Discussion of everything related to the Theory of Evolution.
Hello all, this is my first post in this forum. I used to be at the Richard Dawkins forum when it was still active and I've missed the interesting discussions.
Investigating the relationship between complexity, order and evolution has been a hobby of mine, for several years. I have come to believe that increased complexity is linked to trait variation and offers significant evolutionary advantages. Of course I know that in periods when selective pressures are strong, particular traits are favoured, reducing variation. However, natural selection usually leaves enough slack for 'useless' variations to appear, which eventually lead to more complexity. Now, the wonderful thing about all the complex organisms around us is that they exist because physics permits them to. A universe with slightly different laws might not be so hospitable to complex structures.
Although I've been an atheist for over a decade, there was a time when I was looking for a way to reconcile religion with science. I had come to the conclusion that creationists were fighting the wrong fight and that if one has the need to believe in a creator, one should accept that Genesis is a myth and believe in the creator of the big bang. The point is that people who want to believe can be left to believe and they can finally leave scientists alone. I recently discovered that such a turn may actually be happening, by reading this old post: http://whyevolutionistrue.wordpress.com/2009/05/13/biologos-pushes-dubious-science-why-the-evolution-of-humans-was-not-inevitable/ . I was surprised though, at the effort to disprove the inevitability of the emergence of intelligence.
I am not convinced by any of the arguments against the inevitability of increased complexity and I'd be happy to discuss them. However, the key issue is that I believe that biologists are now the ones fighing the wrong fight. There is a very good chance that the emergence of intelligence will be proven inevitable, because intelligence offers unquestionable evolutionary advantages. Why should we care if the answer can be used by theists to support the idea of a creator? If a deity's influence is pushed back to before the big bang, then woo hoo for science. It's somewhere science can not go anyway. I would understand a reaction to a theist claiming that God influences the world via Heisenberg's uncertainty principle, but I'm perfectly happy if someone accepts evolution, even as God's tool to produce intelligent beings. Am I missing something?
If intelligence was a truly superior trait, you'd see a lot more of it. It seems to evolve mostly as a side effect of sociality, as a way of dealing with a lot of disparate individuals in the group. And, unlike a truly useful traits such as flight, it doesn't seem to appear all that often (and needs to be very loosely defined to even be applied beyond humans). If it was inevitable, it had plenty of opportunity to arise over the last several eras, and there's no evidence to suggest that it did before now.
Complexity is tied to resources - if enough material and energy is available in a system, it's fair to expect complexity to increase over time.
Thank you for your response.
Would you? Human brains are so incredibly complex, that the likelihood of them appearing seems staggeringly small. Three things make it likely (maybe even inevitable at large timescales) : that physical laws permit such complexity to be robust, the vastness of the universe and ample time. We haven't seen the rest of the universe, so we have no idea as to how common intelligence is.
It hasn't appeared frequently on this planet, because it's so damn hard for a complex brain to evolve. That doesn't render intelligence less useful than simpler traits.
Again, we disagree on the likelihood. I would never argue that intelligence would inevitably arise on this planet, even in another 10 billion years. I would argue that given the number of planets and the billions of years, it would have to appear somewhere, sometime.
We certainly agree on this point. The argument on the post I mentioned was that the only reason organisms are more complex than they used to be is that there was only one way to go from single-cell organisms and that was towards more complexity. Examples of organisms that have dropped energy-consuming traits under demanding circumstances are often cited as proof that complexity does not offer advantages.
I have to disagree with your definition of complexity - a human brain has more processing power, and maybe circuitry devotions that are unusual, but I don't see them as particularly more complex than, say, a crow's brain. I wouldn't say that a supercomputer is more complex than a PC, at least not in a significant way.
Personally, I don't see intelligence as that adaptive. I think that the circumstances that support an intelligence such as ours are very limited. The other species in our genus, several of which seemed close to or as intelligent as us, have gone extinct...
