I understood this to be necessary because of the lack of advancement of science on Rocky’s planet. Evolution was a new concept. If he’s doing it for Rocky, might as well do it for Earth too.
Many years ago I visited Denali and took a tour. I was fortunate enough to see bears mating.
It was both awesome (knowing the rarity of such an event) and terrifying because the tour was on a retrofitted school bus and when the bears were done doing their thing (bearing down?) the make walked right by the school bus. If id had my arm out the window it would’ve touched him.