Why are the cells in our body so different, if they all have the same DNA?
This is a companion discussion topic for the original entry at https://biologos.org/blogs/kathryn-applegate-endless-forms-most-beautiful/genes-arent-blueprints-theyre-switches
I look forward to thinking together about these conundrums. Was this a new idea for anyone, that genes could act as switches?
Hi Kathryn
Not a new idea for me, but I am working on this, so no surprise. My question is what are the implications that you (and others) see of this idea for theism?
We are clearly moving beyond neo Darwinism here, into a much less simplistic view of evolution. Yes, mutations are still important, but we now have all this complexity to deal with (genes turning each other on and off gets very complex real soon). Ard and others are searching for the underlying principles behind these gene networks (or switches). It will be exciting to see what develops. I am willing to bet that there may be some surprises, and that biology may be entering the sort of period that physics went through in the 1920s.
And one question will be (at least for me) will the data be consistent with evolutionary purposelessness, or with some form of teleology? One of the applications of this field might be to shed light on evolutionary convergence and sudden emergence of new forms as described by Conway Morris and Gould and others.
Thanks for posting this, Kathryn, and I look forward to seeing other reactions.
Funny you should mention Simon Conway Morris; my next blog piece will be a discussion of his work and relevance for questions of teleology. I think you’re right that more examples of convergence will be found on the genetic/molecular level; it’s already true for protein folds. I’m not up on the literature of convergence as it relates to genetic switches, so I don’t know how far along that is.
The suite of evolutionary processes is certainly becoming more complex, to the point where now some are arguing about whether we need a new name, the Extended Evolutionary Synthesis (as you are well aware, I happen to know!).
I have a hard time imagining that unbelieving scientists will become convinced in droves of a teleology behind evolutionary processes on the basis of new advances in genetics. Isn’t the level of complexity in a single cell astounding enough, given present-day knowledge? But I might be wrong! Or maybe that’s not what you mean…
To me the exciting thing here is that in light of things like convergence and genetic switches (and even the genetic code, which now seems obvious!), there comes to light a logic in biology, something that begins to be describable mathematically. We already have extensive computational/relational maps of gene activity, just as one example. Where will we be in 50 years?!
Thanks for sharing your thoughts, Sy–
Kathryn
P.S. I’ll mostly be offline for the next few days while traveling, but I’m happy to resume conversation when I return. Take care!
This is not a new idea for me. It’s a necessity. But it is interesting and amazing how the same dna knows when to react and how to react to direct all the multiple processes especially in the formation of the human body in the womb. And sad when some of the switches don’t work the way they should so that we end up with encephalopathy, or missing limbs, or a hole in the heart, etc. Also interesting is the increasing knowledge that so much of the previously thought junk dna serves valuable function as “switches”, activating other dna in order start or stop various processes. God does not make junk, as the popular saying puts it.
I’ve been reading about genes being switched on and off for as long as I’ve read about evolution. So the concept of genes acting as switches is not very novel to me. I fully accept it.
Let’s stick with the analogy presented in the Scientific American video: a master power strip of switches. The cute and savvy host, Christopher Mims, demonstrates something “useful” transforming the ambiance in his office from calm and classical, to disco Christmas, to rockin’ new year using nothing more than switches. Mr. Mims tells us, “The basic idea is simple,” and (this), “…lets us understand evo-devo much better,” “wanna grow a body part?–flip a switch”. Then he sums up, “That wasn’t so hard was it?”
But where did the lava-lamp come from? From switches or from a factory? How were the Christmas lights strung up in the room? By switches or by production assistants? Where did the rock music come from? From switches or from a human creator? This list could continue on and on, but nothing ever leads back to switches. Switches outside of an electrical system do nothing except gather dust in a junk drawer in your basement.
This video and the talk by Ard Louis do not even begin to answer the conundrums presented. Yet in their slick and humorous way they pretend to be providing meaningful content. Who is their intended audience? Ninth grade Biology students? They are asking very good questions, but they are disingenuous in their utter inability to answer them.
While I too am interested in telos/teleology in Nature, I think however, that as scientists, we are obligated to focus on what it is (the “isness” of the object of our research and experimentation). The example of cells is relevant - I am not speaking as a biologist, so my remarks are very general - I have read and heard a great deal about stem cells, and I am fascinated by the statement that these can become a variety of specific cells in the body. This appears to suggest a ‘multi-purpose’ is built in these cells. Perhaps you can comment - are stem cells examples of DNA made ready with many switchs that lead to a variety of specialised cells? Or are stem cells examples of inbuilt teleology of some sort? Or perhaps some other insight.
GJDS
Not an expert in stem cells, but what I do know is that they are cells that have not undergone terminal differentiation. What that means is that all cells in all tissues go through a process of differentiation which does indeed involve the switching on and off of genes that make that cell behave like a liver cell, skin cell, or whatever. How that happens in detail is still being studied, but it very likely involves the same kind of regulatory networks (the technical term for switches) that goes on in development. Stem cells are rare cells that dont go through that process, and are thus free to turn into any kind of cell. Glipsnort or Kathryn might be able to add more detail.
