[Modernman]

Having unique DNA and that DNA is human, those "clusters of cells" are really very tiny humans.

DNA is not enough. Cells can be removed from your adult body-they have unique, human DNA, they even have the potential, through cloning, to become fully human. Is a cell taken from your cheek therefore human?

Granted, given enough time and the proper circumstances, the cluster of cells can grow into a full-blown human. However, given enough time and the proper circumstances, a single sperm cell can grow into a full-blown human. The potential to become human isn't the same as being human.

[Desdemona]

Too many steps of rationalization. Sorry.

Life begins at conception. A "cluster of cells" can't be human one day and not human the next. It just doesn't work that way.

[MHGinTN]

You continue to err, biologically. 'Potential'?... If we look at a toddler, that individual human life 'has the potential to become post-pubescent, but it isn't there yet' ... do you see the absurdity of your arbitrary assignation? The first totipotent cell zygote that you were at one time along your lifetime had something no other cell of you has had since ... 'potential to build everything you needed to survive in the womb, while building the body you are using now' ... but all that followed your zygote age developed at YOUR INDIVIDUAL INSTRUCTION. To err in comparing the somatic cell in your mouth or even your crotch as equivalent to the zygote is very uneducated of you. Try to catch up to the scientific facts, if you're going to pontificate.