DNA mathematically/chemically dictates every species reproduces according to it's kind, to maintain their specific role in maintaining the equilibrium of the biosphere.
"And God went on to say: “Let the earth put forth living souls according to their kinds, domestic animal and moving animal and wild beast of the earth according to its kind.” And it came to be so. 25 And God proceeded to make the wild beast of the earth according to its kind and the domestic animal according to its kind and every moving animal of the ground according to its kind. And God got to see that [it was] good.
26 And God went on to say: “Let us make man in our image, according to our likeness, and let them have in subjection the fish of the sea and the flying creatures of the heavens and the domestic animals and all the earth and every moving animal that is moving upon the earth.” 27 And God proceeded to create the man in his image, in God’s image he created him; male and female he created them. 28 Further, God blessed them and God said to them: “Be fruitful and become many and fill the earth and subdue it, and have in subjection the fish of the sea and the flying creatures of the heavens and every living creature that is moving upon the earth.” Ge1:28

Science is simple, easily observed, measured, documented, stupid contradictory theories are impossible to prove, they only send disoriented minds to chasing the winds of their beloved illusions.