Genetic analysis reveals population structure and recent migration within the highly fragmented range of the Cross River gorilla (Gorilla gorilla diehli)

Anthropology Department, City University of New York Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA.
Molecular Ecology (Impact Factor: 6.49). 03/2007; 16(3):501-16. DOI: 10.1111/j.1365-294X.2006.03159.x
Source: PubMed


Recently developed methods of individual-based analysis of genetic data allow an unprecedented opportunity to understand the relationships among fragmented populations. By defining population structure and identifying migrant individuals, such analyses can provide a framework to aid in evaluating the threats posed by inbreeding and reduced genetic variability as a consequence of limited gene flow among fragments. Here we investigate population structure in the critically endangered Cross River gorilla (Gorilla gorilla diehli) by applying a suite of individual-based analyses to data obtained from between one-quarter and one-third of the estimated total population through the use of noninvasively collected DNA samples. The population structure inferred using data from 11 autosomal microsatellite loci was broadly consistent with geography and habitat fragmentation, but showed no simple isolation-by-distance effects. In contrast to previous field surveys, which suggested that all gorilla localities were isolated from one another, we infer low levels of gene flow and identify migrants between habitat fragments as well as individuals of admixed ancestry, suggesting persistent recent reproductive contact between many of the localities. These results are encouraging for the conservation of the Cross River gorilla population. Conservation efforts should strive to maintain connectivity between subpopulations that are still in migratory contact and attempt to restore connectivity where it has been lost.

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Available from: Linda Vigilant, Mar 23, 2015
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    • "Frequency-based analyses also showed strong differentiation among patches, with those located closer together being less differentiated than those further apart, suggesting that dispersal might be occurring within short distances and between neighboring patches. This tendency for short dispersal distances and between proximate populations was also observed in the common ringtail possum (Lancaster et al. 2011) and southern brown bandicoot (Li et al. 2014) in the same region, and it has been observed in several other mammalian species in fragmented landscapes (Goossens et al. 2005; Bergl and Vigilant 2007; Taylor et al. 2007; Fitzgibbon et al. 2011). "
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