Is devolution inevitable?

Question

Consider that evolution is the process by which genetic mutations are selected by variable mortality. Civilization tends to keep its members alive whether or not they carry mutation that are beneficial to the species. In science fiction it is often stated that : civilizations stop evolving when they build wheel chairs. As negative mutations build up average IQ drops, as shown in our civilization, at some point we will become too dumb to build wheel chairs and keep people with bad mutations alive and we will start to evolve again... and the cycle should repeat....eventually we should stabilize as some point.. just intelligent enough to keep our self from evolving.

on the other hand... that may be where we are now.

Anyway, does anyone have any thoughts?

Answer 1

All of the answers, and the question itself are sort of assuming a direction to evolution.  Like, if the human race keeps evolving it will become stronger, smarter, etc.  Evolution has no direction, so there can be no devolution.  If humans become less able to compete with other species (which considering our track record so far doesn't seem terribly likely) they will be replaced by a species better adapted to the environment.

Answer 2

It is a possibility but I don't think it will happen.  Evolution normally works on very long time frames.  Right now we are building up a population and doing significant mixing.  It is likely that we will have something bad happen one day that continues  the selection pressure that has been reduced by modern science.  It could also come from people managing the genetics of the the future generations better than we are today.  Either way, it is not a problem now and won't be for many generations.  By that time we will have the knowledge to fix it if needed.

Answer 3

I think evolution still works in a civilization, there are plenty of traits that will get people in modern society killed or at least make it difficult for them to breed.

Granted it probably doesn't work as quickly or efficiently since society offers so many second chances.

As far as humanity is concerned the question will probably be irrelevant soon enough anyway. As we delve more and more into genetic manipulation we will inevitably take the helm of evolution and start directing it towards specific goals.

In short, civilizations keep evolving, they just do so in different ways to reflect their changed environment.

Answer 4

So, eugenics isn't dead in your world then.  How many severely disabled people have children?  Amazingly few.  Yes, those so-called "negative genes" are never "bred out."  But treating people with disabilities in a humane way does not make our population any stupider or slower.  I would argue that it makes us better, as compassionate beings.

Answer 5

First of all, devolution is a fictional idea. Secondly, evolution is not about differential mortality, it's differential reproductive success. Plenty of ignorant and unintelligent people in the past have been able to reproduce: history has not shown us that the smart are always the most reproductively successful, instead it's basketball players.

Evolution will always happen. Given that we are making assumptions on trends we have seen in the past 100 years, it seems foolish to make predictions about what will happen in a million.