Science is Clear - Life Begins at Fertilization

“In fusing together, the male and female gametes produce a fertilized single cell, the zygote, which is the start of a new individual.”

-Quoted in Randy Alcorn “Pro-life Answers to Pro-Choice Arguments” (Sisters, Oregon: Multnomah Publishers, 2000)

We know and believe as Catholics that science, specifically biology, only re-confirms what we already know on the matter of when a human life begins within a female's body. It is during conception, specifically fertilization, that a new life is formed within the fallopian tube before there is growth and development within the uterus (womb) after the process of implantation. The life of a human being begins at fertilization. (Mayo Clinic)

When I was at the Capitol in Albany, New York outside the door to the Senate chambers one afternoon at a pro-life rally one of the most memorable signs that caught my eye was "Keep your theology off my biology." Looking across at the woman holding high her seemingly witty words on a poster I could not help but wonder if she really knew and understood "her biology." Biology and theology are not in competition with one another when it comes to the issue of when a new human life is created.

As a high school educator teaching science in a public school, human development, was one of the major topics for the students to learn during the tenth grade. The following standards are a part of the New York State Living Environment Curriculum:

4.1c – The processes of meiosis and fertilization are key to sexual reproduction in a wide variety of organisms. The process of meiosis results in the production of eggs and sperm which each contain half of the genetic information. During fertilization, gametes unite to form a zygote, which contains the complete genetic information for the offspring.

4.1f – The structures and functions of the human female reproductive system, as in almost all other mammals, are designed to produce gametes in ovaries, allow for internal fertilization, support the internal development of the embryo and fetus in the uterus, and provide essential materials through the placenta, and nutrition through milk for the newborn.

4.1h – In humans, the embryonic development of essential organs occurs in early stages of pregnancy. The embryo may encounter risks from faults in its genes and from its mother’s exposure to environmental factors such as inadequate diet, use of alcohol/drugs/tobacco, other toxins, or infections throughout her pregnancy.

When we look at the standards one may argue that the term "baby," is never mentioned, which is true. But let us take a closer look at the meaning of the terms that are used within the curriculum; fertilization, zygote, embryo, and fetus as defined by the Meriam-Webster Dictionary:

Fertilization - the process of union of two gametes whereby the somatic chromosome number is restored and the development of a new individual is initiated

Zygote - a cell formed from the union of two gametes; the developing individual produced from such a cell

Embryo - the developing human individual from the time of implantation to the end of the eighth week after conception

Fetus - an unborn or unhatched vertebrate especially after attaining the basic structural plan of its kind; a developing human from usually two months after conception to birth

Do you still not believe that "science" teaches us that a human life begins at the fertilization stage of conception? Do our biology textbooks have it all wrong? Perhaps, we can also review the meanings of these scientific terms in the Farlex Medical Dictionary:

Fertilization - in human reproduction, the process by which the male's sperm unites with the female's oocyte, creating a new life

Zygote - the cell resulting from union of a male and a female gamete; the fertilized ovum

Embryo -a new organism in the earliest stage of development. In humans this is defined as the developing organism from the fourth day after fertilization to the end of the eighth week. After that the unborn baby is usually referred to as the fetus.

Fetus - the developing young in the uterus, specifically the unborn offspring in the post embryonic period, which in humans is from the third month after fertilization until birth.

Our Catholic faith teaches us that we are called to respect and protect life from the moment of conception (fertilization) because we know that is the beginning of a human life. (Catechism of the Catholic Church, no. 2270) Since the days of early Christianity the Church Fathers have taught that the second commandment; "Thou shall not kill" calls for us to protect a human life; to defend against the killing of an unborn and newborn child. (Didache 2:1–2 [A.D. 70]) We have a moral obligation to safeguard the life of every human being, (CCC, no. 2271) and to defend the truth; that a human life begins at fertilization, and that precious life within the womb has the right to live the same as a human being that has been born.

When we look at the science of human development we see that the biology behind the process only supports and re-confirms what we already know to be true. Why is it so easy for us to believe the science behind the wearing of masks during this Coronavirus pandemic, climate change, vaccines, and genetically modified foods, but find it difficult to believe the science of embryology and genetics behind when life begins for a human person? If we say that we trust the "science" then we need to actually trust the science; really and truly.