Charles Darwin presented three different yet closely related theories to explain species evolution. Our ability to understand the causes of autism is directly related to how well we understand the processes underlying human evolution. Natural selection is academia’s default frame for examining how human’s evolved. Sexual selection has received attention only in the last 40 years. Lamarckian selection, the dynamics of which Darwin named Pangenesis, to this day, is disparaged and ignored. Only a thorough understanding of all three processes reveals how autism is directly related to how humans evolved. Darwin believed all three processes propelled species transformation. An understanding of how autism comes to be, evolutionarily, and why it appears in such force now, suggests the specific actions and treatments that can be taken to prevent and alleviate the symptoms of the condition.
Just as there is a branching relationship between species revealing how one species is related to another through common ancestors, the evolutionary processes themselves are related to one another though a branching family tree. Natural selection was the first selective dynamic - the adam and eve of evolutionary engines. Understanding the branching relationship between the selective processes reveals how humans evolved and how autism surfaces.
In natural selection, members of a species produce more progeny than can survive, progeny with a variety of features or characteristics. The specific features of those individuals that do survive to reproduce are inherited by the next generation. The ability of individuals to inherit features and pass them on to their progeny over time creates variation in species and eventually new species.
Darwin’s second selective process is sexual selection. In The Descent of Man he detailed the powerful effects of sexual selection on animal and human evolution. The peacock was used as an example to show how the choice of females in a species can propel changes in the features of a species when males without those features have no access to procreation. Occasionally males sexually select females to cooperate with a specific visual or behavioral agendas, but the vast majority of examples of sexual selection in nature follow the dynamic of females picking males. With humans both females and males do the choosing. Which sex does the choosing depends on whether they come from a matrifocal or patrifocal social structure. Sexual selection, as a selective process, branches directly off of natural selection - a progeny process, so to speak.
The dynamics of Lamarckian selection was described by Darwin in detail in his work, The Variation of Animals and Plants under Domestication. Darwin did not discover Lamarckian selection, as he did natural selection and sexual selection, but he did feel compelled to explain how it worked, in detail, and its relationship with the other selective processes. Two main tenets of Lamarckian selection are that individuals are shaped by their environment - either directly by its effects or indirectly by the use or disuse of limbs and organs - and that those effects can be carried into the next generation. For example, the actual exposure of an animal to cold and dark its whole life might engender a next generation with longer hair or an increased degree of comfort in the cold - a direct response to the environment. An indirect response might be a highly stressed individual forced to fight over a long period of time creates a next generation with an aggressive advantage because their parent had already engaged in the activity. We believe that Lamarckian selection, as a selective process, also branches directly off of natural selection.
Darwin specified in his theory of natural selection that variation is random. This is, perhaps, the most theoretically conflicted element of Darwin’s works. Both in his The Origin of Species, 6th ed. and in his The Variation of Animals and Plants Under Domestication where he discussed his Lamarckian theory, Darwin makes clear that he believes that variation is not random, that both use and disuse and environmental influences such as climate changes, compel the creation of progeny pre-selected for an environment. Darwin’s inability to form a synthesis of natural selection, sexual selection, and Lamarckian principals revolves around this issue of whether variation is random, not random, or something in between. If evolution is completely random, there can be no sexual selection or Lamarckian selection.
Researchers from Mivart to Steele have focussed on the fulcrum that random variation represents. Darwin was frustrated by his own efforts at the reconciliation of the three selective processes. One way to understand and resolve the relationship between the selective processes, and open a door to understanding the source of a number of modern conditions and disorders, is to note that natural selection is the progenitor, the ancestor of the other selective processes. Natural selection selected for or created Sexual selection, and Lamarckian selective dynamics. None of the products of the other selective processes can meet the requirements of evolution unless they also pass the test of natural selection, that individuals survive to procreation age and procreate.
Cultural selection, learning on an abstract level, is a product of female sexual selection. It lies two levels down from natural selection, but still must past muster when it comes down to an individual’s survival to procreation age. Ideas also die, and must compete for survival. Cultural selection is the grandchild of Natural selection. Cultural selection is unrelated to autism but can be explored in detail by clicking here.
