What was God’s plan behind Creation and why does he need one?

You're assuming that being strong is a matter of degree, whereas being sighted is an on/off condition.But the latter assumption is definitely not true. And if it was, then your further assumption that the two species are in direct competition would be unnecessary to your argument --- if it took 100 steps to produce sight, and the first 99 were useless on their own, then natural selection wouldn't favor the first 99 and it wouldn't happen.But looking at the eyes of living organisms shows that there's a whole range of conditions from mere ability to detect light (which is indeed useful to the organisms that possess it) up to sophisticated eyes such as our own.

Do you also suppose that the phrase "gravitational attraction" implies that planets have the hots for each other? That "electrical resistance" implies some sort of armed struggle? That the "laws" of thermodynamics are enforced by the thermodynamics police? That the "mass" of a proton involves a Catholic priest?Here, let Darwin explain it himself, he coined the term, after all: On the other hand, it can't see. I for one would not allow myself to be blinded if, as a compensation, I would gain the ability to bench-press my own weight.---Amongst your other unwarranted assumptions, you seem to be supposing that an species can only evolve one desirable quality at a time. If natural selection favors large size in species B as well as in species A, then what in the world is going to prevent species B from getting bigger?Edited by Dr Adequate, : No reason given.Edited by Dr Adequate, : No reason given.

How would this "expend energy"? It takes energy to possess an organ, but not, strictly speaking, to evolve it.It's not like evolution happens as a result of effort on the part of the species. You know sharks have eyes, right?---Your question is a bit like asking an economist why not everyone is a plumber. It pays well, it's always in demand, you're your own boss, it doesn't take years of study ... why doesn't everyone do it?And the answer would be rather similar.

Could I point out that if this was a puzzle in biology, it would not particularly be a puzzle for evolutionary biology?After all, if sharks, thanks to their superior size, strength, pointyness of teeth, or whatever, ought to have driven all other species to extinction, then they would have done so whether they were the product of natural processes or whether God made the original set of species by an act of fiat creation.The fact that the other species are still around is sufficient to show that there are biological niches for them to inhabit even given the existence of sharks.

He didn't say that it was a problem. He says, as you quoted, that "the difficulty [...] can hardly be considered real."What he says is insuperably difficult is for people to imagine it happening. He was right about that too. Yes. We can see a whole range of eyes in nature, from the simplest to the most complex. In some cases we can see the whole range within a single phylum --- mollusks are the usual example, but this is also true of jellyfish. Nilssen and Pelger (here) have shown that there is a pathway from the simplest eye to the most complex such that each small step is an improvement. To quote their paper: So such a pathway will be favored by natural selection for so long as the benefits of increased visual acuity outweigh the costs to the organism of producing the eye.For further information, I suggest this article on eye evolution, a work of such penetrating insight and erudite genius that I can only say ... I wrote it.Edited by Dr Adequate, : No reason given.

Darwin --- and I --- were actually talking about gradations found in nature today. They prove the proposition that there are organs of vision, varying in complexity, which are useful to their possessors, and so show in principle that a complex eye could have evolved.However, since you ask, yes, a progression can be seen in the fossil record, for example in the chordates. Pikaia and Haikouella had eye spots, conodonts and agnathans had primitive eyes (as do living agnathans), and "higher" chordates (e.g. bony fish) have lensed eyes. I guess this is something I should add to the article.

I don't quite see your point. I didn't say that any of them had no eyes, but that some of them had primitive eyes. No. The chordates include all vertebrates. We've got quite a lot of them. Good grief. Of course not. All mammals have proper lensed eyes. Can you picture an australopithecine with eyespots?---Anyway, we are way off-topic, so if you want to learn more about eyes, you'll have to start a new thread. Or there are books, of course ...