Reproductive isolating mechanisms are barriers which impeded mating (prezygotic) or prevent the hybrid from developing properly (postzygotic) but the overall effect is to cause speciation by making it difficult for two diverging species to share genes. So one kind of mechanical isolation could be the usage of contraceptives. As of temporal isolation, or behavioral isolation could be exemplified by people who suffer from diseases that cause separation (such as HIV or cancer). I hope that this is the answer that you were looking for and it has helped you.
Harmful because they change how the genes are supposed to form and they can give disorders at times.
The inner core is the hottest part of the earth because the earth is not like the sun very hot with full of sunspots and earth really doesnt have any
Organs of excretion make up the excretory system. They include the kidneys, large intestine, liver,and lungs. The kidneys filter blood and form urine. They are part of the urinary system, which also includes the ureters, bladder, and urethra.