Deep homology and design: why Notch?

The Notch signaling pathway is a golden oldie of genetics in two ways. First, it's a system that was first described at the dawn of modern genetics – named by its founder, Thomas Hunt Morgan – and used to establish some of the most basic principles of "the physical basis of heredity," as Morgan put it. (His book by that title is a founding document of modern genetics, describing in 1919 what we now call chromosomes without any knowledge of their chemical makeup.) Second, it's a system now known to be as ancient as animals themselves.

Why Notch? The name refers to the appearance of some of the first mutant fruit flies described by Morgan and his colleagues in their famous work in the early 20th century. They found flies with notched wings, and found that the trait was dominant.

Figure 1 from T.H. Morgan, "The Theory of the Gene." American Naturalist 51:513-544, 1917.

So aside from its importance in evolution and development, Notch is of historical interest to genetics.

Now, Morgan was interested in Notch (the gene name is capitalized because the original trait is dominant, in case you're wondering) because of its mode of inheritance, not specifically because of its biological effects. (I mean, who cares about flies with notched wings?) But twenty years later, things got more interesting when a different mutation in Notch was found to cause a weird (and lethal) overgrowth of the nervous system. Interesting... then, as geneticists began to probe the genetics of animal development 50 years after Morgan's initial discoveries, using the fruit fly as a model, Notch started turning up again and again. Problems in Notch signaling led to developmental problems all over the place: brain, eyes, gut, wings, bristles. By the beginning of the 1990's, geneticists had figured out why its activity is so central to proper development: Notch controls a crucial type of cell-to-cell interaction that leads to a change in cell fate. And they had found Notch signaling in animals of every kind, including in humans, mediating the same kinds of inductive developmental interactions.

It's not as complicated as it might sound – in such an interaction, two cells interact physically (they have to touch) and after the interaction one or both of the cells changes its developmental fate, choosing to become, say, a nerve cell or a skin cell. That weird brain overgrowth in the flies with no Notch activity results from a failure of cells to communicate in this way, such that all the cells on the outside of the fly's head become brain cells. (Flies, like most animals, prefer to have some skin over their brains, but in these mutants there's very little skin and lots of extra brain. Ick. See Figure 1 of this recent paper in BMC Biology for pictures; the green stain indicates nerve cells and the second animal down has the nasty trait.)

The point is that Notch signaling involves direct cell contact, and typically leads to cells making decisions about what to do when they grow up. So how does it work? Well, we know an awful lot about this particular system, and there are myriad details of mechanism and control that I'm going to skip. The very basic outline is as follows.

Some cells make the Notch protein, which is a receptor. Other cells make the Delta protein, which is the signal that activates the receptor. (One useful analogy is that of locks and keys: Notch is the lock, Delta is the key.) Both proteins are displayed on the cell surface. When the two cells come into contact, the Delta protein on one cell activates the Notch protein on the other. When Notch becomes activated, it gets chopped into at least two pieces. One piece leaves the surface of the cell and travels inward to the nucleus of the cell. There, in collaboration with other proteins, it causes changes in gene expression, meaning that some genes are turned on or up and others are turned off or down. This mode of signaling is unique and extraordinary. What we have is a signaling system that takes cell-to-cell contact and converts it directly into changes in gene expression.

Now, let's think carefully about this. We have a system of receptors and activators, in the form of Notch proteins (there are at least four in humans) and Delta proteins (there are several in humans, in a few different protein families), which serve a critical and unique purpose in cell-to-cell signaling. The function is conserved in all known animals, and that's not surprising – having cells send messages to their immediate neighbors, directing them to adopt particular fates, is key to constructing tissues and organs. I hope you'll agree that we should expect to see these inductive mechanisms in the development of complex organisms. More to the point, one should expect this regardless of one's stance on questions of "intelligent design."

