Confused on Fertilization

June 3, 2010

Fertilization in humans and other mammals produces a new member of the species in the embryonic stage of its natural development. That is to say, the entity produced by the union of spermatozoon and oocyte is a complete, though developmentally immature, organism. Unlike the gametes, it is not merely part of another organism; nor is it merely something that can be used to produce a complete organism. At fertilization, the ovum and the sperm cease to be and something new comes to be — an organism (the embryo) whose genetic constitution and epigenetic state orient and dispose it to develop in the direction of maturity as a member of the species. (National Review Online)