personally, i find it hard to swallow that intervention theory
is probable. why?
1) based on the DNA test on the sample extracted from the starchild
skull, it shows that the mitochondrial DNA is exactly the same as
Native Americans. this implies that even if aliens do exist, at the
point of the alien's sperm fertilizing the egg, the human species
is already developed because the mitochondrial DNA sequence is
identical to modern human.
2) interspecies marriage is not very probable to lead to a
successful birth of a baby. it is because the number of chromosomes
in the maternal and paternal gametes must be identical for it to
happen. while it has been shown in the lab that even if the egg and
the sperm have different number of chromosomes, the sperm still can
fertilize the egg, but it will also end up in miscarriage, that is,
the embryo never succeed to be concieved to full term. that is why
human and its closest species, chimpanzees, even cannot have a baby
together.
3) let's assume that both alien and human have same number of
chromosome, so (2) is now void. it is still even more hard to be
convinced that an alien from outer space could evolve until it is
identical to the human species on Earth. this process of convergent
evolution is unbelievable!
