Biological Markers
One of the possible basic requirements for personhood is individuality, which entails differentiation between the person and its parents. Biology offers a number of stages in the life cycle that have been seen as candidates for personhood:
- fertilization, the fusing of the gametes to form a zygote
- implantation, the start of pregnancy, occurring about a week after fertilization
- segmentation, after twinning is no longer possible.
- when the heart begins to beat
- neuromaturation, when the central nervous system of fetus is neurobiologically "mature"
- "brain birth" concepts (compare with brain death):
- at the first appearance of brain waves in lower brain (brain stem) - 6-8 weeks of gestation (paralleling ′′whole brain death′′)
- at the first appearance of brain waves in higher brain (cerebral cortex) - 22-24 weeks of gestation (paralleling ′′higher brain death′′)
- "brain birth" concepts (compare with brain death):
- the time of fetal movement, or "quickening"
- when the fetus is first capable of feeling pain
- when it can be established that the fetus is capable of cognition, or neonatal perception
- fetal viability
- birth
- post-birth development stages
Read more about this topic: Beginning Of Human Personhood
Famous quotes containing the word biological:
“It is not the literal past that rules us, save, possibly, in a biological sense. It is images of the past.... Each new historical era mirrors itself in the picture and active mythology of its past or of a past borrowed from other cultures. It tests its sense of identity, of regress or new achievement against that past.”
—George Steiner (b. 1929)