The expression, “Dumb as a Dodo” came about at the realization that Dodo’s were incredibly dumb.. so, dumb that they actually devolved. They lost the use of their wings & any sort of defenses to protect them from predators which came & completely wiped them out. Their existence was very short lived as well & though they they will be know for their exclusive benefits to a particular tree, still they were too stupid to focus on sustaining themselves. A race having been created only 8,000 years ago, mak8ng many contribution but on their way to being minorities & soon, extinct just like the little Dodo birds that they are, is quite hilarious. Have a great day.