I do enjoy hypotheticals

My theory on kidney regeneration has evolved (lol) what I thought was Wassabi. May actually have been food colored horseradish. I. My attempt to connect the evolutionary dots. During the dark age only certain animal could survive. On the Russian steppe horse survived where cows died from lack of nutrition. Therefore, it is reasonable to conclude the horse may have developed kidneys from the consumption of horse radish which can grow in limited light conditions. It may have been horseradish not Wassabi that was the kicker.