There are four main organelles:
Nucleus
Ribosome
Rough Endoplasmic Reticulum
Golgi Apparatus
However, the ribosome is the most responsible for making protein, even though the other 3 are also important. It isn't a cell organelle but a cell structure that produces proteins.
The possible result of the founder effect would be loss of genetic variation. The reason why this is so is because by definition, the founder effect is often considered to be the cause for a essened genetic variation in a specie or a certain area where organisms thrive.
They are called paleontologists.