Evolution and complexity
 

In the process of billions of years of natural selection, is there an inexorable tendency to higher complexity?

Why did intelligence evolve in animals? Why did it evolve so highly in humans?

If these questions are interesting to you, then the following PDFs will be fascinating. One of them needs to be rotated left in Adobe, but it is entirely worth the read.

http://filebin.ca/wqonxk/Rescher.pdf
http://eplex.cs.ucf.edu/papers/lehman_gecco10a.pdf

---------- Post added at 04:25 AM ---------- Previous post was at 04:16 AM ----------

(I'm aware of a hard, fast rule on the forum that I am required to leave my own "discussion material" in addition to whatever else I link. Having used forums for many years, I have come to notice that if I do provide my own discussion, the forum users inevitably use this as an excuse to not watch the videos, to not read the PDFs, and to not actually read the article I link.)

Having said that. I happen to be a person who believes there is an inexorable push in nature towards higher complexity. This puts me firmly against the philosophy of Richard Dawkins. It may also place me against Dan Dennett.

In the interest of keeping this thread from being closed within a few hours by anxious moderators, I provide a list of items which appear to support my position.

1. The philosophy of Teilhard de Chardin.
2. Genetic Drift as a means of biological change, or even speciation.
3. The Baldwin Effect. In a nutshell, says that when organisms gain the capacity to learn, evolution is sped up dramatically.
4. The work of Stuart Kaufman and Ilya Prigogine.

Based on the preponderance of simpler life extant, I think the tendency towards higher complexity is less than inexorable. Intelligence evolved as part of the group of traits necessary to survive being more complex, I believe, & that the fact of complex life demands more of the same. I think also that the "spark" is inherent to varying degrees for a goodly distance down the ladder. As to why, I'm not even sure why I think that.

I wasn't able to read your first link on this computer...I'll look at it elsewhere.

evolution is continuous across all scales and has no single direction. so no.

Complexity within organisms isn't a goal of evolution, rather it is an outcome of environmental pressures---natural selection, as you have mentioned.

The development of the human brain was an outcome of natural selection in that the most intelligent and socially adaptable humans were the most fit within the environment they were subject to, and so those traits were passed down into future generations because of a higher survivability rate.

Other species remain simple and yet have a high level of fitness. The cockroach for example has a greater environmental fitness than humans if you consider the extremities, and yet they can be said to be nowhere near as complex as we are.

Microorganisms adapt and evolve much more quickly and efficiently (and often) than do more complex life forms, yet they continue to maintain a painfully exquisite simplicity.

Tapeworms are an example of evolution leading to decreased complexity; by living in a host's gut they eliminate the need for a digestive system of their own. Natural selection doesn't increase complexity per se, rather it encourages changes that increase fitness regardless of complexity. As natural selection presumably started with organisms about as simple as possible, most of the beneficial changes happened to be in the direction of more complexity.

Evolution favors success. Complexity can both aid and hinder success. I don't know if it makes sense to average (maybe the median would be more appropriate?) complexity across all life, but I suspect that we've had enough continuous evolution on this planet that this average level of complexity would be pretty stable with respect to time.

Joel Lehman characterizes the complexity in humans as a "Rube-Goldbergian digression." I thought that was kind of funny. I would say he agrees with your claim that "Evolution favors success", because he sees successful reproduction as minimal criterion. Evolution is then finding a myriad of different ways to do this same thing.

In any case. There are other forces at work in changing organisms other than Natural Selection. (If by "natural selection" we mean a straight line towards fitness via competition). I will name several. Genetic Drift, Negative Frequency-dependent selection, and the Baldwin Effect. Frequency-Dependent Selection was mentioned in Lehman's PDF above. If you have never heard of it before, here is a good lecture on it.



---------- Post added at 10:33 AM ---------- Previous post was at 10:10 AM ----------

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Was anyone able to read the chapter in the first PDF?

For those of you can, but are not interested, it talks about the Drake Equation. This is used to calculate the probability that there is other intelligent life in the galaxy. Your personal opinions on the evolution of complexity and the evolution of minds makes a huge difference to how you form the Drake Equation. I had never made a connection between these two things in my mind. If human beings are an accident of an accident, this opens up the real possibility that we are truly alone in the galaxy.


My next question -- did anyone here actually read the PDFs I linked?

There is an implicit fallacy in your question... there really is no "direction" to evolution. Evolution is nothing more than statistics in action. There have been many, many, many evolutionary leaps that had tremendous survival/success potential. Unfortunately, they took place at the wrong time/place and the mutated organism did not survive to pass on the trait. Evolution rewards success only, not complexity, not size, not efficiency. And the most successful organisms are actually the simplest.

An organism that mutates in a manner to more efficiently exploit its environment will succeed ONLY if it manages to reproduce. Faced with an established, competing, less efficient organism that already dominates that niche, the mutation stands a good chance of never succeeding.

Biological evolution is NOT a process of creating better and better organisms. It is merely the statistical proliferation of organisms to fill all possible environmental niches. It is proliferation, not necessarily improvement.

