Biologist John Endler conducted an experiment with Guppies (Poecilia) in a tank without predators.Edit
Hindsight is 20/20 bias - Let's say a population has an abundance of food, and for some good reason the men or women, doesn't matter are selected for any good trait, fast speed, long necks doesn't matter. The meme is rapidly taking away all the food (famine/rapid environmental change) and then the outside observer saying "SEE! These stupid long neck fucks! They should have spent more time focusing on/being attracted to X." When in reality no one in the environment had any idea the environment was going to change so quickly, and thus had no reason to change what was working just fine a moment ago/last year/etc.
Also link to hindsight bias page https://en.wikipedia.org/wiki/Hindsight_bias
Also if one were to argue this fact, please don't use the appeal to authority argument, "The guys a biologist, the guy can't be wrong!"