Max Planck Institute for Evolutionary Anthropology
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Contact: Sandra Jacob (e-mail: info@[>>> Please remove the brackets! <<<]eva.mpg.de, phone: +49 (0) 341-3550 122)
Lethal aggression in wild chimpanzees and bonobos is better explained by adaptive strategies than human impacts.
An international team of researchers from the Max Planck Institute for Evolutionary Anthropology, the University of Minnesota, Harvard University and other contributors has now analyzed the reasons why our closest relatives, chimpanzees and bonobos, sometimes kill conspecifics in a fight. To this aim they compared information they had collected from 18 chimpanzee and four bonobo communities over five decades. The researchers found that bonobos rarely kill conspecifics while chimpanzees do so more frequently. The aggression is directed mainly from males to non-kin males and killings are often committed by a group of males that outnumbers its victims. Surprisingly, the human impact on the habitats of chimpanzees and bonobos did not result in an increase of these killings. The researchers thus conclude that killing conspecifics improves the attacker’s fitness through increased access to territory, food and mates.
Onset of puberty in female bonobos preceeds that of chimpanzees
Puberty is the threshold between childhood and adulthood. Behavior and appearance change considerably during this period – not only in humans but also in our closest relatives, the great apes. In a current study researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have investigated at which age bonobos and chimpanzees, the closest living relatives of humans, enter puberty. In order to determine the onset of puberty the researchers measured the concentration of the hormone testosterone which rapidly increases when male and female primates reach sexual maturity. They found that in males of both species urinary testosterone levels increase at an age of about eight years. Female chimpanzees showed a similar increase at a slightly older age. Female bonobos, however, were found to enter puberty already with five years of age. This is surprising since bonobos are known to be late bloomers whose developmental processes tend to be delayed or take longer in comparison to chimpanzees.
Positive emotional experiences may trigger spontaneous prospective memory retrievals in foraging chimpanzees
An international team of researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and the Félix Houphouët Boigny University in Abidjan, Ivory Coast were the first to study which specific information from previous feeding visits wild chimpanzees take into account when they revisit the same fruit trees. To this end the researchers followed five female chimpanzees from Taï National Park, Côte d’Ivoire, for extended periods of time. They found that chimpanzees direct their travels from longer distances towards trees that carried the best fruit in the past. The study further suggests that these revisits are triggered by positive emotions experienced during previous visits.
Max Planck researchers found that dogs and puppies can locate hidden food by using human voice direction referentially
Dogs and puppies are gifted at interpreting human communicative hints, and previous studies showed that they use human visual cues like pointing or gazing in order to find hidden food. Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have now studied for the first time whether dogs can locate hidden food by relying on auditory information alone. In an experimental setting, an experimenter went behind a barrier and presented adult dogs and puppies with two identical boxes, but only one of them contained food. From behind the barrier, hidden from the dog’s sight, the experimenter vocalized excitedly while looking towards the box containing food. Most adult dogs and socialized puppies successfully followed the direction of the experimenter’s voice to the food source; the puppies even beat the adult dogs in this task. The researchers conclude that dogs do not rely on visual cues only, but on a combination of human communicative hints. These social skills may have become part of the dog’s genetic make-up during domestication.
Prize winner Kathryn E. Fitzsimmons leads the working group for Luminescence Dating within the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology.
Dr. Kathryn E. Fitzsimmons is the winner of the 2013 Albert Maucher Prize in Geoscience of the DFG (German Research Foundation). She has been working in the Department of Human Evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig since 2010. Her research interests concern aspects of environmental change and human-environment interactions. The prize, worth 10,000 euros, was donated by Munich geologist Albert Maucher, who himself received DFG funding at the beginning of his scientific research career. According to Maucher's wishes, the prize expressly recognizes unconventional research approaches and methods. Dr. Fitzsimmons will be awarded the Prize on 23 September 2014.
Max Planck researchers reveal relationships between rare languages in the Colombian Amazon
The only linguistic data available for Carabayo, a language spoken by an indigenous group that lives in voluntary isolation, is a set of about 50 words. This list was compiled in 1969 during a brief encounter with one Carabayo family. Frank Seifart of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and Juan Alvaro Echeverri of the Universidad Nacional de Colombia in Leticia, Colombia, have now analysed this historical data set and compared it with various languages (once) spoken in the region. The analysis showed that Carabayo shares a number of similarities with the extinct language Yurí and with Tikuna, a language still spoken in the region nowadays. From the results of their study the researchers conclude that the Carabayo – directly or indirectly – descend from the Yurí people whose languages and customs were described by explorers in the 19th century, before they took up voluntary isolation.
An international team of researchers has for the first time deciphered the intestinal bacteria of present- day hunter-gatherers
The gut microbiota is responsible for many aspects of human health and nutrition, but most studies have focused on “western” populations. An international collaboration of researchers, including researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has for the first time analysed the gut microbiota of a modern hunter-gatherer community, the Hadza of Tanzania. The results of this work show that Hadza harbour a unique microbial profile with features yet unseen in any other human group, supporting the notion that Hadza gut bacteria play an essential role in adaptation to a foraging subsistence pattern. The study further shows how gut microbiota may have helped our ancestors adapt and survive during the Paleolithic.
