# What happened "before" evolution?
**URL:** https://boards.straightdope.com/t/what-happened-before-evolution/605156
**Category:** Factual Questions
**Created:** [December 5, 2011, 7:23pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156 "2011-12-05T19:23:01Z")
**Posts on this page:** 20
**Page:** 4
### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [December 7, 2011, 4:14pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/61 "2011-12-07T16:14:01Z")
> [@Frylock](#):
>
> What **Indistinguishable** and **Chronos** are trying to explain to you is that this is incorrect. Instead, if there are any _plausible_ alternatives to X, then X is not a theory.l.
No, abiogenesis is not a theory as it is not supported by evidence. Instead, it is a hypothesis where we have been able to try some experiments that so far don’t disprove the hypothesis. A Scientific Theory “refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence.”
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [December 7, 2011, 4:30pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/62 "2011-12-07T16:30:15Z")
> [@Frylock](#):
>
> You’re not fighting misconceptions. You’re not fighting against a strategy. You’re just _wrong_.
>
> In this latest post you don’t offer an argument or even an explanation for your view, you simply assert that the people you disagree with are “desperate.” This is incorrect. The people you disagree with are attempting to explain facts to you and you are not listening.
>
> See my previous post. “Possible” alternatives are irrelevant to the question of whether something is an established fact in science or not. What are relevant are “plausible” alternatives. The possibility of biogensesis by time travel doesn’t render abiogenesis a non-fact, because biogenesis by time travel is not _plausible_.
>
> It is an established fact that the earth goes around the sun. Yet–time travelers could have systematically and subtly screwed around with all our observations on the matter. Maybe the sun goes around the earth after all. Hey it’s possible!
I don’t need to show any plausible alternatives to prove abiogenesis is not a fact (It’s a hypothesis, but a damn good one.). The supporters of abiogenesis must show that it is “supported by a vast body of evidence.” Of course, they have not and can not do so.
That’s how science works. You need to prove to me that the luminiferous aether hypothisis is valid by a vast body of evidence , not just that I can’t come up with a better idea. In fact, the luminiferous aether hypothesis is a perfect example of why abiogenesis is a hypothesis and not a theory or a fact- it was the ONLY plausible scientific explanation for centuries of how light propagated. Based upon your idea here, that would make it a “fact”. However, the Theory of Relativity (and others) showed that the luminiferous aether hypothesis was in fact completely wrong- even tho it did explain things well and was the only hypothesis the best minds of that era could come up with.
Thus, the luminiferous aether hypothesis as an example disproves solidly the idea “well, my hypothesis explains the situation, and no one has any other plausible alternatives, thus my hypothesis must be a fact”.
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### Author:  [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)
#### Post date: [December 7, 2011, 4:40pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/63 "2011-12-07T16:40:27Z")
Quote:
Originally Posted by Xema View Post
What categories of food do dogs today eat that dogs 10,000 years ago didn’t?
> [@Voyager](#):
>
> My daughter’s panties. :eek:
That is just plain wrong to share; TMI. 😃 What your daughters boyfriend does with her panties should stay between them.
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### Author:  [@Frylock](https://boards.straightdope.com/u/Frylock)
#### Post date: [December 7, 2011, 6:51pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/64 "2011-12-07T18:51:17Z")
> [@DrDeth](#):
>
> No, abiogenesis is not a theory as it is not supported by evidence. Instead, it is a hypothesis where we have been able to try some experiments that so far don’t disprove the hypothesis. A Scientific Theory “refers to a comprehensive explanation of some aspect of nature that is supported by a vast body of evidence.”
Though I used “theory” above I shouldn’t have. I’m not talking about theories and hypotheses in their technical senses–just things we are justified in believing. Abiogenesis is, for all intents and purposes, an established fact in the sense that we’re justified, by strong reasoning, in believing it took place, and there are no alternatives to it which we are justified in believing took place.
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [December 7, 2011, 6:56pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/65 "2011-12-07T18:56:50Z")
> [@Frylock](#):
>
> Though I used “theory” above I shouldn’t have. I’m not talking about theories and hypotheses in their technical senses–just things we are justified in believing. Abiogenesis is, for all intents and purposes, an established fact in the sense that we’re justified, by strong reasoning, in believing it took place, and there are no alternatives to it which we are justified in believing took place.
So was luminiferous aether.
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### Author:  [@Frylock](https://boards.straightdope.com/u/Frylock)
#### Post date: [December 7, 2011, 6:57pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/66 "2011-12-07T18:57:46Z")
> [@DrDeth](#):
>
> So was luminiferous aether.
