I got the urge to google "stochastic biology" and ended up in possession of a free-to-download .pdf file that is the first chapter in a 2013 book on stochastic proceses as they affect inferential studies in biology. I can figure out what the text says, but not the math. Have a look at the copy in my dropbox and let me know whether YOU understand the math: https://www.dropbox.com/s/d23mx3sxj35rg0d/9783642321566-c1.pdf?dl=0