Well let’s start off with, what is the TH gene? The TH gene is a “protein encoded by this gene is involved in the conversion of tyrosine to dopamine. It is the rate-limiting enzyme in the synthesis of catecholamines, hence plays a key role in the physiology of adrenergic neurons.” How does this even relate to human and chimpanzee brains?
However, here’s a little background to the dimensions of the human brain compared to the chimpanzee brain. Modern humans share about 95% of their genetic code with chimpanzees. Yet, human brains are three times larger, have many more cells, and would therefore have more processing power than a chimpanzee. Does this mean chimpanzees do not function as efficiently as the human brain or are there just some areas a human brain can be efficient on better as for the chimpanzee brain as well ?
According to two researchers from Yale University, Ying Zhu and André Sousa, TH was found highly expressed in human neocortex, but absent from chimpanzee neocortex. Sousa states, “The neocortical expression of this gene was most likely lost in a common ancestor and reappeared in the human lineage.” Since the gene is absent from the chimpanzee cortex, does this mean that they do not produce any dopamine? Do chimpanzees produce dopamine in a different way?
At the end of the day, we can conclude that human and chimpanzee brains do have a vast majority of similarities. Alternatively, there are certain aspects to the chimpanzee and human brain that allow us to differentiate the two and continue to allow for extensive research in such fields. I challenge you to discover something specific about the human brain and chimpanzee brain that are both extremely similar and different. What will you discover next?