Because your parents named you that, most likely.
Answer:
Polygenic inheritance
Explanation:
When multiple genes present at different loci on chromosomes regulate a single genetic trait, the trait is said to be polygenic and the inheritance is a polygenic inheritance. The phenotype of the individual is regulated by an allele of each gene in an additive manner. The sum total of phenotypic effects of each allele of all the genes determines the final phenotype of the individuals.
These traits not present in discrete contrasting pairs (such as tall and short) but exhibit quantitative variations. For example, skin color in humans is regulated by multiple genes and the phenotype of the individual ranges from very light to very dark with many intermediates in between.
In lieu with your question, only 10% marine life are adapted to withstand the immense hydro-static pressure below 180 meters. Other 90% are adapted to live in surface of ocean or on their evolutionary way to land.
