In my post concerning the Chicken or the Egg? riddle solved! story, I made a point of saying that while we can now point out the differences between a domesticated chicken and a red junglefowl, at one point it would’ve been damn hard. My ultimate point was to show that while we may view the world in an essentialist mode of thought (a chicken is always a chicken), the world-as-it-is doesn’t necessarily agree, i.e., chickens change.
Kestrels and Cerevisiae 