Doubting Didymus

This paper was inspired by a particularly excellent question from the pen of Albert Cipriani in this thread.

I must thank Albert for the opportunity to write this. Rarely does a creationist raise such stimulating points. Without further ado:

Does evolution always favour complexity?

Short answer: no.

From the time of Aristotle until only comparatively recently, one of the central themes of biology was that of the “great chain of being”. Usually derived from natural theology, this is the idea that all life can be placed on rungs of a single spectrum from small, simple and stupid to big, brainy, and bogglingly complicated. Humans are, of course, always placed at the top of this ladder. The advent of the theory of evolution might have challenged this anthropocentric view of life, but really did not. The great chain of being persisted in the form of the idea that evolution favours complex, (and large, and smart, and generally human-like), organisms. Humans are again at the top of Natures Most Favourite Things list, being the smartest and the most complex organism of all. Could it be any other way?

Well, yes it can. There is certainly nothing inherent in the theory of evolution by natural selection that should make complexity a goal. The only goal is reproductive fitness, and few biologists could deny that simple organisms are amongst the most fit of all. Insects are easily the most successful animal, and few would argue that bacteria, the simplest known self sufficient reproducers, are definitely the most common, and probably the most fit, of all known life. ‘Keep it simple stupid’ has shown its value in the form of tiny, simple, and highly fit bacteria. That’s right! Evolution has favored kissing with germs.

Another example of evolution favouring simplicity is the atrophication of unnecessary system components, such as the reduction and removal of eyes in cave dwelling fish, and the way that sea squirts eat their own brains when they settle on a rock and become sedentary. This phenomenon is often likened to professional academics. They are quick and brainy in their youth, but soon enough they settle in an institution and, not needing it any longer, devour their own cerebrum. The lesson we learn from these cases is that complexity is not only NOT inherently favoured, but is frequently a fitness detriment: a resource expenditure that does not pay its way.

Generally, simplicity is good. I drink coffee with a cup, not with a solar powered electric antigravity intravenous tube system (a guy can dream, though). When you have a goal, be it a caffeine hit or a huge gaggle of descendants, doing it simply is often much better than doing it in a roundabout complex way.

Does evolution ever favour complexity?

Given the advantages of simplicity, can it be said that evolution would ever favour a complex organism over a simpler form? There are a few theoretical conceptual frameworks that might provide for this.

First, the Red Queen effect. Named after the queen from alice in wonderland who had to run as fast as she could just to stay in the same place, the enigmatically titled red queen effect refers to evolutionary arms races. The cheetah must be fast to catch gazelles, and the gazelles must be fast to outrun the cheetah. Evolution in both populations will favour faster and faster individuals, yet neither ever gets an upper hand on the other, or there would be extinctions all round. This effect is known to drastically change features, and can theoretically apply to all sorts of things: weapons might be locked in an arms race with armours, potent chemical poisons locked in an endless challenge with their antidotes in prey species. Two species of bacteria might develop more and more sophisticated attack, defense and reproductive systems, each simply struggling to keep up with the other. Fenced in by the economics of simplicity, it may be that the only way to go is up, to develop more complex reproductive strategies, become larger, and evolve all the necessary equipment to allow it to happen.

Why would complexity be a bonus in this case? Well, apart from making intuitive sense, someone’s spelled it out in a theory, in this case one W. Ross Ashby’s Law of Requisite Variety, which goes like this:

The larger the variety of actions available to a control system, the larger the variety of perturbations it is able to compensate.

For a detailed run-down see: this page . This is the gist, as it applies to evolution:

Evolutionary systems would be fitter if they could have greater control over their environments, because it improves their ability to survive and reproduce. The more control the better, and the more organization and interwoven complexity the more control the organism has. A bacteria is great for randomly swimming around, absorbing nutrients from its surroundings and mindlessly replicating, but most metazoans are a veritable swiss army knife, incorporating many solutions to hundreds of different natural problems by comparison. Since incorporating a solution for EVERY problem nature throws at populations is probably impossible, evolution might exhibit a constant upward trend.

Evolutionary history – there IS an upward trend. Why?

The fossil record, which started the whole evolutionary ladder of life bruhaha in the first place, DOES demonstrate that life has become more complex on average over time. There are two primary perspectives that people like to look at this from.

The first one I shall refer to as the ‘drunkards walk’ hypothesis. The basic idea is that if you take a bunch of randomly moving drunk men and place them together in the center of a room they will naturally radiate outwards. Nothing is driving them to move away from their start location, but basic statistics will ensure that some of them move out more than the move back, and you end up with a gradient. Most drunkards move out as much as they move in, and end up with no net movement, some will move out a little more than they move in, and some will randomly move almost entirely out, giving you your probability curve. Now, what happens if you do the same thing, but start them out against a wall? You’ll find that on average they move away from it, based solely on random motions. Most will stay put again, many will move partly out and partly back, and you end up with a probability curve in which the average distance from the start location has increased.

