D is for Dodo.
If you're not very smart, don't know how to hide, and are harmless and the least bit edible, the dodo is a good example of what will happen to you.
Dutch sailors marveled when they discovered the bird in 1589. "They're completely unafraid of us! What a bunch of simpletons! I wonder if they're edible!"
They named the bird, Dodo, meaning "simpleton," or else possibly "fat ass," instead of say, Yummy-Bird, because although it was edible, it was nothing to write home about. Perhaps if the dodo had been better tasting, it would be with us today. Then we would have bred it.
The first recorded human encounter with the dodo is indicative of what would become of them later. The sailors managed to corner a group of these and seized one by the foot, it made a "great noise" at which the other dodos "came running to its assistance." What a bunch of flightless birds thought they could do against Dutch sailors molesting one of their friends is unclear, but these sorts of good intentions only get you in trouble, survival-of-the-species-wise.
Within a hundred years after their discovery, the dodo was extinct: prey to invasive species such as dogs, rats, and humans, and particularly zoologists, who were eager to get a taxidermied specimen of their own before supplies ran out. Also, I forgot to mention, the dodo laid one egg at a time. Really, it's remarkable they lasted as long as they did. They must not have been very good-tasting.
Now other animals are discovering how dangerous humans are even if you are clever, a good hider, and bad to eat, but dodos were the first to go, making them the poster child for extinction. Or at least they would be the poster child if we knew what they looked like. The preserved specimens fell to pieces hundreds of years ago, and the drawings don't agree with each other. The dodo is so dead, our collective memory of them is gone as well. You can't get much more extinct than that.