Dogmafood Message 57: Intelligence is certainly not a prerequisite for survival. But if you take 2 cephalopods and one is more intelligent than the other, which is more likely to survive any particular environment?
My guess would be that it would be marginal in some situations and neutral in others, that intelligence needs to be considered to be more important when communication is involved.
jar Message 58: No idea. If you take 2 humans and one is more intelligent than the other, which is more likely to survive any particular environment? I have no idea there either. A bunch of the brightest most intelligent folk I knew were dead before they were 25. Also irrelevant. Biology and evolution involve populations not individuals.
And your anecdotal evidence applies to individuals not populations. If the advantage in organisms with intelligence is marginal or neutral then it can spread within the population until a level is reached where some threshold his passed. That threshold, imhysao, is when communication kicks in.
Blue Jay: But, with intelligence, a single individual can learn how to exploit a new food source within a single lifetime. And, the more intelligence, the more new food sources an individual can learn to exploit in a single lifetime. This is highly useful in a variable environment, or in an environment in which food is difficult to find.
What we see in other species that we recognize as intelligent in varying levels up to where some select apes are measurable more intelligent than some (clinically moron) humans ... is the ability to communicate.
A single organism that learns how to exploit a new food resource or other means of survival will have an advantage in some situations compared to the others, but when it can pass that information to others then the whole population benefits.
We see many animals (mostly mammals) where the young stay with the mother for extended periods learning how to survive. A mother bear cares for their offspring for 3 years or so (iirc) in order that they learn how to use the available food sources. Birds teach their young how to find food, and many other examples exist of similar teaching of survival behaviors.
Dawkins coined the term "meme" to refer to this passage of knowledge from one generation to the next within a breeding population.
That intelligence offers evolutionary advantages is pretty obvious.
That intelligence + communication offers evolutionary advantage is documented fact.
Give a person a fish and you feed them for a day, teach them to fish and you feed them for life, teach a village how to fish and you improve their overall ability to survive.
... my personal opinion is that curiosity and creativity are more important aspects than plain vanila intelligence, and this accounts for some anomalies in humans -- high IQ people are not notable for attracting mates, rock stars are. Imho, sexual selection of creative people (artists) is increasingly more important in the recent (last ~8million years) evolution of humans than survival selection. See Sexual Selection, Stasis, Runaway Selection, Dimorphism, & Human Evolution for more of my thoughts in this regard.
The inevitable rise of intelligence through evolution
If intelligence is a beneficial characteristic (which I think is undeniable) then does it not stand to reason that organisms with more intelligence than their co-habitants ...
... will evolve?
Yes, it seems to me that it is inevitable - you can't get stupider than dead but there is no limit to how intelligent you can get, and this results in a skewed curve with lots of comparatively low intelligence organisms but no limit to the top end ... the pattern we can see -- even within humans (an IQ of 50 or less cannot survive iirc, while the average is arbitrarily set to 100, and there are a lot of people with over 150 IQ ... meaning there are as many people between 50 and 100 as there are over 100 ... including the ones between 150 and 200).
There are also several stages we can see in the development of usefulness for intelligence:
marginal intelligence, marginal or neutral survival benefit
communication, allows memes to be passed from one generation to the next
self-awareness, allows cognition of self as an entity within a larger whole
tribe awareness, allows cognition of the value of cooperation with other humans
global awareness, allows cognition of the value of all organic life in an integrated whole for long term survival (a process we seem to have trouble getting through)
There may be more.
If this is true would it not lead to an accumulation of intelligent creatures over billions of years and billions of planets?
Again, yes. In my personal opinion, if there were a purpose behind the use of evolution by and intelligent designer, that it would be to create intelligent organisms, that we may just be one stepping stone or one trial along that path that is still evolving.
Re: The inevitable rise of intelligence through evolution
I don't see the need to invoke 'purpose' but just looking at it as a process of refinement where the more intelligent creatures are more likely to make it through the sieve...but that is just the atheist in me.
Which is why I specified it was my personal opinion (just as atheism is your personal opinion).
Also, with regard to memes, as the general level of education of a population increases do their chances of survival not also increase? We may not be more intelligent than our ancestors from the 14th C but we are more able to survive, say, a plague or an asteroid attack.
Education would be the passing of memes from one generation to the next.
Technology is also the accumulation of behaviors for making things beneficial to survival (among other things), ie - expressed memes ...
Just as when you build a new business you build it on the shoulders of those that built all the things you use to form your business.
While it's difficult to declare a clear link between brain size and intelligence, there have been cases of species evolving smaller brains. The article I originally read on this subject was about bats, and about Homo floresiensis, but I can't find it now. Possibly, they just stumbled across a more efficient way of being just as intelligent with a smaller brain capacity. But I don't think we can dismiss the idea that, in certain environments, the greater energy efficiency of a smaller brain outweighed the advantages of being a bit cleverer.
What I remember is that it not so much size as it is surface area and interconnectivity. Male and female brains are different sizes on average but have the same degree of surface area and interconnectivity.
Increase in area and interconnectivity can also be seen in the degree of wrinkles in the outer layer. Apparently (iirc) one thing of note from Einsteins brain was a high level of interconnectivity between the two halves.
Is there any species who's evolutionary history shows that they have become less intelligent over time?
Well, intelligence is a difficult thing to measure, so that's hard for us to say, but I'd say it's probable.
I would agree -- evolution is a drunken walk that staggers back and forth -- in general.
But I also think there are thresholds, that intelligence alone is not sufficient to predict survival and reproductive success. Communication is such a threshold, with the ability to pass memes to following generations. Of course memes can be deleterious, neutral or beneficial, and they can change status in different ecologies ... but that they are a part of the hereditary lineage of a breeding population.
To balance and move in a single direction. This is also done by snakes and worms by using peristaltic muscles along their length.
But once you get up on legs, I am not so clear. Consider a fish\amphibian evolution where the front fins become hand\fins and then legs and arms, while the tail becomes foot\fin. A resulting organism could be a hopping animal or a three-legged runner with a gait similar to a horses gallop.
Technically it could still be bilateral, but the tail/leg would not have to be for it to work (perhaps it forms into a spring for instance).