Gene-culture coevolution in whales and dolphins

Area of Science:

• Marine Biology
• Genetics
• Animal Behavior

Background:

• Cetaceans (whales and dolphins) exhibit advanced social learning and strong mother-calf bonds, fostering stable cultures.
• Some cetacean species display sympatric groups with distinct cultures, suggesting cultural transmission of behaviors.
• Evidence suggests that cultural transmission in cetaceans may influence gene distributions.

Purpose of the Study:

• To explore the impact of cultural transmission on gene distributions in cetaceans.
• To investigate the role of culture in the formation of distinct ecotypes and genetic variations.
• To understand the mechanisms of gene-culture coevolution in whales and dolphins.

Main Methods:

• Analysis of genetic data (mtDNA, functional genes) in relation to observed cultural behaviors.
• Comparison of genetic diversity across different cetacean ecotypes and social structures.
• Review of existing evidence on cultural transmission of behaviors like foraging and migration.

Main Results:

• Cultural transmission appears to have driven the formation of distinct killer whale ecotypes, potentially incipient species or subspecies, with ecotype-specific gene selection signals.
• Matrilineal whale species show low mitochondrial DNA (mtDNA) diversity, with cultural hitchhiking proposed as a mechanism, particularly in sperm whales.
• Habitat-specific mtDNA haplotype distributions in several species and fine-scale differences in bottlenose dolphins are linked to maternal cultural transmission of migration and foraging behaviors.

Conclusions:

• Cultural behaviors in cetaceans significantly impact their genetic makeup, driving ecotype divergence and influencing genetic diversity.
• Cultural hitchhiking is a plausible explanation for reduced mtDNA diversity in species with strong cultural transmission.
• Gene-culture coevolution is a key factor in cetacean speciation and adaptation, though further socio-cultural research is needed.