The Bible says Genesis 1:28 English Standard Version Revision 2016 (ESV)
And God said to them, “Be fruitful and multiply and fill the earth and subdue it, and have dominion over the fish of the sea and over the birds of the heavens and over every living thing that moves on the earth.”
Science says that the purpose of every single life form from a single cell organism to a whale to a human is to reproduce as much as possible.
When you ignore your religion as well as science, what do you have left to guide you? Selfishness?