A new study suggests that the size of the brain of an individual plays an important role in determining its potential to survive in different situations. It highlights how creatures with larger brains tend to have better cognitive skills, which often lead to better survival rates.

Researchers from the Stockholm University in Sweden and the University of Veterinary Medicine (VUW) in Austria studied the importance of investing in a larger brain.

They wanted to find out how it can provide an evolutionary advantage in order to compensate for the expensive development and maintenance of the brain mass.

Alexander Kotrschal, a biologist from Stockholm University and the lead author of the paper, said that their research was able to provide the first scientific proof that a larger sized brain does offer an evolutionary advantage to an individual.

In their study, Kotrschal and his colleagues observed how the size of the brain of guppies was able to help the fish adapt to living in an environment far away from its natural Caribbean habitat.

The researchers conducted an experiment on artificial selection to successfully breed guppies with large and small brains.

They then released 4,800 of these guppies into large semi-natural streams, which also included a natural predator of the fish, the pike cichlid.

When they checked on the guppies after half a year, the researchers found out that more of the larger-brained guppies have survived their new environment. This suggests that fish with larger brains had an advantage in terms of survivability against predators, according to Kotrschal and his team.

The researchers also discovered that large-brained female guppies were able to elude their predators more often, giving them a higher rate of survival compared to small-brained female guppies. The increase in brain size for male guppies, however, did not provide any substantial evidence of better survivability.

Ethologist Sarah Zala from VUW explained that the male guppies were more colorful and noticeable compared to the female ones, making them an easy target for the predators. She said the larger brain did not compensate for this liability.

"Our findings support the hypothesis that large brains provide a survival benefit under predation pressure," VUW biologist Dustin Penn said.

The Stockholm University and University of Veterinary Medicine, Vienna study is published in the journal Ecology Letters.

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