Two years ago, I bought a compound bow at a garage sale and took up archery. One of the most exhilarating things about this sport is watching the arrow fly to its target. But perspective is everything. Watching from the side, the arrow is barely more than a blur: no sooner does the bow string snap before the target is twirling around with a vibrating arrow through it. But from my vantage point, directly behind the arrow, I can watch the arrow arc smoothly up, then float down before hitting the point I’d intended. Sometimes, when the fletching (feathers) at the back end of the arrow gets torn, it’s fun to watch the arrow corkscrew and veer suddenly at the end like a curve-ball thrown by a major league pitcher.
But what does this have to do with the faith-and-science dialogue? Well, a couple days ago the BBC news reported on a study which found a virus stealing genes from the Black Widow spider.
Yes, that report has something to do with archery. Bear with me.
I’ve blogged before about how, even though standard Darwinian evolutionary theory was enough to explain so many complex changes in life forms, its failures were also becoming more and more evident. I compared this to the situation in physics when Newtonian mechanics were able to explain everything … from billiard balls colliding to planets revolving around stars … until we started looking at ever smaller things like molecules and sub-atomic particles and then it completely failed, only to be rescued by a whole new paradigm: quantum mechanics. It seemed that standard Darwinian theory too isn’t enough, and that we needed another mechanism to complement it (not replace it, just like quantum mechanics and Newtonian mechanics are complementary, not contradictory).
This latest report about the virus and the Black Widow spider is another example of a new kind of genetics that we’re only beginning to understand, and which can explain many surprises in evolutionary biology.
The standard idea has long been that all life forms inherit their genetics from their parents. When we found a new function in one organism that was absent in more primitive organisms from which it presumably evolved, we previously interpreted the new function developing by mutations within the more primitive organisms and being passed on down that particular branch in the metaphorical Tree of Life. From that viewpoint, evolution was only a series of very small steps accumulating till they eventually create a new species. “A journey of a thousand miles begins with a single step” (Lao-tzu; Chinese philosopher and founder of Taoism).
But we’ve since learned that genetic information can suddenly jump across whole different branches in that Tree!
We’ve known for quite a while that different species of bacteria can, and often do, exchange genetic information between each other, even though they’re different species. This is a major problem in the development of resistance to antibiotics. We’re now learning that that kind of transfer of genetic information doesn’t only occur between bugs on slightly different twigs of one branch of the evolutionary Tree-of-Life, but can also occur between entirely different branches on entirely different parts of the tree. This report of the virus and the Black Widow spider is the latest such example.
Basically, the venom of that spider is a cocktail of nasty molecules. One of them … latrotoxin … breaks down the membranes of your nerve cells, forcing them to release all their neurotransmitters. The result is an incredible amount of pain, and sometimes death!
The research study found that a certain virus picked up the gene for making latrotoxin from the spider, apparently by infecting a bacteria which itself had infected the spider, and gene transfer occuring across all three species groups. Two gigantic leaps between entirely different parts of the Tree. Instead of the journey of a thousand steps that Lao-tzu referred to, this was like the transporter on the SS Enterprise on the TV series Star Trek. Beam me up, Scottie!
And why would this virus pick up that gene? It found latrotoxin to be a particularly useful tool for breaking down the membranes of the bacteria it preyed upon, using it to get into the bacteria and reproduce, or possibly to help the viral “babies” escape from the bacteria, just like the alien crawling out of Mission Executive Officer Kane’s chest in James Cameron’s 1979 block-buster movie Aliens. And it wasn’t just this one gene for latrotoxin: the research study also found other stolen genes in that virus.
So now we’re learning about a whole different form of genetic inheritance. It isn’t just passed down from parents to children, something we now call “vertical transfer,” but can also be passed sideways from one species to another very different species … “horizontal transfer.” Some people today get worked up over scientists creating genetically-modified organisms by inserting genes from one animal or plant into a different one, but nature’s been doing that for millennia!
So what does this have to do with archery? Basically, it’s the idea that something that works well in one setting can be introduced into an entirely different setting to solve entirely new problems.
