Reply from Dr. Ken Miller

Dr. Ken Miller of Brown University graciously took the time to respond to my onen letter that was addressed to him and Dr. Francis Collins.

He has given me permission to publish his reply in full.

I will not be making any editorial comments or raising additional questions at this time.

I only wish to add my sincere gratitude to Dr. Miller for his kindness and the sincerity with which he answered my questions. I did take the liberty of highlighting excerpts from my original letter in bolded italics to make it easier to distinguish my questions from Dr. Miller’s answers.

Trust me, my questions are not more important than Dr. Miller’s answers. That is not an impression I’m trying to create. Highlighting was added solely for purpose of improved readability.

Without any further ado, it is my distinct pleasure and an honor to present Dr. Miller’s unexpurgated, detailed reply:

Dear Mr. Leonard,

I don’t know if Dr. Collins will find the time, in the midst of his public duties, to respond to your open letter. But I do have a few minutes right now, after submitting all of my grades for the semester and having finished my last set of recommendation letters, to respond to your inquiries.

One thing that you and Professor Miller seem to share in common with Professor Coyne is your apparent belief in the infallibility of evolution theory, and that descent is the only viable explanation for the origin of species.

I cannot speak for either Coyne or Collins, but I suspect they would answer this statement the same way I will. No scientific theory is “infallible.” That’s a word that does not belong in science, but finds its use within the confines of religion. Rather, I find the scientific evidence for evolution to be compelling, and that many different lines of evidence, from paleontology to physiology to biogeography to genetics to molecular biology all support the notion that present day organisms are descended from earlier forms by common ancestry. No scientific theory is ever beyond dispute, and that includes evolution. But as the decades have gone by, the evidence for evolution has become stronger and stronger.

I don’t believe my personal religious beliefs will keep either of you gentlemen from answering my questions because we are all professed Christians. I’m merely asking you to help a brother understand why design is stupid and unscientific and how common descent makes perfect sense, even to describe the relationship between plants and animals.

I have never said that design is “stupid.” I see no reason to use such insulting language. But let’s consider what is meant by “design” in this context. “Design” in its current usage in the US is centered around a series of arguments made against evolution and intended to demonstrate that evolutionary mechanisms cannot generate the changes that are documented in the natural history of species. As an alternative, “design” argues that organisms were in fact created by a force acting outside of nature (a supernatural force) and therefore is actually a theory of special, supernatural creation.

Could an all-powerful creator have created every transitional sequence we see in the fossil record so that they give an appearance of evolution over time? Of course, if that creator chose to give us a deceptive impression of natural history. Could such a creator have fashioned the genomes of every living organism so that they give an illusory picture of being related by descent with modification? Of course? And could such a creator have created the world a 1 PM this afternoon, installing false memories in each of us and false evidence of a past history for the universe? Of course, once again. But that is exactly why “intelligent design” and other such ideas are not science, because even if they were true, they would not be testable by scientific means.

I sincerely seek truth — if the truth turns out to be descent and not design, so be it. Quid est veritas?

I will take you at your word, of course, as I hope you will do for me.

Design makes sense to me. Descent does not. Humans have 23 pairs of chromosomes, and all apes supposedly have 24 pairs.

That’s not quite true. There are many apes with different chromosome numbers. Gibbons are an example of this, which I will return to in a moment. But what you are most likely referring to is the fact that the other great apes (gorillas, orangutans, chimpanzees, and bonobos) have 24 pairs of chromosomes, while humans (and yes, we are also classified among the great apes for very clear biological reasons) have 23 pairs.

But how exactly did ape-like primates evolve to become human?
Of course, I know that biologists have “widely accepted” the theory two “ancestral” chromosomes fused end-to-end and formed human chromosome 2. Professor Miller even says as much in this video.

You are missing something very important here. Human ancestors split from the ancestors of today’s great apes between 5 and 9 million years ago, depending on which of the other great apes one is considering. However, the fusion of two chromosomes (originally numbered 12 and 13 in the other great apes) to form human chromosome 2 was not a driving force in the development of our species. Indeed, it’s likely that this event produced very little in the way of genetic or physical change for our species.

Rather, the structure of chromosome 2 indicates something far simpler, and that is merely that we are descended from a species that once had 48 chromosomes instead of our present 46. That’s all.

My concern specifically revolves around Professor Miller’s use of the word “fusion” to describe this alleged freak accident of nature. Because in every science text I’ve read, fusion typically describes the process when two atoms collide at high speed and bond together.

Well, perhaps that’s because you’ve been reading a lot of physics books, and I grew up in a working class household headed by my grandfather, a welder. As he taught me the use of tools, I became familiar with the processes used to fuse metals together to form a strong bond, so I use the term “fusion” to apply to any process that links two structures together.

