Cultural hitchhiking is a hypothesized gene-culture coevolutionary process through which cultural selection, sexual selection based on cultural preference, limits the diversity at genetically neutral loci being transmitted in parallel to selective cultural traits. The process is thought to account for exceptionally low diversity in neutral loci such as control regions of the mitochondrial genome unaccounted for by any other selective forces. Simply put, selection for certain learned social and cultural behaviors can manifest in specific shaping of a population’s genetic makeup. While the notion that culture plays a significant role in shaping community genetics is widely accepted in the context of human populations it had not been considered or documented in non-human organisms until the late 1990s. The term was coined by the cetologist Hal Whitehead who ’s studies the cultures and population genetics of matrilineal whale communities. In Whales The process was initially proposed by Whitehead in a 1998 paper as an explanation for this low genetic diversity in matrilineal whale species. In these communities  female individuals remain grouped together with their mothers and other female relatives.Whitehead H. GENETIC DIVERSITY IN THE MATRILINEAL WHALES: MODELS OF CULTURAL HITCHHIKING AND GROUP-SPECIFIC NON-HERITABLE DEMOGRAPHIC VARIATION . Marine Mammal Sci. 2005;21(1):58-79. doi:10.1111/j.1748-7692.2005.tb01208.x They appear  select mates from outside their immediate community based on culturally valued social traits and aptitude. Sequencing of the mitochondrial genome of individuals within these communities revealed them to have a significantly reduced diversity in certain control loci compared to comparable panmictic populations. Whitehead discovered that the relative frequency of mitochondrial haplotypes characteristic of groups exhibiting more highly adaptive socially-learned traits would increase, while the frequency of these haplotypes in groups with less adaptive socially learned traits would decrease. This coincidental selective pressure is thought to have led to an overall reduction in haplotype diversity across the entire species population. In dolphins In 2014 a team of biologists from the University of South Wales attributed a remarkable geographic distribution of mitochondrial haplotypes among adjacent populations of bottlenose dolphins in a bay in Western Australia to cultural hitchhiking.Kopps AM, Ackermann CY, Sherwin WB, Allen SJ, Bejder L, Krützen M. Cultural transmission of tool use combined with habitat specializations leads to fine-scale genetic structure in bottlenose dolphins. Proc R Soc B. 2014;281(1782):20133245. doi:10.1098/rspb.2013.3245Whitehead H, Vachon F, Frasier TR. Cultural Hitchhiking in the Matrilineal Whales. Behav Genet. 2017;47(3):324-334. doi:10.1007/s10519-017-9840-8 The researchers found Whitehead’s hypothesis that selection for learned social traits affected diversity in neutral gene loci fit well with their observations. It was discovered that dolphins with two of three mitochondrial haplotypes were found predominantly in water deeper than 10m while those with the third haplotypes were found predominantly in depths less than 10m . This geographic distinction between these populations is also associated with different learned behaviors. Some of the dolphins predominantly found in deeper waters exhibit foraging strategies that implement tools such as a sponge placed on their beak. This 'sponging' behavior is found to be spread through vertical social transmission along a matrilineal pattern (i.e. the mothers teach the behavior to there offspring). All dolphins exhibiting one of the deep water haplotypes belong to a single matriline. The researchers ultimately concluded that these fine-scale genetic structures, the distinct mitochondrial haplotypes, have probably arisen based on socially transmitted behaviors or in other words, through cultural hitchhiking. A study in the same area and species shown that shelling is also marginally learn from URL
Cultural hitchhiking is a hypothesized gene-culture coevolutionary process through which cultural selection, sexual selection based on cultural preference, limits the diversity at genetically neutral loci being transmitted in parallel to selective cultural traits. The process is thought to account for exceptionally low diversity in neutral loci such as control regions of the mitochondrial genome unaccounted for by any other selective forces. Simply put, selection for certain learned social and cultural behaviors can manifest in specific shaping of a population’s genetic makeup. While the notion that culture plays a significant role in shaping community genetics is widely accepted in the context of human populations it had not been considered or documented in non-human organisms until the late 1990s. The term was coined by the cetologist Hal Whitehead who studies the cultures and population genetics of matrilineal whale communities. In Whales The process was initially proposed by Whitehead in a 1998 paper as an explanation for this low genetic diversity in matrilineal whale species. In these communities , female individuals remain grouped together with their mothers and other female relatives.Whitehead H. "Genetic Diversity in the Matrilineal Whales: Models of Cultural Hitchhiking and Group-Specific Non-heritable Demographic Variation" . Marine Mammal Sci. 2005;21(1):58-79. doi:10.1111/j.1748-7692.2005.tb01208.x They appear to select mates from outside their immediate community based on culturally valued social traits and aptitude. Sequencing of the mitochondrial genome of individuals within these communities revealed them to have a significantly reduced diversity in certain control loci compared to comparable panmictic populations. Whitehead discovered that the relative frequency of mitochondrial haplotypes characteristic of groups exhibiting more highly adaptive socially-learned traits would increase, while the frequency of these haplotypes in groups with less adaptive socially learned traits would decrease. This coincidental selective pressure is thought to have led to an overall reduction in haplotype diversity across the entire species population. In dolphins In 2014 a team of biologists from the University of South Wales attributed a remarkable geographic distribution of mitochondrial haplotypes among adjacent populations of bottlenose dolphins in a bay in Western Australia to cultural hitchhiking.Kopps AM, Ackermann CY, Sherwin WB, Allen SJ, Bejder L, Krützen M. Cultural transmission of tool use combined with habitat specializations leads to fine-scale genetic structure in bottlenose dolphins. Proc R Soc B. 2014;281(1782):20133245. doi:10.1098/rspb.2013.3245Whitehead H, Vachon F, Frasier TR. Cultural Hitchhiking in the Matrilineal Whales. Behav Genet. 2017;47(3):324-334. doi:10.1007/s10519-017-9840-8 The researchers found Whitehead’s hypothesis that selection for learned social traits affected diversity in neutral gene loci fit well with their observations. It was discovered that dolphins with two of three mitochondrial haplotypes were found predominantly in water deeper than 10 m while those with the third haplotypes were found predominantly in depths less than 10 m . This geographic distinction between these populations is also associated with different learned behaviors. Some of the dolphins predominantly found in deeper waters exhibit foraging strategies that implement tools such as a sponge placed on their beak. This "sponging" behavior is found to be spread through vertical social transmission along a matrilineal pattern (i.e. the mothers teach the behavior to their offspring). All dolphins exhibiting one of the deepwater haplotypes belong to a single matriline. The researchers ultimately concluded that these fine-scale genetic structures, the distinct mitochondrial haplotypes, have probably arisen based on socially transmitted behaviors or in other words, through cultural hitchhiking. A study in the same area and species showed that shelling is also marginally learned from URL
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GENETIC DIVERSITY IN THE MATRILINEAL WHALES: MODELS OF CULTURAL HITCHHIKING AND GROUP-SPECIFIC NON-HERITABLE DEMOGRAPHIC VARIATION
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