Here's what is surprising. The same Notch proteins are used for this purpose in every known animal. And here's why that's surprising: as far as we know, there's no reason to insist on those particular proteins playing those particular roles. It's easy to envision – and then design and create – a set of locks and keys that bear no resemblance to Notch or Delta but that can accomplish these somewhat basic purposes just as well. There's no need for such a specific solution to a basic challenge. Why does every animal use Notch?

Recall the previous post in this series and how we approached this question of common design. Here, again, are our options.

1. These inductive signaling events could only be accomplished by Notch. There is a design constraint, currently unknown, which forces that choice. It may seem that the system could have been effectively constructed using a different lock-and-key combination, but in fact it could not function (or function well) any other way.
2. These inductive signaling events could be mediated in various ways, but the choice of Notch has been forced by common ancestry. The earliest animals settled on this choice, and their descendants have used it ever since.
3. These inductive signaling events could be mediated in various ways, but an intelligent designer has repeatedly chosen Notch for reasons known only to her/him/it.

Option #1 is, in my view, unreasonable. The system is not complicated in its basic design. There are no clear constraints on the choice of lock and key. A designer who is crafting an organism from the ground up need not select that particular lock/key combination, and someone who intends to argue otherwise needs to demonstrate how that particular combination is superior.

Option #3 is, I think, perfectly reasonable. The only problem is that one must know quite a lot about the designer to begin to surmise her/his/its goals and proclivities. Without that knowledge, it is no more reasonable to assume a preference than it is to assume a constraint.

The point is not that we can ever rule out preferences or other characteristics of a creator or designer. The point is that we can rarely make explanatory use of them. Consider that while we may assert that the Creator/Intelligent Designer prefers that pine trees have needles, we would not advance that as a useful explanation for why pine trees have needles. Specifically, we would never advance that as an alternative explanation in place of one that notes that today's pine trees have the same needles that last century's pine trees had, by virtue of biological ancestry.

Notch signaling represents one of the classic examples of deep homology. It seems to me that design theorists need to deal with deep homology before they can ever be taken seriously as scientific thinkers. Deep homology is crying out for explanation, and those who believe that the biosphere cries "design" are remiss in not offering a serious design-based explanation for the fact that every animal on the planet uses the same lock-and-key mechanism to achieve basic cell-to-cell inductive communication.

Next, we'll look at a recent and very interesting example of new findings that illustrate the striking conservation of Notch-mediated developmental events – an example of deep homology that could arise from the very root of animal ancestry.

Weekly sampler 24

1. Get your genome sequenced for $48,000. I would so do this. In the meantime, we bought the Matheson family DNA test for my dad for Father's Day.

2. I'm following this series at Siris: Philosophical Sentences explained. You know the old chestnuts: Cogito ergo sum, God is dead, virtue is its own reward, cleanliness is next to godliness... heh. Brandon tells us where they came from and a little about them. Latest installment is Santayana's famous quote etched at Dachau.

3. A very cool illusion that, like all good ones, tells us something interesting about how the brain processes visual information. Don't click till you're ready to follow these instructions: display the image on your computer screen so that you can slowly back away from the screen and still see the image. The idea is to view it up close then back up at least a few meters.

4. Two of my favorite bloggers, John Lynch (of Satan's University) and John Wilkins (from Down Under) have left ScienceBlogs and set up shop independently. Lynch formerly blogged at Stranger Fruit and his new place is called a simple prop. Wilkins is an important antidote to brainless anti-religious bellowings from Coyne and like-minded simps. Both are skeptics who know a lot about evolution. Recent important posts: Lynch on The Roots of ID and Wilkins on The Demon Spencer.

5. Strangest species discovered in the last year. The ghost slug wins for weirdness, but the big news is that someday we might be able to drink decaf that's still coffee.

6. Becoming Creation is an important blog by a homeschooler, evolutionary creationist, accomplished biologist and good guy: Doug Hayworth. Up right now is an interview with Denis Lamoureux, author of Evolutionary Creation.

