Because they would need to compete over resources.
Testosterone is an example of a steroid. Its physiological functions include:
1. Determines the the gender of a developing embryo.
2. Development of reproductive organs and the prostrate gland in males.
3. Responsible for secondary sexual characteristics in males such as deeper pitch, increased muscle bulk, hair on the upper lip.
4. Regulates normal sperm development.
Another steroid is cholesterol. Physiological functions include:
1. Helps maintain the structure of cells and vessels improving overall health and function in the body.
2. Precursor to important sex hormones such as testosterone and estrogen.
3. Used as an insulator around nerves and is absolutely essential for brain function.
4. Precursor to Vitamin D, which supports a healthy immune and nervous system
