Zygotes are Persisting Organisms.

Zygotes are persisting organisms. That is, zygotes are organisms and most born human beings are identical to the zygotes from which they originated. I defend these claims against recent critiques. Chunghyoung Lee, for example, argues that for any zygote, z, z may develop into one of several, numerically distinct infants. If so, then for any infant, that infant is not identical to the zygote from which he or she originated. If Lee is correct, then zygotes are like gametes, which may give rise to mature human beings, but cease to exist along the way. This, Lee claims, suggests that zygotes are not organisms. I respond that Lee (like many others) confuses zygotic parts with whole zygotes. The error lies in identifying zygotes (and embryos) with their inner contents alone. Zygotes are more than their internal parts, however, just as the reader is more than their heart, lungs, and kidneys. To advance these claims, I defend a version of "zona-essentialism," which maintains that the zona pellucida-the membrane surrounding zygotes and early embryos-is essential to their identity during early stages of life. By distinguishing between zygotic parts and whole zygotes, I show that Lee's (and others') arguments fail to establish that zygotes are not organisms. I conclude by discussing practical implications for finding that zygotes are human organisms. Clinicians and researchers must embrace reality: individual human beings are routinely killed in the name of scientific advancement and reproductive autonomy. Failure to acknowledge this-e.g., by using euphemisms to obscure the truth-is problematic.