If you prefer, we could use the proper genetic term for an event like this, which is a “Robertsonian Translocation,” and refers to any event in which part or all of a chromosome becomes attached to another chromosome. But I find the term “fusion” simpler, less jargon-laden, and very appropriate. The fact that you’re more familiar with nuclear fusion does not invalidate its use here, believe me.

In this case it would seem that the collision could have only occurred inside the first atom formed at the moment of conception, then replicated in every additional cell formed in this new organism — sort of a chain reaction. After all, fusion is an instantaneous process.

Surely your argument isn’t that two ancestral chromosomes “gradually” fused into one single chromosome over thousands, or even millions of years, is it?

Nope, that’s not my explanation at all. Rather, the best explanation for our second chromosome is that in one of the germ line cells of one or more of our ancestors two chromosomes underwent a Robertsonian tranlocation and became one. This event would then have resulted in a fused chromosome, today’s number 2, being passed along to descendants.

In the video link provided above, Professor Miller said the chromosome missing in humans could not have ever been lost without causing fatality in the offspring. Therefore, if fusion is truly the only means by which this new human chromosome 2 could have formed (as Professor Miller suggested)

then Goldschmidt’s hopeful monster theory would seem to best describe the ape-to-human evolutionary process, wouldn’t it? And if that is so, the mating problem of the hopeful monster is reintroduced into our discussion, correct?

No, that is not correct, if you will permit me to speak plainly. It turns out that the fusion of two chromosomes has only a very slight effect on fertility, and does not turn the recipient of the fused chromosome into a “hopeful monster,” or any sort of monster at all.

Here are the facts. Chromosome fusions exactly like the one that produced our second chromosome are common in the animal kingdom, and happen al the time. Examples? Well, the most common chromosome number reported for mice is 40 (20 pairs of chromosomes). However, isolated populations of mice have been discovered with 24 and 22 chromosomes, the result of multiple chromosomal fusions (Nature 403: 158, 2000). Such fusions (and fissions) have also been reported in goats and horses, and especially in gibbons. A 2014 report (Nature 513: 195-201) showed that different populations of gibbons in southeast asia had chromosome numbers of 38, 44, and 52, indicating that chromosome fusion and splitting are common events that do not produce strongly adverse effects on species viability.

In plain language, chromosome fusions happen all the time, and they have only minimal effect on viability.

If Australopithecus had 24 chromosomes, then it was some sort of an ape. If Homo Habilis had 23 chromosomes, it was human. If Australopithecus evolved into Homo Habilis by fusing two chromosomes into one, it would only seem possible if it occurred within one single generation.

This is also wrong, for the reasons I have outlined above. The fusion of two chromosomes did not make us human. In fact, it probably had very little effect on us at all. So you are mistaken in trying to equate 24 chromosome pairs with the genus Australopithecus and 23 pairs with Homo.

If the parents of Adam (the first human with 23 chromosomes) had 24 chromosomes, then Adam was not even biologically compatible with his own parents. Therefore, Adam could only have mated with another lucky product of fusion, a female “Eve.”
Eve would have had to be born within Adam’s lifespan and within close enough proximity for them to meet and of course, reproduce to create viable offspring that perpetuated the new species. That would seem to make descent twice as unlikely than if it only needed to happen for Adam within a single generation.

Here’s one more key thing to consider if you are really interested in Quid est veritas, as you state. It is clear that such chromosomal fusions continue to occur among present-day humans. A recent report in fact described an individual with just 44 chromosomes (22 pairs), resulting from a fusion between chromosomes 14 and 15 (Biomedical Research 24: 171-174, 2013).

What this means, of course, is that your concerns about your 23-chromosome Adam finding a suitable Eve to mate with are misplaced. In small population groups, such as those that characterized the early human population, a chromosome fusion could easily have become established as the norm, just as has happened today for breeding groups of mice and gibbons as I have noted. Therefore, there is nothing particularly remarkable about human chromosome 2 that makes its emergence in its present form unlikely. Rather, all it does is to show that we have recent common ancestors that carried 48 chromosomes.

Are biologists wrong to use the word “fusion” to describe the formation of human chromosome 2? Is there any possible way that the forming of this particular chromosome could have taken a very long period of time? Inquiring minds would like to know…

No, there is nothing wrong with using the word “fusion” to describe this particular form of Robertsonian translocation. And the formation of such a chromosome, as we can see from studies of other organisms and from that family with 44 chromosomes, is an event that can take place in just one or a very few generations.

I hope very much that I have answered your questions.