Instigator / Pro
1484
rating
6
debates
25.0%
won
Topic
#5264

THBT: The Silurian Hypothesis is not feasible.

Status
Debating

Waiting for the next argument from the contender.

Round will be automatically forfeited in:

00
DD
:
00
HH
:
00
MM
:
00
SS
Parameters
Publication date
Last updated date
Type
Rated
Number of rounds
5
Time for argument
One week
Max argument characters
10,500
Voting period
Two weeks
Point system
Multiple criterions
Voting system
Open
Minimal rating
1,650
Contender / Con
1760
rating
88
debates
76.14%
won
Description

(Inspired by a previous debate.)

"The "Silurian Hypothesis" is a speculative concept in astrobiology that suggests the possibility of an ancient, technologically advanced civilization existing on Earth long before the rise of human beings."

Pro's burden will be to provide evidence that it probably didn't happen. Con's burden will be to prove that it is a logical possibility. If Con's justification is convincing enough to successfully refute Pro's near certainty that it didn't happen, then Con wins.

Definitions:

Feasible- Possible to do easily or conveniently.

Probably- almost certainly; as far as one knows or can tell.

Possibility- a thing that may happen or be the case.

Logical- natural or sensible given the circumstances.

Rules:

1. A forfeit is the loss of a conduct point. Two is an auto-loss.

2. No plagiarism.

3. No kritiks.

Round 1
Pro
#1
Intro

Hello, readers. 
We’re brought up with a thought experiment that challenges the current foundation of scientific knowledge. Essentially, this hypothesis proposes the idea that an ancient technological civilization existed, predating the birth of humanity. The time gap being so significant, that any traces of this civilization are invisible, leaving this hypothetical civilization a mystery. 
I will be arguing that our current evidence suggests humanity is the first advanced civilization and that any civilization preceding us did not happen. 

Bop

This debate is slightly on-balance, but the burden leans slightly more on Pro.
I shall be required to argue and defend the idea that the Silurian Hypothesis most likely didn’t happen and is not a credible idea worthy of speculation. Con must provide valid reasoning and justification that the theoretical explanation of the Silurian Hypothesis is probable enough to be worthy of consensus in the eyes of the scientific community.

Framework

Voters shall evaluate this debate on two things.:
  • The likelihood that the Silurian Hypothesis did or did not occur.
  • Why & whether or not it should be a more popular subject in the scientific community.

My framework establishes a solid foundation and a clear direction for this debate that leaves enough room for both sides to argue their positions, present facts, and question opposing viewpoints. We will use these two factors to decide if the Silurian Hypothesis makes sense or not.

C1: The Founders

Scientists Adam Frank and Gavin Schmidt took inspiration from this idea by referencing a science fiction novel called Inherit The Stars by J.P. Hogan. Despite this trope also being used in the series, Doctor Who, the two scientists recall that it is rarely utilized in science fiction.
But as they debated the possibility, the scientists did finally test it and came to the conclusion that advanced life before mankind probably didn’t happen.

Frank and Schmidt come to the conclusion that another civilization may not have lived on Earth before humans.” 1 Gavin and Adam were the ones who wondered if any such life existed, what kinds of evidence would need to be left behind in order to serve as signs of its existence? The abundant resources would have included a huge supply of metal, plastic, concentrated use of large-scale energy, and artificial pollutants.  The time-based hypothetical makes too many assumptions about the feats of such a technological civilization, that if any of these things were true, would have inevitably left some form of traceable evidence behind. 
A lack of observable evidence of the hypothesis’s historical accuracy and the idea’s unpopularity suggests that sci-fi enthusiasts and realists do not see it as a credible explanation for the events that occurred.

C2: Hypothetical Models & Decay

If we want to postulate this ridiculous idea, then we need to examine all the different variations in which a fictitious civilization could reasonably exist, under certain circumstances. 
While a small percentage of fossils from former species are left behind, if we are to assume that such a civilization were technologically advanced, then it is a guarantee that some preservation of this geological record would remain intact. To leave behind no observable trace is just improbable. 
If we consider the decay of structurally engineered societies that are land-based, the types of decay would be detectable in paleosol. Under-water terrains would need a form of constructional fortitude that could withstand the weight of water and be designed for longevity. The reason this is highly unlikely for a species like the Silurians is because of the amount of time it would take to develop this engineering ability. 
Not to mention the time and resource allocation. 


Con
#2
Thank you


What is the Silurian Hypothesis
PRO gravely misrepresents the Silurian Hypothesis. He treats it as a positive assertion, saying that if humans were probably the first advanced civilisation, the Silurian Hypothesis would be incorrect, have no credibility and be unworthy of speculation. But even a cursory glance at the scientific paper which proposed it, this characterization turns out to be false. 
If an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today? We summarize the likely geological fingerprint of the Anthropocene, and demonstrate that while clear, it will not differ greatly in many respects from other known events in the geological record. We then propose tests that could plausibly distinguish an industrial cause from an otherwise naturally occurring climate event. [Cambridge]
The Silurian Hypothesis is nothing more than an observation that we still lack the evidence to demonstrate that humanity is the first advanced civilisation on Earth. To disprove it fully you have to provide evidence that clearly and unambiguously disproves the possibility of previous civilisations. And nothing short of a time machine can achieve that. 


