Fig. 3. Graphical representations of the multiple regression analyses we performed
on the morphological, gait characteristics and performance data in the 11
lacertid lizard species. (A) All potential relationships. Each arrow
represents one analysis. Independent variables introduced into the same
multiple regression are boxed. Arrows are drawn from the independent variables
box to the dependent variable box. We performed two series of analyses: one
that included the (contrasts of the) values for the four gait characteristics
at maximal sprint speed, and the second on the (contrasts of the) slopes of
each of the four gait characteristics against speed. (B) Significant
relationships in the multiple regression analyses including the contrasts of
the estimated values of the four gait characteristics at maximal sprint speed.
(C) Significant relationships in the multiple regression analyses including
the contrasts of the slopes of each gait characteristic against speed. By
definition, the contrasts of the slopes of stride length and stride frequency
against speed are inversely related so we never introduced them simultaneously
into the analyses. Instead, we included only the contrasts of the slopes of
stride frequency against speed in the analysis; including the contrasts of the
slopes of stride length against speed gives the opposite result
(r=0.56; P=0.075).
