Even someone who has read Richard Dawkins rant against essentialism

This is kind of a jarring use of the word "rant". Dawkins's argument seems calm and well-reasoned. (Except where he says "Indeed, every one of the series was the child of its neighbor on one side and the parent of its neighbor on the other...". Wouldn't there be at least one animal in the series who was the parent of both its neighbors?)