Intelligent Design Isn’t Science

The topic tonight is “Intelligent design is the best explanation for the diversity of life.” We’re going to tackle this statement in a number of ways, none of which are going to be favorable to intelligent design.

What Is An Explanation?

 First, Science is defined as “the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment. Basically, Science is used to describe our reality the best that we can. This description of reality allows us to explain phenomena as well as predict them. The only way for something to be an explanation for a particular phenomenon is for it to not only be able to describe it but also give us accurate predictions about that phenomenon. That being the case any explanation that hopes to be the best explanation must also be a scientific explanation. If it’s not a scientific explanation, then it cannot describe the reality we live in. So, what is the intelligent design hypothesis, if we can even call it that? To quote the Discovery Institute “The theory of intelligent design holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.” So, is this a scientific explanation?

Intelligent Design Isn’t Science

No, certainly not. In science, explanations for phenomena must include all or most of the current data on a subject and must be able to make accurate predictions about future data. Intelligent design doesn’t make sense of any naturalistic phenomena. It appeals to a causative agent that can neither be observed nor tested. We can’t make predictions about it. In science, natural processes are mechanistic; we know how they work now, and that allows us to understand how they’ll work in the future as well as how they have worked in the past. If these processes did not work in this fashion then cell phones, computers, motor vehicles, ships, and just about everything else wouldn’t work. Our world would look very different if this simple principle didn’t hold true.

Irreducible Complexity?

Where are the experiments and observations of an intelligent designer meddling with natural processes? When intelligent designers propose that a designer crafted the bacterial flagellum, How can we test that? Intelligent design proponents claim that irreducible complexity is evidence of design; however, there are no examples of irreducible complexity that have withstood scrutiny from researchers.

Bacterial Flagellum

You can’t say the bacterial flagellum is irreducibly complex for multiple reasons. We have been able to delete or mutate proteins from these flagella and it only affected how much motility they had. It did not remove the flagellum at all. These bacterial flagella most likely evolved through the duplication of a single gene. This is one example of how irreducible complexity fails to provide any kind of explanation or prediction. The eye isn’t irreducibly complex either. We can trace the development of the eye because most if not all versions of the eye currently occur in nature.

Intelligent Design Is Supernatural

But, even if we didn’t have an explanation for how some biological structure came to be, it would be a monumental jump in logic to say a designer is the only explanation. It only means our current explanation is unable to account for the structure. My failing to account for something doesn’t mean my opponent is right by default. Any natural explanation that we can posit will be so much more likely than a supernatural explanation, which is what Intelligent Design is at its core. It’s a supernatural answer for natural questions.

Giant And Red Pandas

Let’s see if Intelligent design can explain the Giant and Red Panda’s thumb. It’s a 6th pseudo-digit on the hands of the pandas that is evidently a modified version of a bone in the hand: the radial sesamoid. How can the hypothesis of intelligent design explain this feature?

It can say “the designer wanted Pandas to have the 6th digit, and so it created them in this way.” If the designer is really creating organisms from scratch, it has the ability to completely overhaul the design of the Panda’s hand in order to produce the desired morphology. If that’s the case, why does it appear as though the designer *modified* the radial sesamoid to do it? Why does the designer appear to be so keen on modifying pre-existing structures, as would be expected according to a process like evolution, rather than creating new ones from scratch? You could also say that the Designer just copied the blueprint from one organism and changed it a little bit. But that is just an illogical special pleading argument. There are genetic and physiological similarities that connect different species of animals in an evolutionary chain and that removes the need for any kind of Designer.

Evolution would predict that the Giant and Red Pandas would have a common ancestor. Through adaptation to their environment, both Giant and Red Pandas would develop the pseudo-digit to help them survive in some way. That’s exactly what we find in reality. The Giant and Red Pandas have a common ancestor 40M years ago. Due to their diet of almost exclusively bamboo, they developed the 6th pseudo-digit which helped them eat bamboo to survive in their environment.

