Biologically, the point of life is to survive and pass on your genes (if you are genetically worthy, in theory).
Philosophically, the answer is the same.
The biggest problem is that humans have enough intelligence to cheat Mr. Darwin and so muddy the gene pool that there are only rare pockets of genetic material that are truly worthy of being passed on to our posterity. Of course, this propensity to to procreate is also a biological imperative, therefore, we will simply breed ourselves out of meaningful existence.
This leads to the controversial topic of eugenics.
Eugenically-speaking, we all know that some people simply shouldn't be allowed to breed, but to deny them that freedom would defy the basic principles of what we know as "rights".
In the meantime, the so-called "elites" have been following a (more or less) successful breeding plan for millennia: those that have the desired traits are married off, within a certain genetic circle, to others with those traits. Occasionally, someone from the "lower classes" will exhibit and take advantage of similar traits to move "upward" and breed within the proper genetic pool.
However, this too is beset with problems. Just as the "Royal Families of Europe" began to develop genetic "frailties" so too has the new crop of "elites" diluted the gene pool with their "inadequate" DNA: they simply aren't as adaptable as they need to be.
Adaptability is what will ensure survival in the long run. "Fittest" has nothing to do with strength or intelligence, only adaptability.