Neurodiversity, Neuropsychology and Evolution

livingstonIn ancient cultures across the world, there are myths describing a time when women controlled society with a magic more powerful than men’s. These stories go on to describe that there is a loss of the women’s power. Yet the stories also express that there still remains an awesome strength tied to female menstruation; the monthly moon blood is to be feared and respected.

Not unlike the experience of traveling to little-visited, far-flung corners of the earth and finding surprisingly similar myths describing origins of local culture; we find ourselves filled with a similar wonder upon traveling to little-visited academic sub-disciplines. Just as two far-apart aboriginal cultures might have no contact with each other, the heterochronic practitioners of evolutionary biology have little traffic with the neuropsychological theorists who may be located less than a hundred yards away in another building on the same campus. Strangely, we find these different scientists discussing identical processes in different terminologies with almost no published awareness that they have much in common.

How might two different scientific disciplines be discussing the same natural dynamic and not know it, like two aboriginal societies fearing menstrual blood half a world apart, unaware of another culture with the same belief?

The followers of heterochronic theory, tucked within the discipline of evolutionary biology, follow the influence of the relative rate and timing of development and maturation on species transformation. These theorists believe they have discovered a shortcut in the process by which Darwin’s selective processes, natural selection and sexual selection, cajole and curtail the way species transform and go through metamorphosis. The concept is elegant. Instead of waiting for chance mutations or unusual random variations, the selective processes act to retain specific useful features characterized by changes in maturation. A simple variation in, for example, the speed with which an individual can reach maturity, could mean that this faster-growing individual could defend himself or herself against a threat to which another, slower-developing individual might yield to. By passing on this ability to grow faster, this individual’s progeny would also have an increased chance to survive.

This example is one of several ways of manipulating the development and maturation process. Growing smaller is an advantage in many situations, as is growing slower. For example, spending more time at a specific maturational stage, the stage when brain size increase is the most rapid, might result in a far larger brain when that individual reaches adulthood; for example by having a more prolonged early infancy, some species might attain a larger brain size. All that changed may have been the rate of maturation at a specific age for a specific or extended period of time.

Stephen J. Gould suggests that the prolongation of the stages of infant growth into adulthood, since our divergence from chimpanzee-like ancestors five million years ago, would result in many features we identify as human. Human adults look like chimpanzee infants; in this case, a human’s ancestral infant stage prolongs its features into its descendant’s adulthood. An awareness of the rates and timing of maturation leads to an understanding of how humans evolved.

So how do rate and timing changes in hominid evolution relate to the studies of neuropsychologists?

Evolution is not just a record of the processes of the past leading to the present. Evolution is the process by which life unfolds in the here and now. The biggest block to understanding the connection between these two disciplines is the belief by many evolutionary theorists that the genes you pass on to your progeny cannot be revised once you have been conceived. The confusion has to do with the belief that our genes are randomly dealt according to a randomly created sperm impregnating an egg randomly created by the female’s parents. Overlooked is that long, long ago, embryos and animals were genetically programmed, naturally selected, to respond to changes in their environment, passing on these adaptations to their progeny in a form that their progeny could use to revise the rate and timing of their development and maturation to conform with what their parent’s bodies had learned.

Changes in diet influence the onset of puberty. The onset of puberty has been dropping for 100 years, with teens now starting their changes three to four years earlier. It has been suggested that increased high fat diets, non-meat fats, carbohydrates, hormone-infused meats or even plain protein trigger earlier puberty, which generates a change in the body’s environment that gets communicated to the next generation genetically when eggs and sperm are produced. Eggs and sperm are produced from the body’s hormonal constellation at the time of egg and sperm creation; for the woman, her eggs are created when she herself is an embryo; for the man, sperm creation is within days of ejaculation. The parent’s body knows hormonally that there has been an increase in specific elements of the diet. The message is passed on through genes that were naturally selected to be able to discriminate hormonal changes. It is an important message. It is a message that, over the course of several generations, can mean a huge difference in the number of descendants walking the globe. Early puberty means early procreation. A message that higher dietary reserves exist accelerates puberty, increasing the potential for more offspring to take advantage of the increased resources. Puberty has been dropping for 100 years as each generation has passed to the next the information that those resources still exist.

This is evolution in the here and now–individuals making it possible for their progeny to flourish in a changing environment. They are creating progeny prepared for the specific world they are entering. We pass on the information that directs our children into appropriate maturation rates based on how our hormonal systems fluctuate with the environment we live in. It is our hormonal systems that guide the creation of the egg, the sperm and the uterine environment that guide our children to a fertile adulthood.

Many neurological conditions and diseases are a direct result of hormonal messages guiding the rate and timing of development and maturation of individuals in circumstances that convention does not view as useful for survival. Extremely maturationally delayed individuals can evidence autism. Heterochronic theorists and neuropsychologists are both describing the effects of environments on the rate and timing of maturation. Both are describing the identical processes. Neuropsychologists see the effects of rate and timing changes on a time scale of the present–fast time. Evolutionary biologists have difficulty speeding up enough to see it. Without the perspective across time–slow time–characteristic of an evolutionary biological point of view, neuropsychologists behave unaware that a condition may have an evolutionary foundation. Observing autism, they don’t see its evolutionary origins. In both cases, because nonrandom changes can lead to single-generation changes, theorists trained to note only random changes do not see them.

Those ancient myths describing the power of women, the magic of menstruation, may be grounded in those same processes that make up the world of the evolutionary biologist and neuropsychologist. Aboriginal myths may be describing the power of the female womb to determine the specific nature of the child within. It has recently been discovered by a neuroscientist that a mother’s hormone levels while her child is in the womb dramatically influence that child’s maturation rates. Artificial and environmental interventions change an embryo’s maturation speed by changing the mother’s testosterone levels. The blood of a woman carries a heavy magic.

Ancient peoples across the planet have myths grounded in a magic we are only starting to understand. Scientists in different disciplines may be actually exploring the same aboriginal territory, unaware that they have colleagues mere feet away in the very same jungle.

Proceed to author’s FREE book download on this subject (The book is called Evolution, Autism and Social Change). 10 minute introductory video here.

on 11/2/09 in Art/Play/Myth, featured | No Comments | Read More

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