What criteria (or physical characteristic) must be met by a biological molecule so that you can use a spectrophotometer to determine the concentration of a solution of that molecule by using a standard curve?

the denominator has a very specific role.

i think i can answer even without the example. over time with environmental changes, sometimes a group of animals will adapt to better survive. take a moth for example. if the trees the moths use to camouflage themselves from predators, started to die or change colors themselves, the moths may, overtime of course, change color too. its just adapting to its surroundings. hope i was of any : )