white butterflies because it is difficult to see them due to the dirty air.
| "When we reflect on this struggle, we may console ourselves with the full belief, that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply." - Darwin |
JR's answer (written before reading all of your thoughts):
I don't buy it at all: I think it's a cop-out. He has in the preceding actually made a pretty good case that the "war" is incessant, with rare interludes (as when an expanded habitat suddenly becomes available). Moreover, I think plenty of fear is probably felt, and death from starvation or disease can be prolongued.
My sense of this last sentence is that he realized that the picture that he'd just painted of life was a disheartening one: that the life of the vast majority of individual creatures occurs in a regime of struggle for existence in which the species is just barely able to sustain its numbers (steady state)... a situation that would seem to make it necessary that the indiviual's life is harsh and marginal. And he's trying to make the concept more palatable by softening the conclusions.
His description of the struggle for existence brings to my mind the situation we had in Buffalo until a just few years ago concerning air travel. There was essentially a monopoly by USAirways, and the airline optimized their profits by setting the prices of tickets at level that was painfully high and discouraged many people from flying - so many that if the price were even a little higher the profits would decrease because the lost revenue from drop-outs would outweigh the increased revenue from those who still chose to fly. So you had most prospective flyers thinking "This is so expensive. Should I drive instead? But that would mean sitting in the car for 10 hours. :-(", etc. Travellers were uncomfortable either way: either from the expense of flying or from the inconvenience of the alternatives.
Perhaps this unhappy quality is indeed unavoidable. Looking at the history of humanity, in particular, we might conclude that human existence has been (for all but a lucky few) quite marginal and tough. And we can see today many examples of struggles for existence (involving war and misery) because the populations have grown to the carrying capacity of the territory, e.g. Israelis and Palestinians.
But perhaps (I'm now backing off the same way Darwin did!) there are ways by which population is regulated without making life uncomfortable for the individual: for example if fertility were to drop with increasing population. Adults might not suffer from being less fertile than they could otherwise be.
Now we've had a century and a half of the study of ecology since the time of Darwin, and if you're interested in exploring further, you could consult, for example, "Ecology" by Robert Ricklefs.