Science & Technology, UK (Commonwealth Union) – For humans, Scientists are often undeniably fascinated by our own origins and the intricate workings of many other species. To unravel the mysteries of human evolution, scientists turn to our closest living relatives: primates. Primate studies play a pivotal role in shedding light on our biological, behavioral, and cognitive heritage, providing invaluable insights into what makes us truly human.
Studying primates allows researchers to draw comparisons between their anatomy and physiology and that of humans. By examining the similarities and differences, scientists gain a deeper understanding of the evolutionary changes that have shaped our own bodies. For example, investigating the musculoskeletal structure of primates helps elucidate the transition from quadrupedal to bipedal locomotion, a defining characteristic of human evolution.
A new study has revealed that masturbation is a behavior prevalent in primates, and has long been a subject of curiosity and debate. Previously considered either abnormal or merely a consequence of sexual arousal, the fragmented nature of recorded observations hindered a comprehensive understanding of its distribution, evolutionary origins, and adaptive significance. However, recent research published in Proceedings of The Royal Society B suggests that masturbation may indeed serve an evolutionary purpose, unveiling surprising findings about this behavior.
The study, led by Dr. Matilda Brindle from the University College London (UCL) Anthropology, presents compelling evidence indicating that masturbation is an ancient trait among primates. Remarkably, the research suggests that this behavior, particularly in males, contributes to increased reproductive success and serves as a mechanism to reduce the risk of contracting sexually transmitted infections (STIs).
To achieve these findings, Dr. Brindle and her team assembled an unprecedentedly large dataset on primate masturbation. The comprehensive compilation encompassed nearly 400 sources, including 246 published academic papers, as well as 150 questionnaires and personal communications from primatologists and zookeepers. By analyzing this vast array of data, the researchers traced the distribution of autosexual behavior across different primate species to unveil the timing and evolutionary drivers behind its emergence in both males and females.
The study yielded significant insights, indicating that masturbation has a deep-rooted evolutionary history among primates. It appears to have been present in the common ancestor of monkeys, apes (including humans), and potentially other primates. However, the data for the latter group, consisting of lemurs, lorises, and tarsiers, were comparatively limited, making it more challenging to determine whether masturbation was prevalent among their ancestors.
These findings shed new light on the understanding of primate behavior and its evolutionary implications. The research highlights the significance of masturbation as a natural and ancient behavior within the primate lineage, suggesting its potential adaptive value in terms of reproductive success and mitigating the risk of STI transmission.
By unraveling the mysteries surrounding this behavior across primate species, this groundbreaking study contributes to our broader knowledge of primate biology and evolution. It underscores the importance of studying the diverse behaviors exhibited by our primate relatives, ultimately deepening our comprehension of the intricate tapestry of life and our place within it.
To learn of the reason evolution may form this seemingly non-functional trait, Dr Brindle as well as colleagues ran tests several hypotheses.
The “postcopulatory selection hypothesis” indicates that masturbation assisting successful fertilization. This is achievable in various ways. 1st, masturbation can raise arousal prior to sex. This may be a specifically advantageous tactic for low-ranking males who face a greater chance of interruption during copulation, by assisting them to ejaculate faster. 2nd, masturbation permits males to lose inferior semen, resulting in fresh, high-quality sperm present for mating, which have a greater chance to outcompete those other males according to researchers. They further discovered backing for this hypothesis, exhibiting that male masturbation co-evolved with multi-male mating systems where male-male competition is elevated.
Researchers indicated that the significance of female masturbation was unclear. While regular, there are less reports describing it, lowering evaluating power of statistics. The team argue that an increase in data on female sexual behaviour is required to gain further knowledge on the evolutionary part of female masturbation.
