Genetic drift occurs when there is no random mating across a population. This causes a change in allelic frequency due to a random sampling of the population.
As the aboriginal population explored the earth, a small part of the population became geographically isolated either due to continental drift and climate changes. As the isolated population grew bigger, they established their own gene pool. This resulted a change in genotypic frequencies from that of the aboriginal population.
Answer and Explanation:
The lymph node are the sites for the formation of lymphocytes and monocytes. These are concerned with antibody formation and phagocytosis of foreign materials respectively. In the lymph nodes, bacteria and other harmful materials are removed from lymph.
The outer ear consists of two things and they are the auricle and the ear canal , which is also called the auditory canal.
The auditory canal goes from the outer ear to the middle ear.
The auricle is what we see of the ear...the physical part of the ear. It can be called the pinna as well.
I hoped that this helped and good luck.
The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.
