Question

Construct an explanation as to how natural selection might produce an effect of the giraffes neck length changing over time

Answer 1

Evolution has led giraffes to have very long necks. Trees in the savannah have less leaves on bottom branches because of other animals. For the giraffe to survive, their necks slowly became longer as they could eat more leaves from upper/top branches. If they had not evolved longer necks, they would not exist today.