The Genome of the Endangered Dryas Monkey Provides New Insights into the Evolutionary History of the Vervets.

Genomic data can be a powerful tool for inferring ecology, behavior, and conservation needs of highly elusive species, particularly, when other sources of information are hard to come by. Here, we focus on the Dryas monkey (Cercopithecus dryas), an endangered primate endemic to the Congo Basin with cryptic behavior and possibly <250 remaining adult individuals. Using whole-genome sequencing data, we show that the Dryas monkey represents a sister lineage to the vervets (Chlorocebus sp.) and has diverged from them ∼1.4 Ma with additional bidirectional gene flow ∼750,000-∼500,000 years ago that has likely involved the crossing of the Congo River. Together with evidence of gene flow across the Congo River in bonobos and okapis, our results suggest that the fluvial topology of the Congo River might have been more dynamic than previously recognized. Despite the presence of several homozygous loss-of-function mutations in genes associated with sperm mobility and immunity, we find high genetic diversity and low levels of inbreeding and genetic load in the studied Dryas monkey individual. This suggests that the current population carries sufficient genetic variability for long-term survival and might be larger than currently recognized. We thus provide an example of how genomic data can directly improve our understanding of highly elusive species.

The history, taxonomy, and geographic origins of an introduced African monkey in the southeastern United States.

The origins and taxonomy of the introduced vervet monkey population in Dania Beach, Florida has been unconfirmed due to a lack of documentation and genetic research. Our goal was to determine the introduction history, species identification, and geographic origins of the monkeys. Through interviews, historical archives, and popular media, we traced the monkeys to an escape from the Dania Chimpanzee Farm in 1948. The facility imported primates from Africa for medical research purposes. Historical archives suggest the monkeys were caught in Sierra Leone. We tested the hypothesis of West African origins using three genetic markers: one mitochondrial DNA gene (cytochrome b) and two fragments from the Y-chromosome, the sex-determining gene and the zinc-finger gene. We ran Bayesian and maximum-likelihood analyses to reconstruct phylogenetic trees. Results from all loci confirmed the species identification is Chlorocebus sabaeus. We found no variation among the sampled individuals and found the cytochrome b haplotype to be a complete match to a C. sabaeus sample from Senegal. Phylogenetic analyses showed strong support for the Dania Beach mitochondrial and Y-chromosome lineages to group within a monophyletic C. sabaeus clade endemic to West Africa. Our study provides critical baseline information to the scientific community about a little-known population of Chlorocebus monkeys that have adapted to a novel environment in the southeastern United States.