John Endler performed an experiment involving guppies in which he demonstrated evolution driven by natural selection that worked through a predator-prey relationship. Which of the following are true statements about the results of his experiments? (Select all that are correct.)
a. Males with longer tails and brighter coloration were more frequently eaten by predator fish.
b. Females preferred to mate with dull- colored males.
c. When males were put in a predator- free environment, brighter coloration and larger tails evolved in them.
d. In the predator-free environment, the average brightness of females increased.
e. When predators were reintroduced, duller coloration and smaller tails evolved in the males.
Adv.
The guppies, observed by John Endler were driven by natural selection to evolve in two ways. It was found that the females choose the males, which were brightly coloured with long tails more frequently for mating. But these brightly coloured, long tailed males were easily identified by predators also. However, when the guppies were kept in an environment, free from predators, bright coloured large tailed males evolved within few generations. But when the predators were reintroduced, small tailed less brilliant coloured males evolved over subsequent generations.
Hence, the correct option is (a) males with longer tails and brighter coloration were more frequently eater by predator fish.