As previously stated, if there were no common designer then we could expect to see little to no similarity between organisms.
Why? If evolution is correct then one would see similarities. The lack of similarities would be evidence that there was a designer. The similarities show descent. Similarities among non closely related species still show descent, but from a different start point.
There is no better love between 2 people than mutual respect for each other WT Young, 2002
Who gave anyone the authority to call me an authority on anything. WT Young, 1969
Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008