Isn't it a bit odd to say that genes belong to or are a part of a "pool"? A pool is normally a body of water, e.g. a swimming pool
The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species. This also proves to be the basic level at which evolution occurs. [...] A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can survive bouts of intense selection
Merriam-Webster defines it as
biology: all of the genes in a particular group of people or animals
Full Definition of GENE POOL
the collection of genes in an interbreeding population that includes each gene at a certain frequency in relation to its alleles : the genetic information of a population of interbreeding organisms e.g.the human gene pool
First Known Use: 1946
A pool can be a single mass of liquid, a reservoir of water; a number of people who share the same profession, a typing pool; people who share a car, or, travel as passengers for part of the journey, carpooling. The terms gene banks, sperm and egg banks express the concept of preservation and a place where one can have easy access, but we never mention sperm pool, egg pool or bone marrow pool and yet each individual sperm, egg, bone marrow and human gene is unique unto itself.
- Who coined the term gene pool and why was pool specifically chosen (if there was a reason).