The concept of possibility
PRO defines logical and possibility seperately in the description. But this does not suffice to clearly define the concept of logical possibility. The conjunction of the two words refer to a very specific academic concept. It is similar to how a black hole cannot be described just by defining "black" and "hole", you must define the concept of black holes directly. 
Logical possibility is possibility in the broadest sense: whatever is conceivable, whatever can be imagined or thought, is logically possible, even if it isn't physically possible [edu] 
The three main types of possibiliies:
  • Logical possibilities are propositions that are not self-contradictory.
  • Physical possibilities are logical possibilities that also do not violate the laws of physics. 
  • Historical possibilities are physical possibilities that do not contradict the positive historical evidence that we have. 
It is historically impossible that JFK is still alive, because we have positive evidence that he died: videos and witnesses, and his burried body. But say he just dissapeared someday, with no trace. That would leave us with a plethora of historical possibilites, one of which would be that he lived on in secret. An important concept here is that absence of evidence is not evidence of absence. So even if we had no positive evidence that JFK was assasinated, that event would still be a historical possibility, regardless of its probablity. The event where JFK just stopped existing and his body disappeard into thin air, that would not be a historical possibility, because only physical possibilites can be historical possibilites. But this event would still be a logical possibility. 


Framework
Here is the BoP that PRO himself assigned from the description:
  • Pro's burden will be to provide evidence that it probably didn't happen.
  • Con's burden will be to prove that it is a logical possibility.
  • If Con's justification is convincing enough to successfully refute Pro's near certainty that it didn't happen, then Con wins.
He cannot change the BoP to make his case easier now after the debate has already started. That would be moving the goalpost.

Evidence that it didn't happen
The Silurian hypothesis does not claim any specific event to have actually occured. All it does is point out the existence of a broad category of possibilities. And if you are just talking about the idea itself then its inception is obviously an event that happened, otherwise we would not be discussing it. So it would be impossible to say that the hypothesis itself didn't happen. PRO has also added the clause that he has to demonstrate how the idea itself is neither credible nor worthy of speculation. That instantly destroys his entire case, because his own R1 has demonstrated that scientists have taken the idea seriously and judged it worthy of speculation. 

Near certainty that it didn't happen
Let us say that PRO manages to successfully argue that we are probably the first advanced civilisation. That would still not be enough to win him this debate as per his own rules. He has to provide evidence that clearly and unambiguously demonstrates with near certainty that no advanced civilisation existed on Earth in any form at any point. Absolute certainty on this matter would require a time machine to go back to every point in history and verify that at no point was there a civilisation. So near certainty would require some form of evidence only slightly less convincing than that. Absence of evidence is not evidence of absence, so pointing out lack of evidence can never bring near certainty that something never happened, especially something from potentially hundreds of millions of years ago. So by PRO's own admission, all I have to do is cast sufficient doubt on PRO's argument. If I can successfully defend the silurian hypothesis as even just somewhat plausible, then it would be inaccurate to say that we have near certainty that it didn't happen.

BoP moving by PRO
PRO in R1 completely ignores his own description and writes a new and completely different set of BoPs. But that is moving the goalpost and should be ignored. 
Voters shall evaluate this debate on two things.:
  • The likelihood that the Silurian Hypothesis did or did not occur.
  • Why & whether or not it should be a more popular subject in the scientific community.
There are only to ways to reject a scientific hypothesis:
  1. It is unfalsifiable.
  2. We have tested it and disproved it.
If the hypothesis is unfalsifiable, then it would be impossible for PRO to disprove it and fullfill his BoP. But if it can actually be tested and disproved, that makes it an excellent hypothesis worthy of scientific interest. Lack of popularity does not detract from a hypoethesis' validity, and it certainly does not prove it to be incorrect or unfeasible.


Affirmative case
PRO has made my case extremely simple:
  1. An ancient civilisation is conceivable and not self-contradictory, so therefore it is a logical possibility. 
  2. An ancient civilisation also does not violate any of the known laws of physics, so it is also a physical possibility.
  3. An ancient civilisation also does not contradict any of the positive evidence we have about the past. So it is also a historical possibility.
Point 1 alone is enough to win me this debate because PRO himself defined my BoP in the description to be limited to only needing to prove it a logical possibility.


Defensive case
First up it is important to note that the founders of a hypothesis do not automatically have the last say on the topic, or the authority to shut down a subfield of science. Even Isaac Newton, who completely solved physics, was actually wrong about gravity as later scientists like Einstein would come to discover. So to quote their words is not the end all be all.

The reason why the founders of the Silurian Hypothesis concluded the way they did is because they found no positive evidence that an ancient civilisation existed. They never claimed to have found conclusive evidence that such a civilisation could not have existed. Just that the geological traces of such a civilisation would be hard to distinguish from other geological events. In fact, that we have yet to correctly identify a geological phenomema  as a result of an ancient civilisation is easily compatible with its possible existence. So it is untenable to say that an ancient civilisation is not a historical possibility. PRO does not even have good sources for his claim.

The fossil record doesn't go back further than 2.6 million years ago. Fossils would exist but only very few. Adam Frank says that the fraction of life that gets fossilized is tiny and depends on factors such as the time and habitat of the organism. This would make it easy to miss an industrial civilization that lasted 100,000 years. [PRO's own source] 
Even the articles he links to disagrees with his claim that we would be likely to find fossil evidence of an ancient civilisation. And if they had a culture of cremation we would find nothing. 