Somewhere in human history, someone noticed that adding a few feathers onto the end of an arrow made it fly more straight and accurate. Even though they may not have understood the underlying physics, that realization catapulted those archers into a whole new league of competitive archery (in other words, made them far better killing machines). We don’t know who first came up with the idea of putting fletching (feathers) on arrows: that seems to precede recorded history. Perhaps the idea came from a particularly imaginative Neolithic scientist who knew that a keel and/or a rudder on a boat were a great way to steer a boat or keep it running straight. That idea in turn might have come from noticing that many fish are long and thin and have various fins that run the length of the body, and some broader fins at the back end to help steer the fish. Fast forward a few thousand years and we find humans understanding better the aerodynamics behind the fletching, and then refining that to produce the first airfoil. Before you know it, we see Orville Wright piloting the first airplane, with his brother Wilbur running alongside at one wingtip. A few decades later, someone thinks about putting that airfoil on the end of a combustion engine, and we have the first helicopter. Later yet, when race-car driving became too dangerous because their high speeds too often sent them skittering into the ditch, someone realized that putting an airfoil on the back end of the car would increase its grip on the road, and allow even faster speeds.
The point in that long paragraph is about how a great idea can be deployed in entirely different settings to suddenly solve an entirely different major problem. You don’t need to make a long series of small incremental changes in each of those different settings.
And that’s what this idea of horizontal transfer of genetic information allows. Who knows how many major leaps in evolutionary biology will be explained by horizontal gene transfer?
Some will argue that this doesn’t explain how the idea came up in the first place. But some great ideas happen by accident, and then can be improved by relatively minor adjustments.
Percy Spencer was an engineer working on developing radar technology during World War II. One day, while standing in front of an active radar set, he noticed that the chocolate bar in his shirt pocket had suddenly melted. Being the keen scientist he was, he investigated what was going on, and a few decades later, we see the invention of the kitchen microwave. An entirely new and unexpected application of something that was already in place, and just needed to be tweaked a bit.
Those who keep up with the Faith-Science dialogue will likely have heard about Michael Behe’s idea of “irreducible complexity,” and how that idea is used to conclude only a Designer can explain the appearance of something as complex as the bacterial flagellum (the outboard motor on the back end of a bacterium). However, a bit of investigation shows that the bacterial flagellum might have come about from an entirely different and less complex machine that the bacteria already had on hand, one which allowed it to punch holes in its host cells … basically a syringe needle. By adding some extra parts borrowed from yet other machines in the bacterium and/or by some minor adjustments to existing parts, the syringe needle became an outboard motor, just like the fletching on an arrow eventually became a helicopter and then the airfoil on the back of a race car.
Others will argue that this just shows how you need an intelligence to take the idea and make the minor adjustments. Again, not so much. This is nothing like the analogy I’ve frequently heard of a hurricane blowing through a junkyard and randomly assembling a jumbo jet out of individual parts. Instead, envision a factory constantly churning out parts, some fully assembled and some in various stages of assembly, as well as extra pieces, some made to specifications but others with various modifications and yet others made completely not to specification. In this scenario also imagine workers that are constantly picking up those various products and putting them together in different ways. Usually the parts naturally fit together to produce the intended machine. But sometimes the workers come up with a new combination, and an entirely weird and wonderful new product in the process. Before you know it, the factory slaps a patent on that and starts churning out more of those as well.
The fact is that living organisms are always producing a bewildering variety of molecules and finding new ways to stick one set of molecules onto another one and coming up with a different function. Even the gene sequence for a part of a protein can be moved around and, by chance, find itself beside a gene sequence for another protein, and a whole new outcome is possible. That’s what happened in this example of the virus and the Black Widow Spider. And whenever a combination gives that organism a competitive advantage, the idea sprouts legs and starts running to the finish line.
This idea of horizontal gene transfer is a new chapter in our understanding of how genetics work. Constant small incremental changes (“vertical genetic changes”), large dramatic changes (“horizontal gene transfer”) and an unceasing mixing and matching of those ideas can explain so much in biology.
Or we attribute those changes to an intelligent Designer, but that leads to other embarrassing problems, as I’ve blogged before.
Does any of this mean that a theist needs to set aside their ideas of God? Not if they’re able to attribute our weather to solar energy being injected into the atmosphere and ocean, and creating gradients in temperature, pressure and humidity … a global machine that works like a clock, and can be modeled by computers … rather than embracing the Bible’s explanation (in the book of Job) of God breathing out the dew and opening one storeroom holding the rain and the other one in which the lightning is kept.
What are your thoughts on this? …