[js1138]

In fact, scientists are finding that the kingdoms show almost no relation to each other.

The molecular machinery that interprets DNA is virtually the same in all living things, even in the lowliest bacterium.

[johnnyb_61820]

Almost. There are actually a few species who have alternate readings of the DNA code. However, the differences between the kingdoms are so vast, that the existence of the DNA-code-reading mechanism has not been shown to salvage the common ancestry path, and some are believing that it is the result of "convergent evolution".

Of course, note that each instance of "convergent evolution" is an addition to the theory that similarity need not imply common origins.