Question

The guppy is a species of small freshwater fish. Many years of scientist observations revealed that the average size of guppies in a pond, decreased. It was surmised that this decrease was due to the introduction of a natural predator. Which of the following best explains the change in guppy size? a natural selection - scientists influenced the average size of the guppy to protect the species b genetic mutation - a change in DNA occurred causing a decrease in average guppy size c natural selection - smaller guppies became less visible to predators d selective breeding - predators select prey based on preferred traits

Answer 1

Answer: c natural selection - smaller guppies became less visible to predators d selective breeding - predators select prey based on preferred traits.

In nature, predators prefer larger individuals. They will provide sufficient nourishment, not only to compensate for the used energy during the hunt, but also to sustain the individual for a period of time. Smaller individuals are hunted only if they are infants and thus vulnerable and easily caught.

Thorugh the introduction of the predator, being small became evolutionary advantageous. Thus, large guppy where preyed upon and did not succeed in reproducing. However, small guppy survived and reproduced successfully, thus passing on their genes. The next generation will be composed by the offspring of the smaller fish.