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Scientific Evidence Strongly Supports the Theory of Evolution by Common Descent

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Voting Style: Open Point System: 7 Point
Started: 1/1/2013 Category: Science
Updated: 5 years ago Status: Post Voting Period
Viewed: 3,330 times Debate No: 28629
Debate Rounds (5)
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Resolved: Scientific evidence strongly supports the Theory of Evolution by common descent over the "theory" of Creationism.


No semantics please. These are the definitions that will be used throughout this debate.

Theory - A well supported, conceptual framework that encompasses a large body of scientific facts, inferences, data, and observations and explains them in a coherent way (Fairbans, 2012)

Evolution - Genetic changes over many generations ultimately result in the emergence of new and different species from a single ancestral species”. (Fairbanks, 2012)

Scientific evidence - "Scientific theories are validated by empirical testing against physical observations. Theories are not judged simply by their logical compatibility with the available data. Independent empirical testability is the hallmark of science—in science, an explanation must not only be compatible with the observed data, it must also be testable. By "testable" we mean that the hypothesis makes predictions about what observable evidence would be consistent and what would be incompatible with the hypothesis. Simple compatibility, in itself, is insufficient as scientific evidence, because all physical observations are consistent with an infinite number of unscientific conjectures. Furthermore, a scientific explanation must make risky predictions— the predictions should be necessary if the theory is correct, and few other theories should make the same necessary predictions." (Douglas Theobald, 2012)

The logic of such is seen in this syllogism:

Premise 1: Theory T predicts observation O.
Premise 2: Observation O is observed
Conclusion: Therefore, theory T is probably true.

or conversely:

Premise 1: Theory T predicts observation O.
Premise 2: Observation O is NOT observed
Conclusion: Therefore, theory T is probably false.

Supports - The supporting evidence (see above) is consistent with the Theory of Evolution and makes evolution more probable than not.

Creationism - The view that God created life in its present form on earth within the passed 10,000 years.



(1) Acceptance;

(2) Opening statements;
(3) Rebuttals;
(4) Rebuttals/Closing


(1) Debater must have typing experience, internet access, and should have sufficent knowledge of the Theory of Evolution.

(2) Place your arguments and sources inside the debate
(3) Structure the debate in a readable, coherent fashion.
(4) No semantics,or trolling.
(5) Burden of proof is shared. My burden is to prove that scientific evidence supports the ToE and your job is to show that it doesn't.

Additional information:

(1) This is not a debate on God's existence;
(2) This is not a debate on whether the Bible is God's word;
(3) This is not a debate on the age of the earth.

Good luck and thank you for this debate.


Douglas Theobald, P. (2012, April 16). 29+ Evidences for Macroevolution, 2.89. Retrieved July 18, 2012, from Talk.Origin Archive:

Fairbanks, Daniel J. Evolving: The Human Effect and Why it Matters. Ahmester: Prometheus Books, 2012. Print.



I accept. This debate will be about the scientific evidence supporting common descent in terms of evolutionary changes incompatible with creationism.
Debate Round No. 1


Thank you, Muted, for accepting this debate. I look forward to an interesting discussion with you on the Theory of Evolution.

Pro 1: Evidence from Our Bodies

Our bodies have yielded much evidence as to how life evolved on earth, as Theodosius Dobzhansky once said, “Nothing in Biology Makes Sense Except in the Light of Evolution.” These words reign true throughout the study of biology and throughout our bodies.

Vestigial Structures

Definition: “A vestigial character is reduced and rudimentary compared to the same complex structure in other organisms. Vestigial characters can certainly have functions; non-functionality is not a requirement.”[1]

P1: If evolution by common descent were true, we should see such instances of vestigial structures.
P2: We see many examples of these structures.
C: Therefore, common descent most likely occurred.

There are many examples of rudimentary and nonfunctional vestigial characters carried by organisms, and they can help uncover new information in terms of evolutionary history. For example, there are many flightless beetles (i.e., weevils from the genus Lucanidae, which retain perfectly form wings underneath fused wing covers (image 1-1) [2] and even blind, cave dwelling fish and salamanders with eyelids – albeit no eyes (figure 1-2)![3]

Figure 1-1

Figure 2-1: This Typhlotriton spelaeus is completely blind, yet retains the eyelid and eyes, though they are fused shut.


There are many vestigial structures than can appear in multiple species. These vestigial structures yield valuable evidence for the Theory of Evolution.


