The article makes it already, no need for more. One can 'imagine' whatever one likes but to build such a system (which is only a small part of a greater system, which is intself only a small part of the greater system - the whole organism) takes a lot more than imagination.
Indeed it does - it takes millions of tries each and every single year, during the time frame of billions of years. And with a selection process that is able to weed out ever so slightly less successful models.