Unwaranted assumptions
PRO is working under the assumption that if you do not pollute the enviroment on a large scale, then you are not advanced. This is obviously a very flawed and human-centric perspective on what constitutes advanced civilisation. The bow and arrow are advanced technology, and so is biodegradeable plastics. To work under the assumption that an advanced civilisation cannot exist in harmony with nature is completely unwaranted. And even if they did pollute the earth they could have elected to clean the ecosystem up again, and then live  more sustainably. The founders of the Silurian Hypothesis only rejected it because they defined it as "an industrial civilization" comparable to humanity in terms of enviromental impact, and then looked for the types of traces they believed humanity would leave for the future. But they themselves acknowledges this method is very flawed because their assumptions might not even hold true with regards to humanity:

There is an interesting paradox in considering the Anthropogenic footprint on a geological timescale. The longer human civilization lasts, the larger the signal one would expect in the record. However, the longer a civilization lasts, the more sustainable its practices would need to have become in order to survive. The more sustainable a society (e.g. in energy generation, manufacturing or agriculture) the smaller the footprint on the rest of the planet. But the smaller the footprint, the less of a signal will be embedded in the geological record. Thus, the footprint of civilization might be self-limiting on a relatively short timescale. [cambridge]
Consider the fact that in less than 100 years we may have solutions that will be able to clean up the plastic in the ocean and the gasses in the atmosphere and genetically engineer extinct species back to life. Why would an ancient civilisation that went through an industrial revolution not be able to do the same. It sounds ridiculous to work under the premise that no industrial civilisation could cover up their footprint on the enviroment. It doesn't even need to be a perfect cleanup, just good enough to make the traces indistinguishable from other geological events hundreds of millions of years later. 

What evidence would we expect to find
The pyramids, the most resilient structures, will be around for a few hundred years at most. We cannot expect that any technology would survive for more than a couple million years. 

On large timescales, plate tectonics will subduct almost all evidence for technology with the crust it sits upon, erasing it from the surface entirely. The parts of the surface that escape subduction also change substantially on tectonic timescales, so regions that are easily accessed today might have been practically inaccessible at the time a prior species existed (under miles of ice, for instance) and so show few or no signs of their technology. [cambridge]
This excerpt is from the founding paper of the hypothesis. And it acknowledges that we wouldn't expect to find clear pieces of evidence in the crust even if there was an ancient civilisation. The very same paper demonstrates that the traces humanity will leave in the geological record are very similar in type and magnitude to previous geological events. PRO wrote that we would probably find traces of an ancient civilisation if it existed. But the opposite is actually true. "Even if an industrialized alien society existed 200 million years ago and lasted for 100,000 years, 300 times longer than industrial humanity, it still might be easy to miss it in the geological record". [kurzgesagt]. So there is no contradiction between an ancient civilisation existing and the lack of clear traces.


Conclusion:
The existence of an ancient advanced civilisation is a logical possibility, fullfilling my BoP. But PRO has not yet disproved with near certainty that a previous civilisation could have existed.



Round 2
Pro
#3
I propose the following definition for "logical possibility."
Logical Possibility - The chance that something happened or may have happened based on reasoning or good judgment. (Cambridge Dictionary.)


Evidence of a Lost Civilization

In my round 1, I have demonstrated that the founders of the hypothesis have tested it and came to the conclusion that an advanced civilization preceding humanity most likely did not exist.

Now I have went into depth about how climate change are one of the significant signs of an advanced civilization, since the pollution and energy waste of mankind on a massive scale is causing damage on a global level. Con is suggesting an alternative possibility that it is perfectly capable for an advanced reptile-alien race to have existed undetected, with technology that exists in perfect harmony with nature. Which raises another problem. And that second problem is by introducing more assumptions into the Silurian Hypothesis, we also have to bring in some form of justification for entertaining this possibility, and such justification would require you to suspend disbelief. "The road to civilization required more organization and increased efficiency."  https://c3teachers.org/wp-content/uploads/2016/06/WH1-Geography-and-the-River-Valley-Civilizations-.pdf 

Organisms and species are not born with a natural understanding of the physical world. The amount of time it took humanity to evolve on such a level to be capable of creating technologically-advanced civilizations took 6 million years. It would've taken a similar species a proportional amount of time. And if they ever do evolve to a level where they can start a industrial civilization that exists with harmony in nature, we have to consider precisely how much energy-efficiency and understanding of engineering that would take. To reach that level of sophistication would take time and stages of committing serious, disastrous mistakes that would have manifested in some form of catastrophic damage to the environment. And putting all doubt aside at least temporarily, the remnants of that catastrophic damage would also remain long enough for our modern technology to detect because even superior technology is still bound by the laws of the physical world. So suppose that such a civilization is capable of existing hypothetically and are able to address deeper issues such as pollution and climate change, the next question is how could they magically repair all the damage they caused?

For us to accept that such a situation is technologically feasible, Con will have to explain the simplicity and practicality for such an advanced civilization's limitations and why it is reasonable they could achieve this.
Con
#4
Thank you.


BoP analysis
PRO has not refuted that If Con's justification is convincing enough to successfully refute Pro's near certainty that it didn't happen, then Con wins. So he accept that the BoP is heavilly slanted against him. He has to demonstrate near certainty that it didn't happen, but if I can establish even a tiny bit of doubt, or just prove that it is a logical possibility, then I automatically win.


