Darwin and Complexity: Another Genetic Solution?
It remains one of the biggest obstacles to belief in evolution that a random, unguided process could build an eye, a wing or any of thousands of complex structures that abound in living things on earth. To a Darwinist, who sees all life in terms of common ancestry, none of these structures existed in the first cell. Evolutionary theory is an attempt to reduce the challenge of life’s complexity to small changes at the genetic level that, though contingent, exhibit some law-like behavior that can produce increasing complexity over millions of years. Does a new paper in Nature1 succeed at making Darwin’s mechanism plausible?
The team from Yale, Washington University in St. Louis, and University of Sussex realized they were tackling one of the big questions. “As perceived by Darwin,” they began, starting with the Big Man of evolutionary theory himself, “evolutionary adaptation by the processes of mutation and selection is difficult to understand for complex features that are the product of numerous traits acting in concert, for example the eye or the apparatus of flight.” They didn’t use the ID-tainted phrase “irreducible complexity” but the reference was clear.
Their paper is rather thick in jargon and math, but a somewhat simplistic interpretation was reported by PhysOrg. In short, they knew that they had to navigate between a Scylla and Charybdis of genetic catastrophes. Darwin, of course, knew nothing of DNA and genes. Evolutionary theory evolved into the neo-Darwinian synthesis in the 1930s to incorporate the 20th-century findings about genetics, mutations, and molecular biology – then underwent successive descent with modification as the structure of DNA and proteins was elucidated.
What are the dangerous extremes? The first is dilution. R. A. Fisher worried in 1930 that any beneficial mutation would channel or “canalize” an organism onto a fitness island, and that mutations would be diluted in more complex systems. The other is called pleiotropy: mutations, even if involving just one gene, tend to affect multiple traits. If a developmental gene mutates, for instance, the change could have a ripple effect through numerous organs and systems. This has been called the “cost of complexity” – the more complex a system, the more a mutation may damage than build things. By analogy, consider a change in a power supply on a computer that burns a memory chip and makes a printer unavailable. So if a complex animal or plant becomes canalized, it loses “evolvability” to gain more complexity; if pleiotropy is universal, the organism could die.
The authors bred several generations of mice. They measured genetic effects on body size when they let separate groups inbreed, and then cross-breed. Particularly, they measured 102 genetic effects on 70 skeletal characteristics. Then, they performed a mathematical analysis to try to estimate the effects of pleiotropy. The more they massaged the data (adding various assumptions and making decisions about relevance), the more two findings emerged: pleiotropy only tends to affect a few characters, not a lot. Second, a mutation can hold its own: a mutation for one trait has more effect when more traits are affected. “This suggests that evolution of higher organisms does not suffer a ‘cost of complexity’,” they said, “because most mutations affect few traits and the size of the effects does not decrease with pleiotropy.”
They believe their results affect predictions about the consequences of pleiotropy in two ways. First, they alleviate Fisher’s worry that mutations affect all traits (universal pleiotropy). Second, they undermined the assumption that mutations are additive in a linear fashion (constant total effect). Mutations are neither diluted by complexity nor magnified by pleiotropy. Evolution navigates a safe path through the catastrophic extremes. They concluded on a somewhat speculative yet triumphant note:
The constant-total-effect model, however, has the consequence that the average effect per character decreases and thus the rate of response to directional selection also decreases, leading to another cost of complexity prediction. However, our data show that the total effects of mutation actually increase with pleiotropy. It therefore seems that in real organisms the combination of restricted rather than universal pleiotropy, and increasing total effects, could be seen as evolution’s answer to the challenges of evolving complex organisms with random variation and selection.
Gunter Wagner, the lead author, used a homey analogy for the lay people reading the PhysOrg summary. “You wouldn’t expect to make a lot of random adjustments – at the same time – to tune up a car,” said Wagner. “Similarly, it appears that tuning up a complex trait in a living organism is well coordinated and the effects of pleiotropy are more focused than we thought.” You should be able to drive away with that.2
1. Wagner, Kenney-Hunt, Pavlicev, Peck, Waxman and Cheverud, “Pleiotropic scaling of gene effects and the ‘cost of complexity’,” Nature 452, 470-472 (27 March 2008) | doi:10.1038/nature06756.
