When does human life begin? For decades, science has had a clear answer: fertilization.
Below we recall 5 occasions when science pointed out that human life begins with fertilization.
1. The book of medical embryology by Jan Langman
In 1975, in the third edition of Jan Langman’s famous book Medical Embryology, it was explained that “the development of a human being begins with fertilization, a process by which two highly specialized cells, the male’s sperm and the female’s oocyte, unite to form yes it rises to a new organism, the zygote ”.
The latest edition of the book insists that “development begins with fertilization.”
2. The Foundations of Human Embryology, by Keith Moore
Keith Moore’s book Essentials of Human Embryology (published in 1988) agrees that “human development begins after the union of male and female gametes or germ cells during a process known as fertilization (conception).”
The fertilized egg, “known as the zygote,” says the book, “is a large diploid cell that is the primordial beginning of the human being.”
3. A study published by Nature
“The life cycle of mammals begins when a sperm enters an egg,” said a study published in 2010 in the journal Nature by Yukinori Okada and other scientists, entitled “A role for the elongating complex in demethylating the zygote paternal genome.” ”.
4. A new investigation in 2012
Research by Janetti Signorelli and other scientists in 2012 concluded that “fertilization is the process by which male and female haploid gametes (sperm and eggs) unite to produce a genetically distinct individual.”
5. “The Human Being in Development”, by Moore, TVN Persaud and Mark Torchia
In 2015, in the latest issue of their book The Developing Human: Clinically Oriented Embryology, scientists Keith Moore, TVN Persaud and Mark Torchia stated that “human development is a continuous process that begins when an oocyte from a female it is fertilized by a sperm from a man ”.
“Human development begins with fertilization when a sperm fuses with an oocyte to form a single cell, the zygote,” they wrote.
The scientists also noted that “all major external and internal structures are established between the fourth and eighth week” and “foci of the upper extremities are recognized on days 26 or 27 as small swellings on the walls of the ventrolateral body.”
At the end of the eighth week, they remarked, “the embryo has unmistakable human characteristics; however, the head is still disproportionately large, constituting almost half of the embryo ”.