To an outside observer, it might appear that the process of evolution has been guided either by bacteria or viruses. Many bacteria subsist through the bio-degradation of more complex bio-material provided by the more evolved (?) organisms. Hence, they promoted more and more complex organisms to provide better food sources. Viruses need organic hosts for reproduction, and so developed bacteria and then more complex life-forms to provide just that - the appropriate hosting mechanism. In this light, evolution is guided by the needs of the simpler organisms.

An odd argument, but it illustrates the fallacy of assuming that intelligence is "evolutionarily desirable". There really is no such thing. What is desirable is that which breeds true. Is there an environmental niche that promotes intelligence? If so, it will succeed. If not, it won't. Given our current state of affairs, I wouldn't be surprised if, in a few millennia (no time in evolutionary terms), evolution has ruled out intelligence as a desirable trait.

We can imagine a future scenario where sentient life leaves the earth and ends up colonizing the galaxy. I take it you don't find this story very compelling.

Did you read the PDF by Rescher?

Yes, I did read the PDF. It is an interesting philosophical discussion, but I discount almost all of his rather esoteric, flawed analysis because of his tendency to make sweeping pronouncements of opinion as fact.

Do I think we will ever be able to move beyond the Earth? I dearly hope so. Unfortunately, these days I despair of getting much beyond the end of the year (mixed spatial/temporal analogy, I know).

It is an interesting read , but fundamentally ignores an awful lot what was known even in 1985. His understanding of what constitutes science (versus technology) is completely at odds with reality.

Natural Science (as opposed to Social Science), by its nature, and regardless of the starting point, will lead to the same fundamental results, not inherently different understandings of the universe. Intelligence may result in flawed hypotheses of the basic workings of the universe, but science WILL overcome those as amassed experience dictates changes in those hypotheses (assuming the intelligence is combined with some time-binding ability). He confuses technology with science.

As for the rest of his argument regarding intelligence... it falls simply into the philosophical. Again he makes sweeping assumptions of intelligence that cannot be refuted because they fall outside any possibility of experiential confirmation. Is there an evolutionary imperative to intelligence? Of course not. Evolution has no imperatives. It is random. Where there is an evolutionary advantage to intelligence it will occur. Could that be in a mole-like creature? No one can say. Could it be in a non-carbon-based life form? No one can say. It is an inherently moot philosophical question. I can argue just as well as he that there is an absolute bias for intelligent technological life, and that the Universe must teem with it.

Finally, he simply fails to understand the enormity of time and the basic concept of time-binding (the passing on of learned knowledge). His comparisons of human civilisation are of necessity incredibly limited in that aspect. An intelligent organism capable of time-binding will eventually form a society of some sort. If that develops into a civilisation, the mere fact of time-binding WILL lead to technological change and advancement. It is the existence of the civilisation that will form the technological imperative, not simply the intelligence (one of his points). However, the rest of the his argument simply relies on too much assumption to be anything more than speculative.

I feel you are mindlessly regurgitating the Richard Dawkins mantras. I understand his book was very popular when it came out. A gene-centric view of biology is fine, but its not all that is out there.

Is there some aspect of the Drake equation you completely disagree with? Rescher appears to be far more conservative than Sagan was with the same variables.

When you say "random" it is almost as if you mean to say anything and everything is possible with evolution. To answer this you will need to be more specific about what you mean by the word "random", when you say evolution is random. There may be upper bounds on it, that even Dawkins is unaware of. It seems to be that a single upper bound on evolution No matter how small, insignificant it may seem to us -- that will cause the process to no longer be random (in any sense of the word random).

An example of what an "upper bound" means would be, for example, something to do with the range of temperatures in which water is liquid, for instance. This could later come to have unforseen effects on the distances planets can be from stars and then put limits on the energy available to ecosystems, and so on. Then we get small bounds on "what is possible". In turn, arguments for "randomness" look weaker.


Time-binding. (Time measuring?) What are you saying here?

In General Semantics, time-binding is the attribute that separates animals from humans (or non-sentience from sentience). It is the ability to perceive and be aware of the passing of time; of aging; and the ability to pass on learned knowledge. It is a basic requisite for the understanding of self versus non-self. Time-binding implies the ability to progress through the use of knowledge accumulated by earlier generations.

For a long time it was felt that humans were separated from animals by our use of tools. We now recognise that many animals use tools instinctively and in in surprisingly intelligent fashion. But they do not learn this behaviour, it is inate. Humans (all sentient beings) are able to pass on what they have learned, and thus build on that.

I can't speak for GreyWolf, but I think you're confusing terms here. "Upper bound" is a term that has implications in formal statistical theory. The number of possible outcomes in all real random processes are bounded. That doesn't make them less random. The classic example is the flip of a coin.

Evolution is essentially random, in that it can accurately modeled as a random process. Whether anything is actually random is a philosophical question wholly separate from the success of random models at accurately describing reality.

Whatever #'s might provide, evolution's randomness has only been random in its production of such as us. Evolution's joy is in what it does. Our living belief in what it is comprises what we would tend to be. What floor are we on?