Did the chicken come first or is it turtles all the way down? | Hacker News Reader

Did the chicken come first or is it turtles all the way down?

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37 pointspseudolus44 comments

"The second is the idea that as we go backward in time, life-forms get simpler and simpler(...)"

I'm not sure this is a very accepted idea anymore in modern evolutionary biology. Sure, over massive timescales it holds true (a proteotypic single cellular organism is less complex than a multicellular, eukaryotic animal), but the reverse conclusion (the arrow of evolution points towards increasing complexity) doesn't hold up.

A modern chicken is not more 'complex' (whatever the definition of complexity is) than its Dinosauria ancestors.

Fair enough in general, but when the issue is the origin of life, we are explicitly considering the longest timescale.

It is still accepted on geologic timescales, as you mentioned, and exactly as the sentence stated, "as you go back in time, life forms get simpler". We started with lipids and other molecules that then appear to have formed membranes. Amino acids collected in those membranes, formed longer self-replicating molecules, and prokaryotic organisms. Eventually you wound up with incredibly simple, chemical ingesting single cell life, and not long after, eukaryotic organisms with separate nuclei. This then gave way to multi-cellular colonies, which then lent itself to cellular specialization in multi-cellular organisms. Then you start to see highly specialized organisms like plants and animals. Complexity doesn't mean body parts, it means specialization within an organism and within a species in the beginning. We see that clearly. Specialization into new niches and adaptations to changing ones continues even if complexity does not, presently. However, we still might see something evolve into a more complex, 5 dimensional, dark matter eating, electro-plasma brained creature.

As an elementary school student [0], I struggled with the incompatibilities of evolution and the literal Christian creationist model I was taught. I thought that "the chicken and the egg" was a question of faith. One who believes that the Earth was created in seven days believes that the chicken came first, in whole form, on Day Five. One who uses evolution and natural selection as a model thinks it most likely that the first animal that could be identified as a chicken grew from an egg that was a mutation from non-chicken parents.

0: https://enki.org/2018/07/30/things-i-learned-in-elementary-s...

>I struggled with the incompatibilities of evolution and the literal Christian creationist model I was taught.

I had the opposite problem, with parochial school teachers well versed in shifting back and forth between "it was a metaphor" when evidence contradicted it, to biblical literalism when there wasn't clear contrary evidence. So it was right when right, and meant to show us what is right when it was false.

I thought C&E was a philosophical question, like the ship of Theseus, it can't have a reductive answer because it represents ideals rather than logic.

To be devil's advocate for your stance, the '... an egg that was a mutation from non-chicken parents' were themselves derived first from an egg, which could be said to be the origin of the chicken, but itself laid by antecedent.... So eventually it must go back to the first entity that laid the first egg, and whenceforth they, etc...hence a philosophical perspective.

>an egg that was a mutation from non-chicken parents' were themselves derived first from an egg

But that's irrelevant. The argument isn't about where eggs come from, and simply laying eggs doesn't make something a chicken.

If we define "chicken" as the biological creatures we know today that has a certain genetic makeup, then at some point in their evolutionary history there would be the first such creature that has this makeup being hatched from eggs made by creatures that don't. Just as, at some point in the past, there was the first genetic modern human born from pre-human parents.

Hence, the egg must have come first. This is only an unsolvable problem if you hold that there have always been chickens that never evolved from earlier creatures, i.e. the Creationist model.

No, the Creationist model would have Chickens born whole. Shazam - there's a chicken! It would have come first. If an egg had come first in that model, it would have died from not being incubated.

That's a good point. So either way, we have a definite solution. Huzzah!

But in that model if the egg had come first then God would have incubated it, right?

The creationist position is that if it is not in scripture, it didn't happen.

So, my bad date last Wednesday didn't happen?! Huzzah!

I believe in both Creationism and Evolutionism, but in a modified way: For each entity there was a proto entity that was created by some process. Like you have some primordial elements that are intelligently organized in a way that creates life. Then, this first entity, evolved , during billions of years, following certain laws created by this Creator, to the form we have today. In sum, I don't believe everything came from Chaos by chance. There must be a sentient force, with a consciousness far beyond what we can conceive, that manipulated this Chaos , primordial elements and created everything from it. Chaos, by it's very nature cannot create order from itself. This is the only explanation that makes sense to me. To me we all got pieces of the truth. One day we'll merge it all and understand everything.