This is not empty hypothesizing, either. The work of one Daniel McShea in the last decade has been focused on empirically demonstrating that the predictions of the drunkards walk are, in fact, what we find. He ran a very intricate and involved set of experiments on vertebrate backbones, measuring the evolving complexity of the various parts and how they interacted.



From:

“Dan McShea and the Great Chain of Being:
Does Evolution Lead to More Complexity?
by Frank Zoretich

In the image you see, figure A is the trend we should see if all of evolution always favoured complexity. Figure B is what we should see if no driving force is present. What we DO see looks most like figure B: mostly simple organisms that persist throughout history from their origin, with a gradual increase in average complexity on top of that. Does this mean that the drunkards walk hypothesis is the explanation? Not quite.

One problem with the drunkards walk is that, in the total absence of a pressure favouring complexity, a return to simplicity is favoured. We see this in atrophication, and can theorise about it with respect to its economy. Even if there is no active drive, there must at least be a fitness benefit strong enough to preserve the complexity once it appears. McShea is well aware of this, which is why his hypothesis refers to a ‘passive trend’, rather than an absence of any benefit. Once the population has evolved complexity for whatever reason, there must be enough of a benefit to keep it there. Given this, it is hard for me to see why that selfsame fitness benefit would not simultaneously count as a selection pressure. I confess I do find it hard to swallow the idea that the myriad benefits of metazoan complexity are merely neutral to natural selection. In my eyes, complexity should count as a kind of ecological niche, opening new doors for those life forms with the right stuff, lifting them out of the bacterial rat race and into the unexplored and competition free world of eukaryotic organisms.

In any case, McShea’s work sparked a lot of interest in this area and a lot of data is being gathered. There is a growing body of experimental data that seems to support the idea that no universal selection pressures exist, and that increases in complexity are not more common than decreases, on average. The important thing to remember is that even if complexity is not universally better for survival and reproduction than simplicity, we should still see a general increase in the mean complexity, simply due to the Brownian motion of the drunkards walk effect.

Albert Cipriani

Dear Doubting,
You wrote,
The long answer is that evolution doesn’t favor simplicity either. But it seems to me that you cannot have it both ways even tho you try to. To simplify the question, look at it only in terms of sexual evolution. Non-sexual reproduction is as simple as it gets and those sexless single-celled organisms have the advantage of never dying of old age.

Yet, our immortal single-celled brethren have not inherited the earth. They occupy a backwater from the currents of time that have swept us complex sexually reproducing creatures into dominance. Just watch a male peacock strut its stuff. Don’t watch an X-rated movie! In either case, (as dumb as X-rated movies are) we’re talking highly complex and extraordinarily inefficient behavior. ‘Taint natural that natural selection ought to have selected us over immortal amoeba.

You wrote:
I am prepared to accept this hypothesis. That’s why I am having such difficulty with the evidence of us reproductively unfit and inefficiently complex creatures inheriting the earth.

You wrote:
Then how does one explain the origin of the complex courtship rituals of peacocks and men? If evolution favors simplicity, why isn’t rape our standard modus operandi? Certainly it is simpler and more efficient than chocolates and dinner-with-the-parents.

Thank you for your thoughtful article. I will continue to respond to it as time permits. Take this as my installment payment. – Cheers, Albert the Traditional Catholic

GodLessWarrior

Are you being serious?

Salmon of Doubt

No? So why are there more bacterial cells in your body than there are human cells?

Albert Cipriani

Dear Godless,
I'll be sure to signal you when I'm not not being serious. For now, it is safe to assume that I'm serious. Do you dispute the fact that rape is more efficient at replicating genes than dating?

Dear Salmon,
There are more single celled creatures than multicellec ones cuz they are smaller. Duh. If you mean to associate mere numerical superiority with superiority, then I expect to see you at your local beach worshiping the sand. For surely there are more grains of sand than people so sand must be superior to us. Geez.

Hurry back, Doubting, for I don't know how much longer I can maintain my standards of politeness with your cheering section here. Albert the Traditional Catholic

Quetzal

Hopefully it is permitted to respond to Albert without being relegated to the status of “cheering section”. I don’t know – this is my first attempt. We’ll see.

There appear to be at least three questions, one fallacy, and at least one hidden assumption contained in your reply:

1) Why/how did sexual reproduction first evolve?

2) Why is (according to Albert) the inefficient process of sexual reproduction maintained?

3) What is the basis of extravagant sex-linked, overtly non-adaptive traits such as peacock tails? As a corollary, what is the basis of sex-linked, overtly non-adaptive behaviors such as avian courtship rituals?