Types of possibilities.
In the previous round I provided a way to define and categorize possibilities, based on the theory that possibilites are fundamentally defined by the absence of contradictions. This framework is very simple and intuitive, and has a high utility because it actually works. Using it makes it possible to easily and effectively verify and analyse different type of possibilities, where the hierarchy between then is robustly defined and highly usefull. PRO has not disputed this framework, meaning he implicitly accepts it. Now let us delve into each category. 

The three types of possibilities:
  1. Logical possibilities, which are propositions that do not contradict the laws of logic. 
  2. Physical possibilities, which are logical possibilities that also do not contradict the known laws of physics.
  3. Historical possibilities, which are physical possibilities that also do not contradict the available positive evidence.
PRO provided no framework of his own to categorize possibilities, nor did he try to adress mine. This is a very large issue. Let me adress his attempt to redefine the words.

Logical Possibility - The chance that something happened or may have happened based on reasoning or good judgment. (Cambridge Dictionary.)
There are numerous issues here:
  • First off, he falsely attributes this definition to Cambridge dictionairy, but if you try to type logical possibility in their search bar, you will get no result. What PRO has actually done is seperately search up their definitions of logical and possibility, and then picked the ones he liked and mashing them together. But as I already explained, those two words have a very specific technical meaning, similarly to "black hole", that is not captured by combining two colloquial definitions together.
  • Secondly, his definition is not very specific or usefull. Whereas my framework defines logical possibility very robustly using the absence of contradictions with the laws of logic, his uses more vague terms like reasoning and good judgment. What types of reasoning, which principles are we to analyse the proposition with, and how do we evaluate all that? PROs definition falsely implies that we have to actively establish logical possibilities, when the opposite is the case. Anything is logically possible, untill someone can demonstrate a violation with the laws of logic. 
  • Lastly, his definition jumbles words redundantly. The chance that something happened already implies that it may have happened. No need to state the same thing twice.
For these reasons, I reject PROs definition of logical possibility, and voters should as well. Logicians agree that logical possibilities are all propositons that don't contradict themselves.


Concessions
PRO in R1 made some ridiculous claims about what this debate was about, such as me having the burden to prove that the hypothesis should be popular among scientists. I extend my objections to these attempts at moving the goalpost, since PRO did not even try to refute my R1 rebuttals.


Most likely did not exist.
PRO claims to have demonstrated that the founders of the hypothesis TESTED IT and came to the CONCLUSION that it was most likely false. This is unfortunately a grave misrepresentation.
The authors of this paper are not convinced of the correctness of their proposed hypothesis. It cannot be regarded as likely merely because no other valid idea presents itself.
There is a very large difference between not being convinced of an idea, and having actually disproven it. The founders of the silurian hypothesis never claimed to have proven the hypothesis false, and definitely never implied to have established NEAR CERTAINTY that humanity is the first civilisation on Earth, which is what PRO would have needed them to say. Instead, as good scientist, they analysed the data, found the evidence unconvincing, and concluded that the hypothesis remains unproven due to lack of positive evidence. Even if we take PRO's very flawed analysis of their paper, there is still a big difference between being improbable and being logically impossible. The very fact that the two scientists even made a research paper about the hypothesis to begin with, shows that they don't deem it something at odds with the laws of logic that can be dismissed without further analysis. They viewed it and treated it as a logical possibility.


The silurian hypothesis is definitely possible
The idea of a previous civilisation on Earth does not violate the laws of logic, it is not a self-contradictory proposition. Therefore, it is definitely a logical possibility. Furthermore, it does not violate the laws of physics, because advanced civillisations with technology is not prohibited by natural law, as evidenced by humanitys progress. So it is also definitely a physical possiblity. Now whether or not it is a historical possibility depends on what positive evidence PRO can provide that contradicts it. For example, the burried body of JFK proves that him being alive is not a historical possiblity. But there is no such positive historical evidence that an advanced civilisation did not exist. We have no time machine to go back and verify that at no point in time was there another civilisation. PRO has not even attempted to prove that every species in history was incapable of making a civilisation. So the silurian hypothesis is also definitely a historical possibility. 


Absence of evidence
PRO continues with his only argument, that being that we have not yet found any evidence proving the existence of a previous civillisation on earth. I agree with him. If the silurian hypothesis asserted that we have evidence for an ancient civilisation, then it would be wrong. But unfortunately for PRO's case, that is not what it does. All it does is point out that the possibility of an ancient civilisation has still not been disproven -- which is absolutely correct. PRO is commitng a logical fallacy. Absence of evidence is not evidence of absence. Especially when we are talking about hundreds of millions of years in the past, where all technological remnants would be eroded and burried in the mantle by now, and where their effects on the climate and geological layers would be indistinguishable from that left by natural phenomena. 

Extraterrestrial life
We have found no evidence that life exists on another planet, and we also do not see any of the signs we would expect to see if there were intelligent alien races. Large space structures would not be eroded, and radio communications would not just disappear into the mantle. And despite this, you would be hard pressed to find even a single astronomer who claims that aliens existing is not a logical possibility, or that we can have near certainty that they don't exist. This is terrible for PRO's case. Because if scientists agree on the possibility of extraterrestrial alien civilisations, despite the lacking evidence for them being way less excusable, then PRO simply has no foot to stand on. He cannot assert the impossibility of ancient terrestrial aliens solely based on the current lack of evidence which is very easily explained. Nor can he say that it does not merit scientific investigation, because the extraterrestrial aliens who are similarly unproven, clearly attract and warrant scientific attention.