7. A recent piece in the Chronicle of Higher Education presents a very interesting take on teaching science in the context of religion (and other social influences). The concluding paragraph:

Science professors should explicitly engage the rich social and ethical context of the subjects that they teach, engaging new generations of students in the science that so many now fear and reject. A careful, thoughtful approach to teaching the sensitive issue of evolution represents merely the beginning of a challenging, less-traveled-by path, but one that could, nevertheless, make all the difference.

8. My research concerns some very interesting proteins called formins. Michael Behe's scholarship includes a focus on the malaria parasite, P. falciparum. A recent paper reports that a formin protein in P. falciparum is critically involved in the process by which the parasite invades red blood cells. I always knew that Professor Behe and I were destined to be collaborators.

Theistic embryology: the talk

I previously posted the abstract of a talk I gave at Calvin last month in which I test-drove my "theistic embryology" metaphor that I'll present at the North American Paleontological Convention in Cincinnati in two weeks. Now the audio and my simple slides are posted on Calvin's e-zine, Minds in the Making. Lots of jokes. And now my name's spelled right.

About halfway through, I refer to "10 dangers of theistic evolution" at Answers in Genesis. Later I read from Jerry Coyne's steaming pile. And speaking of steaming piles, I then read from one of my favorite posts in The Cesspool. In case you wanted to follow along.

Deep homology and design: common design and its implications

Consider these not-so-random samples from the animal world: a cockroach, a zebrafish, a mouse. What do these creatures have in common?

Left to right: American cockroach (Periplaneta americana), zebrafish (Danio rerio), house mouse (Mus musculus). Cockroach image from Wikimedia Commons, zebrafish and mouse from Wellcome Images.

Well, they're all animals and that means they're all eukaryotes, for example. They all have DNA-based genomes. They all like water to some extent. They all have muscles that cause them to move. And so on.

But let's think of them in a different way. Let's think of them as things that exhibit design. (Not Design. Just design.) We see similarities like the ones we just listed, and we see some dramatic differences. Insect, exoskeleton, open circulatory system. Fish, gills, egg-laying. Mammal, milk, hair, live birth, temperature control. We can see elements of common design (limbs and joints, eyes, nerves) and elements of specialized design (lungs, fins, antennae).

Now let's forget everything we know about common descent and adopt an Intelligent Design perspective. This isn't hard to do: just think of each animal as a machine that was designed to be the way it is. The machines have some common design elements and some specialized design elements. Now this is important: let's assume that each machine was designed separately, such that design decisions were made on a case-by-case basis (for each type of machine, not for each individual machine). In other words, let's think of the cockroach as designed from the ground up to be a cockroach, and the fish and the mouse likewise.

Simple, right? I think so. Now, let's look under the hood of each machine and ask detailed questions about how it's built, again with the assumption that it was designed. Not just its overall structure, but also the procedures used for its assembly. Let's look, in other words, at its molecular machinery – machinery for signaling between cells and tissues, machinery for signaling within individual cells, machinery for directing gene function during development and normal function. And let's focus specifically on the signaling systems in these creatures and in their developmental stages. What would we expect to see?

Well, let's consider some basic scenarios.

1. Maybe the signaling systems will be roughly the same – or even largely the same – in all three animals. This would imply that such systems are hard to assemble and perhaps even harder to tune and maintain, and therefore we would conclude that there are very few ways to make a working system. The only other explanation would refer to preferences on the part of the designer, who was unconstrained by design limitations but nevertheless insisted on doing things a certain way.

2. Maybe the signaling systems will differ between the three animals, to such an extent that it is clear that the choice of a system is somewhat arbitrary, arbitrary in the sense that the choice of a particular system is largely independent of the context or the function that is specified. The implication is that there are plenty of ways in which cells and molecules can communicate, and no strong constraints on the designer's choices.

Now of course we may find examples of both scenarios in our analysis. Perhaps some signaling systems will appear to be highly constrained while others will be largely different among the three species. The point, though, is this: when examining machines that were separately designed, common design implies either design constraint or designer preference. Divergent design implies a lack of design constraint. There are no further options: either the designer was constrained, or she wasn't; if unconstrained, she could nevertheless choose a favorite scheme and leave the impression that she was somehow constrained.