As for your question about stem cells and teleology, that is a very good question. I dont know, but I think its worth thinking about.
Orion,
I like this paragraph, and agree with it. Of course a switch needs to switch something. And calling genes switches is also an oversimplification. Genes are both blueprints AND switches, and proteins are the lava lamp, and the Christmas tree. But I dont agree with your last paragraph. Ard Louis was discussing one aspect of evolution related to genes, and the clip shows that. Nobody can address all the aspects of evolution, let alone all of biology in one talk. His audience (I was one of them) included some scientists, but a lot more non scientists, including pastors, theologians, and interested lay folk.
I spoke to him later about his research, which is very exciting (though over my head). He might have sounded humorous during his talk, to help get the point across (actually the funniest person there was John Walton, the super eminent Biblical scholar, whose talk was fabulous, and very accessible to non theologians like me).
Thanks Sy - it is a fascinating area and I would be interested in hearing more from any expert on stem cells how these may perhaps receive ‘information’ that turns them into particular kind of cells. On teleology, I too think it is worth thinking about, and I suspect a great deal of discussion is needed within a science context - often teleology is used within the context of ultimate ends or goals (one reason for my comment on what something is scientifically).
Those experts you are interested in hearing more from work in the field of developmental biology. Stem-cell experts tend to spend most of their efforts preserving stem-cell pluripotentiality.
Of course, I agree entirely. The irony here is that I have been pretty heavily into population genetics, and genetics in general. But I think you are right. I completely bought the whole selfish gene position, coming from a very DNA centered scientific world view. Shapiro and Wagner are two of my current heroes, and I am now a firm proponent of the EES. (Even working on some theoretical aspects of it).
I also think you raise a very good issue for Biologos to consider (If memory serves, which it often doesnt these days) you and Jon Garvey have been raising these questions for years here. What position should Biologos, as the major force behind EC, take regarding the new ideas in evolutionary theory?
I dont think the answer is straightforward. As we see from this very post, Ard Louis, an important member of the Biologos Foundation (member of the Board of Directors) is quite open to and in support of the rebellion against strict neo Darwinism. After all, genes as switches adds a completely new dimension to the role of DNA in life, and pretty much demolishes the selfish dream paradigm as the only way to view evolution.
On the other hand, more traditional approaches are not wrong, and they have their use in outreach and educational activities to a large extent. I think all of this is rapidly evolving (sorry) and we certainly do live in exciting times.
Eddie
I asked because I I thought you meant something else. In fact you answered my question with this
In other words you do agree, (as I thought) that evolution can be teleological. I also agree with that. Does Biologos? I think they do, and I dont think its fair to say that an emphasis on random events shows that they dont. Teleology certainly implies the hand of God. Since Biologos is a Christian and not a Deist organization, I think its fair to say that everyone there believes that God did in fact create the universe with a purpose and that purpose includes life and us.
As far as random events and chance go, they arent dead in evolutionary theory. I think the Biologos view is that God can and does use what we see and label as “random” as part of the creative process. In other words randomness does not imply lack of teleology (at least not for Christians). The atheist argument is that random events rule out God, but they have no idea about the power of God, and that argument is false.
I think the confusion here is that teleology is extremely hard to insert into science. As a matter of faith, I (and Im sure most of the Biologos writers) believe that everything we see has purpose, derived from God’s design. But that is not a provable issue in a scientific sense. The argument with Steve Meyer is actually all about that. While his arguments (especially regarding origin of life) can be very persuasive, they dont (yet?) fit into any recognized scientific framework.
I think we would all love to be able to find strong pointers to God in biology analogous to the fine tuning evidence from physics. Evolutionary teleology is to me the golden prize. But it is very difficult to get there, and we arent close yet. I think ID has indeed made some headway here, but unfortunately, some of their arguments fell apart, and I happen to think they are focused on the wrong thing (evolution, rather than origin).
Anyway, I do understand your frustration, but remember that EC walks a fine path (to me of Truth) between atheists who claim foul at anything that isnt recognizably scientifically valid on one side, and creationists who insist on a strict literalism of Biblical interpretation and label any deviation from that as the Devil’s work, on the other. So lets give Biologos a break. It aint easy, but then defending the true path seldom is.
Of course that is a legitimate concern, but I dont know anyone who wants to do that. For the reasons you state. At some point I believe very strongly that faith and science will merge, because there is only one Truth in the universe and that is the Truth of Christ. But at the same time, the Book of Works is also our gift from God, and two truths cannot be at odds. We are far from that point, but I believe we will get there. Until we do, all we can do is learn as much as we can about the creation, and as much as we can about the best way to interpret Scripture. But these should be done independently of each other. When they do intersect, we will know we have understood some part of the mind of God, and we can rejoice.
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Sounds interesting. Wish I could have been there too.