Scientific method would be the answer.
The answer is speciation. It could have been caused by the separation
of the two populations by a geographical feature such as a wide river (hence causing allopatric speciation) or could
have been caused by behavioral isolation
between the two population (hence causing sympatric
speciation).
The first triploblastic phylum is Platehelmenthis
These are known as Hormones. Hormones are chemical messengers that are released in one tissue normally endocrine glands for example, adrenal glands, pituitary glands, and transported in the blood stream to alter the activities of specific cells in other tissues. Hormones serves as messengers, controlling and coordinating activities or processes such as growth, metabolism and fertility in the body.
