Why We Break Narial (Coconut) tp god?

In ancient time human or animals being  used to kill to donation to God.
but, in Indian culture doesn't follow this.
Then Dharma Shastri(Rhishi)  got idea to donate coconut which  is known as Nar (Male Human) and it also have hair, eyes, etc. and for the color of blood they suggested to use Sindur/ Kumkum