General Question

iamthemob's avatar

Assuming the that the theory of evolution is true, does human intelligence work to slow down our evolution comparatively?

Asked by iamthemob (17123 points ) September 24th, 2010

The theory of evolution works based on (in simplest terms) the concepts of natural selection, isolation of populations, natural selection, and spontaneous mutation which is both beneficial and inheritable.

Assuming that this is exactly what causes the diversity of life on earth, the fact that we’re intelligent undercuts many of these factors. Intelligence allows human beings to adapt themselves through various environments through tool usage. And with modern medicine, we prevent the demise of individual examples that would not have survived naturally in the environment, all other things considered. And because we’ve become a “global phenomenon,” there is no real isolation of populations, and where there is it doesn’t seem it will be permanent.

Therefore, it seems that the one thing that might cause an evolutionary change in humans is spontaneous beneficial genetic mutations, such as those fictionalized in the X-Men. If this is the case, pre-mutation humans will be equipped to continue surviving on their own if they choose not to interbreed.

In this sense, do you think that intelligence is actually an evolutionary hindrance rather than a benefit?

Observing members: 0 Composing members: 0

31 Answers

laureth's avatar

In those cases, the ability to make tools would probably allow us to adapt to many more environments, thereby allowing more children to happen. As far as diseases, a lot of the ones that kill us off now are old-age ones like cancer, which tend not to happen until you’ve had kids anyway. If it doesn’t kill you before you breed, it matters less, evolutionarily speaking.

One thing I notice, though, is that the number of children a family has seems to decrease as the education level rises. (I like to think of it as the “too smart to have kids” factor… I am childless, yet some drunk teenager who gets knocked up has won a place in the next generation and I have not.) This would seem to be detrimental.

cockswain's avatar

I thought a similar thing recently. As you mention, advances in technology allow the preservation of individuals that would have surely perished before reproducing fit young in a less advanced, compassionate environment. I would say the human gene pool is widening greater than ever due to flows of populations, but within the context of your description you make a reasonable case our advances may be slowing evolutionary change. But at such a tiny, tiny rate as to barely be measurable.

Simone_De_Beauvoir's avatar

Hmm, I am under the impression that intelligence is a trait that aids people in survival – I have read that it has been intelligent people who can think outside the box at times that have helped our entire race along when the masses were unable to figure out what to do. In general I don’t think it’s all about biological evolution these days or…rather biological and social evolution are completely interconnected. Our brains have evolved to conceive of the technology we’re discussing and I’m all for pushing the limits of our intelligence, regardless of evolution – I consider myself more than an evolutionary imperative.

lillycoyote's avatar

Overall intelligence is more beneficial than harmful, but yes, modern medicine certainly has had an impact on “natural evolution.” But that has been the case with humans for a very long time. There is sort of a feed back loop between our evolution and our intelligence, the evolution of the brain itself, and our ability to use tools, for example, our ability to adapt to our environment and to manipulate and control our environment to make it adapt to us. __Homo habilis__, e.g. made and used stone tools 2.3 million years ago. That has been a part of the human evolutionary process for fairly long time. But there are other issues involved. We just need to keep one step ahead of ourselves. We are smart enough to have invented and manufactured a nuclear arsenal that could cause our complete extinction in a relatively short time. Hopefully, we are smart enough to understand that cooperation has also always been an important evolutionary strategy in many species, including humans.

iamthemob's avatar

@cockswain

I don’t know if it’s such a tiny rate though – considering that it seems most development intraspecies seems to be due to adaptation to environmental pressures and the natural selection working do to that…that seems to be the faster mechanism at work. So we may not notice it because, as required, the evolution takes place over time, I think that the human population will not exhibit new features or more adaptive features due to those pressures and only through mutation…which means that until mutation, we may not really evolve at all…

cockswain's avatar

@iamthemob Well, likely our intelligence and ability to overpopulate and ruin resources could contribute to our quicker demise, thus undercutting our evolution. So from a natural selection standpoint, I agree with what you’re saying. But from a genetic perspective, the mutations happen so slowly.

