor start laying eggs? (Or chicken’s children stop laying them, I suppose.) And why? That’s quite a micro-evolutionary change, don’t you think?
Steve, the earliest known amniote (i.e. animal capable of laying an egg which had a shell and could survive out of water) is called Casineria and lived 340 million years ago, in what is now Scotland. Funnily enough, that’s where I am right now.
Why? It was an adaptation waiting to happen, the evolutionary pressure existed. To put it another way, as the tetrapods (vertebrate animals with four limbs) were moving out of water and colonising the land, they were limited by the fact that they had to go back to water to reproduce. In these circumstances, any animal able to lay eggs which could better tolerate the dry terrestrial environment had a big advantage.
Modern birds, reptiles and mammals are descended from these, or similar, early amniotes. The chicken came about by the domestication of a type of junglefowl around 8000 years ago. The egg came first, by well over 300 million years.
Of course, the ancestors of the amniotes also came from eggs. Just different kinds of eggs. So the circular chicken/egg thing continues, but with an end point. If you go all the way back to the evolution of sexual reproduction – biological life predates the evolution of the egg.
To whom it may concern:
How do you think these two said non-chickens or chickens evolved? Do you reAlly believe that an egg just fell out of the sky? Where did the egg come from? Was it an amoeba or something? Seriously, I feel sorry for you guys that you have wasted all that research, time and effort to be back to where you started from: clueless. I will tell you the answer to the age old question….it had to have been the chicken.
chicken. An egg could not have produced itself. Whether you are an evolutionist or not, it only makes sense that something had to have created that chicken
Nicole,
If you follow the evolutionary logic explained in the post, you can see how the genetic variations that arise every time a new embryo is formed (themselves selected form) can, over thousands of generations, produce an embryo that is morphologically different from its parents.
Consider it this way: The genes that you got from your mother and your father make you genetically human. However, because the process of DNA replication is not 100% accurate, you will have some mutations in your DNA that your parents do not. If these mutations were naturally selected for over the course of thousands or millions of years, they could come to dominate the gene pool. These mutations are different from your original parents and, given enough time and variation, can produce a species that is no longer the same as the older “parent” species.
This means that over the course of time, as the ancestors to chickens were reproducing, mutations were selected for that eventually led to the embryo that was the first “true” chicken. This also means that the first chicken had non-chicken parents (though they were very close, close enough to be parents). Therefore, the first “true” chicken, produced over millions of years from the selection of various DNA mutations, was born from the first “true” chicken egg (from non-chicken parents). All of this means that the egg came before the chicken.
Not to split hairs, but all offspring are different from their parents by tiny degrees. What we would now call a chicken would have been impossible to determine at any specific point in time, and wouldn’t come down to one specific animal. All we can say is that a population of proto-chickens became over time more and more like what we now call “a chicken” but along the way they passed through a long phase of being nearly indistinguishable from modern chickens. But, yes, at some point the first modern chickens recombined just so inside of an egg, from parents who were just a little less what we would call “chickeny.”
The view that I am trying to express is best represented by your comment Scott.
Ahh, but the question itself is one of scrutiny to me. Does the question imply a literal interpretation such that your answer may be correct or is the question a metaphor asking if life arose from evolution (the egg) or suddenly appeared (the chicken). If taken as a metaphor, as I take it, life (on earth) suddenly appeared and gave way to evolution. Which of course leads to a much greater debate. How did life suddenly appear? God, aliens, delivery by stray space material, sudden spark on earth that combined materials in the perfect combination to create life, or some other theory?
Literally, based on evolutionary theory, the egg (containing the first “true” chicken) had to have come first.
The diversity of life that we see is a product of billions of years worth of evolution. When we ask how did life suddenly appear, we have no definitive answers. But we do have some plausible hypotheses. Panspermia (life on Earth being seeded by microorganisms from another planet) and abiogenesis (life arising on Earth from a fortuitous combination of self-replicating molecules) are two possible explanations which are both far more plausible and in line with the science than anything supernatural.
As a student of speciation, I would say that it is implausible that a chicken came from non-chicken parents in one generation. More likely, a series of mutations occurred and where fixed over time either by selection strong enough to overcome gene flow or in isolation. After some period if the divergent population came back in contact with its ancestral population and they were reproductively isolated then you would have a chicken. The eggs would have been there the whole time too. That is, it would be a continuous process and not a discrete one. And it’s a population level phenomenon, not an individual one. So neither really came first.
Of course, that’s in general. In specific jungle fowl were taken and isolated by humans while they were slowly changed over into chickens, eggs and chickens being there at the same time as well.