Unwaranted assumptions
My opponent attacks my R1 rebuttals with only a single objection. He says that I am introducing assumptions into the hypothesis without providing adequate justification.

PRO has it completely backwards
What he does not understand, is it that he is the one who arbitrarily introduces unjustifiable premises. But PRO has presented a false dichotomy. According to him, there was either no civillisation in Earths past, or there was a civilisation in Earths past that left a lot of evidence able to last hundreds of millions of years without becoming hard to distinguish from natural causes. But this is very clearly not true. There are numerous ways an ancient civilisation could affect the enviroment, and not all of them would make them easy to detect. 

An ancient advanced civilisaton could:
  1. Be very carefull with the enviroment when developing industry, developing it slowly and with considerations for ecological concerns 
  2. Experience progress at breakneck speeds, make some big mistakes like climate change, but then progress to the point where they can fix their mistakes
  3. Make lots of mistakes, destroy the enviroment and fail to fix their mistakes, but the traces of those mistakes are indistinguishable from natural catastrophes
  4. Destroy the enviroment in such a way as even hundreds of millions of years later, the impact of their mistakes are still clearly distinguishable from other geological events
Notice how each of these are valid options. There is no logical or physical laws preventing option 1 through 3 from being true. But when PRO argues that we would definitely find evidence of their enviromental destruction, he has already assumed that only option 4 could be true. But option 1-3 are examples of advanced ancient civilisations whose technological progress are totally compatible with a clean geological record. But PRO just ignores those possibilities because they are the iceberg to the titanic that is his argument. This goes back to my initial criticism of his case. The silurian hypothesis does not assert the existence of any specific type of advanced civillisation, all it does is point out the possibility of some ancient civilisation having existed. PRO is introducing arbitrary limitations on what that civilisation could look like, all I am doing is pointing out that these are unwaranted. When you remove these unjustified assumptions, PRO's case crumbles to dust.

How to magically repair all the damage they caused?
First I will repeat that the type and magnitude of damage the civilisation would cause has not been properly established by PRO. He has no evidence that every possible type of  technological progress must incur a high toll on the enviroment. Humanity has walked on the past of hypercapitalism and consumerism, but there are many other ways to organize the economy and technological progress. However, if we assume that the damage has already been done, that is in now way the end of it. Technology that is able to clean up the enviroment is very plausible, and is already being developed and proven to work today. The process of reversing damage to the enviroment is firmly grounded in realistic scientific and technological principles, and cannot be brushed of as "magic" like PRO tries to do. But even if we 21st century humans could not conceive of non-magical ways to fix our footprint, that doesn't mean the ancient advanced civilisation many times older than ours would have the same limitations. Sufficiently advanced technology is indistinguishable from magic. 

What if they could not?
Going one step further, even if they were reckless and caused climate change and were somehow unable to reverse it, we would have an extremely hard time distinguishing this industrial global warming from what we know many natural catastrophes have caused. Furthermore, as my R1 sources explained,  all remnants of their technology would be pulled into the mantle. "Even if an industrialized alien society existed 200 million years ago and lasted for 100,000 years, 300 times longer than industrial humanity, it still might be easy to miss it in the geological record". [kurzgesagt].

I extend that PRO all of my arguments, and point out that PRO did not refute my sources that explain in detail why the geological record does not disprove the Silurian Hypothesis.

Conclusion:
PRO has not come anywhere near establishing the NEAR CERTAINTY that he absolutely needs. I have clearly demonstrated it not only a logical possibility, but also a physical and historical.
Round 3
Pro
#5
The Origin of Earth & Stages

It is common knowledge that Earth used to be a ball of molten rock in its earlier stages, too hot to sustain life. When Earth would eventually reach the cooling point with a temperature good enough to sustain life, the earliest organisms were bacteria. There weren't a variety of different species and the earliest traces of life fell under the category of Precambrian. During the Precambrian era, we had jellyfish and we had worms, but the lands were empty.

"Soft-bodied creatures like worms and jellyfish lived in the world's oceans, but the land remained barren."


It wasn't until after the Cambrian explosion that varieties of species would begin coming into existence, thus eventually giving birth to the diversity of life. But the phases in which this took place was too insignificant to conclude a species preceding humanity. We have fish as the first stage, and then eventually forming the first land-based animal. Mainly, amphibians. Reptiles and dinosaurs would eventually become prevalent, but the idea of an advanced civilization co-existing at this time is improbable and absurd.


Survival Technique & Resource Accessibility

The Earth back then had a huge rise of predatory creatures that were animalistic and primal that would have inevitably ensured the extinction of any species requiring technology for survival. The materials and resources required to address environmental issues, without having enough time to properly develop and acquire the knowledge would have taken more than 30,000 years of evolution which Con insists is possible, but seems to contradict what we currently know about scientific history. Which means the Silurian Hypothesis is neither valid, according to mine or his definition and seems to fall short of being either logical or a possibility.
Seeing as there are differing variations of the Silurian Hypothesis. Con needs to establish which model is the most likely and which time era, this hypothetical species could have realistically existed under certain circumstances because none of these periods suggest that the ability to acquire resources for technological advancement was possible.
Con
#6
We are talking about periods of hundreds of millions of years with scarce geological record. As stated before, an ancient civilisation from 200 million years ago could easily last 100.000 years without leaving identifiable evidence. PRO is completely wrong that I have to prove a specific time, species and place for an ancient civilisation. All I have to do is defend the existance of a prior civilisation being a logical possility, as in, not being self-contradictory. I have done more than that, to prove that it is also is a physical and historical possibility. Instead of adressing my defense he is bringing up totally irrelevant tangents and tries to constantly move the goalpost. He is both failing to fullfill and totally ignoring his self-assigned BoP that requires establishing ABSOLUTE CERTAINTY that a previous civilisation on earth is logically impossible.

