When we listen to statements on early embryo development such as how a human embryo is not a human being, or that it is only a cluster of cells, or its biological significance is questioned or other similar phrases that try to minimize or take away importance from the early stages of human life, we must remember something as basic as that after fertilisation, the human zygote, resulting from the fusion of a human ovum (egg) with a human sperm, which receives human genes, is the first biological reality of a human life.
Th early embryonic development is as a clock of life starting
Once the zygote has been formed, the clock of life is started, and the integral elements of that simple cell are triggered to begin a dynamic process that is unstoppable (unless external factors intervene), so that the life that has just been established develops. Developmental Genetics is a modern and attractive branch of Genetics that tries to explain how a complete organism is organised from one cell. It reveals to us the genetic causes of the morphological transformation observed throughout the development of living beings, applicable equally for an insect, a plant or a human being. In a first approach, we know that allmulticellular beings start from a single cell, which by successive divisions and copies of the genetic information that the zygote already possesses, will give way to the different stages of development, growing not only in number of cells, but also in complexity. At first, the cells that make up the embryo seem to be the same, but this is not so; from practically the first cell division there is already a division of roles, and the two resulting cells will follow different paths in development: one will give rise to the outer protective structures and the other to the embryo itself.
The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.