International Symposium on Biodiversity Sciences - Genome, Evolution and Environment
July 31 to August 3, 2010
Hotel Rubura Ohzan, Nagoya, Japan

Link to the Symposium page

Wild chimpanzees in fragmented habitat: Diversity in genetics and behavior
Makoto Shimada
(Section II, Genetic diversity in populations of organisms, #2  Invited)

Link to Presentation Slide

Abstract:
Decrease of natural forests have been accelerated by development of human activity, which leads to loss of biodiversity.  Populations of great apes are vulnerable to forest loss because of their low fecundity and their high dependency on forests for their habitat.  What forest fragmentation will bring about to wild ape populations is becoming more important question.    

The wild chimpanzee (Pan troglodytes verus) community in the Bossou, Republic of Guinea, whose core area is restricted to approximately 6 km² by human activity, with a size of approximately 20 members, is one of the smallest chimpanzee communities among long-term studied communities.  There are a few neighboring chimpanzee community in the Nimba mountain area, however the Bossou community has no evidence of contact with neighboring populations, and no female immigration after initiation of observation in 1976. 

We collected samples of chimpanzees non-invasively from the Bossou and Nimba mountain areas, and sequenced 605 bp from the most variable region in mitochondrial DNA (mtDNA), to reveal maternal genetic relationship among all individuals of Bossou community and to infer their breeding history and mating strategy.

We found the followings: 1) no clear population structure emerged as in other populations of West African chimpanzee (P. t. verus), suggesting that gene flow was sufficient in the common ancestral population of West African chimpanzees; 2) there is no matrilineal gene exchange between Bossou and Nimba chimpanzees among the current generations; 3) 4 of the 8 original adult members of the Bossou community are likely matrilineal relatives, which results in a skewed frequency of one mtDNA haplotype occupying about 50%; 4) so far, the matrilineal genetic diversity of the Bossou community is still relatively stable, but there is a high risk of haplotype extinction due to a skewed haplotype distribution and a predicted relaxation of incest avoidance; 5) finally, hair samples showed an inferior result to other sample types, such as urine, feces, and wadges (chewed up fruit remains).