Do all animals know the sex of their offspring? Do they smell differently or do they go by looks?
Dolphin Moms Teach Daughters to Use Tools
....The hunting tactic was almost wholly confined to a small group of females and their daughters among the Shark Bay population, with just a single male showing the same behavior. The challenge for the study team was to find out whether sponging is acquired through social learning—and therefore evidence of culture—or is transmitted genetically.
The researchers analyzed the mitochondrial DNA (DNA passed down by females) of 13 spongers and 172 nonspongers. They found the trait appeared to be passed on mostly within a single family line from mother to daughter and that sponging most likely originated in a recent ancestor.
"This is the first study of cultural transmission that actually looks at different modes of inheritance both on the family and the population level," Krützen said. "If sponging was coded on the Y chromosome [found only in males], only males would sponge. If sponging was coded on one of the nonsex chromosomes, then one would expect as many males as females to be spongers. This does not seem to be the case. We ruled out that sponging might be a genetic propensity."....
Dolphin Moms Teach Daughters to Use Tools
....The hunting tactic was almost wholly confined to a small group of females and their daughters among the Shark Bay population, with just a single male showing the same behavior. The challenge for the study team was to find out whether sponging is acquired through social learning—and therefore evidence of culture—or is transmitted genetically.
The researchers analyzed the mitochondrial DNA (DNA passed down by females) of 13 spongers and 172 nonspongers. They found the trait appeared to be passed on mostly within a single family line from mother to daughter and that sponging most likely originated in a recent ancestor.
"This is the first study of cultural transmission that actually looks at different modes of inheritance both on the family and the population level," Krützen said. "If sponging was coded on the Y chromosome [found only in males], only males would sponge. If sponging was coded on one of the nonsex chromosomes, then one would expect as many males as females to be spongers. This does not seem to be the case. We ruled out that sponging might be a genetic propensity."....