Mitochondrial genetic diversity and divergence dating of Angolan colobus monkeys (Colobus angolensis) in the eastern forests of Kenya and Tanzania: Implications for subspeciation and reconstructing historical biogeography

Abstract

Whether the Colobus angolensis that reside in the fragmented forests in eastern Kenya and Tanzania represent one subspecies or two has been debated for 50 years.Morphological and more recent genetic and ecological studies suggest that these populations represent two subspecies, C. a. palliatus and C. a. sharpei. However, their distribution of mitochondrial variation remains unresolved since the genetic study only characterized four populations at the range ends. Therefore, we characterized five populations in the area of the hypothesized subspecies divide. We identified eight new haplotypes which, combined with those previously identified, provided 26 haplotypes from nine populations for analysis. Haplotypes found south of the Rufiji River cluster together but separately from northern haplotypes. The largest sequence differences within cytochrome b occur between population pairs representing opposite sides of the river; their mean difference (1.5%) is more than that of other primate subspecies. Analysis of molecular variance attributes most of the variation to that north versus south of the river. These results support the previous subspecies distinction between C. a. palliatus (northern) and C. a. sharpei (southern), divided by the Rufiji River. The estimated time of the most recent common ancestor of all haplotypes indicates that the subspecies have been isolated from each other for approximately 550,000 years. The common ancestor of northern and southern haplogroups was 370,000 and 290,000 years ago, respectively.Nevertheless, the correlation between genetic and geographic distances suggests that isolation-by-distance contributed to population structuring. Significant variation among populations, with only three haplotypes shared between populations, also indicates that an extended period of isolation drove population distinctiveness.Considering these results, we evaluate hypotheses about the founding and

Wild origins and mitochondrial genetic diversity of Angolan Colobus monkeys (Colobus angolensis) in AZA‐accredited zoos and its implications for ex situ population management

“…The haplotype phylogeny indicated that the PT1 haplotype ( n = 1, from founder 11) is most closely related to the Rufiji River haplotype (R2), and the PT2 haplotype ( n = 2, from founder 9) is most closely related to a Shimoni, Kenya haplotype (S2) (Figure 3). These two new haplotypes differed from their most similar haplotypes in either cytochrome b or D‐loop, or both: 0% to 0.2% (cytochrome b ) and 0.4%–1.5% (D‐loop) (McDonald et al, 2022).…”

“…Our analysis also included 26 haplotypes identified from nine wild Vulnerable by the 2020 IUCN Red List Assessment (Cunneyworth et al, 2020;Rovero et al, 2020) (Figure 1 and Supporting Information: Table 3). Using MEGA 10.1.7 (Kumar et al, 2018) and (Huelsenbeck & Ronquist, 2001) in Geneious 7.1 (https://www.geneious.com) and maximum likelihood (ML) analyses using PAUP 4.0 (Swofford, 2003) to characterize the phylogenetic relationships among the combined zoo and wild data set and to identify the likely geographic origins of the founding zoo population (McDonald et al, 2022). Finally, we assigned the zoo haplotypes to their founder and founder event using the AZA Angolan colobus studbook (Fogarty, 2018) and compared the founder and haplotype representation of the managed zoo population using the 2018 AZA Breeding and Transfer Plan (Gibson et al, 2018).…”

“…Mountain names in gray are unsampled populations. The dashed line indicates the purported boundary, along the Rufiji River, between C. a. palliatus (upper right) and C. a. sharpei (lower left) subspecies (McDonald et al, 2022) (map adapted from Eastern Arc Mountains CEF— http://www.easternarc.or.tz/eastern-arc-mountains/index.html). [Color figure can be viewed at wileyonlinelibrary.com]…”

“…nov.). Wild colobus were sampled in South Pare, East Usambara, Nguru, Uluguru, Rufiji River, Diani, Shimoni, Udzungwa, and Southern Highlands (McDonald et al, 2022; McDonald & Hamilton, 2010). Location names in boxes reflect the zoo animals' likely location of origin based on their haplotype and the phylogenetic results.…”

A Comprehensive Overview of Baboon Phylogenetic History

“…A fine-scale analysis of mtDNA enabled the precise localization of the boundary between northern and southern mitochondrial clades within the distribution of yellow baboons in central Tanzania from the coast to the eastern shore of Lake Tanganyika along the Ugalla-Malagarsi and the Ruaha-Rufiji rivers [ 35 ]. Interestingly, the Ruaha-Rufiji rivers seem to constitute a dispersal barrier also for other taxa, e.g., dwarf galagos [ 62 ] and subspecies of Colobus angolensis [ 63 ]. The contact zone of the current distributions of phenotypically well-differentiated olive and yellow baboons is also localized in East Africa but does not correspond to the boundary between northern and southern mtDNA clades.…”