I have been thinking: the term natural selection means that natural conditions, over time, produce the best creatures for the environment. Correct?
Doesn’t this imply that nature is intelligent?
No, it happens by itself. Let’s say a hundred men are trapped on a raft in the ocean. If there isn’t enough food or water, the weaker ones will be killed by the stronger ones. Once the remaining ones are rescued, there will only be strong men left. This doesn’t mean that the raft or the ocean or the ship that sunk are intelligent.
Natural selection works the same way. If a species of small mammals live where there are lizards that like to eat small mammals, the mammals that are best at avoiding lizards will survive to have children; the others won’t. Thus lizard-avoiding is inherited from parent to child, and soon the small mammals are very good at avoiding lizards. But mammals aren’t intelligent, nor are lizards. It happens entirely by itself.
The men on the ship make this hypothetical judgement (given of course that the strong ones are all rational egoists): “There is limited food, I must try to ensure my survival, I will take what I need forcefully.”. The ship is not intelligent (it got sunk after all) and nor is the raft, but quite clearly intelligent behaviour is involved.
You are mistaking sentience for intelligence here, even some small insects display intelligent behaviour (although in much smaller proportion to conditioned response).
But my point is that the underlying mechanisms, of DNA as a dynamic code for life changes only due to the reason inherent in the processes of nature.
Intelligent behaviour is involved, but that doesn’t make nature intelligent.
Yeah, I did mean “sentient” rather than “intelligent”, sorry about that.
Yep. How does that make nature intelligent? That’s like saying the stock exchange is intelligent because some people make money there while others go bust.
If an organism is not suited to its environment, it stands a greater chance of dying before it procreates than an organism that is better suited; there is no evidence to suggest that the process is anything other than purely mechanistic.
In the sense that it achieves something when perhaps it might not have done, I suppose you could call that intelligence, but I think it would be stretching the definition too far.
Intelligence implies the ability to plan, exercise judgment and rationality; evolution by natural selection does not do this - it just tries loads of different things and a few of them work, others do not work.
Under identical conditions, an intelligent force would be less inclined to retry something that previously failed miserably; there is no reason to imagine that nature would exercise this sort of restraint.
There is an interesting flip side to natural selection that most people forget about–sexual selection. There are plenty of examples in nature where mating habits cause a species to become weaker. The peacock and his ridiculously large tail feathers is the most obvious. Can I use this to prove that nature is brutally incompetent?
This is a great question! Parallels might also include:
Why are humans the only animals to have evolved consciousness?
“Societal intellegence” continually advances forward (we are individually smarter, on average, than humans were a 1,000 years ago) does this mean that intellegence also evolves?
(Ex: The more intellegent members of society tend to live longer, have more kids, etc??)
Is intellegence an “by-product” of communication? For example, if dolphins (or mice…) had greater population density, would they also develop “societal intellegence”?
Very interesting questions!
I don’t think so; the peacock must be at least adequately suited to survival in its environment, otherwise there would be no peacocks.
We don’t know for sure that we are.
One would assume so, but I’m not at all sure that humans are objectively smarter today than a thousand years ago, if such a thing is even possible to measure.
Depends on what you mean by “societal intelligence” (note that it’s intelligence), but it’s probably impossible to know.
I guess I didn’t evolve along with the rest of you… I can’t believe I typed that, I always spell intelligence correctly… maybe my subconsious is trying to send me a message…
You’re right of course, it is hard to quantify intelligence. I could try to use the argument of literacy rates, but you’d undoubtedly point out that perhaps 1,000 years ago if the King of England held a literacy campaign the rates would equalize.
Maybe we haven’t gotten any smarter (see typo) perhaps our collective knowledge has grown merely because it was written down (you don’t have to reinvent the wheel every generation.) But what does the collective knowledge of a society mean in an evolutionary perspective? Is that a trait we developed (written history that is)?
That’s a pretty big raft.
Actually, let me give you an example does not involve intelligent self-selection of the group:
Realisticly, 100 people trapped on a raft are not going to start killing each other (since they expect to eventually be rescued). But a raft in the middle of the ocean is still a pretty harsh environment. After awhile people will start to die of natural causes. Heat stroke, dehydration, malnutrition, getting swept overboard and eaten by sharks, hypothermia, etc. As the environment gets more extreme, those individuals with the traits that best enable them to survive - strength, stamina, creativity, will to live, etc - will have the best chance of being rescued.
No intelligent behavior is involved, except perhaps individual intelligence in coming up with ways to prolong survival.
Nature isn’t perfect and animals don’t have to be either. There’s an old saying - You don’t have to run faster than the cheeta, you just have to run faster than the slowest guy in the safari.