I will give him another try to seriously up his game and make an argument that actually supports his BoP.
Round 4
Pro
#7
Thank you, Con.

I would like to use the first part of this round to clarify the resolution, and Con's misinterpretation of the BOP. I am not here to prove beyond absolute certainty that the Silurian Hypothesis did not happen because that is bogus and proving a negative is impossible. The description states "near-certainty," but even I admit that was a mistake wording things like that because it is subjective, but that does not mean absolute certainty. While Con undermines exactly what his responsibility is by deflecting his side of the burden, by using the definition of "logical possibility," as a justification.
Here is the problem that rises with it.:
The semantics should not be applied so literally when taking into account the BOP because words are sometimes too loosely defined and applying too many limitations for the argument actually derails the convo instead of getting it back on track because the subject is very clear.

The Resolution

I am arguing that the Silurian Hypothesis is not feasible, that is possible to do easily or conveniently. I am also required to support that the available evidence suggests that that the Silurian Hypothesis most likely did not happen. (This I did in Round 1 by showing a link to the scientific study and showing the citation where the founders of the hypothesis reached the conclusion, that it most likely didn't happen. Extending my quote from earlier as proof that this gets addressed.:

Frank and Schmidt come to the conclusion that another civilization may not have lived on Earth before humans.”
I proceed to give other justifications supporting this by namely pointing out that an advanced civilization would require the following.:
  • Engineering
  • Architecture
  • Clever exchange of resources
A level of sophistication in these three things is generally unattainable because of the amount of time it would take for a creature to evolve to acquire the ability of intelligence, including the amount of time it would take to upgrade to this level of critical thinking. The fact that the geological record shows creatures are primitive at this point, and they are still materializing from the first signs of life, this indicates a certain level of improbability to the claim that the Silurian Hypothesis is making.
Since we can only use the human species as the model for what standards an advanced civilization or intelligent species needs since another intelligent species like mankind has not been observed to exist, the time requirements of the evolutionary stages alone make the Silurian Hypothesis infeasible.

Extending my other argument about how some preservation of the geological record remaining intact in the form of traceable evidence is inevitable, given that the technology of an advanced civilization would not decay so easily, as the Silurian Hypothesis assumes that this intelligent species has developed a civilization capable of surviving through superior architectural and constructional fortitude.
The Con side of this subject means giving some form of justification for why we should consider the Silurian Hypothesis a logical possibility while also showing that the circumstances do allow for an advanced civilization to exist or form easily or conveniently, since the resolution deals in whether the Silurian Hypothesis is feasible or not feasible.
Without any justification, the Silurian Hypothesis has no explanation or reason to show why it is possible, and remains unsubstantiated speculation.

The Silurian Hypothesis Is Impractical

Proving professional authority in certain subject matter is tricky.
What we currently know is clay-fired pottery, porcelain, and glass are solid and steady, thus making decomposition or decay very unlikely. Detectable remnants of these things would have been discovered in sedimentary layers, including the abandoned resources and materials required for the advanced technology capable of sustaining an intelligent civilization at this time. Gaining access to these resources would have meant a lot of mining, and if such mining did occur, there would be proof of this mining happening all around the world.
Maintaining continental landscapes would be very simple, so this would be easy to identify in the paleo-soil. There are rock formations where you can physically observe the sedimentary structures that transformed into desiccation cracks and these are 300 million years old. Now if an advanced civilization existed, this would mean former shells of construction terrains also being identifiable. Going back into detail about the high use of energy. We have Climate Change & Global Warming as physical proof that mankind exists, so an artificial tampering with energy would significantly change the way these locations on the planet works and these environments would work so incredibly differently from natural geological incidences and chemical patterns.
So this, once again, highlights the unlikelihood of an advanced civilization existing.

To illustrate the impossibility, we need to treat the Silurian Hypothesis as a creative literary concept for sci-fi plotlines rather than a practical idea suitable for scientific application for another idea that is commonly overlooked.

  • Regardless of how fragile and degradable an intelligent species's resources and architectural technology are, preceding variations of their species used materials such as bronze, stone, and wood. Those are findable.


The subject of Evolution & Natural Selection

The fact that humans evolved the way they did is by chance and an extremely random process. It is not easy to acquire the capacity for critical thinking and awareness on the level such as we do, this is a extremely lucky occurrence. Arguing that a similar species before mankind that possesses these same specific attributes being feasible is arguing another unrealistic concept, that it is easy for organisms to evolve to this level and certain brand of intelligence. But if that is possible, then the likelihood of another intelligent species co-existing with humanity around the same time without having dealt with extinction is also likely.
But the fact that science proves that other apes or other forms of life will not transform into a humanlike species suggests that humanity's strongest attributes are a rarer and unattainable quality, the result of a very specific combination of selection pressures and genetic mutations over millions of years. That data does also imply that a similar combination will ever happen again. Which also reinforces the idea that it didn't happen before mankind either. https://www.pbs.org/wgbh/evolution/library/faq/cat03.html#:~:text=It%20is%20possible%20that%20in,we%20know%20as%20apes%20today.

