Onset of puberty in female bonobos precedes 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.
During puberty, rising hormone levels stimulate somatic growth and the development of secondary sex characteristics, and the child becomes a grown-up individual. The timing of puberty depends, among others, on environmental conditions, nutrition and social factors. From a biological point of view puberty is the starting signal for the race of passing on one’s own genes to future generations. While pubertal changes in humans and male chimpanzees have been well investigated, this has not been the case so far for bonobos and female chimpanzees.
In their current study researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have measured the concentrations of testosterone in the urine of 42 male and 97 female chimpanzees and of 48 male and 64 female bonobos. They found that female bonobos enter puberty around three years earlier than female chimpanzees and males of both species. “Given the early onset of puberty, one would predict to assume that female bonobos give birth to their first child earlier than chimpanzees. Yet, this does not seem to be the case“, says Verena Behringer, researcher at the Max Planck Institute for Evolutionary Anthropology and first author of the study.
In contrast to most other primates, young female chimpanzees and bonobos leave their birth group when they reach sexual maturity. Entering a novel range and exposure to an unfamiliar social environment bears high potential costs for the young female. Especially in chimpanzees this is not always easy because food is limited and each additional group member’s needs may raise competition. The social pressure is partially compensated by the fact that young females become more attractive to males. This motivates chimpanzee males to protect female newcomers against the aggressive behavior of other female group members.
In bonobos, female teenagers start their search for a new group between two and three years earlier than female chimpanzees. In contrast to them, female bonobos joining a new community encounter curiosity rather than aggression. “Possible advantages from entering puberty earlier are a greater search area for a new group and more time to obtain social experiences and to develop their sexuality”, says Verena Behringer. “The latter is a central element in the behavioral repertoire of bonobos which helps to solve conflicts, and establish friendly relations with others.”
The urine samples used for this study came from apes living in zoos. Therefore, the nutritional status can be excluded as a reason for the time discrepancy between both species. “The earlier onset of puberty in bonobos seems to be a characteristic feature that emerged during the evolutionary development of both sister species“, says Verena Behringer.
Dr. Verena Behringer | Max-Planck-Institute
Fish Oil-Diet Benefits May be Mediated by Gut Microbes
28.08.2015 | University of Gothenburg
Bio-fabrication of Artificial Blood Vessels with Laser Light
28.08.2015 | Fraunhofer-Institut für Lasertechnik ILT
A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...
A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...
In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.
These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...
Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.
For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...
It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.
Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...
20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
28.08.2015 | Physics and Astronomy
28.08.2015 | Health and Medicine
28.08.2015 | Life Sciences