A team of Drexel University scientists at the department of biology’s Gonder Lab has discovered more genetic diversity within a chimpanzee subspecies from Central Africa than previously thought to exist.
Conducted primarily in the rainforests of central Cameroon, their non-invasive sampling techniques of the chimpanzees they encountered, along with genetic analyses, show that there are not two, but three distinct populations of chimpanzees within the Nigeria-Cameroon subspecies of chimpanzee.
The team’s three research articles, published last week in scientific journal BMC Evolutionary Biology, reveal not only the complex evolutionary past of the chimpanzees, but also their endangered future.
“The most important application of our research is conservation,” Matthew Mitchell, a postdoctoral fellow, said. “The chimpanzees that we focus on, the Nigeria-Cameroon chimpanzee, are the most endangered of all chimpanzee subspecies. If our findings about their evolutionary history, population genetics and habitat ecology can be used to preserve them just a little bit, then we’ve done our job.”
These chimpanzees, living in the savanna-woodland mosaic region in Central Cameroon, are threatened by habitat loss. The rapid economic growth of West-Central Africa has increased habitat destruction and intensified other dangers to these chimpanzees, including illegal hunting and trafficking of the species.
“Central Africa is a challenging place to work,” Mitchell said. “It’s hot, wet and the forests are more dense than anything we’ve got here. I’ve been chased by all sorts of animals — including hippopotamuses, forest elephants and safari ants. Honestly, the ants are the worst, but I can hardly tell you how immensely satisfying it is to encounter chimpanzees in the wild, especially after searching for them for days in the rainforest.”
The initial purpose of the research was to understand the genetic difference between the Nigeria-Cameroon chimpanzees and the Central Africa chimpanzees, located south across the Sanaga River. Findings suggest, however, that there is a distinct gene pool within the Nigeria-Cameroon subspecies, pointing to levels of adaptation and potential speciation that scientists had been unaware of before.
“Habitat variation is much more important in shaping genetic diversity in Nigeria-Cameroon chimpanzees living in both the rainforest and the savanna-woodland mosaic, than it is for Central African chimpanzees,” Paul Sesink Clee, a graduate student in the Gonder Lab, and Mary Katherine Gonder, associate professor in the College of Arts and Sciences and research adviser, report in their BMC Series Blog.
While much of this research in Cameroon is fieldwork conducted in the rainforest, there is a lot of time spent collaborating with members of permanent research camps, like the Ebo Forest Research Project. Gonder and her team are working with the Cameroonian government to develop educational workshops and conservation strategies. They are also involved in diplomatic work with the U.S. embassy in the capital, Yaounde.
“A key element of our work is ensuring that the information we gather while in the field, just like this recently published research, will actually be put to use and help bolster chimpanzee conservation efforts,” Gonder said.
The Gonder Lab has two programs that offer opportunities abroad to Drexel students, one in Cameroon and one on Bioko Island, Equatorial Guinea. More information about these programs can be found on the Gonder Lab’s website: http://www.pages.drexel.edu/~mkg62/.