Oh come on! How do you define intelligence? Are we still of the outdated opinion that animals do all the complex and fantastically clever things they do, out of 'instinct? Define instinct. If it has nothing to do with intelligence then one could say that the Earth revolves around the sun by instinct. All right so our brains are hard wired. If they weren't we wouldn't be able to see or hear. Even our speech is hard wired to some extent. As is the song (speech) of birds and whales etc. Intelligence is something that grows out of this hard wiring, and reasons. Its purpose is to direct interactions with the environment in a way beneficial to the organism it lives in. Without this direction it would be impossible for the organism to survive.
Increasing intelligence is rather like increasing physical offense and defense mechanisms in the organism, a part of the constant striving to keep up with the competition.
Props to the OP for a thought-provoking post.
I'm not sure what to think. I have always thought that cognition was the key advantage that allowed humans to basically (for a geological eyeblink) dominate the planet, but the sad fate of our near relatives does demand an explanation.
And then there is the concept of success; bacteria win by the numbers, after all. Just because we build cities and write symphonies, does that make us winners? Maybe the whole concept of "winning" is irrelevant here.
I never thought of complexity as a drawback before, but it does seem like the more complex an organism is, the more delicate it becomes, in a way: specialized and sensitive to perturbation.
I can't shake the notion that intelligence is almost universally advantageous. Granted, it doesn't ensure survival, but it's one of those adaptations that is useful in almost any environment. Maybe it's not always useful *enough*, but surely it's not a drawback?
In any event, I would agree that the question is a scientific one, and does not demand a theistic answer.Just because some theists would use it to justify their beliefs doesn't mean that it must be false.
If arguing with people on the internet helps me understand science, then I will do it. FOR THE CHILDREN.
I'm glad we agree that religious beliefs should be irrelevant to this discussion. Your questions go to the heart of the matter. The thing with simple life forms like bacteria is that they tend to become extremely specialized. Change the temperature or acidity a bit, and they will die off. There may be exceptions and I'll be very happy if and when we discover space-faring bacteria, living inside asteroids. It's not the number of an organism at any point in time that matters though, it's how likely it is that it will still be around a million, or even a billion years from now. The longer the timescale, the higher the likelihood of drastic environmental changes. A very strong test is which organisms might survive past the death of our sun. Space-faring bacteria aside, the only candidate is us.
I've read quite a few arguments in the same line of reasoning and I couldn't disagree more. The classic example is that of 'catastrophic failure', i.e. that a single part going bad might lead to the collapse of the entire system. IMHO, the systems provided as examples are in fact incredibly simple and that's why they run the risk of failure. Nature has come up which infinitely more complex systems than anything we have come up with. A body like ours is full of negative and positive feedback loops and hundreds of thousands of complex interactions between structures from simple molecules to autonomous organisms. Our bodies have evolved to predict what may go wrong so they can fix it and to be able to adapt to the unexpected (immune system, epigenetics). So I think that simpler systems are far more delicate than complex ones. As a final example, take a system consisting of a plant and a single insect species that can pollinate it. If the insect becomes extinct, so will the flower. If the plant can accept various insects though, its risk of extinction is reduced. A system with one plant and one pollinator is clearly less complex than a system with several possible pollinators.
I entirely agree that a complex organism is more highly adapted and therefore more likely to survive in changing conditions. But I think that by bringing in mention of specialist pollinators the argument has rather shot itself in the foot. Why should such incredible specialisms have evolved if they were not useful? The question is, useful to what?
There is the selfish individual ,the selfish gene, AND the selfish environment. The environment is always striving for complexity, and specialist pollinators and associations between for instance a specific mould and plant species, are a very good way of increasing that complexity. If a pair of organisms are in this kind of symbiotic relationship it makes it harder for them to hybridize with other organisms, thus preserving the complexity of the environment. A stable environment throughout its life produces more and more of these interactive complexities, often in long chains. If there is a perturbation to the environment, then some chains may be lost, but I would put my money on a complex environment surviving better than a simple one, for probably exactly the same reasons as a complex organism.
