Answering the anti-choice statement that a fertilized egg is a human being:
Definitions are all man made., anyway, so all of this is arbitrary. Currently, the definitions of both human being and person are born entities, not unborn. Even the scientific designation of Homo Sapien is of a born entity, not an unborn. However, scientific classification is also man-made.
One reason a fertilized egg is not considered a human being, or more accurately a Homo Sapien, is that a fertilized egg, or zygote, is a single cell. Humans are not single celled animals, we are multi celled animals. A single cell could not even meet the definition of a mammal, which human beings of course are.
Please read the following communication with a biologist for more information:
Expert: Dana Krempels, Ph.D.
Date: 7/31/2007
Subject: Classification of Homo Sapien cells as HS themselves
Question
QUESTION: Hi,
I'm doing research on biological identity and wanted to clarify whether different humans cells can be considered Homo sapiens themselves? To me Homo Sapeins is a colonial organism with a life cycle that includes a single cell stage. Therefore only the zygote and the colonial stages are Homo sapiens, while individual cells sex, skin and blood cells etc aren’t Homo Sapiens.
It would be helpful if phenotypes regarding Homo Sapiens was also cleared up.
I’ve also had it put that cells themselves are considered just another phenotype of Homo Sapiens, so just as gender or a human with blonde hair are phenotypes so are zygotes or sex cells phenotypes of Homo sapiens. To me this doesn’t make sense, there may be phenotypes of types of cells but to conflate that with phenotypes of Homo sapiens runs into the same problem as above.
Can you help clear this up?
ANSWER: Dear Simon,
I don't know any biologist who would classify a single cell from a Homo sapiens as a Homo sapiens. Even a zygote, which may have the *potential* to become a Homo sapiens, but is not an organism by any stretch of the imagination, is not considered an individual Homo sapiens by any members of the scientific community that I know.
A colonial organism is defined as one being composed of loosely organized cells, sometimes with a division of labor. In many truly colonial organisms (e.g., Volvox; some would include sponges), the cells can survive on their own, when taken out of the colony, and even undergo mitosis to produce a new colony (without the help of cloning technology). So in the strictest, biological sense, no eumetazoan (including a human) is a colonial organism.
An organism that exhibits *true multicellularity* (as opposed to being colonial) is defined as one composed of various types of cells that are coordinated to perform particular functions by organizing into organs and organ systems. The individual cells cannot survive for long outside the whole organism.
I do not believe the scientific community in general considers a zygote, blastula or gastrula containing the human genome to be a Homo sapiens. To a biologist, those cells or conglomerations of cells have only the *potential* to become human. This may be a matter of debate in social and political circles, but not in serious scientific ones.
http://en.allexperts.com/q/Biology-664/Classification-Homo-Sapien-cells-1.htm
For my own interest, when you say, "If we do for them it calls into question some current thinking on biological classification of zygotes etc."
...are you aware of any biological classification of zygotes? I've actually not heard of anyone even discussing whether a zygote is an individual organism or not--with the notable exception of Homo sapiens zygotes when it come to arguments about abortion rights.
But no other species I know of is considered an individual organism at the zygote stage, which makes me wonder why Homo sapiens should be considered any different from them. We differ from other species only in degree, and not in kind.
http://en.allexperts.com/q/Biology-664/Classification-Homo-Sapien-cells-1.htm