A recent study led by researchers from UCL reveals that chimpanzees possess genetic adaptations that enable them to thrive in diverse habitats, including forests and savannahs, with some of these adaptations potentially offering protection against malaria.
As our closest living relatives, chimpanzees share over 98% of their DNA with humans. The researchers assert that their findings, which were published in Science, not only shed light on our evolutionary past but also enhance our understanding of malaria biology in humans.
Chimpanzees are currently endangered due to various threats like habitat loss, poaching, and infectious diseases. The insights gained from this study may aid conservation efforts by indicating how varying factors such as climate change and land use can differently impact distinct chimpanzee populations.
Professor Aida Andrés from the UCL Genetics Institute, the study’s lead author, noted, “Only a few hundred thousand chimpanzees exist today, and they inhabit diverse environments, from east Africa to the western parts of the continent, which include dense rainforests and wide-open woodlands and savannahs. This unique situation sets them apart, as all other ape species live solely in forested areas, except humans.”
“Our research indicates that, in addition to behavioral changes, various chimpanzee groups have also developed genetic variations that help them survive in their specific environments.”
“Given that chimpanzees are confronting multiple threats, from climate shifts to human-induced disruptions, it’s vital to conserve their genetic diversity to ensure their resilience and long-term survival as an intelligent species.”
To explore genetic adaptations, the team of international researchers, representing institutions from Africa, Europe, and North America, collected DNA from elusive wild chimpanzees while minimizing disturbances. They achieved this by analyzing faecal samples gathered through the Pan African Programme: The Cultured Chimpanzee (PanAf). Advanced laboratory techniques enabled the team to perform the largest examination of local adaptations in endangered mammals to date.
The researchers analyzed exomes, which are the protein-coding segments of the genome, from 828 wild chimpanzees, narrowing their final analysis to 388 individuals from 30 different populations across the geographical and ecological spectrum of four chimpanzee subspecies. By contrasting genetic data with information about each population’s environment, they identified specific genetic variants that were more prevalent in certain regions, suggesting these variants provide advantages for survival in particular habitats.
They discovered signs of genetic adaptation in genes associated with diseases among chimpanzees inhabiting forested regions, where pathogens are particularly abundant. The strongest evidence pointed to genes related to malaria. Notably, two genes linked to malaria resistance in humans, GYPA and HBB—which causes sickle cell anemia—were also found, indicating a similar adaptive response in chimpanzees.
This suggests that malaria poses a significant risk to wild forest chimpanzees and highlights that adaptation to the malaria parasite may have occurred independently in both chimpanzees and humans through similar genetic changes.
Dr. Harrison Ostridge, the first author from the UCL Genetics Institute, remarked, “The close genetic similarities between great apes have enabled diseases like malaria and HIV/AIDS to transfer from apes to humans. Thus, studying wild chimpanzees is exceedingly valuable to understand these and other infectious diseases in humans, potentially aiding the development of new treatments or vaccines.”
“The discovery of malaria adaptation in chimpanzees linked to the same genetic factors that influence human resistance is particularly noteworthy from an evolutionary standpoint, as it implies limited pathways for evolving resistance to the malaria parasite.”
The research also indicated that chimpanzees have adapted to savannah environments, characterized by higher temperatures, reduced rainfall, and scarcity of food. Examining these savannah-dwelling chimpanzees may provide insights into how our human ancestors adapted to similar conditions millions of years ago, when they transitioned from forest life to savannah.
Co-author Dr. Hjalmar Kuehl, co-director of PanAf and affiliated with the Senckenberg Museum of Natural History in Germany, stated, “This pioneering study on local adaptations in chimpanzees was made possible by the exceptional collaboration among an international team of scientists who worked diligently to gather non-invasive data, including faecal samples from across the chimpanzee’s habitat.”
Dr. Mimi Arandjelovic, another co-director of PanAf from the Max Planck Institute for Evolutionary Anthropology in Germany, expressed, “We invite anyone interested in our research to participate as community scientists at ChimpandSee.org, where individuals can help annotate videos collected alongside the genetic samples from the chimpanzee range.”
