a list, with each element being one-dimensional lower bounds for a trait.
upper_bounds
a list, with each element being one-dimensional upper bounds for a trait.
par
current parameters values.
dimen
Number of dimensions (number of traits being analyzed).
Value
Returns the loglikelihood according to a brownian motion usign ranges.
References
Quintero, I., Keil, P., Jetz, W., Crawford, F. W. 2015 Historical Biogeography Using Species Geographical Ranges. Systematic Biology. doi: 10.1093/sysbio/syv057