Question

Giraffes use their extremely long necks to reach the leaves high up on acacia trees, which other animals can not reach, giving them a food source for which they have few competitors. What can you conclude about natural selection from this observation?

Answer 1

Giraffe necks get longer over a lifetime of stretching, and their offspring inherit the longer necks of their parents.
All giraffes are born with short necks and, eating acacia leaves causes them to stretch over a lifetime.
Other animals will mimic the giraffe and grow longer necks.
The giraffes with the longest necks survive and produce offspring.

Answer 2

Good

http://evolution.berkeley.edu/evolibrary/article/evo_25

Answer 3

The giraffes with the longest necks survive and produce offspring.