I’m not sure why you think that’s relevant. Can you elaborate?
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### Author:  [@Frylock](https://boards.straightdope.com/u/Frylock)
#### Post date: [December 7, 2011, 7:04pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/67 "2011-12-07T19:04:15Z")
**DrDeth** I’ve looked back over your posts and I don’t see where we disagree. Who I’ve been disagreeing with is **Mijin**. “Disagreement” isn’t even the right word–I am just arguing that he’s eliding between different senses of justification in a way that amounts to equivocation. Sometimes he’s relying on facts about justification in the practice of science. Sometimes logical justification. Sometimes inductive justification in general. These are different. (Though of course inductive justification has a large role to play in scientific practice.)
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### Author:  [@Frylock](https://boards.straightdope.com/u/Frylock)
#### Post date: [December 7, 2011, 7:07pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/68 "2011-12-07T19:07:29Z")
Also, **DrDeth** , I think you’ve misunderstood me. I said:
> [@](#):
>
> If there are any plausible alternatives to X, then X is not a theory.
But this does _not_ mean (and I don’t believe) that if there are no plausible alternatives to X, then X is a theory. It appears to me that you have misunderstood me to be saying the latter, not the former.
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [December 7, 2011, 7:24pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/69 "2011-12-07T19:24:30Z")
> [@Frylock](#):
>
> I’m not sure why you think that’s relevant. Can you elaborate?
Luminiferous aether= “\*by strong reasoning, in believing it took place, and there are no alternatives to it which we are justified in believing took place.” \*It was also completely false.
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [December 7, 2011, 7:26pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/70 "2011-12-07T19:26:08Z")
> [@Frylock](#):
>
> Also, **DrDeth** , I think you’ve misunderstood me. I said:
>
> But this does _not_ mean (and I don’t believe) that if there are no plausible alternatives to X, then X is a theory. It appears to me that you have misunderstood me to be saying the latter, not the former.
OK, I see what you mean.
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### Author:  [@Frylock](https://boards.straightdope.com/u/Frylock)
#### Post date: [December 7, 2011, 7:38pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/71 "2011-12-07T19:38:40Z")
> [@DrDeth](#):
>
> OK, I see what you mean.
Reading back through my posts I can see I was _extremely unclear_ on this point, so I’ll just offer my apologies and move on…
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### Author:  [@njtt](https://boards.straightdope.com/u/njtt)
#### Post date: [December 7, 2011, 8:41pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/72 "2011-12-07T20:41:38Z")
> [@Polar\_Iceman](#):
>
> Thanks; what I am thinking about is the contention that all life forms have a common origin. I am wondering how this would be shown using DNA analysis.
>
> I understand (and I concede that my understanding comes from reading cheap magazines) that all life shares something like 96% of DNA.
>
> The implication of this is that the remaining 4% is what defines the species.
>
> So, is this remaining 4% embedded throughout the DNA, or attached as a module to some larger structure? Is this larger structure the basis for the contention of the common origin?
>
> Repeating my earlier question: could this 4% be mixed and matched to produce viable life forms?
I think that you are confusing two issues. Yes different species share the same or similar DNA sequences, and these days (since fairly recently) the amount of similar sequences\* shared by different species is often used as an index of how closely the evolutionarily related those species are.
I do not know if it is true that there are DNA sequences (of meaningful length) that are shared by all species whose DNA has been sequenced. It is possible, but frankly I rather doubt it (I am pretty sure it will be false if we are counting viruses as living things), although there may be some that are shared by all eukaryotes. Certainly your figure of 96% is way too high. I think you are thinking of the similarity between the human genome and that of the chimpanzee, our closest evolutionary relative. We differ more than that from gorillas, let from alone oak trees or bacteria.
However, the DNA evidence that all life has a common ancestor comes not so much from sequence similarities (although they can point towards it, when a lot of such evidence is taken together) but from the fact that all living things on Earth do use DNA (or, occasionally, its close relative RNA) as their genetic material, and more surprisingly, the fact that the DNA of all living things for whom the matter has been investigated - everything from bacteria to oak trees to humans - uses the same genetic code. The genetic code is, as it were, the translation manual by which DNA triplets (sequences of 3 bases/nucleotides) code for the amino acids that make up proteins. So far as we can tell, the code is at least somewhat arbitrary (it did not have to be the way it is) but (with some rare, trivial variations) it is the same for all living things on Earth. I think that if we were to find alien life, then, even if it were like Earth life in using DNA as its genetic material and protein as its main type of workhorse molecule, nevertheless it would be surprising if its genetic code was not at least somewhat different. The fact that all Earth life shares essentially (in most cases, absolutely) the same genetic code is excellent evidence of a common origin for all life, quite regardless of any shared DNA sequences.
¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬
\*That is, sequences of meaningful length. As DNA only has 4 “letters” (bases/nucleotides) in its “alphabet” there are bound to be similar short sequences all over the place, just by random chance. I am not sure how long a sequence has to be for its similarity to be considered meaningful for the purposes of inter-species comparison.
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### Author:  [@Mijin](https://boards.straightdope.com/u/Mijin)
#### Post date: [December 7, 2011, 10:39pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/73 "2011-12-07T22:39:53Z")
> [@Frylock](#):
>
> **DrDeth** I’ve looked back over your posts and I don’t see where we disagree. Who I’ve been disagreeing with is **Mijin**. “Disagreement” isn’t even the right word–I am just arguing that he’s eliding between different senses of justification in a way that amounts to equivocation. Sometimes he’s relying on facts about justification in the practice of science. Sometimes logical justification. Sometimes inductive justification in general. These are different. (Though of course inductive justification has a large role to play in scientific practice.)
And yet, I completely agree with **DrDeth** and feel that he’s summed up very well what I was saying.
If I’ve differed from **DrDeth** ’s point, please point out where I have done so.
But to summarise again, I think it is flawed reasoning to conclude that something must be true because we cannot think of alternatives.
I agree that, practically speaking, it’s a pretty safe assumption that something like abiogenesis happened. But concluding we _know_ it happened, and even “correcting” those that disagree, is irrational, and contrary to the principle of skepticism.
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### Author:  [@Polar\_Iceman](https://boards.straightdope.com/u/Polar_Iceman)
#### Post date: [December 7, 2011, 11:25pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/74 "2011-12-07T23:25:24Z")
> [@njtt](#):
>
> I think that you are confusing two issues. Yes different species share the same or similar DNA sequences, and these days (since fairly recently) the amount of similar sequences\* shared by different species is often used as an index of how closely the evolutionarily related those species are.
>
> I do not know if it is true that there are DNA sequences (of meaningful length) that are shared by all species whose DNA has been sequenced. It is possible, but frankly I rather doubt it (I am pretty sure it will be false if we are counting viruses as living things), although there may be some that are shared by all eukaryotes. Certainly your figure of 96% is way too high. I think you are thinking of the similarity between the human genome and that of the chimpanzee, our closest evolutionary relative. We differ more than that from gorillas, let from alone oak trees or bacteria.
>
> However, the DNA evidence that all life has a common ancestor comes not so much from sequence similarities (although they can point towards it, when a lot of such evidence is taken together) but from the fact that all living things on Earth do use DNA (or, occasionally, its close relative RNA) as their genetic material, and more surprisingly, the fact that the DNA of all living things for whom the matter has been investigated - everything from bacteria to oak trees to humans - uses the same genetic code. The genetic code is, as it were, the translation manual by which DNA triplets (sequences of 3 bases/nucleotides) code for the amino acids that make up proteins. So far as we can tell, the code is at least somewhat arbitrary (it did not have to be the way it is) but (with some rare, trivial variations) it is the same for all living things on Earth. I think that if we were to find alien life, then, even if it were like Earth life in using DNA as its genetic material and protein as its main type of workhorse molecule, nevertheless it would be surprising if its genetic code was not at least somewhat different. The fact that all Earth life shares essentially (in most cases, absolutely) the same genetic code is excellent evidence of a common origin for all life, quite regardless of any shared DNA sequences.
>
> ¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬
>
> \*That is, sequences of meaningful length. As DNA only has 4 “letters” (bases/nucleotides) in its “alphabet” there are bound to be similar short sequences all over the place, just by random chance. I am not sure how long a sequence has to be for its similarity to be considered meaningful for the purposes of inter-species comparison.
OK, continuing to demonstrate my ignorance:
When we look at an elephant, a frog or a human, they are all functionally the same. Ie: all of their biological systems have the same functional components, all of which work on more or less the same principles.
The only thing that differentiates an elephant from a frog is the packaging.
So, DNA contains the design specifications for the functional components; attached to that somehow is a specification for the packaging.
This suggests that the process of evolution was a two part process: first the design specification for the functional parts developed; then a second process developed the individual packaging designs.
So the thing that suggests the common origin is the fact(?) that all living creatures have the same functional component specification?
In principle, is my analysis correct?
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### Author:  [@Smeghead](https://boards.straightdope.com/u/Smeghead)
#### Post date: [December 8, 2011, 12:16am UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/75 "2011-12-08T00:16:37Z")
> [@Polar\_Iceman](#):
>
> In principle, is my analysis correct?