2. That is, unless you ponder the fact that cars are usually built and tuned up by intelligent agents, not random mutations.
It’s tempting to want to be gentle with these Darwinists. After all, didn’t they do all the right scientific things? They published their work in a peer-reviewed journal. They used scientific jargon (to the hilt). They used mathematics, the language of science. Look; they even did experiments on lab mice. What could be more scientific? What does a Darwinist have to do these days to get a little respect from the Visigoths and get them to stop the siege?
How about telling the truth. We were told this paper was going to be about Darwin’s grand story that eyes (03/31/2008), wings and other complex structures could emerge by blind processes of random mutation and natural selection. Instead, what we got was a thick fogma (05/14/2007) of bluffing about everything but the main point. The question of evolution of complex structures kept standing there, like a trumpeting, stomping elephant in the room, with these guys quibbling, as if down on their knees examining carpet dust under a magnifying glass, about correlation coefficients of specific genes and their relationships to other genes and microscopic skeletal changes within one species of animal, who already have eyes, and were apparently not embarking on an origin of species project via a random walk. Irrelevant details that miss the main point are not worthy of a respectful response.
Why irrelevant? Because they started with lab mice, and the ended with lab mice, and no evolution whatsoever occurred! The mice were one species, interfertile, the whole time. Did they watch an eye or a wing evolve? No! Did they observe the emergence of new complexity and order? No! Did their lab mice sprout wings and take off? No! Did any mutation lead to any measurable improvement in fitness? No! Did they observe anything that a young-earth creationist would have any trouble with? No! Did they accomplish anything to vindicate Darwin? No! None of their “findings” contributed a micro-meme to Darwin’s myth unless one was already committed to it from the beginning. It’s the girder over the Grand Canyon again, suspended in mid-air from a helicopter (re-read the 05/22/2002 commentary).
They cannot assume that the critics are going to trust the Darwinian web of belief, because the critics already know it is insufficient to support the weight of empirical evidence required (Cambrian explosion, molecular machines, irreducible complexity, etc.). Darwinism can no longer be regarded as a default position. A few irrelevant details about how genetic mutations might be able to navigate between the extremes of universal pleiotropy and dilution, within one species of mice, according to a rigged mathematical model, is not enough to pay the cost of complexity. The Darwinists have been in default on this tax for 149 years. Such details do not provide either progressive or cumulative currency for Darwin’s account, when so much other observational evidence is draining it. Responding that, “according to our own records, we don’t owe any Complexity Tax,” is a bald lie. Making small payments in counterfeit currency from your own presses won’t work, either. The Visigoth tax collectors (05/09/2006) demand, stop lobbing pennies over the wall and lower the drawbridge. We have you surrounded.
You can bet these scientists are not as thick as their jargon about what is going on in the Darwin wars. Critics have been hammering them on this with increasing intensity ever since Origin of Species hit London shelves. They are sick and tired of 149 years of bluffing, speculation and storytelling about how eyes and wings came into existence by chance. This is now 2008. Everybody knows how much more complex biology turned out to be than Darwin ever imagined. His Victorian-progressive myth, like a tottering wall, cannot survive another coat of whitewash and fancy frescoes. The Darwin Party usurpers need to stop slapping one another’s backs about how clever they are, and go out to face the revolt. They need to answer the ultimatum signed by 700 scientists surrounding Darwin’s Castle, who shout in unison, “We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged.”
It’s another safe bet this is the best the Darwinists could come up with. The authors hail from Yale and two other distinguished pro-Darwin universities. It was published in the most prestigious pro-Darwin scientific journal, Nature, where publishing real estate is scarce and each entry goes through multiple rounds of editorial screening. In light of the outcry and controversy these days, if the Darwinists had a better defense for the most controversial claim in the theory, they surely would have published it. Instead, we got a bunch of hand-waving, some water-balloon arguments that are wobbly and all wet, and a fallacious anthropomorphic statement that somehow pleoiotropic mutation is “evolution’s answer to the challenge.”
What this amounts to is an admission of futility. A sufficiently weak defense is indistinguishable from capitulation. Deduction: Darwinism is de facto defunct. It is in default on its Complexity Tax because it is bankrupt. Watch Expelled, join the rebellion, break down this wall, kick the rascals out, clear out the fogma, restore academic freedom, and bring back honesty to the venerable halls of science.