That's not Creationism though. Creationism really is, there is no evolution and everything was created as is. You can have a Creator but not have Creationism- that's basically what I was taught when raised as a Christian (Genesis is at least to some degree metaphorical or a remnant of an older faith, God was essentially the First Mover, we shouldn't disbelieve science, etc.).

What you describe is more like Deism or Theism, where you believe in some sort of higher order intelligence behind the universe, but it's not incompatible with science and rationality and observation. You can't believe in both Creationism and evolution because Creationism is an explicit denial of evolution, and of anything but a literal reading of Genesis. But you're in good company, as you just described many/most of America's Founding Fathers, who today's Evangelicals would have lynched as heretics if they bothered to read their actual words rather than treat them as cartoon mascots for whatever they want to imagine America stands for at the moment.

Some Creationists believe in microevolution though, such as myself. I totally believe that different subspecies (or even species) have developed since the point I believe God created them, since the difference between species and subspecies can sometimes be blurry. E.G. different dog breeds can look so different from each other, yet can crossbreed without much issue. Cockatiels and cockatoos have even been shown to have crossbreeding potential, producing fascinatingly beautiful hybrids, even though they're technically different species. What I'm saying is that I'm a Christian Biblical Creationist that sees microevolution and natural selection as a feature, not a bug. It allows species to naturally adapt to different environments, or changes within the same environment.

If you believe in microevolution, what do you think happens if "microevolution" continues for millenia?

And why do all the creatures (you claim were created out of thin air) as if they had common ancestors? Both physiologically as well as genetically?

To quote Dobzhansky: Nothing in Biology Makes Sense Except in the Light of Evolution.

Why Evolution is True by Jerry Coyne might help you resolving that last part of the puzzle.

Yeah makes total sense. I think in the end people mostly misinterpreted the Genesis part in the Bible, and most of it for that matter.

My vision is one I grew after reading several texts of several sources and reflecting about them, not only traditional religious texts but more esoteric and occult texts about it. It's very interesting to see that they mostly complement one another. If you get an esoteric hermetic text or something about how creation occurred you see that it doesn't negate the Bible, and it doesn't negate Science at all. It just goes deeper and deeper, mostly using symbolism.

The semantic question is whether an egg is named for the creature that laid it or the creature it contains.

Pretty sure it’s named after the physical structure and not the ortifice that spawned it.

How do you figure? I'm pretty sure we still call it "chicken egg", "duck egg", etc. even if the egg isn't fertilised.

That was my reading as well, sort of like 'have your cake and eat it too' or one hand clapping. An infinite loop not meant for logical reduction as much as contemplation on the 'is' identity.

I thought I was on the right road with Theseus, but maybe not.

Like the ship of theseus though, at what point does it stop being a chicken, i.e. its parent. The progenitor is 'obviously' whatever preceded the chicken, but that's just it - is that itself the egg or the chicken-maker? There you are started down the tautological root back to what first first conceived both whatwouldbe-egg and whatwouldbe-chicken to come.

You're misusing the "Ship of Theseus" concept. That has to do with individual identity.

>at what point does it stop being a chicken, i.e. its parent.

When it doesn't meet the genetic definition of a chicken, however you choose to define that. Once you have a definition, there will be a point in evolutionary history where such a creature arises. Anything before that is not a chicken, so therefore

>is that itself the egg or the chicken-maker

Once again, the answer is "the egg". A pre-chicken creature produced an egg that hatched the first chicken. Problem neatly solved.

But what if ”chicken” is a singelton?

If that were so, everything about the issue would be different, but it is not so.

> mutation from non-chicken parents

Only tangentially related, but that invokes the Sorites paradox: https://en.wikipedia.org/wiki/Sorites_paradox

If you follow the thought exercise further, there's other considerations: The first chicken may not have had any other chickens to mate with.

The protochickens and chickens would at that point be so similar that a protochicken and chicken mating would probably have half of their offspring be chickens. At that point you're talking about one single DNA base difference, or something like that. If you were to watch it happen, it would be a very gradual gradient, and the only way to differentiate chicken from protochicken would be to match them up against an arbitrary list of qualities.

Yeah, ”species” is a vague concept and so biologists fight an endless war over where the limit goes from case to case, perhaps ocasionally cursing Linnaeus for coming up with the idea of a single ordering in the first place.

