Like Charles Darwin, I have come to see that the term "survival of the fittest" is a useful shorthand, but ringed with at least as many shortfalls as advantages.
The biggest by far being the incredibly large number of otherwise intelligent-appearing people who once mistook the survival of the 'fit' as being fully equal to the survival of the 'fittest' ---- when actually they were 180 degrees opposed.
Still the original term remains a useful term ; one well worth salvaging.
A short term to describe a very long and very complex process.
One that sees a tendency, in general and over the long term, for individuals with phenotypes (physical bodies with all their attributes) (created through a peculiar mix of their species' pool of genes) that are better suited to their currently constituted niche in Nature to have more surviving and reproducing offspring.
Over time, this means their descendants tend to outnumber those other individuals in the same population of a particular species whose bodies aren't so suited to that current niche.
Their gene mix and resulting body type, better suits (better fits) their niche in Nature, as it currently exists.
Note that their fellows' keys also 'sort of' fit the lock that is their shared niche.
However, currently at least, our particular individuals are the fittest, the bestest, keys for this lock.
So they tend to get more food and tend to survive long enough to reproduce healthy offspring who (and this is key) inherit the same - currently lucky - mix of genes.
So they also experience extraordinary success in getting enough food and living long enough to produce healthy fertile fecund offspring.
So on and so on --- as long as their niche doesn't change.
Which it always does --- but that is another story.
The term 'niche' brings with it the sense of small, specialized, one among many : as in 'niche marketing', for example.
In Nature, there are not just many different geography-based niches at any current moment in time, there are many different niches over time, based on changes in climate, etc as well as based upon changes in geography.
So the 'fittest' key for a hundred million tiny niche locks means a hundred million tiny niche keys.
The population of "fittest keys" is large and very diverse - as diverse as can be imagined.
By way of contrast, remember what that nagging phys ed teacher always tried to drum into you about the all around virtues of having a healthy fit body.
Mine, both Brits of the old pre-Commonweath mold, were always insisting a healthy body would make us better students, fight off diseases, better soldiers, more attractive employees, better lovers, husbands and fathers, as well as better 'team' players on the field and off.
All around better off - equipped to work hard, play hard, fight hard, love hard, whether in Arctic cold, an air conditioned centrally heated office or Jungle heat.
My phys ed teachers were very old school - they felt that a fit males' natural niche was the entire world. Newer marks of their type would no doubt insist the Universe is our natural niche.
A 'fit' body was an all rounder 'master key' that would fit all locks and all niches. Read master key for master race and you are bang on.
They wanted the human gene pool to be sharply reduced to just two basic types : lots of docile but well built worker bees, bees of color, and then a smaller group of physically well built big brained boss/officer types who could, in theory do hard work or fight hard etc - but rarely did.
Darwin, at least when it came to that part of Nature that didn't include the human animal, never said that or foresaw that.
He saw a world of many many niches and a need for many different gene mixes to survive successfully in each. Perhaps he erred most in seeing these niches changing far more slowly than they actually do, but in general he saw the world (and hence lifeforms) as very diverse.
For him, 'survival of the fittest' meant 'survival of the diverse', not the survival of just one supra-fit being to handle all of one big supra-niche.
The sudden rise of the appeal of big muscles for the ruling elites ("the survival of the fit") did not occur by chance just at the point when muscles meant less than ever in war or on the job ( per the rise of accurate long range rapid fire rifles and labour-saving machines).
In fact, it arose precisely in response to those facts.
We can start by recognizing that the difference between violence and force is that the successful use of force implies successfully bluffing others that one will be violent, and violently success, if the need arises.
For it was no longer morally acceptable, in the late nineteenth century, for lords of the manor, colony or factory, to simply string up unimportant nobody, whenever a small problem arose.
And given the ability for the unhappy-with-a-rife to snipe and assassinate the lord, from a safe distance away, behind some rock ,in the dim of the evening, it was no longer even safe to try it on.
But the big well muscled man who was 'fit' and who looked 'fit' and who exuded the self confidence of someone who was part of the ruling elite, with the force of an entire 'fit' empire behind him, could still usually intimidate others to get his own way, in normal day to day situations.
Tall, well built, well off, self confident men of the elite ethnicity still usually successfully intimidate even policemen at a traffic stop, as well as women, children, employees, etc that are physically smaller and financially less wealthy than themselves.
Muscular Christianity and the well muscled biceps holding a hammer (that were almost the only iconography of trade union imagery until very recently) shows how this cult of the muscle spread to all parts of the culture --- even to groups that might have ordinarily resisted the use of elite led violence.
But the breeding of all rounder fit types, pure of all 'defects', one size key fits all locks and niches, would never let humanity survive for very long.
We can see this with the deliberately inbreed noble families of Europe - we can even look to the deliberately inbreed family tree of Darwin himself.
We can see the results with the deliberately inbreed, 'pure' breeds of horses and dogs that came to be popular in the UK and the USA at the very same time as the rise of muscular modernity and muscular eugenics.
Like their owners, these animals were actually disease prone physical disasters and frequently infertile.
Their owners knew the score yet they still promoted the idea of narrow gene pools --- and amazing example of the intellectual disconnect that is possible in humans and perhaps even particularly possible in university educated humans....