In conclusion, the Silurian Hypothesis probably did not happen.
Con
#8


It is unlikely
Of course it is unlikely, at least as far as we know. Nobody has ever said otherwise.

But it's possible
There has been made no argument as to why it should be impossible. Unlikely things are not impossible, no matter how many zeroes you find in the odds. But PRO has not even proven the odds to be that bad. His PBS source says that it is unlikely that current apes will evolve into humans, which makes sense, since they are not our ancestors, but our cousins. His sources literally says "Humans did not evolve from any of the species we know as apes today. At some point 5 to 8 million years ago, the common ancestor of humans and modern apes diverged to form the two separate lineages we know today. The species at the end of these lineages are a result of a very specific combination of selection pressures and genetic mutations over millions of years. This same combination is highly unlikely to occur ever again." So it is unlikely that apes will evolve into humans specifically, just like it is unlikely that tigers will evolve into lions. That does not mean that our ancestors evolving into us was unlikely, nor that high intelligence sufficient for civilisation is impossible to evolve multiple times over hundreds of millions of years. And once you have that intelligence, you can begin doing engineering and all that good stuff. Humans did not have any evolutionary benefit in any of those 6 million years from our ability to to do math and build rockets increasing, but evolution still selected higher intellect individuals. Things keep evolving into crabs, an extremely specific body structure, so nothing suggests intelligence is so inconceivably special as to be irreproducible. So it would be fallacious to say that it could not possibly happen twice.

Frank and Schmidt come to the conclusion that another civilization may not have lived on Earth before humans.”
Wrong. They only concluded that the evidence was not sufficient to affirm the hypothesis. They never said they had falsified the hypothesis. But even if they did, they would have been wrong.

Regardless of how fragile and degradable resources and architectural technology are, preceding variations of their species used materials such as bronze, stone, and wood. Those are findable.
Not necesesarily. Not after 100 million years they aren't. "Over hundreds of millions of years these signatures may become very subtle and get overlooked or interpreted as natural. Even if an industrialized alien society existed 200 million years ago and lasted for 100,000 years, 300 times longer than industrial humanity, it still might be easy to miss it in the geological record.[kurzesagt].


The Silurian hypothesis does not and have never claimed that a previous civilisation is "likely" or "expected", only that it is a POSSIBILITY. Even PRO acknowledges that distinction.

"The "Silurian Hypothesis" is a speculative concept in astrobiology that suggests the possibility of an ancient, technologically advanced civilization [Description that PRO wrote].
 
THBT: The Silurian Hypothesis is not feasible. [Resolution that PRO wrote].

Meaning of feasible according to English dictionaries:
  • Merriam-Webster: capable of being done or carried out
  • Cambrigde: Able to be made, done, or achieved.
  • Britannica: possible to do
Basically, the word feasible in english is a synonym of possibility, or at least the closest you can get. Something does not need to be "easy or convenient" to be feasible.

Con's burden will be to prove that it is a logical possibility. [Description that PRO wrote himself].
PRO has not even denied that I have proved that the silurian hypothesis is:
  1. A logical possibility
  2. A physical possibility 
  3. A historical possibility
I have gone above and beyond what was needed of me to fulfill my BoP, while PRO has failed to scratch his BoP. But now PRO has attempted to move the goalpost that he himself set.

I am not here to prove beyond absolute certainty that the Silurian Hypothesis did not happen because that is bogus and proving a negative is impossible. [PRO's R4]
 
Debate description that PRO himself wrote: If Con's justification is convincing enough to successfully refute Pro's near certainty that it didn't happen, then Con wins.
PRO has attempted a bait and switch. I did not accept a debate where I needed to prove that the silurian hypothesis probably happened. I accepted one where I had to disprove the extraordinary claim that the silurian hypothesis is not feasible, as in not a logical possibility, and that we can have near certainty that it did not happen. I did not write the resolution or the description, I am not the one that assigned PRO an impossible BoP, that was his doing. Now PRO has conceded verbatim that the resolution is "bogus" and "impossible to prove", so I win, end of story.





Round 5
Pro
#9
Skimming the description, it becomes apparent that I am neither changing or altering anything, but rephrasing & clarifying the resolution and the burden. The definition in the description that I set in this debate, which Con has agreed to are.:

  • Feasible- Possible to do easily or conveniently.
    Probably- almost certainly; as far as one knows or can tell.
    Possibility- a thing that may happen or be the case.
    Logical- natural or sensible given the circumstances.
With this in mind, it is clear that Con has remained inconsistent with the resolution by attempting to add new rules to mitigate his burden. I am not here to prove an absolute, I am arguing that the Silurian Hypothesis probably did not happen. Con likewise needed to argue that the Silurian Hypothesis could have happened and that the circumstances made it easy.

Rebuttals

It is unlikely
Of course it is unlikely, at least as far as we know. Nobody has ever said otherwise.
Concession. Extend all arguments.

