This is certainly not what the marketing people at Apple had in mind when they came up with their slogan.
Researchers at the Chinese Academy of Sciences in Kunming have found that while the prefrontal cortex of humans express the type II splice form of neuropsin – a protein involved in learning and memory – primates brains do not.
Earlier work showed it was not expressed in the brains of lesser apes and Old World monkeys.
- Yi Li, et al. Recent origin of a hominoid-specific splice form of neuropsin, a gene involved in learning and memory. Molecular Biology and Evolution 2004 21(11):2111-2115; doi:10.1093/molbev/msh220.
Now, they have shown the same results for two great ape species, chimpanzees and orangutans.
- Zhi-xiang Lu, et al. A Human-Specific Mutation Leads to the Origin of a Novel Splice Form of Neuropsin (KLK8), a Gene Involved in Learning and Memory. Human Mutation; May 2007; (DOI: 10.1002/humu.20547) [press release]
This is interesting because the ancestors of present-day chimps and humans diverged about 5 million years ago. (Orangutans did the same about 14 million years ago.) It follows that the mutation happened in humans – and only in humans – less than 5 million years ago.
Are we to take from this that the mutation caused human learning and memory to change in important ways sometime after 5 million years ago? That would depend on the importance of type II neuropsin to human cognition. Not being a neuroscientist, and being generally unable to wade through the crowded mass of technical jargon making up the verbiage in most science papers, I will await the analysis of more astute minds.
I’ll also have to wait to see if the research triggers important ethical questions about the future of primate cognition. After identifying the mutation that resulted in human brains’ expression of type II neuropsin, researchers then took things a step further – they put the mutation into chimpanzee DNA, and found this was enough to produce the protein. If the protein is important to cognition, this research appears to be one step towards biological uplift.
In the meantime, while researchers assess the importance of the protein to the evolution of human cognition, I’ll continue to wonder how long humans have been like humans today. When I read ancient texts, I’m always impressed with the degree to which people’s thinking has not changed. Thoughts, feelings and modes of reasoning have been remarkably consistent over the past 5 thousand years or so, although beliefs and cultural norms have altered. (Watch the HBO series Rome for a dramatic take on this.) It would be fascinating to learn how far back human cognition remains recognizable, although establishing a baseline might prove challenging – it is sometimes difficult to understand the minds of people living today.