"Mendel's work was rejected at first in the scientific community, and was not widely accepted until after he died."

The commonalities: they both lived at about the same time, the late 19th century, the importance of their works were only fully acknowledged after their deaths,they were both very influential in their respective fields of study and finally they both had strong backgrounds in religion, one Catholic and the other Protestant. One was a monk-scientist the other was a preacher-artist