No, not at all. For starters, frogs and elephants aren’t that far apart. What about insects? Jellyfish? Plants?
I don’t have time to get into it in detail right now.
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### Author:  [@Polar\_Iceman](https://boards.straightdope.com/u/Polar_Iceman)
#### Post date: [December 8, 2011, 1:55am UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/76 "2011-12-08T01:55:06Z")
> [@Smeghead](#):
>
> No, not at all. For starters, frogs and elephants aren’t that far apart.
Isn’t that the essence of what I am getting at?
The packaging is different, but the content is the same.
So, common origin?
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### Author:  [@njtt](https://boards.straightdope.com/u/njtt)
#### Post date: [December 8, 2011, 5:18am UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/77 "2011-12-08T05:18:45Z")
> [@Polar\_Iceman](#):
>
> Isn’t that the essence of what I am getting at?
>
> The packaging is different, but the content is the same.
>
> So, common origin?
No. Your distinction between packaging and content is not valid. Frogs and elephants and humans look different from one another because different stuff is going on inside (or was going on inside as they grew from a fertilized ovum to their adult form). Although most of this stuff is not different, it is enough different to cause one ovum to grow to be a frog, another to grow to be a human, etc.
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [December 8, 2011, 5:36am UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/78 "2011-12-08T05:36:11Z")
Perhaps an example is in order. All living things (I’m excluding vira here) produce an enzyme called DNA polymerase, which is one of the enzymes involved in the process of DNA replication. Like with any protein, they all have, somewhere in their genome, a DNA sequence that codes for that protein. But even though all of those enzymes do basically the same job, and they’re mostly similar in structure, the exact structure of that enzyme varies from one organism to another. And even in closely-related species where the enzyme has the same structure, the DNA sequence that codes for it might be a little different (there’s multiple ways each to code for most amino acids).
Now, in at least some cases, you could swap the genes for DNA polymerase between two organisms, and they’d both still be viable. In other cases, that wouldn’t work: If, for instance, you put our polymerase gene in one of those critters that lives in the Yellowstone hot springs, it’d die, because our enzymes will fall apart at those temperatures. And there’s probably some tradeoff in play that would likewise mean that their polymerase wouldn’t work very well in us.
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### Author:  [@MrDibble](https://boards.straightdope.com/u/MrDibble)
#### Post date: [December 8, 2011, 2:58pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/79 "2011-12-08T14:58:20Z")
> [@coremelt](#):
>
> I think there’s a good argument to be made that earth during the Hadeon epoch was still a better environment for life than most other places in the Solar System.
Compared to [Mars](http://en.wikipedia.org/wiki/Mars_Ocean_Hypothesis)? The Martian Noachian Period overlaps the Hadean. Or early Venus? Both were at least comparable to earth at the time, _without_ that huge Moon-creating impact event making Earth a bit inhospitable for a time.
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### Author:  [@Smeghead](https://boards.straightdope.com/u/Smeghead)
#### Post date: [December 8, 2011, 3:24pm UTC](https://boards.straightdope.com/t/what-happened-before-evolution/605156/80 "2011-12-08T15:24:23Z")
> [@Polar\_Iceman](#):
>
> Isn’t that the essence of what I am getting at?
>
> The packaging is different, but the content is the same.
>
> So, common origin?
No. You’re positing a dichotomy that simply is not supported by evidence. The best I can offer in the way of support is the observation that genes that affect the external phenotype of an organism are generally amongst the most rapidly evolving genes in the genome (reproductive genes are also in this category, interestingly), but that’s not surprising. Generally speaking, a gene that affects your size or color or jaw shape or musculature are probably going to be more important to your survival than a gene that allows a specific biochemical reaction in your liver. This being biology, of course, it’s important to acknowledge that counterexamples to any general statement could easily be found.
But the idea that there are two general “groups” of genes just doesn’t bear up under scrutiny. Instead, you have tens of thousands of individual genes, each undergoing their own selection under whatever pressures may be brought to bear. Every codon for itself, so to speak. This is looking at it from a population point of view, of course, since for an individual organism’s genes, it’s all or none. Hmm. That’s an interesting thought. I may have to ponder that some more. Anyway…
Now, this does all play into the idea of common descent, because once a useful structure evolves, it tends to stick around in later species. Everyone loves to have a kidney, so two animals with kidneys are likely to be more related than one animal with a kidney and one without. But this division into “functional” and “decorative” genes, if I can call it that, just isn’t real.
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