. I think that bivalves have evolved to have smaller head regions because they have also evolved to have bigger shells or valves than cephalopod
As the head organ in the body which controls, monitors, supervises and influences the different organ system in the body and of the individual -characteristics, personality, traits, cognition, perception, intelligence, sensation and motor responses. The brain controls the endocrine system by its part, located somwhere in the medial temporal lobe called the hypothalamus, the master gland of the body. The hypothalamus influences every gland secretion and hormonal function that preceeds and proceeds in the body of an organism -growth, drives, sex, survival and etc.
The hypothalamus sends sgnals from the different gland organs in the body that either exhibits or inhibits the activity of that particular gland releasing hormone.
The mechanism that affected the gene pool of the immigrants that entered the United states Through Ellis Island is Gene flow.
Gene flow involves the movement of genes or alleles between interbreeding populations of a particular species. In other words it is the movement of genes from one population to another population. Actually it may be an important aspect of evolution; evolution can occur as a result of genes being transferred from one population to another. Gene flow occurs when there is migration, since the loss or addition of people can easily change pool frequencies even without no other evolutionary mechanisms operating.
It’s a bc they both need a wavelength
