This relates to Evolution
ACTH's principal function is to stimulate the cortex (outer layer) of the adrenal glands (located near the kidneys) to secrete a group of steroid hormones called glucocorticoids. Glucocorticoid hormones control the body's use of sugar and also help regulate biological functions during stressful moments
The fact that they can breed but cannot produce fertile offspring shows that they are different species. T<span>hey may have different characteristics which means they cannot breed </span>successfully, too.
I hope this helps! :-)
xo Leafling