The Instigator
Pro (for)
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The Contender
Con (against)
7 Points

Macroevolution is a theory, not a scientific fact.

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Voting Style: Open Point System: 7 Point
Started: 9/4/2017 Category: Science
Updated: 10 months ago Status: Post Voting Period
Viewed: 462 times Debate No: 103798
Debate Rounds (5)
Comments (4)
Votes (1)




Macroevolution = belief that animals from different vertebrate groups (mammals, birds, reptiles, fish, and amphibians) had a common ancestor

NOT evolution within a species


Just to be clear I will use the following definitions for the words in the debate title.
theory = hypothesis (according to
scientific fact = theory (according to

Let the debate begin!
Debate Round No. 1


hypothesis: "a proposition, or set of propositions, set forth as an explanation for the occurrence of some specified group of phenomena, either asserted merely as a provisional conjecture to guide investigation (working hypothesis) or accepted as highly probable in the light of established facts."

We use macroevolution as an explanation for the diversity of life. We cannot observe macroevolution in action, but we can observe microevolution, evolution on a much smaller scale.

Therefore, while macroevolution is a hypothesis, it is far from confirmed.


I guess you will use the word hypothesis then? Agreed, the other word then is "scientifi fact" ok?

Well, you say that microevolution (evolution on a much smaller scale) can be observed, well that _is_ macroevolution (belief that animals from different vertebrate groups had a common ancestor) which is a subset of evolution (belief that all life had a common ancestor) on a much smaller scale.

So if we can observe smaller scale macroevolution, and expand it to a bigger scale, we get macroevolution.
Debate Round No. 2


We can observe microevolution, certainly. If we use microevolution to assume macroevolution, that might be extrapolating the data a bit. The more you assume, the more uncertain the idea becomes.

For example, is 100 degrees Fahrenheit hot? It probably is, but it depends on where you are from. What about 99? 98? The more you decrease the temperature, the shakier the idea is until we reach 0 degrees Fahrenheit, which is pretty cold.


Yeah extrapolating data gets shakier when you go long distances. The thing is that nobody went too far.

You can pick any animal or living thing and find species that are very close, either by morphology or molecular biology.
Debate Round No. 3


I would like you to explain your point fully.


Pick any animal. I"ll pick whales for you. You have a continuum around them of similar animals, by both morphology and molecular biology.
By looking at the diagram in you can go from whales to hippos in some 20 million years.
You can do that with many living extinct or living animals. Of course also for bacteria and fungi and plants and viruses. You may find some isolated beings here and there, but it"s mostly a continuous flow from one species to the other.
Debate Round No. 4


Okay, so I guess it is possible that macroevolution is true, but that does not mean that it is true.

Take the Sun and planets rotating around the Earth. It was an okay explanation, but not true.

This is why I said it was a theory, not a fact. It might be a good explanation, but that does not mean that it is necessarily true.

Overall, you showed that macroevolution was feasible.


It's hard to debate while not agreeing on the definition of ambiguous words, I will use the terms defined in the 1st round.
I will also interpret your word theory in the sense of hypothesis and your word fact for the scientific meaning of theory.
A good explanation, while not necessarily true, is called a theory (fact in your terms) when it has a great (but not necessarily absolute) explanatory and predictive power.
We may never know with absolute certainty if macroevolution is 100% true, still it is a theory (fact in your terms) because it is consistently used to make prediction about biological findings.
The planets rotating around the Earth stopped being a theory when it failed to explain the phases of Venus. The new theory, heliocentrism, can account for Venus' phases, and thus geocentrism is now a discarded hypothesis.
If tomorrow we find evindence of more than one ancestor, or we get findings that, after torough examination, contradict macroevolution, it will cease to be a theory (or at least it would become a controversial or weak theory).
Debate Round No. 5
4 comments have been posted on this debate. Showing 1 through 4 records.
Posted by KostasT.1526 8 months ago
Con's arguments were kind of a letdown. Had he tried a bit more, he could have easily won the debate, in my point of view.
Also, please use the term "theory" correctly. It is not that difficult, and it helps avoiding the "evolution is just a theory" misinterpretation.
Posted by Spud 10 months ago
The title of this debate is making me cringe inside. Mate, if you don't even know that a scientific theory differs from the "theory" that we use in everyday usage, you need to pay more attention in science class.
Posted by Surgeon 10 months ago
Equivocation fallacy on the word "theory" for a change! Please look up the proper definition of a scientific theory, as compared to the common garden use of theory by the GP meaning an "educated guess". They do not mean the same thing.

Also note the macro evolution is merely micro evolution on a larger timescale, rather like seeing evolutionary branching in a strobe effect as opposed to every single transition. If you accept micro evolution, you have to accept macro evolution. Any attempt to accept one and deny the other is mendacity, pure and simple.
Posted by byaka2013 10 months ago
noun, Biology.
major evolutionary transition from one type of organism to another occurring at the level of the species and higher taxa.

Change the definition to that and I will debate.
1 votes has been placed for this debate.
Vote Placed by BryanMullinsNOCHRISTMAS2 7 months ago
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Total points awarded:07 
Reasons for voting decision: Con by default!