Hello @alexanderalexis,
I love it when you get into a subject 😇 This one grabbed you. My impression, from my reading (remember, Wallace is new to me) is that Wallace had been working on this theory for many years. He had traveled extensively in South American and had collected a trove of specimens. These were all lost in a shipwreck. Undeterred, he went to Southeast Asia and continued to collect. Not only that, his observations about unique species in land separated by a small body of water led to something called the Wallace Line. This line actually predated discovery of plate tectonics, and actually traced the line where two continents had separated millions of years before.
Again, Wallace is new to me. I am introducing him to others as I am introduced to him myself. There is also this from the Natural History Museum in the UK
Wallace began his travels through the Malay Archipelago (now Malaysia and Indonesia) in 1854. Over a period of eight years, he accumulated an astonishing 125,660 specimens, including more than 5,000 species new to western science
He sounds like more than an accidental, incidental figure.
But then, it's all new to me😃.
Thanks for stopping by @alexanderalexis. Always a pleasure.
😒