But it's possible
There has been made no argument as to why it should be impossible. Unlikely things are not impossible, no matter how many zeroes you find in the odds. But PRO has not even proven the odds to be that bad. His PBS source says that it is unlikely that current apes will evolve into humans, which makes sense, since they are not our ancestors, but our cousins. His sources literally says "Humans did not evolve from any of the species we know as apes today. At some point 5 to 8 million years ago, the common ancestor of humans and modern apes diverged to form the two separate lineages we know today. The species at the end of these lineages are a result of a very specific combination of selection pressures and genetic mutations over millions of years. This same combination is highly unlikely to occur ever again." So it is unlikely that apes will evolve into humans specifically, just like it is unlikely that tigers will evolve into lions. That does not mean that our ancestors evolving into us was unlikely, nor that high intelligence sufficient for civilisation is impossible to evolve multiple times over hundreds of millions of years. And once you have that intelligence, you can begin doing engineering and all that good stuff. Humans did not have any evolutionary benefit in any of those 6 million years from our ability to to do math and build rockets increasing, but evolution still selected higher intellect individuals. Things keep evolving into crabs, an extremely specific body structure, so nothing suggests intelligence is so inconceivably special as to be irreproducible. So it would be fallacious to say that it could not possibly happen twice.
It's possible that unicorns inhabited mountains, shat crayons, and communicated in their own language. Doesn't make it logical.
By conceding that the Silurian Hypothesis is unlikely, Con acknowledges that it is not a logical possibility.

This is also a strawman argument. My argument isn't literally saying that apes can evolve into humans, my point is quite clearly that the intelligence required for a technology-based species is too advanced to be replicated again by nature. It was a very specific type of intelligence that is unattainable due to its rarity, complexity, circumstances, and amount of time it requires for organisms to potentially evolve to that level. While I cannot say with absolute certainty that it couldn't possibly happen, I do make the case that it is extremely unlikely.
Crabs are an entirely water-based species, with natural circumstances making a certain build more likely for survival with others dying off, and their high production rate makes it more likely for crabs to evolve.

Wrong. They only concluded that the evidence was not sufficient to affirm the hypothesis. They never said they had falsified the hypothesis. But even if they did, they would have been wrong.
According to the article from the quote I cited from, while Frank and Schmidt could not affirm the accuracy of the hypothesis, they did decide that the hypothesis was most likely not true.

Not necesesarily. Not after 100 million years they aren't. "Over hundreds of millions of years these signatures may become very subtle and get overlooked or interpreted as natural. Even if an industrialized alien society existed 200 million years ago and lasted for 100,000 years, 300 times longer than industrial humanity, it still might be easy to miss it in the geological record.[kurzesagt].
Extend argument.:

"What we currently know is clay-fired pottery, porcelain, and glass are solid and steady, thus making decomposition or decay very unlikely. Detectable remnants of these things would have been discovered in sedimentary layers, including the abandoned resources and materials required for the advanced technology capable of sustaining an intelligent civilization at this time. Gaining access to these resources would have meant a lot of mining, and if such mining did occur, there would be proof of this mining happening all around the world.
Maintaining continental landscapes would be very simple, so this would be easy to identify in the paleo-soil. There are rock formations where you can physically observe the sedimentary structures that transformed into desiccation cracks and these are 300 million years old. Now if an advanced civilization existed, this would mean former shells of construction terrains also being identifiable. Going back into detail about the high use of energy. We have Climate Change & Global Warming as physical proof that mankind exists, so an artificial tampering with energy would significantly change the way these locations on the planet works and these environments would work so incredibly differently from natural geological incidences and chemical patterns.
So this, once again, highlights the unlikelihood of an advanced civilization existing."

Meaning of feasible according to English dictionaries:
  • Merriam-Webster: capable of being done or carried out
  • Cambrigde: Able to be made, done, or achieved.
  • Britannica: possible to do
Basically, the word feasible in english is a synonym of possibility, or at least the closest you can get. Something does not need to be "easy or convenient" to be feasible.

Con has already agreed to my definition from Oxford Languages.:
Feasible- Possible to do easily or conveniently.

Especially, since the second definition from Oxford Languages dictionary applies to this debate, just as much as my definition in the description.
Feasible- Likely; probable.

PRO has attempted a bait and switch. I did not accept a debate where I needed to prove that the silurian hypothesis probably happened. I accepted one where I had to disprove the extraordinary claim that the silurian hypothesis is not feasible, as in not a logical possibility, and that we can have near certainty that it did not happen. I did not write the resolution or the description, I am not the one that assigned PRO an impossible BoP, that was his doing. Now PRO has conceded verbatim that the resolution is "bogus" and "impossible to prove", so I win, end of story.
Con has attempted to change in the definitions in the description and add ones that don't quite apply to the scope of our discussion.
What Con needed to do was prove that the Silurian Hypothesis was a sensible explanation. By agreeing with me that the Silurian Hypothesis is unlikely, Con has not only agreed with my side, but agrees that the Silurian Hypothesis is not logical.

Possibility- a thing that may happen or be the case.
Logical- natural or sensible given the circumstances.

These are both of the definitions I left in the description. The definition I gave in the preceding rounds in-fact was the one in the description, but with the two terms compounded.: Logical Possibility - The chance that something happened or may have happened based on reasoning or good judgment. (Cambridge Dictionary.)

Since Con concedes that "It is unlikely Of course it is unlikely, at least as far as we know."
Then Pro wins, end of story.


                   https://www.nps.gov/articles/000/the-precambrian.htm
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