I agree, and the post never specified the number of generations. However, the general idea, that the was some point along the continuum of mutations at which a biologically non-chicken produced a biologically modern chicken still holds.
It’s probably worthwhile to remember that the labels we use like “chicken” refer to a whole collection of features, which themselves are subject to change. It may happen that with another couple millennia of chicken breeding we end up with animals that have extra features or that lack features we previously attributed to the “chicken” and so we might have to call it something else.
One of the great sources of human confusion about many things comes from the epistemological method of assigning names to collections of properties. It’s a very rough way of defining things.
Horsemonkeys; there was never a first “true chicken”. Never mind that taxonomic terms are not that laser-focused, even one of the standard bellwethers of species does not apply here, and that would be *interfertility*.
The only way this scenario could be true is if the “first true chicken” divided asexually but one of the clones mutated to the opposite sex. Otherwise, the question “what did the first true chicken breed with” becomes an issue.
It doesn’t seem very useful to ponder when the “first” true chicken was laid in an egg by a non-chicken. After all, which particular mutation separates chicken from non-? It seems more realistic to discuss how some population of protochickens became modern chickens over time as mutations accumulated. Regardless, the modern chickens evolved from egg-layers, so the egg came first, which I believe was the point of the article.
Doesn’t this mean the chicken actually came first? You have to draw the line at specifically chicken eggs in the question, as eggs would predate chickens as already stated earlier in the discussion. Thus, the first chicken came from a non-chicken egg, which would have then gave way to the first chicken.
Thus, the chicken actually came first.
You’re welcome.
This is incorrect.
If you are arguing that the first biologically modern chicken had to come from a biologically modern chicken egg, then yes, the chicken came first, but this does not mean much. It still does not answer the question about how chickens came to be. If they were already there to lay chicken eggs, we are back to the beginning of the problem.
Rather, because the non-chickens that gave rise to the first biologically modern chickens were still egg-layers, the first biologically modern chicken came (generally) from an egg.
Thus, the egg came first.
Thanks.
It’s still a population level process, not an individual one. So no chicken came from non-chicken parents. And it’s doubtful that there was one mutation to point to where “chicken” began and non-chicken ended.
I never claimed it was a one step process, nor that there was a singular mutation. However, at some point in the past, there was the first biologically modern chicken developed from a zygote of non-chicken parents. It has to reduce to some point, crossing the continuum from what we do not consider chickens to what we do. The line is fuzzy of course, but it still happened, and in the same way.
There are still a lot of gaps in what we know about speciation as a process. But I am confident that a chicken never came from non-chicken parents. And that like all evolutionary process it is a population level effect and not an individual one. One chicken does not make a species. No matter what species concept you use.
If we have criteria about what a modern chicken would be, you are saying that at no point did non-chicken parents (fitting nearly all of the criteria save for a few, for example) have offspring with mutations which fit that criteria. This, if I am not mistaken, is not the evolutionary view. How do new species arise if not from separations and different mutations that get exacerbated by natural selection?
How about this. If you need one set point, it won’t be at the individual level where the mutations occur, but at the population level. So it would be when your one important mutation (still skeptical about this, but for the sake of argument) increased to some frequency. It could be as low as being in two chickens (I guess) but probably more and certainly not in one chicken. Because one chicken isn’t a species. So the relevant mutations end up in one individual when they are a zygote (as you described). But it’s not a species yet, so it’s not a chicken. It’s just a morph in a population. If it is isolated enough it won’t find a mate and its lineage will end before it’s even a species. But say its not so isolated. The important mutation (really set of mutations) will increase to some clear cut point where there are enough individuals in the population to call it a species. That’s when all the individuals suddenly “become” chickens. Before that they (or “it” if two individuals is enough for a species) was just a morph of non-chicken. When they all simultaneously become chickens, when chicken becomes a real species, there will be genetic eggs and genetic chickens. Yes, in that scenario there is a mutation in an egg you can point to, but without the population level effect it is not a true species. This isn’t trivial. Out of all the taxonomic levels a species is supposed to be the only “true” one…as in not just made up by us for convenience of labelling. And it needs to happen at the population level.
Are you familiar with Dobzhansky-Muller incompatibilities? That’s a great example. You would need more than one individual for that to make a species.
I agree with you Frank, and I thank you for adding interesting nuance to the post.
I asked God when I spoke to him, “Which came first? The chicken or the egg?” It was an age old question I thought everyone would like to know, and was a question that comes up fairly often. He simply replied, “The egg you dumb bitch”, and sent me back to Earth. I guess no explanation was necessary.
