The role of rivers as geographical barriers in shaping genetic differentiation and diversity of Neotropical primates

We quantitatively tested the riverine barrier hypothesis and its influence on biogeographical distributions and molecular variation in New World monkeys (Parvorder: Platyrrhini). Using mitochondrial markers (cytochrome oxidase subunit II and cytochrome b), we analyzed taxonomic differences and the effects of geographical barriers on molecular patterns across Central and South America. Nearly 80% of described species are separated by geographical barriers, including several mountain chains. River width exhibited a negative correlation with molecular similarity in adjacent taxa for both molecular markers. Several presently described taxa were not supported based solely on these molecular phylogenetic markers, including Saimiri, Mico, Cebus, Sapajus, and Cherecebus. These taxonomic issues are far more common where river barriers do not exist. In conclusion, we found a significant correlation between river width and molecular divergence in adjacent taxa, indicating that wider rivers were as..., All molecular data and associated sampling locations used in the main river barrier analysis were obtained from NCBI (https://www.ncbi.nlm.nih.gov/). Partial mitochondrial sequences (i.e., cytochrome b and cytochrome oxidase subunit II) were trimmed to the smallest consensus size for both overall phylogenetic analysis and analysis between adjacent or sympatric taxonomic groups. A minimum of 200bp sequence and a maximum of 1104bp were available. The two mitochondrial genes were not concatenated but analyzed separately to independently verify results since sequence data was not necessarily available from the same individuals and for the same taxonomic groups. , , # Data from: The role of rivers as geographical barriers in shaping genetic differentiation and diversity of Neotropical primates

[https://doi.org/10.5061/dryad.gb5mkkx1x](https://doi.org/10.5061/dryad.gb5mkkx1x)

## Description of the data and file structure

The mitochondrial sequences were trimmed to the smallest consensus size to ensure consistency in downstream analysis. Sequence lengths ranged from a minimum of 200 base pairs (bp) to a maximum of 1104 bp. This range was used to standardize the dataset for both general phylogenetic analysis and the comparison of adjacent or sympatric taxonomic groups.

To independently validate the results and minimize biases associated with sequence availability, the two mitochondrial genes (cytb and COII) were analyzed separately. Since sequence data was not always available for the same individuals or taxonomic groups, concatenation of the two genes was avoided, ensuring that each gene's contribution to the analysis could be verified independen...,