PBA201H: The Biology of Prenatal Human Development

• EHD DVD / TED Talk / EvilCatProductions video
  • some facts and milestones about development (e.g. heartbeat, viability)

• Maybe introduce fetal origins (Annie Murphy Paul): TED Talk or article (but see also PBA401H)

* Embryology presentation used by CCBR

• From Oriyana Hrycyshyn (can sub in name of any child for her sister Inessa)
• approx. 45 min, covers all the major milestones of prenatal development + leaves time for questions/practice
• Link to Google Doc of notes: https://docs.google.com/document/d/16o1oh6ClzosIVa1SHByPgNXtNkTKHv1m8rrZteoxnno/edit?usp=sharing

* Intro: close your eyes, imagine that you're in a small, dark, enclosed place, and you can only communicate with the outside world with a small cord.

• Not talking about being in the womb, but the Chilean miners crisis
• SLED

• Timeline ( visual)
  • zygote
  • blastocyst
  • embryo: until 8 weeks
  • fetus: 8 weeks until birth

• As we learned in PBA100Y, a new human being comes into existence at Fertilization.
  • description, DNA, hair colour, eye colour, etc.
  • Sperm-egg fusion: A mature egg will leave the ovary and the sperm that travels through the Fallopian tube will fuse with the egg; the first sperm that fuses, uses the enzymes to crack through the outer layer (zona pellucida) of the egg and fuse with the inner membrane; then, there's an outer barrier created that will prevent any other sperm from fusing with that egg

• Four Principles: At fertilization, a unique, whole, living human being comes into existence.
  1. Unique:
     1. The genetic code of the zygote is unique, distinct from the mother and father
     2. Illustrate: A woman could be pregnant with a male zyogote = different DNA
  2. Whole:
     • Illustrate: a single-celled zygote vs. a single cell of, say, human skin. Both are living, human, diploid cells; but one is a human whole vs. a human part. Give each cell time, nutrition, safe envt, wait 9 months or 15 years…which one continues developing into a toddler, a teenager?
     • Illustrate constucted vs developing with Mr. Potato Head, a Polaroid camera
  3. Living:
     1. Law of Biogenesis: living things come from other living things.
     2. If the pre-born child isn't biologically alive, why would a woman need an abortion?
  4. Human:
     1. If someone has human parents, aren't they human offspring?
• Cellular biology and sperm/egg fusion: composition, behaviour
  • While the zygote is a very young individual composed of only one cell, that one cell is substantively different from the sperm cell or egg cell. We can see this by considering the criteria science uses to distinguish between different cell types: cell composition and behavior. In other words, what the cell is made up of and what it does.
    • Composition: Whereas a sperm is composed of 23 chromosomes from the father and an egg is composed of 23 chromosomes from the mother, a zygote is composed of both. Sperm and egg, i.e. gametes, are haploid; the zygote is diploid. ( include technical language of haploid vs. diploid?)
    • Behaviour: And where the behavior of sperm and egg is to penetrate or be penetrated (respectively), the zygote’s behavior is to do neither. The zygote acts in a coordinated manner for the health of the whole, and she self-directs her own growth. And so, the zygote is fundamentally different from sperm or egg. No human can claim ever having been a sperm or an egg, but as Drs. Moore and Persaud explain, the formation of the zygote 'marks the beginning of each of us as a unique individual.'

• Using the definition of death to mark the beginning of life
  • cardio-pulmonary death is the legally recognized point
  • complete irreversible brain death (this specifically), when all coordinated functioning for the overall good of that human being ceases to exist, is how we can define death more accurately (most medically accurate)
  • fertilization is when we first gain that coordinating functioning

http://www.unmaskingchoice.ca/training/classroom/science/implantation

https://www.endthekilling.ca/training/classroom/science/twinning

Determining precisely when the pre-born feel pain is largely dependent on technology to detect this. While it is an interesting topic, it has no bearing on the morality of abortion. After all, is it wrong to kill someone because she feels pain or because she’s human?

Consider Gabby Gingras, an American girl with a rare condition called hereditary sensory autonomic neuropathy, Type 5²⁾. In short, she cannot feel pain. As a baby, she poked and scratched her eyes, causing significant damage—she never felt pain to tell her to stop. May we kill her because of her inability to feel pain? Why then may we kill the pre-born because they don't feel pain at certain points during pregnancy?

To make the point even more simply: would it be permissible to kill a 3-year-old as long as we give him anaesthetic first?

http://www.ehd.org/prenatal-summary.php

“A fetus is just a blob of tissue, just a clump of cells. It doesn't even look like a human being.”

Terms like “blob of tissue”, “clump of cells” etc. are dehumanizing terms that are ultimately meaningless. It's true that a pre-born child is a “clump of cells” – but so is a born human being! Although pre-born children are obviously less developed than older humans, they are still human beings with human rights.

Pre-born children also look different from born children; a zygote looks different from a 10-week fetus, who looks different from a toddler, etc. But how would we expect a human being of that specific age to look? For instance, we would not expect a toddler to undergo the same body changes that a teenager undergoes during puberty. Pre-born children look exactly the way they are supposed to look for their age and level of development.

So many embryos miscarry anyway, so what's the big deal about abortion?

- high rate of miscarriage in 1st trimester - miscarriage is a tragedy - cause of death is different: one child dies naturally, we couldn't prevent it. Another child is purposefully killed. Ex. difference between 1 person dying of a heart attack and another person being stabbed in the heart.

“A fetus isn’t human, it’s just a parasite feeding off of a woman’s body!”

While a fetus does require nutrients from her mother via the umbilical cord in order to survive, it is unscientific to call the fetus a parasite. By definition, a parasite must be of a different species than the host organism–for example, a flea on a dog. Since a fetus and her mother are of the same species – human, it doesn’t make sense to call her a parasite.

“a tumour”

condensed version of the rest of Oriyana's presentation, such that anyone else could give it, in an hour-long discussion format