Stepwise Model Path 
Analysis of Deviance Table
Initial Model:
topt ~ (Ala + Arg + Asn + Asp + Cys + Gln + Glu + Gly + His +
Ile + Leu + Lys + Met + Phe + Pro + Ser + Thr + Tyr + Val) *
(Ala + Arg + Asn + Asp + Cys + Gln + Glu + Gly + His + Ile +
Leu + Lys + Met + Phe + Pro + Ser + Thr + Tyr + Val) -
1
Final Model:
topt ~ Ala + Arg + Asn + Asp + Cys + Gln + Glu + Gly + His +
Ile + Leu + Lys + Met + Phe + Pro + Ser + Thr + Tyr + Val +
Ala:Cys + Ala:Glu + Ala:Phe + Ala:Pro + Ala:Ser + Ala:Tyr +
Ala:Val + Arg:Glu + Arg:Pro + Arg:Ser + Asn:Gln + Asn:Glu +
Asn:Gly + Asn:Tyr + Asn:Val + Asp:Glu + Asp:Gly + Asp:His +
Asp:Leu + Asp:Lys + Asp:Pro + Cys:Leu + Cys:Met + Cys:Pro +
Gln:Pro + Gln:Ser + Gln:Val + Glu:His + Glu:Ile + Glu:Leu +
Glu:Lys + Glu:Phe + Glu:Thr + Gly:Leu + Gly:Lys + His:Ile +
His:Lys + His:Phe + His:Tyr + Ile:Met + Ile:Ser + Leu:Thr +
Lys:Phe + Lys:Pro + Met:Val + Phe:Pro + Ser:Tyr - 1