Descripción: “...lucifer and possibly C. t. medemi which has not yet been studied genetically).Based on our cytogenetic finds from cell cultures from 11 specimens from different populations of Callicebus, we have found that our karyological data are concordant with the species groups and permit us to differentiate C. ornatus, C. caquetensis and C. discolor as independent species in the cupreus group. In the torquatus group there were no detectable differences between a “lugens” phenotype from Florencia, Caquetá and a C. t. lucifer from the Colombian trapezium (both were 2n=20), increasing the distribution of the species with that karyotype in the Colombian Amazon.Although initially we supposed that C. lugens (2n=16) was not present in the Colombian Amazon, the discovery of a C. lugens (2n=16) in the Matacaña Zoo strongly suggests the presence of this species in the Colombian Orinoco, although this must be confirmed with field studies.Based on our results a discussion of the evolutionary process in chromosomes is presented for this monogamous, territorial primate genus and some hypotheses regarding the evolution of this group are proposed.Key Words: karyotype, chromosome evolution, Callicebus, cytotaxonomy. ...”

Descripción: “...The FOSM method was implemented using the Matlab program, while the FORTRAN language was used for the Monte Carlo method. The independent variables of the slope stability model considered to be random variables were cohesion and friction angle. ...”