At what point 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 in fertilization.
1. Book of Medical Embryology by Jan Langman
In 1975, in the third edition of Jan Langman’s famous book Medical Embriology, it was explained that “the development of a human being begins with fertilization, a process by which two highly specialized cells,” the sperm of the male and the oocyte of the female, come together to give rise to a new organism, the zygote. “
The most recent edition of the book insists that “development begins with fertilization.”
2. Foundations of Human Embryology, by Keith Moore
Keith Moore’s Essentials of Human Embryology 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,” the book states, “is a large diploid cell that is the beginning, or primordial, 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 elongator complex in Zygotic paternal genome demethylation “.
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 egg) come together to produce a genetically different individual.”
5. “The Human Being in Development,” by Moore, TVN Persaud, and Mark Torchia
In 2015, in the latest edition of his 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 is fertilized by a sperm from a male. “
“Human development begins in fertilization when a sperm fuses with an oocyte to form a single cell, the zygote,” they wrote.
Scientists have further noted that “all major external and internal structures are established between the fourth and eighth week” and “upper limb outbreaks are recognizable on days 26 or 27 as small swellings on the walls of the ventrolateral body. “.
By the end of the eighth week, they indicated, “the embryo has unequivocal human characteristics; however, the head is still disproportionately large, constituting almost half of the embryo.”