The bacteria flagellum is one of the world's many evolutionary mysteries. The main function of this organelle is to propel the bacteria and allow it to move. Skeptics of the theory of evolution usually cite this organelle, along with the human eye, as one of the weak points in the theory. The reason behind this is that the bacterial flagella is a very intricate system composes of several different parts. If any one of these parts were absent, the organelle could not function as a whole. However, a counterargument to this case is that the flagellum was arose from a similar structure, the bacterial syringe. These two structures are similar in size and shape so it is a plausible conclusion to an interesting question.