I like what lillycoyote is saying, in that staying a step ahead of the game is critical. But we’re really narrowing that edge.

iamthemob's avatar

@cockswain

In that sense, though, in either case we’re slowing our evolution down…either because we are not forced to adapt to the environment and continue this way, or we overpopulate and misallocate our resources so that we die off a bit, which is a non-natural force and doesn’t require we adapt to the environment, but rather we change our strategy in adapting it to us.

So it’s solely the mutation factor – which is basically us waiting for our bodies to randomly evolve us.

Further, again, if there is a mutation, there’s nothing to say that there would not be one species of human and then us still, holding on and waiting for the next mutation to create a third….

cockswain's avatar

Also our populations flowing throughout the planet (rather than isolating populations, which speeds speciation) will slow humans from forming new species. Not that that is either good or bad, just less likely to occur.

But if you consider a nuclear holocaust, with isolated pockets of survivors cut off from each other around the world, given enough time and interbreeding that could spawn separate human species that couldn’t mate. The nuclear holocaust would have derived (arguably) from our intelligence. So we would have increased the rate of evolution. Hmmm….

lillycoyote's avatar

@cockswain Unless there are no human survivors and then it’s the end of the game.

cockswain's avatar

@lillycoyote A very narrow edge….

iamthemob's avatar

@cockswain

Given our ingenuity, though, do you think that the populations would remain isolated long enough for full speciation to occur?

We still have populations that have, for all intents and purposes, been isolated for thousands of years. They are still human, however, and we would have no problem interbreeding with them (think of Amazon tribes, for example, and the Spanish tactic of breeding out the native population in modern Mexico to make a race caste system).

cockswain's avatar

Yes, I guess that’s true. We’d find ways around again. We’d have to have our intelligence devastated through the holocaust, and that would have proven your point too. You might be on to something.

iamthemob's avatar

There’s no reason, of course, to say whether this is beneficial or harmful, in a general sense.

But it’s kind of weird, because, in essence, it becomes reasonable to claim that evolution ends with us…

ETpro's avatar

Great question. The answer is not entirely clear. We aren’t a fast evolving species to begin with. Granted intelligence and the use of it to adapt to changing environments gives us the ability to buffer our survival against environmental stresses that might force change in other species. But viruses and diseases can interact with us as well as with less intelligent species, and we do not always know how to counteract their effect. For instance, one might expect that cycle cell anemia would soon eliminate itself from the human gene pool, but this has not happened. One reason it hasn’t is that it confers immunity to malaria. So in areas where malaria takes a large toll on human life, cycle cell is at least as much pro as con survival.

A far more powerful complication is that we are now turning our intelligence toward deliberately fiddling with our own genetic code. What happens when we do that, and I have no doubt that we will, is an open guess. Probably good and bad will come from it. Nature will decide which survives. Full speciation could also easily occur if we begin to colonize distant worlds via space travel, and a population remains isolated for long periods with completely different environmental stress factors than their Earth-bound cousins face. And so our intelligence in the long haul may accelerate rather than impede our evolution.

All I know for sure is that at my age, I probably don’t need to concern myself with it.

iamthemob's avatar

@ETpro

Interesting point regarding colonization. However, this would really have to occur (1) outside our solar system, and (2) with space travel subject to limitations of relativity.

If there’s an ability to travel between the planets still, I doubt that you’d be able to see full speciation, considering again that it would require far more isolation than we’ve seen since the dawn of civilization.

Nullo's avatar

Perhaps this is more akin to a possible case study, but eh.
I’m rather of the opinion that the creation of the computer – by far our finest tool – will eventually quash other sorts of technological development. Why go to the moon in person when you can remotely pilot a robot in your place for less money? Why pursue long-range spaceflight when you can just simulate it?
Is it stagnation? Would we simply have plateaued?

iamthemob's avatar

@Nullo

I’m not sure how that’s responsive to the question.