So, just as there is a branching tree of species representing their relationships over time, there is a smaller branching tree of selective processes representing their relationships and how one selective process generates another. With each branching there is a more select group of species effected by the processes at issue. Natural selection affects all species. Sexual selection and Lamarckian selection affect many. Cultural selection affects perhaps only humans.
What drives the dynamic of natural selection spawning other selective processes is the immediate advantage any individual has if he or she can transcend the barrier of random variation. Any feature that an individual can generate, preadapted for the environment he or she (or his or her progeny) will be born into, is a huge advantage over an individual without a preadapted feature. Fast, targeted evolutionary flexibility is what it’s all about. Whatever the individual is competing for: more sunlight, prey, speed, smaller or greater size; if that individual’s genetic predispositions can discern which direction to evolve in, he or she will have an advantage. it’s progeny, when they inherit that ability and will be more likely to survive to procreate. Among humans, the ability to shift or change features in a single generation, features preadapted to fit into a changing culture, is a direct result of this branching tree of selective processes.
How does understanding the relationship between selective processes help us understand the origins of autism?
The two most powerful selective processes propelling human evolution are Sexual selection and Lamarckian selection. At a particular stage in human evolution, once humans had firmly established themselves at the top of the food chain perhaps 2 to 3 million years ago, natural selection ceased to influence the offspring of human beings except through these two progeny processes. Sexual selection was the primary player responsible for the exponential increase in human brain size and the advent of language and culture. Lamarckian selection molded more subtle elements of the human physiology and character. Sexual selection creates the path along which humans evolve. Lamarckian selection propels individuals back and forth along the established path as it influences individuals and their progeny converting environmental influences into changes in neurology and physiology.
Our species is carried forward (and backward) through evolutionary time on the wings of maturational acceleration and maturational delay. The single most profound influence on individual human personality is the rate and timing of maturation. Stephen J. Gould, the late great evolutionary biologist, believed that this one variable is primarily responsible for the specific evolutionary trajectory that human beings have taken since branching off from the other great apes between 4 and 5 million years ago - humans only vary from chimpanzees through 1% of our chromosomes, which is less than some intra species variation. The rate and timing of maturation is also responsible for the wide variation of contemporary humans, the left to right arc. Deep variations between humans is not about cosmetic differences between ethnicities - color in skin or hair, size or girth, but rather about degrees of maturational development. There is often far more variation within ethnicities than across ethnicities. Those profoundly influential variations between the left and right are the differences in speed and timing of maturation. It is at the ‘left’ end, the far left side of the human maturation spectrum, that children with delayed maturation rates often exhibit autism or other related disabilities. And, it is at this left end, that a huge number of contemporary individuals exhibit extraordinary talents in music, dance, athletics, architecture, rhythm, art and mathematics.
Sexual selection creates the path, Lamarckian selection can propel individuals back and forth along that path. How is the path is created?
Sexual selection is the process by which individuals in a society choose a mate considered most desirable by that culture or social structure. In a large society exposed to frequent wars the ideal male is strong, strong enough to live long enough to have children, has access to powerful aggressions, and works well in hierarchy. The female is supportive and cooperative. Patriarchal social structures have ideal male and female types that engender an ideal mate: powerful males and cooperative females. Those males closest to the ideal type are married to the most ideal females. Female infanticide and multiple wives for a single male reinforces the process by removing females from the mate pool leaving the less than ideal males unable to procreate. The ideal types are reinforced when the paradigm mates are picked for procreation in these societies complying with the ideal types. Humans have been evolving according to the patriarchal model of ideal types for at least 6,500 years, perhaps several thousand years longer. Female infanticide has only faded from most cultures in the last 200 years and is still widely practiced in Asia. The values of patriarchal social structures are the values of most contemporary societies. Only in the last two generations has that begun to change. One of the results of these recent changes is the rise in autism.
