Researchers at Northwestern University are investigating why animals on land have evolved to become so much smarter than animals in the ocean. Their latest study suggests that complex landscapes forced animals to plan ahead rather than just behaving in a habitual manner.
“We speculated that moving onto land poured jet fuel on the evolution of the brain as it may have advantaged the hardest cognitive operation there is: Envisioning the future,” said study lead author Professor MacIver. “It could explain why we can go out for seafood, but seafood can’t go out for us.”
According to the experts, the ability to plan greatly increased survival rates, so evolution selected for brain circuitry that allowed animals to consider different futures.
“All animals – on land or in water – had the same amount of time to evolve, so why do land animals have most of the smarts?” said Professor Malcolm MacIver. “Our work shows that it’s not just about what’s in the head but also about what’s in the environment.”
“And, no, dolphins and whales do not fall into the category of less intelligent sea creatures. Both are land mammals that recently (evolutionarily speaking) returned to water.”
Life on land has many obstacles compared to life in the water. Animals can plan ahead and take cover from predators, and predators can find places to hide for sneak attacks.
However, the researchers report that planning did not give terrestrial creatures the upper hand in every landscape. Based on computer simulations, the experts identified the perfect blend of barriers – not too few and not too many – where planning ahead was the most advantageous. In simple landscapes, like an open field or a dense jungle, planning offered little or no advantage.
“In those simple open or highly packed environments, there is no benefit to planning,” explained Professor MacIver. “In the open aquatic environments, you just need to run in the opposite direction and hope for the best. While in the highly packed environments, there are only a few paths to take, and you are not able to strategize because you can’t see far. In these environments, we found that planning does not improve your chances of survival.”
The research is the latest in a series of studies conducted by Professor MacIver that explore how land animals evolved the ability to plan.
In previous work, Professor MacIver’s team showed that when animals moved onto land 385 million years ago, they gained the ability to see about a hundred times farther than they could in water.
Supercomputer models revealed that while seeing farther is beneficial to planning, it was not enough on its own. The combination of long-range vision and complex terrain, like patchy savanna landscapes, was necessary for animals to master the art of planning ahead for survival.
“Interestingly, when we split off from life in the trees with chimpanzees nearly seven million years ago and quickly quadrupled in brain size, paleoecology studies point to our having invaded patchy landscapes, similar to those our study highlights, as giving the biggest payoff for strategic thinking,” said Professor MacIver.
The study is published Nature Communications.