Brain Evolution in rodents: What did our ancestor’s brain look like?

When I first get into this seminar, I was shocked as did not expecting too much of medical terms but of course it is impossible to talk about anatomy and brain without using this much of medical term. Hence, I think it is necessary for me to include some simple definition copied from any internet sources just for the sake of better understanding.

Neocortex: a part of the cerebral cortex concerned with sight and hearing in mammals, regarded as the most recently evolved part of the cortex

Endocast: the internal cast of a hollow object, often specifically used for an endocast of the cranial vault. Endocast can be manmade for examining the properties of a hollow, inaccessible space, or occur naturally through fossilisation.

Euarchontoglires: taxanomic superorder within Placentalia. This includes rodents and primates

Main Point

This interesting talk is about the journey of the brain evolution of mammal brain through time by comparing the brain of ancient rodent and its nearest relative now. The comparison of the brain anatomy and the functionality is basically the main focus of the research by Dr Ornella Bertrand.

Technique

The main method used is the CT scanned in order to obtain a virtual endocast of 11 fossils of primitive rodents; Ischyromyidae, 4 mountain beavers and its relatives; aplodontidae and 22 modern squirrels.

Results

The results show that the size of the brain in changing throughout the time. They have tried to relate this change with the change of body mass, but it is not correlate with each other.  There is no continuous increase in the changes occurred.  The hypotheses is the changes might be due to a change in locomotion behaviour. They find that species that spend more time on trees has higher EQ compared to species that spend time underground. This can be related to their vision in which much clearer and sharp vision as well as the amount of light hey are exposed to. More light exposure and sharper, clearer vision needed for the species living on the trees. As light is significantly less underground, vision might be less important for this species.

Importance and application

In conclusion, this new insight of the mammal brain evolution might have the same equation on the functionality and evolution of human brain. As human are now more exposed to use in technologies and wider opportunity to travel, this might have affected the brain as it has been proven from the research that brain of mammal does and can change throughout its lifetime timeline in response to the change of environment.

More on human brain evolution:
https://www.scientificamerican.com/article/how-has-human-brain-evolved/

Next post : The Geological Record of The Earthquake Cycle in The Lower Crust

Date: 25/10/2018

Venue: LT 201

Speaker: Dr Ornella Bertrand