Question

which statement is correct?
giraffes have long necks due to small changes to their dna over many generations.
giraffes have long necks due to daily stretching while reaching for food.
giraffes have long necks due to artificial selection.
giraffes have longer dna which has affected their neck length.

Explanation:

• The first option aligns with natural selection (evolution). Over generations, genetic (DNA) changes that favored longer necks (for food access, survival, reproduction) accumulated.
• Daily stretching (second option) is a Lamarckian idea, rejected as acquired traits aren’t inherited.
• Artificial selection (third option) is human - driven breeding; giraffes evolved naturally.
• DNA length (fourth option) isn’t related to neck length; specific genetic variations (not overall DNA length) drive trait evolution.

Answer:

A. Giraffes have long necks due to small changes to their DNA over many generations.