One interesting scientific question is whether brain cells can be increased or replenished. People say the brain is the only body part where the cells are not replaced every seven years. That seems reasonable since replacing brain cells could cause us to lose stored memories. Doctors are limited in what they can do to help people with brain injuries because of the inability to repair or replace brain cells. Scientists have found some interesting facts in a recent study of mountain chickadee brains.
The study at the University of Nevada has shown that brains can change when environmental factors demand it. Researchers comparing the brains of chickadees separated by a few kilometers in the Sierra Nevada Mountains found substantial differences in the brains of the two populations. Chickadees living at an elevation of 7800 feet showed significant brain differences compared to those living at 5900 feet. The hippocampus of the higher-elevation chickadees was larger, and the neuron density was greater. Tests showed enhanced spatial cognition at higher elevations, so caching and recovering food will be better for the higher mountain chickadee brains.
If you assume that both populations of chickadees came from a common ancestor, then brain development genetic change has been catalyzed by environmental factors. For example, a greater need for food caching and recall has led to physical changes in mountain chickadee brains.
The question is, could we apply this to humans with brain injuries? Is the brain designed to allow this kind of change? The brains of chickadees living in the harshest environment must develop better spatial memory to survive. Does this mean human intelligence can be affected by life challenges and environments? We need to point out that intelligence is not necessarily related to brain size because a bigger brain does not mean you are more intelligent.
Studies like this demonstrate the flexibility God designed into the DNA of living things. So maybe being called a “bird brain” is not as derogatory as people previously thought.
— John N. Clayton © 2023
Reference: Living Bird magazine from the Cornell Lab of Ornithology for the winter of 2023, pages 46 – 53, and “Harsh Mountain Winters Have Made Chickadees Smarter” at allaboutbirds.org