There are many co-existing species concepts used in practice that are statistically rigorously defined, selected according to the biology of the lineage in question (e.g. it makes little sense to apply the same concept to both recombining and asexual lineages). It's an intensively researched area that becomes more refined and more explanatory with time, like any other area of science.

Delving into the recent literature might enable you to make a less clumsy critique. Independently evolving units of biological diversity exist. Any accurate knowledge about them, and about all the edge cases and fuzzinesses and genetic phenomena that make systematization complicated, comes from biology itself.

If you took a chicken today, and looked at every single one if its direct ancestors down its lineage for the past billion generations, any single ancestor would probably be indistinguishable from their own parents, yet the last ancestor would look nothing like the chicken. It's because the incremental change with each generation is absolutely tiny, but those changes are magnified as they accumulate over countless generations.

The same is true about the evolution of language. Parents and their own kids can always communicate just fine, but across 5, 10, 20 generations it can be completely unrecognizable (see: Middle English).

Do you think that this will still be the case now that we have the internet? I wonder if the English of 3000 AD will be as different from 2000 AD as 2000 AD is from 1000 AD. I feel like the big players in tech have the capability to direct language evolution somewhat. Consider the pronunciation feature Google offers if you look up the definition of a word (the little speaker icon) -- the pronunciation they provide there could influence learners. I'm not suggesting anything insidious, just recognizing the potential that seems to be there.

You make an interesting point, but I’m not sure I find it entirely convincing. To feel out the limits of your argument, what is it that you see as fundamentally different between the Internet and the dawn of recorded sound? The ubiquity, the geographical homogeneity, and ease of recording? Would the same argument apply to vocabulary and spelling of the written word?

I'm not trying to convince anyone, I myself don't know! Yes all around to your questions though, pretty much. Cheaper, faster, easier, etc. What do you think the effect of spellcheck technology will be on the rate of change of the spelling of words? We increasingly _let computers write for us!_ Google Smart Compose, Grammarly, etc. In my opinion, these things are leading to the homogenization of spelling, pronunciation, and even word choice all across the world.

Whilst I have no doubt that computerised spelling checking is standardising spelling, this has been a trend going back centuries. As writing has becoming more widespread, spelling and grammar has become more fixed. Shakespeare signed his name about a dozen different ways and the spelling we all agree on today only became standardised about a hundred years ago. Essentially, I don’t buy the argument that there’s something special about the Internet, it’s just that as widespread communication becomes more ubiquitous, the variability in that medium reduces - be it languages, vocabulary, grammatical style (I’d be interested to know if anyone has done a study into accent homogenisation).

My gut feeling is that as a species we are reducing the total variability whilst accelerating the change along the increasingly standardised forms I.e. I don’t think a US-UK English split would occur today but we are adding new words faster than ever

Interesting point.

These days I can visit Imgur and appreciate a joke that someone has made using only 4-5 memes. Also language is still evolving, and the Internet of the era forces changes, such as people becoming used to being limited to 140 letter limits etc.

But even then I'm sure change to the core language must be slower overall.

Chickens have 78 chromosomes.

There is nothing incremental about moving from 76 to 78. Or, from 78 to 80 (turkeys).

How is incrementing by 2 not incremental?

It's discontinuous. It's obvious what the post implied... that the changes are gradual and continuous.

Evolution is a feature of populations, not individuals.

If the proto-chickens had 76 chromosomes, and some had a tendency to have offspring with 78 chromosomes, there would be some 78 chromosome chickens born within the population. As long as those chickens bred with each other it would work. Soon they would become a distinct population of individuals breeding with each other.

How often do chicken have offspring with an extra pair of chromosomes?

Do you have data on this?

Relating the question of species-ness to the sorities paradox is more than tangential - quite insightful, in fact. An individual that is too different from its peers to breed is never the founder of a new species, so the concept of 'first chicken' is at best a matter of convention, and is more likely to add confusion rather than insight.

The idea of "species" is only a good simplification that work 99.99% of the time.

Just to add some confusion, the border of species is fuzzy in time, but in some strange cases it is fuzzy in space https://en.wikipedia.org/wiki/Ring_species

I think it's important to state with almost certainty the first chicken died without having baby chickens (or laying a chicken egg)

Theirs a fair chance it also just dies without breeding.

I'm not sure I see this discussed much?

It's not a clear way down, that's not how evolution works.

Jim Holt's book "Why Does the World Exist?" is an interesting tour through different approaches to this topic.

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