I think the main obstacle is not the ethical one, but the very long gestation period of elephants (more than 18 months). Mice, in contrast, have a gestation per

I think the main obstacle is not the ethical one, but the very long gestation period of elephants (more than 18 months). Mice, in contrast, have a gestation period of 20 days. So each iteration of your experiment will take 20 times longer when you use elephants. A postdoc might be there for 2 iterations, while a tenured professor could perform maybe 10 iterations throughout their career.