There are many differences between the personality structures/physiological/neurological profiles of individuals in matrifocal and patrifocal social structures or the males and females selected first as mates in those cultures. The males in matrifocal social structure are characterized by maturational delay with a cluster of features very different than the ideal male (maturationally accelerated) in a patriarchal social structure. The matriarchal male is not hierarchical inclined, is far more present oriented with less inclination to focus on future goals, is acutely aware of pattern and the relationship between patterns (specifically music and dance and relationships in space and across time from a present time perspective), rhythm, art and associational thinking. The maturationally delayed male has a slower metabolic rate than his accelerated relations. Ambidextrousness, and increased left handedness are associated with this individual because maturationally delayed males are less cerebrally lateralized exhibited by their two cerebral hemispheres being closer in size than their maturationally accelerated patriarchal relations. And so, in personality, they are less split. Though, at the same time, they are less acutely self aware. The cult of individuality often characteristic of patrifocal societies is not evident in a matrifocal tribal culture.
The female in a matrifocal social structure is the complementary opposite. She is chosen for her strength, fortitude, and ability to wield authority. In a matriarchal society the male does not know his progeny and does not accumulate wealth to be passed down to his sons. A male’s authority is through his sister, whose children he is related to through their parents. Males compete with males for procreation opportunities through the exhibition of their skills in dance, rhythm and song. Matrifocal social structures select the male artist, with the most successful performers mating the most frequently. Procreation is indiscriminate in matriarchal social structures, though serial monogamy is common. Authority and wealth do not accumulate with the male, but with the female or the tribe. A man passes on his genes more through his artistic prowess, not his warring abilities, or his skills in the hunt. His ability to kill benefits the tribe. His ability to astonish benefits himself and she whom he has impressed.
When a society and its individuals idealize and select males and females for temperments, skills and inclinations along this left to right, matrifocal to patrifocal spectrum, humans evolve in those selected directions far faster than the slower selective powers of natural selection. Hence the exponential rise in human brain size and the incredible slowing of human maturation rates and timing over the last 2 - 3 million years. As we humans have selected for the artists among us, far more cerebral capacity was engendered than needed for mere survival. And so, for millions of years, an evolutionary path was layed through our genetics, a path characterized by maturational delay (also called neoteny), the single most powerful variable leading to increased brain size that has culminated in the last few thousand years with a sudden movement toward maturational acceleration.
For the last few thousands of years males have been selecting the females least likely to stray and so provide them with male heirs. Males have been selecting females less likely to wield authority, females who are willing to cooperate with a patriarchal agenda. Females have been selecting males most likely to accumulate wealth, who can stay alive long enough to provide babies and provision a large brood in a relatively monogamous society. Revered features of the ideal male in a matrifocal society are disparaged by patriarchy. But it is these features, and the characteristics of the individuals that thrive in that kind of world, that is the world of the autistic child.
Without constant exposure to the primary features of the matrifocal world, the neurological structure of a child organized physically, mentally, and emotionally to experience the world in that way will languish. Unceasing interactional music with highly evolved rhythms and constant touch with sophisticated dance are essential to a child inclined toward maturational delay. A diet familiar to the physiology of tens of thousands of years ago is appropriate for the facile functioning of that physical system. Their brains crave highly sophisticated pattern in sound and physical space. Their bodies crave protein, vegetables, fruits, nuts, natural oils, roots. How sad and ironic, that a brain created to perceive and appreciate subtle nuances in relationship in space and time, understimulated by a society relatively devoid of song and dance, and a diet characterized by wheat, dairy and other unfamiliar substances, ends up in relationship with itself only, unable to cross bridges to other human beings.
Sexual selection creates the path, Lamarckian selection propels individuals along that path. How is it that individuals move back and forth along the path? How is it that some individuals propelled into deep maturational delay seem to become lost there, unable to communicate with others? By understanding the dynamic of Lamarckian selection we can understand how to prevent and retrieve individuals from becoming lost and alone - Matrifocal social structure humans floundering in a world of the patriarch.
Newton knew he couldn’t perceive how gravity works, but he could perceive its effects. Newton understood that he couldn’t break down gravity into manipulatable variables, but he could make gravity a variable to explain other processes.
