In his anti-Darwinian book... (and eponymously named The Neck of the Giraffe), Francis Hitching tells the story... "The need to survive by reaching ever higher for food is, like so many Darwinian explanations of its kind, little more than a post hoc speculation." Hitching is quite correct, but he rebuts a fairy story that Darwin was far too smart to tell - even though the tale later entered our high school texts as a "classic case" nonetheless.

"The Tallest Tale", p. 314 - Leonardo's Mountain of Clams and the Diet of Worms (1998)