Mammals’ Brain Evolved Due to Sense of Smell

The evolution of brain started in the mammals because an improvement in the sense of smell, paleontologists say. This study can help us understand why mammals have such a developed brain.

The scientists reconstructed the fossils of Morganuocodon and Hadrocodium, two Jurassic mammals. They found that the brain of a mammal evolved in three stages.

The first stage was the improvement in the ability to smell. The second stage was an increase in touch because of body hair, and the third stage was a better neuromuscular coordination using senses, as reported by the journal Science.

The study was conducted using X-ray computed tomography, a technique for medical imaging. By this technique, the scientists reconstructed the brain of the Morganuocodon and Hadrocodium fossils, whose age is 190 million years.

Tim Rowe of the University of Texas, who headed the study said, “Now we have a much better idea of the historical sequence of events and of the relative importance of the different sensory systems in the early evolution of mammals. It paints a much more vivid picture of what the ancestral mammal was like, how it behaved and of our own ancestry”.

Rowe added that though humans have compromised some sense of smell for a developed vision as well as hearing, other mammals like dogs still depend heavily on smell.