Research: Orcas’ Evolution Shaped By Culture Similar To Humans

Orcas' evolution may have been shaped with the help of the cultural experiences. Based on the research conducted by Andrew Foote at the University of Bern in Switzerland, there is evidence that the killer whales may take a similar pattern to humans.

The orcas, like humans, are scattered from the tropics to the poles. However, several numbers appear to stay in one location where they have established a specialized niche, chasing a specific target by a modern hunting technique. Some feed on fish by rounding them up into bait balls, while others aim at mammals like the seals by intentional standing on beaches where the seals can be found.

Individual orcas live in stable groups for many decades, which means juveniles have several opportunities to learn specialism from the older ones that biologists call "culture" to describe learning of the notable behaviors. To determine if the orcas' cultural groups are genetically distinct from each other, Foote studied the genomes of 50 killer whales from five niches - three from Antarctic Ocean and two from the Pacific Ocean, according to NewScientist.

It was observed that the genomes have five distinct groups that represented the five cultural niches, with some genes appeared to have been separated between the different cultural groups. Even if killer whales shared the same ancestor as recently as 200,000 years ago, the individual cultural groups have become genetically unique, which means the killer whale culture and genome have co-evolved, Seeker reported.

The evidence also helps to describe how killer whales have obtained their genetic variety.

The genomes show that the five groups started when a small founding number conquered every new niche and expanded.  When juveniles learn some social behaviors from adults, it strengthens the group's identity and reinforces its unique genetic mark.

However, some researchers are not certain if co-evolution of culture and genomes will become a common feature across the entire animal kingdom. Most important is that fact that humans and the orcas share several unusual features like longevity, social natures and intelligence that work together to build a suitable environment for social learning.