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Young Mongooses Learn Life-Long Habits from Role Models Not Their Parents

Young mongooses learn life-long habits from role models rather than inheriting them from genetic parents, new research shows. Banded mongooses live in social groups where pups are consistently cared for one-to-one by a single adult known as an "escort" - not their mother or father. The young mongooses develop "niche" diets and, by studying these diets, University of Exeter researchers showed that pups inherit the behavior of their escort, rather than parents. The findings offer a fascinating insight into one of the great puzzles of evolution - how diversity persists rather than disappearing with passing generations. "It was a big surprise to discover that foraging behavior learned in the first three months of life lasts a lifetime," said Professor Michael Cant, of the Centre for Ecology and Conservation on the University of Exeter's Penryn Campus in Cornwall. "This is pretty remarkable, because we have no evidence that pups and escorts preferentially hang out together after pups become independent. "Cultural inheritance, the transmission of socially learned information across generations, is a huge influence on human behavior: we behave the way we do, not just because of our genes, but also because of what we learn from parents, teachers and cultural role models. "It is less well appreciated that cultural inheritance is a major force shaping behavior in a wide range of non-human animals, from insects to apes - and mongooses." To explore the influence of escorts on eating habits, the researchers chemically analyzed the whiskers of individual mongooses. The findings help explain how diverse behavior persists in nature. Early critics of Darwin's theory of natural selection argued that, if his theory was correct, the result should be the erosion of the very variation he suggested as the engine of evolution. The genetic reasons why this does not happen have long been understood, but the same criticism could be made of cultural inheritance: when everyone learns from the same teacher, or where each individual learns from everyone, variation should disappear. But the new research on mongooses shows that where individuals learn from their own personal teacher, cultural inheritance can work to maintain diversity. "Cultural inheritance is usually expected to lead to uniformity within groups," said Dr. Harry Marshall of the Centre for Research in Ecology, Evolution and Behavior at the University of Roehampton, a co-author of the study. "But our work confirms a classic theoretical prediction that where individuals learn from their own personal teacher, cultural inheritance can work to maintain diversity." The open-access article, published online on May 24, 2018 in Current Biology, is entitled "Decoupling of Genetic and Cultural Inheritance in a Wild Mammal."

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From the age of around 30 days until they reach nutritional independence at 90 days, pups are cared for by adults that are no more closely related than random group members. Escorts provision pups, help them to find food, and carry them away from danger. (Photo credit: Dave Seager).

[Press release] [Current Biology article]