Definition: The reappearance of a lost character specific to a remote evolutionary ancestor and not observed in the parents or recent ancestors of the organism displaying the atavistic character. These are different from vestigial structures as vestigial structures are found in all or most species whereas atavisms are found in relatively few and rarely show up.[4]

P1: If evolution by common descent were true, atavisms should appear.
P2: Atavisms do appear.
C: Therefore, evolution by common descent most likely occurred.

Atavisms also offer powerful and concise evidence for evolution. Atavisms can be quite strange such as a human newborn with a full tail (figure 1-3)[5]

This is an x-ray of a 6 year old girl's atavistic tail.

Figure 3-1: This is an x-ray of a 6 year old girl.[6]

Dolphins have also been known to have been born with extra sets of hind-limbs, most likely originally used for land. See figure 4-1.
On October 28, 2006, Japanese fishermen captured a four-finned dolphin off the coast of western Japan, and donated the whale to the Taiji Whaling Museum where it is currently being studied. This bottlenose dolphin has an extra set of hindlimbs, two well-formed palm-sized flippers that move and flap like the normal fore-flippers (see Figure 2.2.2). As with other atavistic structures, these limbs are likely the result of a rare mutation that allows an underlying, yet cryptic, developmental pathway

Figure 4-1: The hind-flippers of a bottlenose dolphin found in Japanese coastal waters. Yellow arrows indicate the location of a well-formed atavistic set of hind limbs.


Atavisms are very strange should we expect creation to occur. Why would God give a human a tail, or a dolphin with hind limbs? This makes no sense except in the light of evolution.

Pro 2: Evidence from the Genome

Perhaps the most powerful evidence of common descent comes not from our bodies – but from our DNA and from the human genome. Our genome is full of abundant evidence for evolution.


Definition: A segment of DNA resembling a gene but lacking a genetic function [7] in other words, it is a segment of DNA that has been disabled.

P1: If evolution by common descent occurred, pseudogenes should be observed.
P2: There are many such cases of pseudogenes.
C: Therefore, evolution most likely occurred.

Malaria is one of the most horrific human diseases. However, at one point in our evolutionary history, humans enjoyed immunity to malaria. What happened for humans to gain and lose resistance to malaria?

Malaria is caused by a microorganism known as Plasmodium falciparum. It cannot be transmitted from person to person but must be carried via a mosquitoes and acquired and transmitted when a mosquito bites a person.

Chimpanzees suffer from a less severe form of malaria caused by a microorganism called Plasmodium reichenowi. What happened is the following: The human parasite evolved from the chimp parasite by jumping hosts from humans to chimpanzees.

Plasmodium reichenowi recognizes a substance on a gene called CMAH. Our genome carries this gene and we have it in the same strand of DNA as chimpanzees do. However, the only difference is it is disabled – a pseudogene if you will. No-one has the original non-mutated version.

The mutation that disabled the CMAH gene had a distinct advantage of those that did not – they became resistant to malaria.[8]

So, what happened? Why did we lose our resistance to malaria? The answer lies in the evolution of malaria itself. Mutations in a gene called EBA-175 allowed those parasites that carried the same mutation to recognize another substance which is abundant on human red blood cells about five to ten thousand years ago. The results: Plasmodium falciparum evolved as a new species. We are highly susceptible to this new form of malaria and the new version of malaria is much worse than the old one.[9]

Pro 3: Evolution in Action

Observed Cases of Speciation

If evolution by common descent is true, we should be able to observe evolution. We have observed speciation many times thus irrefutably confirming the fact of evolution. Moreover, there have been cases where the documentation of evolution is overwhelmingly strong, we can trace the origin of specific diseases and development of entirely new species.

P1: If evolution is true, we should observe speciation.
P2: We have observed speciation.
C: Therefore, evolution is most likely true.

"Three species of wildflowers called goatsbeards were introduced to the United States from Europe shortly after the turn of the century. Within a few decades their populations expanded and began to encounter one another in the American West. Whenever mixed populations occurred, the specied interbred (hybridizing) producing sterile hybrid offspring. Suddenly, in the late forties two new species of goatsbeard appeared near Pullman, Washington. Although the new species were similar in appearance to the hybrids, they produced fertile offspring. The evolutionary process had created a separate species that could reproduce but not mate with the goatsbeard plants from which it had evolved."[10]

There are many other cases of this; however with space running out I will use this one example. This is so powerful that creationists themselves have even admitted that speciation has occurred on Earth. As CMI admitted, “new species have been observed to form”[11]


The Theory of Evolution is powerful – it has made numerous predictions that have been confirmed and more evidence is uncovered every day. If I had more room (and I’ll expand in the next round), I would show how we can actually make our knowledge of evolution relevant in our lives.