Chromosome 2 in Humans

Let’s take a look at something else that intelligent design can’t explain. Taxonomically we are part of the great ape family that also consists of Orangutans, Gorillas, and Chimps. One of the reasons we know this is because of Chromosome 2. The other great apes have 24 pairs of chromosomes while we only have 23 pairs. How does intelligent design account for this discrepancy?

ID Explanation

ID could say “The designer created humans different than apes” but that doesn’t explain what we observe in Chromosome 2. In Chromosome 2, we find that the genetic banding matches two separate ape chromosome pairs. We also find that there are two centromeres for Chromosome 2, with one being inactive. Finally, chromosomes contain telomeres which are repeating strands of DNA that only appear at the ends of the chromosomes. In Chromosome 2, they appear in the middle of the chromosome’s arm. Evolution can easily explain this with the end-to-end fusion of two chromosomes. How does intelligent design explain this? It can’t explain why the designer would do this with any other than “That’s what the designer wanted to do.” If that is what the designer wanted to do, then they have designed everything without any indication that they did so.

Designers Intentions

Eventually, this line of reasoning ends up trying to guess about the designer’s design philosophy and goals, which is something that none of us can know. It’s a dead end. This same problem applies to all features that ID proponents claim must have been designed. In order to say that the hypothesis that “a designer created feature X” is more likely to be true than the hypothesis that “feature X arose in some other way”, the ID proponent is necessarily making assumptions or claims about the intentions of the designer themselves. If the designer really wanted to create feature X, then they may have an argument, but if the designer really didn’t want to create feature X, then it follows that it’s very unlikely that feature X was created by the designer. 

Not An Explanation For Anything

Without knowing the intentions of the designer, we can’t tell if it’s probable that feature X was created by them or not. If we can’t know the intentions of the designer, then the hypothesis of intelligent design doesn’t have a basis for claiming to be a probable explanation for anything. 

Unlikely To Have Designed Anything

This is true even if we grant the premise that a being(s) exists that is even capable of the feats of creation required. If such a being exists, but their design preferences run precisely opposite to the specific features we see in organisms on Earth, then it’s extremely unlikely that they designed life on Earth. Without knowing their intentions, the very best we can say is “intelligent design may or may not be a viable explanation”.

Intelligent Design Predictions

Now, what about predictions? Does intelligent design make any predictions? No, intelligent designers fail to answer pretty much every question regarding the predictive power of their explanation. How was the bacterial flagellum designed? When was it designed? How many design events have occurred in the history of life? If intelligent designers can’t answer any of these, how can they expect to make predictions about the future? 

Does Evolution Predict Anything?

Using evolution, for example, we can observe a morphological gap between, say, fish and tetrapods, which are 4 legged animals, in the fossil record, and then predict where and when we should be able to find transitional forms that fill that gap. That’s what happened with the discovery of Tiktaalik. Can intelligent design make any similar predictions? No, because it doesn’t provide any account of the history of life on earth, so it can’t predict any findings of that history.

Transitional Forms

If we find a transitional form, ID says “the designer designed that organism too”, and if we don’t, ID says “the designer decided not to create that organism”. There’s no real explanatory power there. The ID cannot be considered an explanation for anything because it fails to satisfy the very basic requirements of an explanation. It fails to describe and predict phenomena in our reality.


While intelligent design isn’t viable as an explanation for biodiversity, there is a process that does work and has been rigorously studied for over a century: that is evolution. Evolution operates by mutations and recombination creating genetic variation within a population followed by a number of mechanisms–such as natural and sexual selection, genetic drift, and gene flow–acting on that population. Each of these mechanisms has been studied for at least decades and has been characterized in specific mathematical terms. Nothing like that exists for Intelligent Design. 

So, as Judge John E. Jones noted during the Kitzmiller-Dover case, the verdict is in. Intelligent design isn’t science and can’t account for the diversity of life. Thank you