Designer constraint could arise in various ways. It could be that a particular signaling system is uniquely suited to a particular purpose. It could be that a particular signaling system is highly robust to damage or other challenges. It could be that there are only a handful of different possibilities due to limitations in the raw materials. One variation of that last possibility would look a lot like how evolution is known to work: the designer tweaks the system a little at a time, working with the materials supplied by each generation and therefore constrained by common descent.

Design proponents can be stunningly cavalier about all this. "Common elements in animal biology? Well of course! Common design!" But wait: common design implies either design constraint (that was the best way to do it – or the only way to do it) or designer preference (she just happens to like it that way), and those are dramatically different from an explanatory standpoint.

It turns out that signaling systems in animal development are so universally conserved that they require an extraordinary explanation. The commonality of the elements is so striking that it took most biologists by surprise when it first became evident, and remains one of the most remarkable facts of developmental biology today. We'll look at some recent advances in this area of evo-devo in posts to come. But one last thing: I'd like to try a thought experiment to illustrate how we might approach questions of signaling in animal cells and embryos.

Consider a group of 50 people who have agreed to help with your experiment. You divide them into pairs and tell each pair to send one person out of the room. Then you tell the remaining people to greet their partners upon their return, using a single word of their choosing that is certain to convey the greeting. You observe that all of the people employ either "hello" or "hi" for this purpose. Question: would you conclude that "hello" and "hi" are uniquely suited for the task, and that no other word could possibly have worked? I hope you would seek another explanation and perhaps consider trying the experiment in, say, Shanghai or Guadalajara. You would conclude, I wager, that the word itself is of little explanatory value. In other words, the choice of a word was constrained, but not by anything specific to the word itself. In Shanghai, it's "ni hao." Maybe somewhere it's "duuuuuuude." And in a matter of minutes, you could change it to "ahoy" or "blorp" or anything you want.

And if you really wanted to probe the notion of constraint in human conversation, you would ask your 25 pairs of subjects to come up with an identifying word or phrase that they could call out to find each other in the dark. You would find, of course, that the choice of that word or phrase would be almost completely unconstrained.

What does all this have to do with signaling systems and design? That's for next time. Till then, blorp.

Deep homology and design: a new series

Recently I was reading a superb review article [doi] on the subject of a famous and important cellular signaling pathway called the Notch pathway. The author, Mark Fortini of Thomas Jefferson University, quoted James Puckle (an 18th-century English inventor and writer) on the "wonderful frame of the human body" in which "so many strings and springs" which all must "be in their right frame and order" for life and concluding that "it is next to a miracle we survived the day we were born." (If you must know, it's maxim #914 in The Club, in a section called "Death.")

This reminded me of some personal tragedy in our own family, after which Puckle's conclusion was repeated almost verbatim. It also reminded me of my need to write about the amazing homology of developmental signaling mechanisms in animals. For many months, I've listed an article on "deep homology" as the subject of my next Journal Club. But this topic won't fit into one article review, so I've decided to turn it into a little series.

Here's what Fortini writes in his introduction, after quoting Mr. Puckle:

Surprisingly, research over the past few decades has revealed that the orderly differentiation and arrangement of these many physiological ‘‘strings and springs’’ are controlled by a relatively small number of developmental signaling pathways. These pathways, including the Notch, Ras/MAPK, Hedgehog, Wnt, TGFβ, and JAK/STAT pathways, among others, are widely conserved throughout the animal kingdom and they cooperate throughout development to pattern a diverse array of tissues in different animal species.

The lingo might seem strange, but I hope the point is clear. The vast diversity of animal life, with "endless forms most beautiful," is assembled through the action of a small set of signaling systems. And, remarkably, the systems are used in the same ways in animals that couldn't be more different in behavior or structure.

