If life is about "Survival of the fittest", surely, we need to worry about our own survival ?... survival of the human being.
Medical science has, for some while, been responsible for the survival of some of the most unfit babies born; I think we can accept that many of these babies would have died some 50 years ago. Equally, that same science has ensured the survival of the elderly (for whom, equally, their life would have ended prematurely. Now, these people are living very much longer than they would have previously done so.
In no way am I being judgemental about the above; I am merely observing the reality of our modern life.
But a thought crossed my mind; are we humans becoming "diluted" in the qualities that made us "the fittest", so that our survival was guaranteed, here upon Earth?
What of all the other creatures that share our Earth? - are they not becoming "fitter"? - will our intervention in our own nature (by means of our own fast growing improvements in medical science) make us weaker, whilst the rest of the occupants of our planet are becoming stronger?
Is this logical, or not? - if not, then, why not?
I used to think about this when i was younger, and it reminds me of that joke 'evolution of man' poster where after the erect homosapien, and the man in the suit, theres a fat couch potato, with the only physical attribute improving being index finger dexterity for tv remote use.
We must remember that 'fitness' is a relative term, and it only means something in relation to the environment that has the respective selection pressure. With an ever changing environment, you cant really stick to some rigid preconceived notion of what it means to 'be fit'.
Its true that many people today live thanks to medical and technical advances, who would otherwise have perished in an era that lacked such. But if one understands the term fitness in relation to environment then you could argue that these ailments arent really examples of 'unfit' people anymore, if they indeed go on to live decent lives and have families.
In a way the 2 forces working are that of an individual human in the propagation of his/her own genes, and that of humanity as a collective promoting its own continued existence and development. Human kind have through intellect, communication and teamwork redefined those selection pressures in which we live by modifying the environment, so that old examples of 'unfit' have become increasingly diminished and irrelevant. This is in a way an example of an overarching 'fitness' of the species being demonstrated.
Now i would agree that if one removes too much challenge /selection pressure then certain attributes that we might desire, particularly physical ones might get diluted down in the population and thus be less pronounced. Note that i describe them as desirable characteristics rather than 'fitness', as if their lack of presence does not really interfere with reproduction and propagation in todays environment its not really 'fitness'.
Additionally by the manipulation of our environment, especially so radically and quickly as we have done with respects to evolutionary timelines, one could worry that we risk actively damaging ourselves rather than simply risking stifling improvement or allowing for increased proportions of undersirable characteristics. Such an example might be diabetes, and how millions of years of evolution has wired us to cope with periods of starvation very well, but not to deal with over eating and high sugar diets, thus introducing new ailments born out of our own manipulations. But then again, such a new selection pressure also may lead to emergence of a new 'fittness' relevent to todays environment, both in genetic fitness aswell and educational and technological.
However the human body and human kind as a whole are very complex entities. They dont fully adhere to simple cause and effect models we have come accustomed to in explanatory ventures.
When we talk of ailments that humankind encounter, its not a progressive funnel of decline with one leading to worse and worse on some fixed scale, but rather its a dynamic state with some ailments sometimes being the gateway to new solutions and improvements. Often highly unpredictable, simple variety and diversity even if it contains more individual 'ill's might be stronger than a more uniform 'healthy' population. Again this all relates to an ever changing and equally unpredictable environment. An example of an ill being coincidently beneficial is that of sickle cell anaemia being protective in areas of high malaria prevalence.
I think we still have a long way to go in effectively modelling these complex systems, and improving our understanding and ability to make predictions.