Any one of these questions would require an essay as long as the OP, or longer. Perhaps you’d care to pick one and start a new thread, since none of the questions relate to the OP?

The fallacy is based on the false dichotomy between “simplicity vs complexity” as somehow mutually exclusive. In essence you are asserting that the mechanisms that produce complexity cannot produce simplicity. This is patently false as an examination of living systems and organisms quite readily shows. Natural selection operating individual members of a population over time can quite as easily favor those individuals who exhibit more complex adaptations as it can those who exhibit a more simplified version – it all depends on the relative fitness advantage of the specific trait or suite of traits. Again, another lengthy reply would be required to detail how this works.

Finally, your hidden assumption is based around an unstated speciesism – that organisms that are more complex are somehow “better”. This leads to your misleading and quite arguable insistence that single-celled organisms represent a “backwater from the current of time”. No matter what criterion you use to measure “success” in an evolutionary context, single-celled organisms (prokaryotes and single-cell eukaryotes) win hands-down. Whether it’s from simple math (such as total numbers of pseudospecies or sheer weight of biomass), or more functional criteria (such as criticality of the role in the biosphere, or role in the evolution of other organisms), single-celled organisms can arguably be labeled as the “dominant lifeform” on the planet. Without them none of us could exist. Without us, they will quite happily continue – after all, they did it for over 3.8 billion years before we showed up on the scene.

pz

I sure do. Rape is only going to be efficient under specific and rather narrow conditions. It is not a particularly good strategy for people, for instance, where child-rearing requires a fair amount of prolonged cooperation.
You've got it all wrong. The point being made is that we can't claim that one species is 'superior' to another. What are your criteria for superiority? You're saying numerical superiority doesn't count, but why not? Do you have some objective criterion, or are you going to do the typical anthropocentric thing and pick some arbitrary property specific to people and declare that the Measure of All Things?

Albert Cipriani

Dear Morpho,
I had my tongue in cheek when referring to you guys as D’s cheering section. You couldn’t see that… and I can’t see how you can make the following assertion:
Any process worthy of its name must produce something. The evolutionary process is no exception. Why shouldn’t we be able to articulate its product? It produces complexity. It produces simplicity. It produces diversity. It produces efficiency. Pick a product, any product or claim the product you pick is better than mine, but pick you must.

Yet you seem to be refusing to pick. You claim the evolutionary process produces both simplicity and its opposite, complexity. That’s having your cake and eating it too. It’d be like some disingenuous Christians who claim that even when God does bad things those actions are really good because God did them. Just as good and evil become meaningless terms when evil can be good and good can be evil depending upon who commits them, so too does the evolutionary process become a non-process if we must believe that it can produce X and also produce the opposite of X.

This is good:
So evolutionary success is based upon relativistic criterion. If I value shear numbers, then prokaryotes and eukaryotes are the greatest evolutionary successes. But if I value functional complexity, then perhaps ant or bee colonies are the greatest evolutionary successes. If I value intelligence, then we are king of the hill. Is this a correct extrapolation of your statement? -- Sincerely, Albert the Traditional Catholic

P.S. Didn’t get what you meant by “OP.”

Secular Pinoy

OP = Original/Opening Post

Danny - DD Cheerleader # 14344

Doubting Didymus

My dear, slave driving Albert.

You seem to have a habit of asking particularly good questions that require substantial answers. I think Morpho sums your questions up nicely:

1) Why/how did sexual reproduction first evolve?

2) Why is the inefficient process of sexual reproduction maintained?

3) What is the basis of extravagant sex-linked, overtly non-adaptive traits such as peacock tails? As a corollary, what is the basis of sex-linked, overtly non-adaptive behaviors such as avian courtship rituals?

Your first and second questions I have already dealt with in another thread, and I will spend some time digging it up and re-writing it. Your third question can be answered by the theory of sexual selection, which is one of Darwins own theories, though it is far more sophisticated today. I might go into this once I've finished with your sex questions, but there might be some helpful invisible elf around who has read Dawkins's discussion of sexual selection and positive feedback in weaverbird tails, who feels like tackling this one before I get to it.

Meanwhile, another article on the evolution of complexity has been brought to my attention, thanks to one Celsus, who is a user here or something.

The evolution of complexity, Adami et al.

It get technical, but the gist of it is that evolution DOES favour increasing 'genomic' complexity (defined here as an increase in the amount of correlation between the genome and the organisms environment, but only when the environment is fixed. Also, the genomic complexity will max out in restricted environments. If you think about how this applies to bacteria, you'll probably find that the 'simple' organisms you are talking about have approached a kind of 'maximum' complexity for their environment, while organisms with much more varied environments are going to have a much much higher maximum genomic complexity to reach for. This is harking back to that Law of Requisite Variety I talked about earlier.