Liberia is home to the second largest chimpanzee population in West Africa
When Liberia enters the news it is usually in the context of civil war, economic crisis, poverty or a disease outbreak such as the recent emergence of Ebola in West Africa. Liberia’s status as a biodiversity hotspot and the fact that it is home to some of the last viable and threatened wildlife populations in West Africa has received little media attention in the past. This is partly because the many years of violent conflict in Liberia, from 1989 to 1997 and from 2002 to 2003, thwarted efforts of biologists to conduct biological surveys. An international research team, including scientists of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has now counted chimpanzees and other large mammals living in Liberia. The census revealed that this country is home to 7000 chimpanzees and therefore to the second largest population of the Western subspecies of chimpanzees. As Liberia has released large areas for deforestation, the local decision-makers can now use the results of this study in order to protect the chimpanzees more effectively.
A team of interdisciplinary scientists arrived in Guinea April 2nd 2014 to investigate a possible epidemic of Ebola hemorrhagic fever (EHF) amongst wildlife in the region were human cases occurred. In a joint mission between the Wild Chimpanzee Foundation – Guinea and Côte d’Ivoire (WCF), the Robert Koch Institute (RKI), the Max-Planck-Institute for Evolutionary Anthropology (MPI-EVA), the Institute of Tropical Medicine and International Health (ITMIH) of Charité – University Medicine Berlin, and the National Laboratory for Agricultural Development (LANADA, Côte d’Ivoire), the team will systematically monitor wildlife around the outbreak areas.
Contemporary Europeans have as many as three times more Neanderthal variants in genes involved in lipid catabolism than Asians and Africans
Although Neanderthals are extinct, fragments of their genomes persist in modern humans. These shared regions are unevenly distributed across the genome and some regions are particularly enriched with Neanderthal variants. An international team of researchers led by Philipp Khaitovich of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and the CAS-MPG Partner Institute for Computational Biology in Shanghai, China, show that DNA sequences shared between modern humans and Neanderthals are specifically enriched in genes involved in the metabolic breakdown of lipids. This sharing of genes is seen mainly in contemporary humans of European descent and may have given a selective advantage to the individuals with the Neanderthal variants.
An interactive world map of human genetic history reveals likely genetic impacts of historical events
When individuals from different groups interbreed, their offspring's DNA becomes a mixture of the DNA from each admixing group. Pieces of this DNA are then passed along through subsequent generations, carrying on all the way to the present day. Researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, Oxford University and University College London (UCL) have now produced a global map detailing the genetic histories of 95 different populations across the world, spanning the last four millennia.
Several thousand chimpanzees inhabit a remote forest area in the northern Democratic Republic of the Congo
With great ape populations in fast decline, it is crucial to obtain a global picture of their distribution and abundance, in order to channel and direct conservation activities to where they are most needed. Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and the University of Amsterdam in The Netherlands conducted hundreds of kilometers of chimpanzee surveys at multiple sites in the Central Uele region of northern Democratic Republic of the Congo and discovered a large, continuous population of Eastern chimpanzees (Pan troglodytes schweinfurthii). The population in the remote Bili-Gangu forest was surveyed in 2005 with line transects and again in 2012, and appears to have remained stable. The total area surveyed, which encompasses about 50,000 square kilometers, is home to several thousands of chimpanzees and, according to the researchers, should be considered a priority site for conservation of the eastern subspecies.
Chimpanzees keep track of other group members’ bonding partners and use this knowledge in conflict situations
To know who your opponents’ family and friends are can be of advantage in a conflict situation. Humans make predictions about other people’s social relationships frequently. Whether other animals also have the cognitive skills to track their group mates’ social relationships across time and beyond close kin has so far not been known. Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig have now conducted playback experiments with wild-living chimpanzees from Budongo Forest in Uganda. Two hours after a subject attacked or had been attacked by an opponent, the researchers broadcast the recording of a third individual’s aggressive barks from a speaker near the subject. If the call provider was their opponent’s close buddy or kin, subjects looked longer and moved away more often from barks than if the call provider was not a bond partner. This shows that chimpanzees know who their group mates’ kin or non-kin bond partners are and that their behavior may have an impact on them.
Chimpanzees who share their food with others have higher levels of the hormone oxytocin in their urine
The ability to form long-term cooperative relationships between unrelated individuals is one of the main reasons for human’s extraordinary biological success, yet little is known about its evolution and mechanisms. The hormone oxytocin, however, plays a role in it. Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, measured the urinary oxytocin levels in wild chimpanzees after food sharing and found them to be elevated in both donor and receiver compared to social feeding events without sharing. Furthermore, oxytocin levels were higher after food sharing than after grooming, another cooperative behaviour, suggesting that food sharing might play a more important role in promoting social bonding. By using the same neurobiological mechanisms, which evolved within the context of building and strengthening the mother-offspring bond during lactation, food sharing might even act as a trigger for cooperative relationships in related and unrelated adult chimpanzees.