Question #233e4

1 Answer
Oct 1, 2017

See below.

Explanation:

Natural selection happens when some members of a species are more successful at producing offspring than others, and over long periods of time, the more successful genes are spread throughout the species because of this.

For example, giraffes born with longer necks could get more food and live longer than ones with shorter necks, and so have a higher chance of reproducing and spreading the gene for long necks.

However, if a short-necked giraffe stretched every day and eventually somehow acquired a longer neck, it couldn't pass its long neck on to its offspring because the instructions for a short neck are still coded into its DNA. Because its offspring still have the same old genes, they aren't any more likely to live longer and reproduce than other short-necked giraffes.