"In commanding Adam to 'be fruitful, and multiply,' God also informed him that he had given the identical command to all his other creatures, and furthermore, that he was putting Adam in charge of things to see to it that his purposes were fulfilled. Specifically, he was to 'replenish the earth, and subdue it, and to have dominion over' every living thing in the biosphere (Abraham 4:28). There are two clearly marked departments—the earth itself as a storehouse and source of life, which Adam is to keep replenished (filled is the word), and the creatures that move about on and over the earth, over which he is to have dominion. As Brigham Young explains it, while 'subduing the earth' we must be about 'multiplying those organisms of plants and animals God has designed shall dwell upon it,' namely, 'all forms of life,' each to multiply in its sphere and element and have joy therein."