Chimpanzees have developed genetic changes that enable them to thrive in various forest and savannah environments, with some adaptations potentially offering protection against malaria, according to a study by an international group of researchers led by UCL.
Chimpanzees have developed genetic changes that enable them to thrive in various forest and savannah environments, with some adaptations potentially offering protection against malaria, according to a study by an international group of researchers led by UCL.
Chimpanzees are our closest existing relatives, sharing more than 98% of their DNA with humans. The researchers, whose findings were published in Science, believe this study can provide insights into our evolutionary history and help us understand the biology of malaria infections in humans.
Chimpanzees are considered endangered, primarily due to habitat loss, poaching, and diseases. The study’s findings could inform conservation efforts, indicating that changes in climate and land use may impact different chimpanzee populations in various ways.
Professor Aida Andrés, the lead author from UCL Genetics Institute, noted: “There are only a few hundred thousand chimpanzees left, but they inhabit a variety of landscapes from East Africa to the far west, including dense tropical rainforests and open woodlands. This diversity makes them quite exceptional, as all other apes, except humans, typically reside solely in forest environments.
“Our research highlights that different chimpanzee populations have not only developed behavioral adaptations but have also evolved distinct genetic traits that allow them to survive in their respective habitats.
“As chimpanzees continue to face various threats, including climate change and human encroachment, preserving their genetic diversity is crucial for maintaining their resilience and ensuring the long-term survival of this remarkable species.”
To investigate genetic adaptation, the international research team, comprised of experts from Africa, Europe, and North America, collected DNA from wild chimpanzees in a way that did not disturb them. They used fecal samples gathered through the Pan African Programme: The Cultured Chimpanzee (PanAf). Armed with advanced laboratory and computational techniques, scientists conducted the largest study on local adaptation in wild endangered mammals to date.
The team analyzed the exomes (the portions of the genome that code for proteins) from 828 wild chimpanzees, focusing on 388 samples from 30 different populations, representing a broad geographical and ecological range of the four chimpanzee subspecies. They compared this genetic data with information about the environments where each population resides, identifying specific genetic variants that appear more frequently in certain areas, likely providing benefits to those carrying them in specific habitats.
The researchers discovered indications of genetic adaptation in genes associated with particular pathogens among forest-dwelling chimpanzees, where pathogen levels are high. The most compelling evidence pointed to genes linked to malaria, including two that also play a role in malaria adaptation and resistance in humans: GYPA and HBB, the latter being associated with sickle cell anemia.
The findings imply that malaria could be a significant health issue for wild forest chimpanzees and that adaptations to the malaria parasite may have taken place independently through changes in the same genes in both chimpanzees and humans.
Dr. Harrison Ostridge, the first author from UCL Genetics Institute, stated: “The close genetic relationship between great apes has led to diseases like malaria and HIV/AIDS crossing over to humans, making the study of wild chimpanzees invaluable for understanding these and other shared diseases, potentially aiding in the development of new treatments and vaccines.
“The evidence of malaria adaptation in chimpanzees, particularly in the same genes that influence malaria resistance in humans, is significant from an evolutionary perspective, highlighting the limited avenues available for evolving resistance to this parasite.”
The study also indicated that chimpanzees have adapted to savannah environments, characterized by higher temperatures, reduced rainfall, and limited food resources. This suggests that examining savannah-dwelling chimpanzees could offer insights into how early human ancestors adjusted to similar habitats millions of years ago during their transition from forests to savannahs.
Dr. Hjalmar Kuehl, co-author and PanAf co-director from the Senckenberg Museum of Natural History in Germany, remarked: “This pioneering study on local adaptations in chimpanzees wouldn’t have been possible without the exceptional collaboration of a dedicated international team who meticulously collected non-invasive data, including fecal samples, from various countries throughout the chimpanzee’s range.”
Dr. Mimi Arandjelovic, also a co-author and PanAf co-director from the Max Planck Institute for Evolutionary Anthropology in Germany, encouraged community engagement: “We invite anyone interested in our research to participate as community scientists at ChimpandSee.org, where they can assist in annotating videos collected alongside the genetic samples from across the chimpanzee’s habitats.”
