They are comparable in light of the fact that they are both compound sources of vitality utilized by cells.
They are altogether different as far as arrangement and structure.
The continental shelf is a gently sloping feature found at the edge of a continental landmass going seaward from the coast. Rivers that empty into the sea can produce currents that are strong enough to erode the material that builds the shelf. When this occurs channels or submarine canyons are formed. These canyons are deep and dark as no light can penetrate these regions. The canyons often lead out to sea towards the edge of the shelf.
After hundreds or even thousands of generations both alleles for sickle cell anemia are still common in those of African ancestry. This is supported by two mechanisms: heterozygote advantage and gene flow.
Heterozygote advantage
When an allele is said to be heterozygous, it is carrying one copy of a gene. For example if one carries a copy of sickle cell allele, it will stay in the population even after many generations — natural selection will not be able to remove it and it will be passed on through generations. So, having one copy of that allele is advantageous but not deleterious.
Gene flow
With humans migrating throughout the different parts of the world, sickle cell allele is passed from one person to another or in different populations. It is actually advantageous to have one copy of this allele especially if there’s malaria in the area, which the allele is resistant.
