Included in that original scenario or hypothesis he advanced was the premise that the "reason why" biological life evolved was to get more fit, get better, become the most fit to survive and survival was thereby guaranteed in any particular ecosystem.
It came down to a statement made by Herbert Spencer which was "the survival of the fittest".
Apologists and revisionist historians, who attempt to clean up this problem, ignore the truck loads of books and scientific papers written about it, and retroactively try to clean it up by saying that is not what Darwin meant, he meant fit enough to survive in a "local" ecosystem. Darwin was not so embarrassed, and flatly said:
"The expression often used by Mr. Herbert Spencer of the Survival of the Fittest is more accurate, and is sometimes equally convenient"
(Wikipedia, emphasis added). Social Darwinism was a reaction to Darwin's early writings, which pit human against human and other species because "fittest" was defined as if fittest meant some militaristic, imperialistic struggle to dominate everything else.
Ecocosmology plainly points out that this cosmos does in fact impose an evolutionary test on all species who inhabit planets near central stars, and that only the fittest will survive.
The fittest are those who pass "The Test".
The nature of "fittest" in that context, set out clearly in the Four Tenets, includes technological evolution as well as behavioral evolution, leaving out biological fitness to dominate as the main criterion in cosmological evolution.
Biological evolution on any one planet circling a central star only sets the stage for the far greater cosmological evolution that must take place in order for species to survive within this cosmos.
In that sense, Darwin was and his progeny are majoring in the minors, that is, being myopic and having a very narrow and limited vision.
There is a chronic need to evolve this thinking and shift the focus onto what the human species must evolve into in order to sustain human existence across the broader cosmos.
It is now clear that memetic evolution is the mainstay, the way to pass The Test, long after biological evolution has reached its apex.
Thus, we can say that evolution does have a purpose, one of which is a kinder, gentler, wiser, and technologically advanced species which sees itself as a caretaker of planets and the species on those planets across the cosmos.