This track shows the difference in alignment between the Mm3X Best and the
Mm3X Mapped tracks. 
<P>Every base aligned by the Mm3X Best track is colored one of
three colors.  The base is colored black if the base on the Mm3X scaffold aligns to 
the same position on hg17 in both tracks.  If the base is aligned in the Mm3X Best
track, but not aligned at all by the Mm3X Mapped track, then the base is colored
gray.  If the scaffold base is aligned by each track to two different positions on hg17, 
then it is colored red.