Human brain sizes are shrinking, one way in which humanity seems to be evolving:
http://discovermagazine.com/2010/sep/25-modern-humans-smart-why-brain-shrinking
Having a big brain is expensive, and in our less stressful modern living environment, apparently evolutionarily wasteful. Therefore, people with smaller brains, which generally correlates to lower intelligence, are able to reproduce more than those with larger brains without any fitness tradeoffs right now.
We have all witnessed "idiocracy" developing in our society. Some fat idiot with six kids in tow while people with what we consider desirable traits put off having kids, or have only a small number of kids. If some people fail to reproduce while others reproduce, that causes our gene pool to change, that is evolution in action.
In fact, as opposed to evolution stopping, in the last 10,000 years the rate of evolution in human populations has drastically increased.
http://johnhawks.net/weblog/topics/evolution/selection/acceleration/accel_story_2007.html
http://www.pnas.org/content/104/52/20753.full
To quote this author:
"Genomic surveys in humans identify a large amount of recent positive selection. Using the 3.9-million HapMap SNP dataset, we found that selection has accelerated greatly during the last 40,000 years... Larger populations generate more new selected mutations, and we show the consistency of the observed data with the historical pattern of human population growth. We consider human demographic growth to be linked with past changes in human cultures and ecologies. Both processes have contributed to the extraordinarily rapid recent genetic evolution of our species."
Before humans left Africa, our environment was less varied than it is today. As people changed their culture from living as groups of a few dozen individuals to living in towns and cities, the factors that contributed to surviving and reproducing changed dramatically, so the types of traits passed down changed as well.
http://discovermagazine.com/2010/sep/25-modern-humans-smart-why-brain-shrinking
Having a big brain is expensive, and in our less stressful modern living environment, apparently evolutionarily wasteful. Therefore, people with smaller brains, which generally correlates to lower intelligence, are able to reproduce more than those with larger brains without any fitness tradeoffs right now.
We have all witnessed "idiocracy" developing in our society. Some fat idiot with six kids in tow while people with what we consider desirable traits put off having kids, or have only a small number of kids. If some people fail to reproduce while others reproduce, that causes our gene pool to change, that is evolution in action.
In fact, as opposed to evolution stopping, in the last 10,000 years the rate of evolution in human populations has drastically increased.
http://johnhawks.net/weblog/topics/evolution/selection/acceleration/accel_story_2007.html
http://www.pnas.org/content/104/52/20753.full
To quote this author:
"Genomic surveys in humans identify a large amount of recent positive selection. Using the 3.9-million HapMap SNP dataset, we found that selection has accelerated greatly during the last 40,000 years... Larger populations generate more new selected mutations, and we show the consistency of the observed data with the historical pattern of human population growth. We consider human demographic growth to be linked with past changes in human cultures and ecologies. Both processes have contributed to the extraordinarily rapid recent genetic evolution of our species."
Before humans left Africa, our environment was less varied than it is today. As people changed their culture from living as groups of a few dozen individuals to living in towns and cities, the factors that contributed to surviving and reproducing changed dramatically, so the types of traits passed down changed as well.