Did Darwin steal his theory of Evolution?

After his trip around the world on The Beagle, Darwin waited 23 years to present his theory of Evolution.  The myth is that he sat on the theory out of fear of repercussions. However, when Charles Darwin published On the Origen of Species in 1859 evolutionary theories had been around for a long time.  There were at least a dozen evolutionary theories, including one by Erasmus Darwin, Charles’ grandfather, in the late eighteenth and early nineteenth century that were openly debated among scientists.

Alfred Russel Wallace 1862 - Project Gutenberg eText 15997
Alfred Russel Wallace 1862

It wasn’t until Alfred Russell Wallace, a naturalist and admirer, sent Darwin his observations and theory of Evolution while still away on a voyage to the Malay Archipelago and Borneo, that Darwin’s theory was (hurriedly?) presented, acknowledging Wallace as co-discoverer, and published, establishing primacy over Wallace.  Was Wallace the true originator of a theory that Darwin had overlooked in his own observations?  Did Wallace provide the link that brought all his speculations together?  Darwin’s claims were backed by his friends Charles Lyle and Joseph Hooker, so we may never know the truth.  It is sure that the scientific reputation of Wallace declined, while Darwin’s grew.  It is interesting to note that Wallace later rejected the theory as lacking both mechanism and sufficient evidence.