Should Darwin be Given all of the Credit for the Theory of Evolution by Natural Selection?

Here’s a Charles Darwin caricature/cartoon that I executed recently for the cover of the magazine Philosophy Now.
As you can see, the cartoon is about Darwin and the theory of evolution by natural selection.

It’s hard to miss Darwin’s presence this year, 2009, what with it being the bicentennary of his birth and 150 years since the publication of On The Origin Of Species.
The illustration is based on a redrawn version of the famous cartoon depicting Darwin as an ape.
Who’s the character in the branches in the background though? What’s he doing there in Darwin’s cartoon?
He’s Alfred Russel Wallace.
Wallace conceived of the theory of evolution by natural selection totally independently of Darwin. Yet he hardly ever gets any of the credit for the theory.
It’s true that Darwin came up with the idea first, but he then sat on it for many years fearing the consequences of putting it out into the world. It was only when Wallace wrote to Darwin explaining his own ideas on the subject that Darwin realised that he’d better get into print soon.
Don’t get the idea that Darwin rushed into print with On The Origin Of Species in order to claim the fame. Darwin was a very decent man by all accounts, and the first public presentation of the theory of evolution by natural selection was actually a joint effort by Darwin and Wallace together. They produced a joint paper titled ‘On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection’, which they presented to the Linnean Society in London in 1858. Strangely, despite the bombshells in the paper, its presentation to the society went almost unnoticed, even within the society. Shame on them!
Darwin published On The Origin Of Species a year later and this time its implications were noted. The rest is history.

Now it’s time for me to go a little iconoclastic.
The fact that Wallace, himself a respected scientist, came up with the theory of evolution by natural selection independently of Darwin means that even if Darwin hadn’t come up with the theory it would nevertheless still have been with us today - thanks to Wallace. I’d actually go further than that, and say that even if Wallace hadn’t come up with the idea either the theory would still be with us, as someone else would have devised it very soon.
The early to mid nineteenth century seems to have been the time when things were just right for the theory to be conceived of. It was in the air. It’s the same with many theories, inventions, discoveries and other products of human endeavour. There may be only a matter of weeks between one person coming up with an idea (and thus becoming immortalised as the idea’s originator) and someone else coming up with it (and thus being forgotten forever). Due to this tendency of ideas to be ‘in the air’ I’m not actually very keen on attributing whole theories, discoveries or inventions to individual people, geniuses though they may be.
On top of this, I’ve now lost count of the number of times that I’ve discovered that a particular idea that’s always been attributed to a particular person was thought up years (or even centuries) earlier by someone else, but that that person either couldn’t prove it or publicise it (or wasn’t such an effective self-publicist). (Note: Darwin definitely didn’t fall into the self-publicist category, being a man of great humility.)
I suppose we like to attribute ideas to specific individuals because it helps us to humanise history, but that doesn’t stop it being a slightly skewed way to look at things, and it’s definitely unfair to all of those ‘almost’ people who were a week late with their ideas.