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The general assumption here is that, mutation happens only in an egg. Is it not possible for a(or a group of) non-chickens(very close to actual chickens), through some “disease” mutate to be the first chickens?
I think considering these things happened over millennia, mutation through a disease has the same probability as a chance of happening in a non-chickens’ egg!
To answer your question, no, I do not think that is possible (or plausible).
I agree with your logic up until the last sentence where somehow you conclude that the chicken egg came before the chicken. The egg that the first chicken hatched from was not a chicken egg, it was an egg that was produced by the mother of the first chicken. Calling this a chicken egg is like saying that an ostrich egg containing a dinosaur is actually a dinosaur egg because a dinosaur embryo is growing in it.
The proverbial question asks if the chicken or the egg came first, and my conclusion was that the egg came first. The “spirit” of the question I think is still answered by considering the zygote as the “egg” in this example.
The term ‘egg’ is only applicable to the gamete produced by the female, so a zygote cannot be referred to as an egg. The oocyte is produced solely by the mother, and contains all of the mother’s DNA (split between the oocyte and the polar bodies) and all of the proteins and transcripts in the egg are maternally produced.
I suppose it depends on our definitions. If we define the first “true” chicken coming into existence at birth, an egg still comes first. The chicken is not a chicken until the zygote forms, which is then birthed from an egg.
But my argument is that the egg is not a chicken egg, it’s the egg of the mother of the first chicken. The chicken may hatch from the egg, but that doesn’t make it a chicken egg.
But we would both agree that the first “true” chicken came from an egg of some sort, correct?
Correct, the first chicken did come from an egg, but that egg wasn’t a chicken egg. The question is not if eggs came before chickens (insects had been laying eggs long before the first chicken), it’s if the chicken egg came before the chicken. The egg containing the first chicken, but produced by the first chicken’s mother, was not a chicken egg because the egg was made by and contained protein, RNA and DNA (1.5 – 2 sets depending on the egg) from the mother.
So we are in agreement: to produce the first true chicken, and egg came first. We are not talking about eggs in general, as that would be pointless, but an egg from an ancestor of modern chickens.
If you look at most post, I never refer to the hypothetical egg as a “chicken egg.”
Thanks for your input, you obviously know a thing or two about development.
It’s quite simple and God has already given us the answer we just refuse to accept it. It may not be a scientific answer, but it is a valid one. He laid a variety of eggs. Since everything is made from an egg, which leads to an arm / wing, and a leg, a head and a tail… Humans are born from eggs. Why not chickens?
Interesting, but I do not think there is any evidence for what you mentioned. I do not consider explanations without evidence to be valid.
Life is the evidence and the explanation. But I can’t explain it. ;-)
By the way Kyle… I LOVE your site. I’m not highly intelligent but I enjoy learning on a daily basis. I’m sure you’ve heard tell of “The Rapture” and think it’s hogwash, as I did. But I know that I was saved the night of May 21st, 2011 by God and after judgment there were a few moments before I was released of my sins, which were many, to come back, that I was able to ask Him a couple of questions. One was about the chicken or the egg… the egg came first. The other was about the strongest force on earth… and it was water. It’s not a coincidence the earth and humans are similar in percentage. Some things just can’t be explained. Of course you do not have to post. I was just sharing that there are some matter(s) that we are not supposed to understand, and we can’t explain. They just are.
Next time ask God why evil exists.
If you’re not going to make any distinction as to what sort of egg, then what did the mother of the first chicken hatch from? It’s my job to know about development, I work on chicken oocytes for a living.
Simone, the earth and humans are not the same percentage water, only 0.02% of the earth’s mass is water, whereas humans are up to 60% water.
At the point of birth from the egg, we have a genetically modern chicken. Before this we do not (a birth from an egg of a genetically ancestral chicken).
Hmmm… understood. Surface has nothing to do with mass.
But the egg is behind by one generation. I don’t think you are getting my point. Just because an egg contains a chicken does not make it a chicken egg, it is the egg of whatever laid it.
I never claimed that it was a “chicken egg.” Refer to the actual post.
But then what is the difference between the egg the first chicken hatched from and the egg the first chicken’s mother hatched from?
It contains the genetic information necessary to “create” a biologically modern chicken.
The egg only contains the information from the first chicken’s mother. The first chicken itself was the first thing to contain the genetic information of a biologically modern chicken.
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There is evidence that is in fact the chicken that came first. Look it up. It’s backed by evidence. The experience was performed in 2010.