This fact raises interesting questions about design and evolution. Why so few systems? Why are they used again and again, for the very same purpose? Are these choices forced by design constraints of some kind, or is there another explanation? Could it have been otherwise? Can it be otherwise? I'll tackle those questions while discussing some recent experiments in evolutionary developmental biology, or evo-devo.

And what of this phrase "deep homology"? It was coined by some of the founding minds of evo-devo – Neil Shubin, Cliff Tabin and Sean Carroll – as they considered the fact that animal limbs of every kind are "organized by a similar genetic regulatory system that may have been established in a common ancestor." And we mean limbs of every kind: whale flippers, fish fins, bat wings, human arms, and, amazingly, insect limbs. Such disparate structures may not be evolutionarily homologous (meaning that they were modified from a common ancestor) but the signaling systems that create them are homologous. This, then, is deep homology: the sharing of signaling mechanisms that are used to create diverse (though often functionally similar) animal structures.

So please join me, and maybe we'll lure interesting commenters into the discussion.

Theistic embryology controversy: a developing story

Get it? Heh. Anyway, go to Clashing Culture to see further discussion of the TE test.

Weekly sampler 23

Okay, so not really weekly.

1. John Farrell has an interesting discussion of protein folding as a problem or challenge for evolutionary theory. His post includes quotes from experts with whom he has corresponded, and he cites the primary literature. (You know, peer-reviewed research articles written by people who are actually trying to understand the biochemistry of an early earth.) Here he's quoting Nick Matzke:

Even the very first polypeptides were pretty certainly not assembled all-at-once-from-scratch from a pool of 20+ kinds of amino acids in even proportions, in D- and L-form, as creationists and various beknighted physicists blithely assume. Probably the first time a proto-tRNA grabbed an amino acid and made a short chain, the chain was composed of glycine and few common hydrophobic amino acids and was quite short. Cavalier-Smith (2001) suggests that the original function may have just been a hydrophobic tail for association with a membrane. All of the improbability statistics are irrelevant in this sort of scenario, chirality isn't an issue, etc.

Let's go with 'benighted' lest anyone confuse an ignoramus in Glendora, California with, say, Sir John Polkinghorne.

2. I never really finished my junk DNA series, but there's still work to be done: falsehoods about non-coding DNA are beyond rampant. Recently at Adaptive Complexity, Michael White scored a direct hit on one of the major issues in this bogus controversy, and as usual it's a basic scientific principle (in this case, the concept of a null hypothesis). His post is required reading for those interested in any aspect of evolutionary genetics and especially those who have seen the standard genomic arguments of intelligent design creationists. Hat tip: Sandwalk.

3. Christians (and others) will find ThinkChristian.net interesting and provocative. I'll be writing there regularly starting this month. About science. And stuff.

4. Alister McGrath on Augustine on Darwin. His (very) basic point is a good one and he equivocates at the right times. But he seems to be allergic to randomness. After mentioning Augustine's emphasis on "divinely embedded causalities," he claims that "Augustine has no time for any notion of random or arbitrary changes within creation." More specifically, McGrath explores notions in Augustine's The Literal Meaning of Genesis that sound like ideas from a thoughtful design advocate. (Ideas, I'll add, that were articulated just as well by Howard Van Till in a slightly different context.) But, like most design proponents, he inveighs against randomness and then identifies it with Darwin:

Augustine would have rejected any idea of the development of the universe as a random or lawless process. For this reason, Augustine would have opposed the Darwinian notion of random variations, insisting that God's providence is deeply involved throughout. The process may be unpredictable. But it is not random.

I wonder if McGrath has thought hard about this. He may be right about Augustine, but I think it's a mistake to take such a hard line against "random variations." Why do so many people think that "embedded causality" is inconsistent with "random variation"? I don't get it.

