146 Before Agriculture
The regression lines drawn here represent: (a) a linear model for 30 and above age group (r^2 =
0.002; y = 0.8176 + 0.00032x); and (b) a linear model for below 30 age group (r^2 = 0.296; y =
0.1786 + 0.017x).
Source: Zent (in press)^13
Figure 5.5 Regression of age and ethnobotanical competence according to age
subgroups among the Piaroa of Venezuela
The regression lines drawn here represent: (a) a linear or binomial model (r^2 = 0.113; y =
0.727 – 0.0667x); and (b) a curvilinear or polynomial model (r^2 = 0.209; y = 0.8154 – 0.226x
- 0.0162x^3 ).
Source: Zent (in press)^13
Figure 5.6 Regression of bilingual ability and ethnobotanical competence among the
Piaroa of Venezuela