Complex sentence: Since both PAM and BLOSUM are different methods for showing the same scoring information, the two can be compared but due to the very different method of obtaining this score, a PAM100 does not equal a BLOSUM100.
Split into simpler sentences: Since both PAM and BLOSUM are different methods for showing the same scoring information, the two can be compared. But due to the very different method of obtaining this score, a PAM100 does not equal a BLOSUM100.