Mahendran asked: “If the gandhabba enters at the time of the application of the electric shock, then, as the percentage of success is low, do we assume that as in the natural process, some gandhabbas will not survive to be a full animal and exit in the womb itself?”
It is not a matter of just gandhabba surviving. It is a matter of getting the conditions right for a gandhabba to be able to use that zygote. Since it is an artificial way of triggering cell division, they may not have it exactly right. For example, the failure rate was much higher initially. It took 720 trials to have success with Dolly.
“Now when we say that when a gandhabba finds a matching zygote, is it a selective process? What will be the matching criteria?”
I already mentioned that it is a gati matching process that happens automatically. No one doing a “selection process”. Gandhabba itself also does not have any control. It is just pulled into the right womb, when a matching womb appears.
“In addition to bhava, is it proportional to the karmic energy in the gandhabba? When the unsuccessful embryo dies, for some reason such as the effects of the environment on the epigenome etc, will the gandhabba has spent some amount of karmic energy as a result of the shot life in the embryo? Or would it start all over again with the same amount of energy as before, because it hasn’t started life as a full grown living being.?”
Unsuccessful embryo may die due to many reasons. We can only guess. As I mentioned, in the other post that I referred to on birth control, selection of the gandhabba depends to the state of the mind of mother at that moment too. So, a good mother may have bad state of mind when the gandhabba is pulled in. If the gandhabba turns out to be very different, it may come out of the womb after days/weeks. This is one reason for some unsuccessful pregnancies. It is not possible to micro-analyze each case. But we can get the basic idea.
A gadnhabba would normally have many hundreds if not thousands of years of kammic energy for that bhava at the beginning of the bhava. But, we don’t know whether a given conception is towards the beginning or the end of that time.
P.S. I see that Tobias had answered at the same time, and glad to see the similarity of our answers.