*4.2. ANCOVA*

In *H. erectus*, the ANCOVA (as illustrated in Table 5) revealed a significant relationship between cerebellar length asymmetric parameter (ML.lr) and both cranial capacity and occipital petalia while other parameters had no such relationship. From the scatterplot (as illustrated in Figure 3), negative allometry can be observed between ML.lr and cranial capacity in *H. erectus*, indicating that individuals with small brain size will have a larger cerebellar length on the left side. However, only two specimens of *H. erectus* have right occipital petalia (as illustrated in Figure 3), making the relationship between cerebellar length and occipital petalia questionable.



\* Significance level is lower than 0.05.

**Figure 3.** Allometric trend of asymmetric parameters in three populations; B, bilateral; L, left occipital petalia; R, right occipital petalia.

Within *H. sapiens*, cranial capacity does not affect the asymmetric parameter significantly. Occipital petalia had a significant influence on cerebellar height asymmetric parameter (H.lr) and horizontal orientation asymmetric parameter (Hori.lr). Endocasts with right occipital petalia tend to have large positive H.lr and Hori.lr, indicating a tall and steep-orientated cerebellar lobe on the left side.

Because all of the four Neanderthal specimens were left occipital petalia, we performed linear regression instead of the ANCOVA in Neanderthals. Results show that Hori.lr is significantly affected by the cranial capacity. A large brain size would be accompanied by a steep cerebellar lobe, as revealed in the scatterplot (as illustrated in Figure 3).
