To be fair I'm pretty sure that Gregor Mendel's (I assume you guys don't mean the guy who did the periodic table ?) work went effectively unnoticed until it was rediscovered in the 1900's, sometime after Darwin's work.
Adonai: seems like a practical person.
Norg: seems very impractical.
Just an opinion from what I've read. Not that being one way is better than the other, it just seems that way from their viewpoints on how to verify and use information.
But then again what do I know, I'm Stoopid.
But Lamark's ideas did pave the early ideas of evolution. I think the context of Darwins's life had the majority believing in Lamarck's ideas, even if they were ridiculous. Lamarck's ideas were a big step up from the belief of traditional creationism that was believed before.
And Mendel's genetics unfortunately didn't affect Drwin's development of natural selection, though both the genetics and evolution described by them re-affirm and support each other.