ТайлбарNatural Selection with Elephant Trunk Size.png
English: A random mutation in the DNA of elephants caused some elephants to have long trunks and some to have short trunks.
The overproduction of elephants caused resources to become scare, so the elephants had to compete for food. The elephants with longer trunks had an advantage because this trait made resources more accessible for them.
Therefore, elephants with longer trunks were likely to survive longer and reproduce.
As a result, long trunks within the population increased because this inheritable trait gave individuals an advantage in their environment.