Yes man has stopped evolving for the most part because everyone today survives whether or not in nature they would have a chance to live at all. So if your feeble and would not have lived to pass on your genes today that doesn't apply to the human race. Survival of the fittest rules the natural world--it's what drives evolution. The idiots survive along with the rest of us so those genes are dumbing us down.

The NYT has an interesting article on the 100m dash. In the first olympic 100m dash in 1986 the bronze time was 12.6 and now kids in highschool are hitting low 10's but the margin between good and best is much narrower today http://www.nytimes.com/interactive/2012/08/05/sports/olympics/the-100-meter-dash-one-race-every-medalist-ever.html
This is a scary subject of research though. The reality is that diversity allows people to bring different skills to the table and excel in different areas.

Measuring the capacity or potential of humans simply by their physiological constraints is so self-evidently silly it makes me wonder what the point is. Does the physiological capacity of the Norman Borlaugs, Marie Curies and Thomas Edisons of the world matter more than their mental achievements and the technological innovations they fostered?

I am unconvinced. This is from the same profession that said it was impossible to break the 4 minute mile barrier. Everything is impossible, until someone does it.

Also unimpressed as you do not mention the mutability possible to all living things. Yes, this present version of humanity may have peaked but what is occurring in the peripheries of human evolution? Where are the studies about those developments and how they are manifesting.

People seem to be diverging. I see some people bench pressing 11000 lbs., while other people never pass 100 lbs. I suspect that the latter are working harder. Some people do 1000's of push ups while others don't get past 20. I think lack of vertical loading may be making people taller, and worse at sports..

The next generation is the first generation expected to have a lesser life expectancy than their parents

Peaked? naw haven't even started, gene manipulation will "evolve" humans far beyond are current abilities.

Natural selection may remove specimens from the human gene pool, but where are the mutations that increase genetic diversity. Movies like X-men suggest that beneficial mutations should be on the increase. So far mutations all seem to be damage to existing working DNA. Our health systems support the “less fit” that would otherwise die out, but this is thought of as good. It allows the average life span to increase, but not bigger, better or stronger humans. Humans have a propensity to create/use substances that are detrimental to health (pesticides, cfcs, radiation), so is it any wonder we continue to be less healthy without sickness support systems.

Interesting- agree entirely. The 4-minute mile argument is obviously specious, using a totally arbitrary target. Human biomechanics is pretty well understood as are its weakest links, which put an absolute limit on performance even if that limit is not completely definable Human performance is asymptotic, therefore has a definite limit.