Onto con.

[2] Coyne, J. “Why Evolution is True.”

[3] Ibid.

[4] Fairbanks, D. “Evolving: The Human Effect and why it Matters.”

[5] Humans have been known to have been born with fully functional tails – with even muscles to voluntarily move the tail. See ibid for more information.

[8] Neanderthals apparently had this same CMAH pseudogene meaning that the disabling mutation occurred before the splitting of the two lineages

[9] Fairbanks, D. “Evolving.”



Firstly, I would like to thank DoubtingDave for beginning this debate. As I have a BoP, I will not refute the Pro argument now. Instead, I will present arguments of mine own. I will assume that everyone reading and participating in this debate is familiar with creationism. Like I said when accepting, Pro must show that common descent has occurred that contradicts creationism. This, in my opinion, he has not done. I will expand on this in the next round. Pro has committed several fallacies which I will point out now as I wish them not to be repeated. This will not be considered a rebuttal. (Just because I cite something, does not mean I agree absolutely with it. This includes creationist sources.)

1. Creationists deny speciation. False. Creationists deny evolution, and speciation in terms of evolutionary changes contrary to the very old creationist teachings. Speciation, in terms of limiting genetic variety and sorting to prevent reproductive interchanges, is very much encouraged. As such, creationists do accept a form of evolution. It is just not called evolution.

2. Affirming the consequent. This perhaps is his most glaring and most oft repeated fallacy. Pro must show that the other alternatives fails as an explanation before announcing the victory of one particular interpretation.

C1: Genetic Degradation

The genome is known to be highly degradational. In fact, the vast majority of mutations is known to be degradational. Nachman has shown that [1:R4:4: (Link fail. Here:] mutations, although there be a higher number of beneficial mutations than bad, is still overwhelmingly degradational.

Even without accounting for noise, most degradational mutations cannot be selected against. This is because the degradational effect of each single nucleotide is so small as to be almost negligible. This is much like small single letter changes in the above paragraph. Individually, they do not much degrade the information I am presenting. Combined, however, their effects is devastating. So much so that evolutionary geneticist researcher has estimated just from mutation and recombination rates in the genome that humans would die out in the next 20 million years (Starting 2006) [1:R2:8].

If one were to consider only the coding regions of the DNA, including recombination during reproduction and excluding regulatory DNA regions, the time to extinction for humans rapidly approaches a vanishingly small period.

This factual evidence forces us to consider the only two logically possible conclusions.

I. There is a retarding factor on this degradation. This would rescue evolution.

There are many major problems with this. Firstly, there is no experimental evidence. This is patently obvious to anyone. The second major problem is that all hypothetical situations involve unrealistic parameters that are not in keeping with the facts.

II. Humans have not actually been around for so long. This would fall right into the ballpark of creationism. I will leave it to Pro to discuss the problems. Needless to say, it is a much more plausible answer which is much more in line with the facts.

With that, I will move on to another argument.

C2: Fast Speciation is in line with creationist predictions

This is such an obvious fact. “[A]ll the modern varieties of land vertebrates must have descended from comparatively few animals that disembarked from the ark only around 4,500 years ago.” [2] This is a simple statement of fact. As such, we should expect to see fast speciation if creation is correct. Indeed we do! I don’t even need to give an example. Pro has already given one!

As can be seen, some interpretations of evolution do not collide with “opposing theories” such as creationism. However, some interpretations do. As a tie-in to my previous argument, genetic degradation actually gives rise to new species because of the well known fact that speciation is a specialization event. That is, the genetic material becomes less and less diverse. This even becomes a problem sometimes. For example, some fruit flies have become so specialized that an increase in global temperature might cause them to go extinct [3].

For evolution and creationism to become incompatible, and as such allow for this particular debate, Pro must show that the change due to speciation actually leads to greater genetic diversity leading to the addition of unique information that can lead to evolutionary common descent, as opposed to creationary common descent. Not new, unique.

With that, I will stop. I will add more arguments, if that is allowed, in the next round. Right now, I’m going out of space.

1. (Whenever I cite this debate, I will cite it as [1:Rn:x], where n=round number, and x=source number, throghout this debate if needs be. Hence, I will in future not have a [1])

2. (J Sarfati, Refuting Evolution 2: Chapter 4)


Debate Round No. 2


Thank you, Muted, for accepting this debate and your swift opening statements. I apologize for the delay for my reply.