Pandora's avatar

Our minds will build and grow and then we will be able to read everyones thoughts and spontaniously heal our selves and grow limbs like starfish until we can breed no longer and then as we die off some of us will ascend into a higher being of conciousness, no longer requiring our human bodies.
Or we will all get fat and lazy and the human race will die from obesity and not be able to reproduce.
Pick one!

Nullo's avatar

@iamthemob I was using the development of technology as a model for your question—one of evolution’s greatest flaws is that nobody has actually seen it wreak large-scale changes. Technology, on the other hand, is driven by similar forces and acts quickly enough that we can observe it doing so.

iamthemob's avatar

@Nullo

The question is very narrow and we are assuming the evolutionary model is true. There is no need to introduce other models by analogy.

Nullo's avatar

@iamthemob The question is narrow, but my mind is broad. I often think in terms of analogy, and as it happens, that’s how your question parsed.

FireMadeFlesh's avatar

I have no evidence for my opinion, but I’ll give it anyway. I tend to think that evolution in humans has reached a point of equilibrium. Humans with beneficial and detrimental mutations survive, so natural selection has been made largely irrelevant as a driving force in genetic evolution. Humans have globalised to a point where we will live or die as a group, and we are subject to group selection a lot more than individual selection.

Intelligence has given us memetic evolution though, which is now far more powerful than genetic evolution.

lillycoyote's avatar

@iamthemob Ask this question in a million, or better yet, two million years and you will most likely get entirely different answers. Humans aren’t bacteria. ;-)

ETpro's avatar

@iamthemob I was thinking more of launching a vehicle that will take generations in flight to reach a distant star. We may seek distant colonies due to resource needs or to an impending cataclysmic event, say a planetoid we discover is going to impact Earth, or who knows what. A supernova of a nearby star.

My bet is with that of @FireMadeFlesh. We are not done changing yet. But what will drive that change has already changed.

iamthemob's avatar

I never really considered how significantly we differ now from potentially every other species on earth in terms of the evolutionary pressures on us…

mattbrowne's avatar

Yes, intelligence can actually be an evolutionary hindrance rather than a benefit. The reason is our ‘gas-guzzling’ brain. Downside 1: it burns more calories than any other organ in our body. Downside 2: only small heads can get through the female birth canal, so human babies and children require longer protection than any other mammal.

An excellent book exploring this issue is

http://www.amazon.com/Evolution-Stephen-Baxter/dp/0345457838/

The author explores the speciation of two human species over the course of 100,000 years which includes one less intelligent species better adapted to a changing environment.

ETpro's avatar

@mattbrowne Great points.

iamthemob's avatar

@mattbrowne

I agree – great points.

I don’t know if the fact that we have a longer rearing period is a detriment or a benefit to selection processes though. In conjunction with the longer rearing period, we have a significantly reduced connection between mother and child when compared with other comparable organisms (e.g., chimp mothers will remain in constant contact with their children, whereas human mothers are much more inclined to leave infants in the care of others). Along with that, we have developed an uncanny ability to read the intentions of others because we have to know whether the person we are left with has the intention of helping or harming us.

I’m not saying this overcomes selection forces, I just think that the protection aspect is actually a product of as well as a cause of other evolutionary developments.

The larger size I think simply plays more into the aspects of our evolution that causes us now to (maybe) evolve more slowly – because of this intelligence, we adapt the environment to us rather than vice-versa. And because of the longer rearing process, we form stronger, more cohesive social groups so that we protect those that might be “left behind” and thereby keep those with features that might be selected out in the DNA game where they might otherwise be left out.

mattbrowne's avatar

@iamthemob – Yes, a large portion of the human brain is just devoted to interpret facial expressions.

iamthemob's avatar

@mattbrowne

Is this expressions – or just recognition (i.e., is that my mother being happy v. is that my mother)? I think you may be collapsing the two – but I’m not sure.

mattbrowne's avatar

Both. So it’s about who is who and who is feeling what.

Answer this question

Login

or

Join

to answer.

This question is in the General Section. Responses must be helpful and on-topic.

Your answer will be saved while you login or join.

Have a question? Ask Fluther!

What do you know more about?
or
Knowledge Networking @ Fluther