Interesting results follow collaborative research between the universities of Exeter, Bath and San Diego State into the question of whether survival of the fittest really does apply. When you first hear how individuals in species that are best able to reproduce pass on advantageous characteristics to the detriment of others it seems convincing and is generally accepted as being behind the idea of evolution. Now studies by the group above show that this is not necessarily the case. Bacteria were used in the test as they reproduce more rapidly than other species but after hundreds of generations there were still many variations in the sample rather than just a small number of dominant types. More about the studies can be read here.
One other thing I wonder about is has the human race stopped evolving? Now that we can prolong life and have such advanced medical capabilities do genes conveying advantages matter so much? For example we can see today that, in the UK at least, children are generally taller than their parents, but on the other hand does that confer on them an ability to cope better with life and be better able to reproduce? In other words is being taller an example of advantageous evolution?