It has been widely understood that the proportion of brain size vs body size is the most common gauge for animals’ intellectual capabilities. Years of scientific work has relied on this measure to predict intelligence in all forms of animal species. It has become fact that as far as brain size is concerned, that of the human’s was exceptionally large in proportion to its body mass. We understand this in the same way we understand, then, that ants are actually stronger than other bigger animals because they can carry things more than their size and weight.
However, what we know of animal intelligence now may be different in the generations to come. A study performed by a group of scientists from German institutions such as the Ornithology Institute of Max Planck and the Universität Konstanz, along with Britain’s Universal College London have discovered that the connection between the development of the body and the brain is orchestrated by different adaptive mechanisms throughout evolution, and animals have different ways of executing it.
One of the more critical scientific findings is that external factors impress more adaptability measures on size, and not on brain growth due to evolutionary demands. In much simpler terms, it is the body that is in constant development flux while the brain goes through a much slower process. To explain this further, let’s take a look at the evolution of the bat species. The change in their physical appearance, as in decrease in size, was faster than the decrease in brain size. Now with a smaller structure, it resulted in the bats’ more efficient flying ability without having to compensate the necessary brain capacity to operate in-flight sensor mechanisms to navigate through different environments.
This finding alone proves that it is not enough to rely on the comparison between brain and body dimensions to size up animal intelligence. To support this Dr. Jeroen B. Smaers, head of the research team and faculty of the UCL Department of Anthropology and Depertment of Genetics, Evolution and Environment, stated that the difference between brain size and body size is no longer enough to measure animal intelligence in different species of animals. The general assumption that the brain undergoes a development process faster than that of the body no longer holds true for most. The recent study on bat species invalidates the assumed notion, as it was obviously shown in the bad analysis that their evolution shows more modification in body features than in the brain.
Furthermore, Dr. Smaers explained that the growth or degenerative aspects of our body’s and brain’s development operates independently of each other, and usually follow patterns different from other animals.
In the study, which is now published in the scientific journal PNAS, researchers did not limit themselves to examining species of bats. They’ve also collected mass data from brain and body samples of different animals. Resulting data was then charted to show comparison. And it was found that throughout years and years of evolution, most animals gained an increase in body size, not the other way around as was the case of bats.