5. And speaking of randomness, our reading group ("Random Readers") recently tackled some articles on determinism and evolutionary theory. We focused on a paper by Roberta Millstein titled "How Not to Argue for the Indeterminism of Evolution: A Look at Two Recent Attempts to Settle the Issue.” The "attempts to settle the issue" were responses to a paper that Millstein describes as a "full fledged defense of evolutionary indeterminism" that put the debate over evolutionary determinism "into high gear." That paper is "The Indeterministic Character of Evolutionary Theory: No 'No Hidden Variables' Proof But No Room for Determinism Either" by Robert N. Brandon and Scott Carson. Wait, Scott Carson? Yes, the same Scott Carson who writes one of the blogs I regularly follow: An Examined Life.

6. An answer to the famous question, "What is it like to be a bat?" Hat tip: Very Short List.

Theistic embryology: the gathering storm

On Friday in the Christian Perspectives in Science seminar at Calvin College I gave a little talk on theistic evolution. The idea was to get some feedback on the simple ideas that I'll present at a symposium at the North American Paleontological Convention (NAPC) in Cincinnati in June. The symposium is titled "The Nature of Science and Public Science Literacy" and it's part of Education and Public Outreach Day at the NAPC. Here's the title and abstract of both the symposium talk and the seminar I gave at Calvin.

Why is there no controversy surrounding theistic embryology? Dissecting critical responses to theistic evolution.

Those who simultaneously express Christian belief and affirm evolutionary theory are said to espouse a position called "theistic evolution." The view holds the peculiar distinction of being reviled by both hard-line creationists (who call it "appeasement") and prominent atheist commentators (who deride it as fallacious). I argue that these critics typically fail to articulate objections that are specific to the view. Most creationist critics of theistic evolution object to one or both of these characteristics of the view: 1) its reliance on naturalistic explanation, a feature common to all scientific theorizing; or 2) its embrace of "random" causal events, a feature common to myriad scientific explanations. Most atheist critics of theistic evolution object to its openness to supernatural explanation, a feature of religious belief in general. Such criticisms, valid or not, fail to address anything specific to theistic evolution. In other words, attacks on theistic evolution are usually attacks on theism or attacks on evolution, but rarely represent specific criticisms of the theistic evolution position. To better understand the controversy surrounding theistic evolution, I propose that critiques of the position be considered in light of a lesser-known position we may (with tongue in cheek) call "theistic embryology." Theistic embryology describes the thinking of those who simultaneously express Christian belief and affirm basic theories in human developmental biology. Although the logic is indistinguishable from that of theistic evolution, the view is uncontroversial and the term "theistic embryology" is practically non-existent. I suggest that critiques of theistic evolution be subjected to the "theistic embryology test." Most critiques that claim to identify weaknesses in theistic evolution make arguments that are equally damaging to "theistic embryology" and so fail the test. Critiques that fail this whimsical test are likely to be arguments against belief, or against naturalistic explanation, and should be considered as such.

Stealing it back

So is evolution a weapon of unbelief, empowering the dark forces of atheism in their assault on Christendom by air, land and sea? It's sure easy to hear the dogs of war howling in the background of the weird debate over whether the NCSE is biased toward belief.

I don't have time to post my thoughts on that debate right now. Instead, I offer a talk I gave in a Calvin College chapel service in 2005, which I've been intending to share here since the beginning. The topic was the Psalms. The title was "Stealing It Back." I've edited it slightly. I think it says a lot of what I think when I see smart atheists (who I like and respect) using the chilling language of armed conflict when discussing the simple question of whether faith and science are "compatible."

Calvin College chapel
19 September 2005
"Stealing It Back"

First, a quick disclaimer about my use of the term "struggles." I do want to tell you about my journey as a Christian academic scientist and the power of God's word to bring strength into our lives. But I don't want you to think that I've had it rough or that I would ever compare the bumps in this journey to the kinds of experiences that we'd call suffering. It helps me in this regard to recall my wife's frequent response when I whine about my "struggles" (mostly unfinished grading): waa waa waa.

So seriously, some thoughts on how God's word has been a rock to me, a light unto my path.

