Helpful Medical Textbooks Quotes for Defending Premise 2

Langman, J. Medical Embryology. 3rd edition:

The development of a human being begins with fertilization, a process by which two highly specialized cells, the spermatozoon from the male and the oocyte from the female, unite to give rise to a new organism, the zygote.

Larsen, WJ. Human Embryology. 2nd edition:

This moment of zygote formation may be taken as the beginning or zero time point of embryonic development.

The Harper Collins Illustrated Medical Dictionary:

Embryo: An organism in the earliest stage of development.

O’Rahilly, RR and Müller, F. Human Embryology & Teratology. 2nd edition:

[F]ertilization is a critical landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed….

Moore, KL. Essentials of Human Embryology:

This fertilized ovum, known as a zygote, is a large diploid cell that is the beginning, or primordium, of a human being.

Carlson, BM. Patten’s Foundations of Embryology:

Almost all higher animals start their lives from a single cell, the fertilized ovum (zygote)… The time of fertilization represents the starting point in the life history, or ontogeny, of the individual.

Gilbert, S. Developmental Biology. 7th edition:

Fertilization: Beginning of a New Organism