Stupid Rats and Evolution

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Humans have a relatively large brain cortex and the evolutionary argument has always been: larger brain cortex, more intelligence. In an attempt to prove this theory, researchers at the National Institute of Mental Health gave pregnant rats a drug that reduced the amount of cortex tissue in the next generation. The researchers expected the offspring to be less intelligent but this was not the case. However, they were more aggressive and short tempered and there was a tendency towards cannibalism; only ten percent of the young made it to adulthood.

The researchers then concluded that the larger cortex had less to do with intelligence but it did enable creatures to deal with complex life situations. In other words, the formula for survival of the fittest had shifted from intelligence to the ability to deal with complex situations. This was claimed to be evidence for evolution. It is well known that prefrontal lobotomy or removing the front part of the brain of human patients does not change intelligence but often leaves the patient antisocial. The truth is the drugs given to the rats not only reduced the size of the cortex but undoubtedly caused brain damage leaving them unable to handle complex situations and antisocial. In other words, it is not a matter of simple cause and effect but two effects from one cause. Time and again the theory of evolution has been found to rest upon such flawed experimental work.