BIOL 1010 Lecture Notes - Lecture 4: Countershading, Melanin, Directional Selection
Document Summary
What the fish did (and how they adapted to stimulus) If one splits from the group, more follows. Dark and light fish don"t behave the same: more agitated in light tub and are more relaxed in the dark tub, dark fish don"t school. Fish actually change color: many light-adapted fish spent more time on the light side of the pan freaking out. Another fish stayed mostly on the dark side and went between a little. Most of the dark-adapted fish stayed on the dark side. Dumped all the fish in the test pan most swam to the dark side. Light fish didn"t school anymore: when fish are vulnerable (when exposed to light), they release adrenaline. Light fish have been releasing adrenaline for 3 days and are in overdrive, which is disrupting their survival instincts: consistently, the light-adapted fish are less consistent about swimming to the dark side. Scientific reasoning: on observations: 2 hypotheses.