By your definition, a human embryo is flushed away (killed!) once each month throughout a nubile female’s lifetime, unless she becomes pregnant. Also, the pill flushes an embryo away, fertilized or not, once each month.
These people are finding ways to use clone tissue for stem cells instead of fertilized embryo tissue (read potential person), why do you have a problem with that, Mr or Ms, microbiologist?
Logical fallacy - “is” doesn’t mean “ought.”
And you’re factually wrong. Unless the oocyte is stimulated to divide and create an embryo, as it is in these experiments, there’s no loss. Regardless, what happens in nature does not mean that it’s permissible - that we humans ought to purposefully set out to do the same.
In nature, more boys are the result of natural conceptions in humans, and more of them die off before reaching a year old. Does this mean that we can kill off neonatal boys if we find that it’s useful to harvest their body parts?
To say that a human embryo is flushed away once a month is therefore misleading. The egg is not an embryo, it cannot divide and develop. That's what is "flushed" once a month!
On the other hand, the embryo, formed by fertilization, is a diploid cell (46 chromosomes), it is the earliest form of life, and if let alone it will start dividing, the cells specialize, and given the time becomes a baby.
Can you tell if a cluster of cells is an embryo, with an inalienable right to life, or just that, a cluster of cells? Sure thing! Do a karyotype, where you can actually see the chromosomes. If the cells have one copy of each chromosome, this is a haploid cell, it is NOT a human being, and as such does not have the rights to which human beings are entitled. But if there are 2 copies of each chromosome, this diploid cell IS a brand new, unique, human being and nobody has the right to take his/her life. What these people are doing is taking an unfertilized egg (haploid), removing the nucleus and replacing it with the nucleus of a somatic cell (diploid). Once they have a diploid cell, it can be activated to begin cell division and an embryo is formed. This is a unique human being, both genetically and spiritually, and this is what I oppose killing.
As for harvesting embryonic stem cells to save your life... don't hold your breath! So far there has not been a single report of treating a condition with embryonic stem cells. On the other hand, there are dozens of treatments with ADULT stem cells, ranging from experimental, to clinical trials, to standard treatments like bone marrow transplant. So, if I was concerned about saving my life, I would go with the research that shows results, not with the one that promises but does not deliver!