De-evolving simply isn't possible.. something making us LESS adaptable to our environment would last a single generation.. "maybe" a few before the organsim fails to procreate and pass on the "misguided" gene. Technology may be able to keep that human alive.. but for how long? And their offspring..?
There is no such thing as devolving, since there is no predetermined direction for evolution. We change in random directions, in random ways, and some of those changes prove more beneficial, in the strictly limited sense of fostering more offspring, than others.
While mutation may be random.. we "change" as a result of our environment. The change is NOT random... and will only express itself because it offers a selective advantage.
There are TWO forces at work here.. their mechanism for action have NOTHING to do with each other.. the mutation is random, the environmental pressure allowing that mutated gene to express itself is not random.
Humans are a VERY unique species in that MANY things the SHOULD give us a selective advantage DO NOT. (because we have a misguided sense of what selective advantages are.. i.e. nice guy syndrome)
Higher intelligence for example.. really reduces your chance of creating offspring.. the smarter you are the less likely you are to have children and when you do.. you will have fewer.
Things we think should hurt our chances, in fact may help.. stupid people, obnoxious people, (lets say of course that I am speaking of genetic traits leading to lower intelligence and/or obnoxious behavior.. ie emotional control centers in the brain).. people like that usually breed like rabbits.
and let's face it... stupid people have stupid kids.. cry egaltarianism all you want. You're wrong. All humans are NOT equal in mental capacity and if you believe that tripe.. well I'll stop there.
So stupid kids.. more bad choices... more offspring they can't afford but as a society.. we have social programs to feed the young stupid offsping of the stupid. While the smart have few children and are expected to fend for themseleves.
Sounds harsh and mean.. but after a few hundred generations what do you think the result would be.
It would be like a social program for fat, slow cheetas. the fast cheetas are treated exactly as they are now.. all their environmental factors working to keep them in check.. but the fat slow, gentically gimped cheetas.. we'll we feed them.. give them cheetah porn to watch .. and next thing you know.. you have.. a hundred thosand fat lazy cheetahs and a few thousand fast ones.
in a much more complex sense that's what's happening to humans...
Things that would absolutely obliterate other species.. are simply blips on our radar because of technology and medicine. With our highly mobile culture.. what do you think would happen to humanity if we didnt have acvure for the plague in this age? It would spread a thousand timesfaster than in did in the past.
If humans completely lacked technology... we would probably have super human immune systems because only those capable of surviving thousand sof generations through countless straines of every nasty bacteria and virus would live long enough to procreate. We would probably have near super human healing ability... asuming you could get the calorie content required to sustain it. (the fantasy example of "Wolverine".. do you have any idea how many calories daily he would have to consume to maintain a heling process that fast? A major injury would take tens of thousands of calories to correct)
edited to add.
One thing we fail to consider are the SOCIAL pressures acting upon evolution. Humans are social creatures.. with many genes controlling behavior and attitude. We make the mistake of only considering "physiological" changes when speaking of humans and evolution.
Have any of you ever considered that we ARE actively evolving.. but purely in a social senseand in our ability to cope with a large complex social infrastructure? genes that control, our ability to communicate, exhibit body language (emotional-physical ceneters in the brain) are changing due to environmental pressure.
In a crude sense we ask ourselevs many times "how come women like bad men" or why "sluts" get more sexual attention.. did it ever occur to you all that that things that create those behaviors are giving their host a selective advantage...
while all our nerdyness and smarts is just killing us off. LOL.