Think of a given environment as a set of parameters which allow a creature to live: it must be able to tolerate this range of temperatures, it must contend with this many competitors, it must deal with this amount of food and water, etc.
Because the individuals in most species will vary in differing aspects, some of these individuals will possess variations of the “core” traits for that species which will either fall outside the range of acceptable parameters, or within the range of acceptable parameters.
On average, those who fall outside this range will either not survive long enough to reproduce, or will simply never get the opportunity. The genes possessed by those individuals which fall into this category do not continue - such traits are considered to be “selected against”.
Those who possess traits which fall within the range of “acceptable” parameters will, on average, survive to reproduce. Their genes will persist to the next generation. Over time, the composition of this population will tend to become such that those traits which best “fit” the environment will persist, while those which do not fit are removed.
Note also that there are some traits which, regardless of the degree of variation, have no affect on the survival of an individual in a particular environment. Such traits are considered “selectively neutral” for that environment.
As environments change, the parameters for survival change as well. Thus, what may have been useful in one environment may now fall outside the range of survivability in a new one. Similarly, traits which may have previously been neutral may now become either detrimental or advantageous.
There is no guiding force, nor is there even a single selecting force. Heat tolerances may act separately from food scarcity to weed out different individuals in the same population. It is the sum total of all the different “weeding” factors which is referred to as “natural selection”.
An argument can be made that intelligence is a consequence of Natural Selection, but I’m not so sure about that argument going both ways…
Sure, but if nature was intelligent, you could argue that the peacock would have a “better” design. A large tail isn’t necessarily “fittest” as far as movement or escaping predators is concerned, it’s selected based on choices made by peahens. Of course, these choices generally start as indicators of characteristics that might make one male a fitter mate than another (ability for getting food to fuel the energy costs of tail growth, ability for escaping predators even with a handicap, etc).
I did some googling to link to the classic “retina wired backwards” design argument, and came across an interesting refutation here, included with some other examples of “bad” design. While the site is biased towards intelligent design, the arguments seem plausible to this non-biologist. Of course, I’m not planning on dropping my belief in evolution and natural selection, but it does remind us that what we think is a poor design might not be considered as such by either natural selection or Creator-of-your-choice.
I have a question about the ‘intellgence evololution’ aspect of this discussion. Do you feel that we as a species have stopped evolving? It seems to me that once we started getting so concerned about making sure the weakest of us could survive (welfare, handicapped parking(God I sound heartless), fast food, etc, etc…) we stopped evolving into what we possibly could be. Technologically we advance, but physically we deteriarate into fat, lazy individuals. What do you think?
Random mutation is an aspect of Evolution and Natural Selection, although the frequency and hereditary signifigance can be debated. Changes in environment can also make an organ or other structure that was not a “deal breaker” for one organism, into a key aspect of survival for another. IIRC, the retina issue was discussed in my Evolution class (an undergad level course devoted to the many facets thereof) proposing that the retina may have evolved the way it did due to ancestral invertebrates moving in and out of different light environments. Seemingly “inefficient” structures/orientations may have evolved in environments where light processing was not crucial, and when the environment changed such that processing light was crucial, natural selection started doing the best with what it had. In the case of the vertebrate retina, what natural selection had to work with (at some point in the past) were structures that were upside-down and backwards from the most efficient design, and the apparent reproductive success of creatures who could still use the given structure, in some manner, to process light.
A better example than the peacock might be the (now extinct) Irish Elk. The vehicles by which Natural Selection operates can be far from “perfect”.
HoviBaby… while I often agree that as a society, humans seem to have hit an evolutionary slump of sorts (and sometimes even regression to more “primitive” states), the Human animal cannot escape Evolution, even with all of our environment manipulation. There are genes being passed down as I type (in the back seats of cars everywhere) that will ensure the survival of some lineages, and genes that are not being passed down that will ensure the demise of others.
Have you ever met some of the peole that are allowed to have children these days??? Many early hominids weren’t given the opportunity to have children, either because they died before they were able (physical weakness), were ostracized by thier peers for physical or mental weeknesses, or couldn’t get a date because their cars had square wheels. If they did have children, the chances of thier offspring surviving were slim to none, as they would be destroyed if they exhibited any signs of weakness; you couldn’t have the dumb guys kid slowing down the clan all the time. Easier to kill it. But now, we don’t stop the less intelligent, less physically able from procreating. It’s an open market; “if you got the parts, give it a whirl” type atmosphere. And if anything, it seems like the lower class reproduces more than the upper class, which is the reverse of what would be historically accepted. So if you look at it this way, we have come along way to be moving backward.