My opponent called me out on several fallacies that I wish to reply to. First, you do not have the BoP – thne BoP is shared between us. As I was typing the debate opening, I forgot to edit the resolution – so thus the confusion. Please forgive me. We will continue to debate as is from this point on.

In the opening round, I defined creationism as the view that God created life in its present form within the past 10,000 years. My opponent has not challenged that definition, so if I am wrong, please correct me.

Con 1: Fallacies Pointed Out

  1. Creationists deny speciation: I never stated that creationists deny speciation – in fact, I cited some that do. I believe that speciation is incompatible with the view that life was created in its present form as it would force the view that evolution has changed species dramatically. Some creationists accept this view point, other’s do not. [1]
  2. Affirming the Consequence: I am well aware of this fallacy. However, I do not address alternative “theories” in this debate as we are debating if the evidence supports evolution or creation – there can be an infinite number of “alternate theories”, so I stick with two for the purpose of this debate. Nowhere did I say that either evolution or creation is true.

Con 2: Genetic Degradation

I believe that my opponent is attempting to argue that the vast majority of mutations are harmful mutations – this is false, the vast majority of mutations are neutral (i.e., not having any noticeable effect on the organism) [2]

The study you have cited is quite long, can you please bring me a quotation from that study that shows the point that most (or all) mutations are harmful? I have been unable to find neither anywhere in that article, nor elsewhere in atheist/evolution circles the claim that most mutations are harmful.

Con 3: Speciation is in Line with Creationism

See the refutation to the fallacies that you pointed out. This depends on what type of creationist you are.

Next, I would like to take time to address the point brought up by my opponent: Creationism and Evolutionism are incompatible.(Note, I specifically address the view that life was created in its present form within the last 10,000 years; presumably by the Christian God, but not necessarily).

Finally, my opponent set me up for this challenge, “For evolution and creationism to become incompatible…Pro [sick] must show that the change due to speciation actually leads to greater genetic diversity leading to the addition of unique information that can lead to evolutionary common descent.”

For this, I would to respond in the next round as I am running out of space and time.

Pro 1: The Age of the Creation

By definition of creationism in round 1, creationism took place within the past 10,000 years. This is absolutely incompatible with the age of the earth and the age of creation (note, it is possible for both the age of the origin of life, which creationism puts in the last 10,000 years and the age of the earth).

We can measure the rate of evolution to determine how fast evolution took and how old the earth needs to be in order for it to work. We measure these in units of Darwin. The video to the right explains much more in depth, but here is a brief summary of the video:

A “Darwin” is a unit to measure evolutionary rates; one Darwin is a change in the charactors by a factor of e in one million years.

Simply put: Creationism is incompatible with evolution because the age of life is too short for evolution to have occurred. “Young earth creationism is simply incompatible with evolution.”[3]

Resolution affirmed.

[1] For example, in Dr. Henry Morris’ essay, The Vanishing Case for Evolution, he argues that no new specie have ever been observed. Morris, Henry M., 1986. The vanishing case for evolution. Impact 156 (Jun.).

[2] Fairbanks, D. 2012. Evolving: The Human Effect and Why on it Matters.

[3] Ibid.



I'm sorry. I have to forfeit this debate for three reasons.

1. I do not support the form of creationism as defined by Pro. I assumed it was something different. My apologies.

2. I do not have the time to write out a full rebuttal to Pro, even though I have a rough draft of how to refute Pro's opening arguments as well as a very, IMHO, impotent rebuttal to my opening arguments.

3. My phone went broke and my computer is not working well.

With these in mind, I apologize for wasting everyone's time. I would love to re-start the debate again in about three weeks time with the definition of creationism being different. I would put the definition of creation as, "The view that God created life in kinds, or baramin, on Earth 6000 years ago, which has since been degenerating into smaller species."

For more on baramin, which has been defined, search the CMI website search-bar. I will not here define baramin.

My apologies. Vote Pro.
Debate Round No. 3


Its fine. I wish you well and sorry for the semantics. I probably should have allowed you to define creationism instead of me using my standard definition that I normally use in debates. Thank you and Happy New Year.


my apologies everyone. If it is possible, could Airmax delete this debate? (with both debaters consent?)
Debate Round No. 4


I concede to have the debate deleted.
Debate Round No. 5
3 comments have been posted on this debate. Showing 1 through 3 records.
Posted by 16kadams 5 years ago
Pro should win this because he is defending a valid theory but he totally misrepresented one of his sources.
Posted by DoubtingDave 5 years ago
Posted by errya 5 years ago
Can I do this at a later time?
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