My example compared a simple network of two species with a network of more than two species. In this simplified world, no other species exist. The argument was that the simpler the network, the easier for it to break down. Specialization is certainly a prerequisite for diversity and therefore for the increase of the complexity of the entire ecosystem. However, a specialized pollinator would need to be complex enough to be able to adapt, after a possible extinction of the plant and vice versa.
I think we are in basic agreement Cakrit. The point I was trying ( rather badly)to make is that where you have a bird or insect adapted to pollinate only one plant, If the plant dies so does the insect and vice versa. So, as you pointed out this is a sacrifice. You lose two for the price of one. BUT if it was the only insect and plant in the environment there would be no need for any special adaptation. The adaptation is only there because there are a large number of specifically related plants and pollinators, and it is this special adaptation which enables them to be separate species, and part of a special cyclical niche. If one plant and its related pollinator die out it makes very little difference to the environment. But if a plant dies out that ANY insect can pollinate, this engenders competition in all the insects, and if the plant was one of only a few flowering at a specific time it causes a large imbalance. In other words, the more separate food chains there are in an environment the better. If one malfunctions the easier it is to replace by small adaptations in related species.
How does ecosystem complexity relate to individual organism complexity? Our cells don't compete with one another, and we can't evolve new types of cells like an ecosystem can evolve new species.
Looking at the context, I think it was a metaphor about having options. More biological pathways means more options (plus the possibility of repairative or regulative mechanisms). (See my emphasized quote below)
I will point out that complexity usually means multiplicity and/or variety. A complex of buildings consists of multiple buildings. A complex process has many unique and highly specific steps. If you have any qualms with my definition of "complexity", feel free to bring them up, but it's the definition that I'm working off of right now.
We could look at complexity in terms of cooperation. Each of us is a mass of cooperating cells. Bacterial populations cooperate too, they have quorom sensing, but AFAIK they don't differentiate into various types like our cells do. Arguably, this lack of differentiation (variety) is essentially a lack of complexity.
Quorom Sensing: http://en.wikipedia.org/wiki/Quorum_sensing - - http://www.ted.com/talks/bonnie_bassler ... icate.html
Now it's time to get speculative!
Be critical! Throw grains of salt in my eyes!
Twin studies reveal that genetic differences can't explain all of the human variation, meaning that each unique genome presents a spectrum of possibilities, not a predetermined outcome. This is because of the role of environment, C and E. Whether this is true of all multicellular eukaryotes, I don't know. I don't know the extent to which environmental influences act on nonhuman organisms.
Some of this wider potentiality may be due to our complexity. While I don't think complexity necessarily results in wider potentiality, that certainly may be the result. Imagine that you are flipping 100 quarters. If order is irrelevant, there's a mere 100 possible outcomes, of which a mere 10-20 are even likely to occur. But what if you're flipping 25 pennies, 25 nickels, 25 dimes, and 25 quarters. There will be 25×25×25×25 possible outcomes, a wider potentiality.
I wouldn't say that all malleable complexity is intelligence, but intelligence does seem to be a sort of malleable complexity. As I ponder this, I wonder if our environmentally induced variation can be attributed to our use of intelligence to choose between survival strategies. We use our intelligence to consider which survival strategy might work in our current environment, and we make a choice. For us, a change in the environment induces a change in strategy. For an organism with narrower potentiality, a change in the environment will likely result in death. Of course, this isn't a big problem if the organism's environment is pretty stable. Maybe this is why some organisms get simpler, as with the tapeworms mentioned in your link.
However, I want to argue that there is complexity in our culture too. It's often said that socialization spurred us to develop bigger brains, but consider what a human is reduced to without socialization. Imagine a wild child that grew up without the benefit of culture, or imagine a human left without language because of a mutated FOXP2 gene. They seem just as complicated as us, but they aren't superior organisms without the benefit of transmitted knowledge. The transmission of knowledge seems to be why, for us, intelligence is clearly worth the cost. A human can focus on learning science rather than on doing all the science themself, which is far more efficient. So it might not be entirely correct to attribute all of this advancement in knowledge to our complexity as individuals.
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