I want to highlight three questions or issues in the journey, and show how Psalm 104, a personal favorite, has been a rock for me.

Early in my career, when I was in graduate school, I'd often find myself in a conversation something like this:

"So Steve, what is it that you're studying again?"

"Oh, I'm interested in the subcellular mechanisms underlying enhanced neurite outgrowth induced by steroid hormones in cultured neurons from the moth nervous system."

Well, not really...I would patiently explain that I was interested in how nerve cells grow and that I was studying the question in a model system where it was easy to do that.

The next question would go something like this: "Why on earth would you want to do that?"

One person did actually ask the question just like that; typically it would be more polite, and would assume that my work had one or both of the following motivations: 1) to cure diseases (in humans, not moths); or 2) to witness to unbelievers. In fact, my work then and now does touch on both those things and they're both of obvious importance. But imagine what it sounded like to me when a church leader said to someone else, about me: "Isn't it great that Steve's there at Harvard Medical School doing research? Think of all the opportunities he has to witness to those people." It didn't seem to enter anyone's mind that studying God's creation could have a more intrinsic value than that.

It was certain of the Psalms that grounded me here, and helped me to see that my calling was not merely a vehicle to get me into the presence of the godless early and often. I'm sorry that I missed Scott Hoezee's message on Psalm 19, because I quoted that Psalm in my dissertation, writing, "the heavens declare the glory of God; the skies proclaim the work of his hands. Same goes for neuronal morphology."

Psalm 104 is an extended reflection on creation. Here's how it describes some of God's interactions with natural creation:

The LORD wraps himself in light as with a garment;
he stretches out the heavens like a tent
and lays the beams of his upper chambers on their waters.
He makes the clouds his chariot and rides on the wings of the wind.
He makes winds his messengers, flames of fire his servants.

– Psalm 104:2-4, TNIV

and later in verse 31 the Psalmist says:

May the glory of the LORD endure forever;
may the LORD rejoice in his works.

Why look intently at the creation and try to understand it? Because it's cool; God thinks it's cool. He gets delight from it, rides around on it. He rejoices in it. To enter the examination of God's creation is to share God's delight in what he has made. It's his creation. He made it. He thinks it's great.

A second struggle I had was one that arises as a consequence of the fact that much biological science can in fact be used to help cure disease or grow food or help meet various human needs. Strangely, at least in the Christian circles we used to frequent, this created a tension between God's miraculous provision and his non-miraculous provision. There was something better about miraculous healing, for example, than healing brought about by, say, antibiotics. In fact, we did occasionally hear claims that one should forgo certain medical interventions and instead seek God's healing.

The problem with this sort of thinking is that it ignores God's claims here in Psalm 104 to be behind all provision of pretty much every kind.

He makes springs pour water into the ravines;
it flows between the mountains.
They give water to all the beasts of the field;
the wild donkeys quench their thirst.
The birds of the sky nest by the waters;
they sing among the branches.
He waters the mountains from his upper chambers;
the land is satisfied by the fruit of his work.
He makes grass grow for the cattle,
and plants for people to cultivate—
bringing forth food from the earth:
wine that gladdens human hearts,
oil to make their faces shine,
and bread that sustains their hearts.
The trees of the LORD are well watered,
the cedars of Lebanon that he planted.

– Psalm 104:10-16, TNIV

I'd love to try manna sometime, because I'm curious, but if you want to eat bread from God's hand, you can buy it at D&W. (If you try to buy some wine to gladden your heart, though, be prepared to show ID).

In Psalm 104, God claims every form of provision as his own. If our scientific efforts to understand spinal cord injury someday get people out of wheelchairs, God will claim that too. Psalm 104 helped me abandon the notion that non-miraculous provision is not God's provision.

