Because to actually use the word evolve an organism must suffice more than one condition, which in this case would be an advantageous trait. Having an advantageous trait (from our eyes at least) must also include the right and stimulating enviironment for procreation. So this answer is multifolded.
All domestic mammals have seven cervical vertebrae.
Saturated fats consists of single covalent bond and they are solid at room temperature and their melting point increases with increasing chain length
<span>hope it helps</span>