Please provide a reference.
Chickens may be the only animal that can produce the protein for a chicken egg but does not mean the egg didn’t come first.
Probably this was what John referred to:
http://www.msnbc.msn.com/id/38238685/ns/technology_and_science-science/t/which-came-first-chicken-or-egg/#.UI60Iq7P1DE
It’s useless to base your answer on evolution genetics as the minuscule changes from one species to another happen over an extremely long period of time. There was never a genetic fine line between the thing that the chicken was before it was a chicken and the thing that we now call a chicken.
I will tell you the real answer straight.
It’s quite simple.
The Chicken came first.
Someone at some point named that bird a “Chicken”.
Before that, there were no Chickens.
I really doubt they looked at the egg first and said “here’s a Chicken egg”.
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Which sciientist have proved the egg came first? Not the ones in the UK, because they claim to have proven that it was the chicken. Note the following excerpt:
More than 100 news organizations recently reported how scientists have answered once-and-for-all the age-old question: Which came first, the chicken or the egg? According to Dr. Colin Freeman of the University of Sheffield, United Kingdom, “[I]t had long been suspected that the egg came first—but now we have the scientific proof that shows that in fact the chicken came first” (as quoted in “Chicken…,” 2010). How did Freeman and the other scientists working with him come to this conclusion? They discovered that “the formation of eggs is possible only thanks to a protein found in chicken ovaries…. The protein is vital in kick-starting the crystallization process [of the egg—EL] (“Chicken…,” emp. added). Thus, “eggs have to be formed in chickens” (“Chicken…,” emp. added)—fully grown chickens with functional reproductive organs and the special protein called ovocledidin-17
“Chicken-and-Egg Mystery Finally Cracked” (2010), July 14, http://www.foxnews.com/scitech/2010/07/14/chicken-egg-mystery-finally-cracked/?test=latestnews
But the chicken had to exist *potentially* before it could exist actually. Although, I suppose the potential of matter to be arranged into the form of a chicken would have occurred at the same time that the potential of matter to be arranged into the form of a chicken *egg* occurred.
For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like a mortal human being and birds and animals and reptiles.
Romans 1:21-23
God made the chicken first and gave it the ability to lay eggs. If any of you think single celled organisms evolved into human beings over millions of years then first explain where the first cell came from with all its magnificent and brilliantly designed machinery. Then explain how mutations and other processes related to “natural” selection gave rise to new information and new functions when there is not one piece of scientific evidence that that can happen or has ever happened.
And while you’re at it, tell us when scientists will be able to create a cell from scratch since, you know, they are so knowledgeable about how it all works.
Seriously?
Read some books dude. And when I say books, I mean authored by some REAL scientists, not those Mickey Mouse self-published creationist-tards.
OPEN. YOUR. EYES.
For although they knew nothing, they needed answers. So the “educated” created an abstract, omnipotent omnipresent omniscient and omnibenevolent being who could be used to explain the unexplained, control the ignorant, and nullify curiosity. But the curious allowed curiosity to get the better of them – and curiosity gave way to discovery, and answers were found. The curious and the ignorant then became enlightened, and reversed roles with the “educated”.
Who are the ignorant now, Tommy?
The science books only contain theories. Every animal that comes from an egg would be non-existent, because how can an egg “evolve?” It is either a fully functional and wonderfully created egg, or it is no life at all. You can’t have a “partial” egg that is “mutating” into something – this would be inconceivable. Unless of course you have faith in time and chance x10 to the billionth power. Every reproductive system known can only function when complete – if literal evolution was really true….we would therefore not exist (a partial reproductive system cannot reproduce). Yikes!!
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I was just interested in how someone who believes in the theory (note theory) of evolution would say in answer to the chicken/egg question, and found this site. I really had to laugh at how people tie themselves in knots trying to answer it from an evolutionary angle. You guys have to have a lot of faith to believe in it! There is no point in my giving an extensive answer because you are too blinded by your faith. You can only have a chicken from an egg – but you can only have an egg from a chicken – ergo the chicken came first, and it was created as a complete, whole chicken by a Creator. To slightly misquote someone, ‘Evolution is a fairy story for those who are afraid of the dark’. If you are an evolutionist you are afraid because if there IS a creator, you have to answer to Him, and you would much prefer not to – right? I can only say that from reading some of these comments, the first thing that popped into my head was: “Professing themselves to be wise, they became fools” (Romans 1:22). Sorry, I am sure you all think we are the fools, but – there you go.