The last struggle I've had as a Christian biologist has been the one you probably assumed we'd spend our whole time on. Yes, the topic is evolution. Early in my development as a Christian scientist I worried that evolution could threaten the idea of God as the creator of life. I think I know why I had this worry, and I'll talk about it in a second, but the worry disappeared over time as I learned more and more about God's limitless claims on this universe. Here in Psalm 104 God is identified as the source of just about every biological process I can think of. We've already noted his hand in the provision of food of all kinds for all kinds of creatures. (We left out lions, who "roar for their prey and seek their food from God.")

Verses 24-30 are central to my hopeful commitment to biology:

How many are your works, LORD!
In wisdom you made them all;
the earth is full of your creatures.
There is the sea, vast and spacious,
teeming with creatures beyond number—
living things both large and small.
There the ships go to and fro,
and the leviathan, which you formed to frolic there.
All creatures look to you
to give them their food at the proper time.
When you give it to them,
they gather it up;
when you open your hand,
they are satisfied with good things.
When you hide your face,
they are terrified;
when you take away their breath,
they die and return to the dust.
When you send your Spirit,
they are created,
and you renew the face of the ground.

That word there in verse 30, "created," I learned recently, is bara, the same word used in Genesis 1-2.

It was Psalm 104 that finally helped me to rest in the knowledge that whatever the process of biology that we're considering, death, reproduction, feeding, whatever...it's all God's hand. Period. Studying animal development is studying creation, Bara Creation.

Now why was this so significant for me? Well surely because it helped remove doubts I may have been harboring about God's wisdom and omnipotence as a creator. But also because it exposed for me one of the biggest lies that often crops up in discussions of biology among Christians. You see, there are two big problems that Christians who oppose evolution seem to have with it. 1) Some Christians say it's a lousy theory and that evolution didn't happen. If you think about it, that's just an empirical question like those faced in any science all the time. 2) Some Christians say evolution can't have happened because that would mean God didn't create living things. There are whole movements in Christianity right now that are dominated by the claim that if naturalistic explanations for life are true, then God is out of the picture. I hope you'll agree that a biologist making that assumption is in dangerous territory while considering the evidence for evolution.

Psalm 104 destroys that assumption. It's simply not true that those things about life that have been explained naturally have thereby been removed from God's oversight or responsibility. Soaking in Psalm 104 helped me to finally stop worrying about what I might find while examining the living world, because whatever I find there already belongs to him.

But one last thing, and an explanation for the title of this talk. This notion that a naturally explainable phenomenon is not in God's purview ought to be laughable on its face. So where did it come from, and why is it still so strong? Why was I worried that evolution could eliminate God as Creator? Don't have time to explore that now, but suffice it to say that some enemies of our faith (and quite a few confused Christians) are deliberately repeating and defending this nonsense, painting a picture of a God who gets smaller every time another scientific experiment is completed.

It seems to me that there's been a robbery. Something rightfully God's, and ours, has been stolen. So what should we do?

Well, this is where my journey as a Christian biologist is now. It's not so much that I want people to accept evolutionary theory. I want us, as Christians, to see God as the ruler and sustainer of creation, however it might be ruled and sustained.

You're probably all too young to know much of anything about Charles Manson. He was a homicidal maniac back in the 1970's, and a famous book about him and his followers got its title from a Beatles song that Manson incorporated somehow into his wickedness. The song is called "Helter Skelter."

On U2's Rattle and Hum album, you'll find a recording of "Helter Skelter" from 1987 (right around the year some of you were born).

Bono introduces the song like this: "This is a song Charles Manson stole from the Beatles. We're stealing it back."

This is how, reflecting on Psalm 104, I see part of my mission as a Christian biologist. Opponents of our faith stole the reverent study of the biological world from the church. We're stealing it back.

...so our response to the living world can be like that of the Psalmist after considering God's creation:

I will sing to the LORD all my life;
I will sing praise to my God as long as I live.

– Psalm 104:33, TNIV

Do you ever have this nightmare?

I think I stopped having this dream sometime when I was a postdoc. Or maybe I didn't shake free till I got a real job... Mine was always a language class, so everyone was jabbering away in Spanish or something, just to magnify the horror.