Darwin perceived the effects of Lamarckian processes, but felt compelled to explain how the processes occurred. He was disappointed that his Lamarckian theory did not satisfactorily outline how these processes unfolded, and his theory was ignored. Later attempts to explain how individuals could translate the experiences of their lives into the features of their progeny also failed to explain how this could occur. Theorists for the last hundred years have rallied around natural selection, only the first of Darwin’s three founding principals to explain how evolution operated. A reductionist frame of reference does not always focus on the most elegant solution, but rather on where the answers seem easiest to grasp. Unfortunately, more questions have been created in the long run by the exclusion of the other processes.
For over one hundred years these unanswered questions have been accumulating. Doctors are now unfamiliar with concepts alternative to natural selection. Lamarckian selection has been made invisible. Evolutionary biologists give the concepts wide berth. A scholar seeking a doctoral dissertation on Lamarckian selection would be unable to find three tenured professors to sit on committee. The ever courageous Stephen J. Gould, who wrote about Lamarckian principals in some detail in several books and many papers, rarely called it by its name, sticking to observing its effects. Neuropsychologists noting its effects when observing the environmentally induced appearance of inheritable conditions characterized by maturational delay have no vocabulary to relate what they are observing to evolutionary processes. Unnamed it operates in secret. Human maladies unfold, unexplained.
The effects of the environment on an individual that result in changes in the children of that individual are considered damage. This is often the case. Contemporary theorists have no other way to view these effects. Yet, environmental effects on an individual that result in changes in his or her children are often not damage. They are the results of evolution - Lamarckian evolution - evolution that occurs over a single lifetime - evolution that follows an already created channel - a genetic history of maturational delay and acceleration dug by millions of years of sexual selection. Specific environmental effects propel changes in the maturation rate of humans and their progeny. When a human has a predisposition for maturational delay, most readily identified as those with histories of left-handedness in their family, the children of that person can be driven even further along the path of maturational delay when the parents experience specific environmental nudges. Even people with little evidence of maturational delay in themselves or their family histories, if the environmental prod is powerful enough, can experience their children swaying far toward the evolutionary left. Without intervention, some of those children will become autistic.
Not surprisingly, its all about sex - the sexual hormones.
For over 20 years periodic studies note a deeply mysterious event that occurs within the mother six weeks before her infant is born. The embryos maturation rates are established based upon the mother’s testosterone levels. The speed at which the little human matures is established at approximately week 33 after conception. If the mother is carrying a male child and her male hormones are high, the baby’s maturation rate will be notched down. If it is a female within her womb, the rate is notched up. If the the mother’s testosterone levels are low, her male baby will mature faster, and her female baby will mature more slowly. The established maturation rates are passed on to the next generation, evolution occurring in a single lifetime.
Incidentally, matrifocal social structure females have relatively high testosterone levels (remember, they are more domineering) and so they produce maturationally delayed males and maturationally accelerated females. In a patrifocal social structure the females have lower testosterone levels producing maturationally accelerated males, and delayed females.
Over the course of our lives, our hormonal levels change. Numerous environmental variables affect these changes, not the least of which are what we eat, drink and smoke. The levels of sexual hormones of the father at the point the sperm are produced also affect the child’s maturation rates. The environment of the father, what he has been exposed to and how he has lived his life, is information coded into the sperm as it genetically notes the father’s testosterone levels and carries that information to the egg. Here again, evolution over a single lifetime.
It’s no wonder that humans have evolved so rapidly over the last several million years. This single easily adjusted variable, mother’s and father’s testosterone levels controlling maturation rates, accounts for massive evolutionary change as sexual selection carved a ‘mind blindingly’ fast human evolutionary trajectory, and Lamarckian selection - occurring in the women’s womb and father’s sperm - adjusted that trajectory to accommodate to local conditions in time and geography.
Yet, perhaps, this variable is too easily adjusted. Many things in contemporary society influence testosterone levels. Those influences are now having far more of an effect upon our evolution than sexual selection or natural selection. Our children are being propelled into maturationally delayed trajectories without the appropriate culture to nurture the gifts that accompany their new - to the modern world - physiological/neurological conditions.
The eight primary environmental variables influencing testosterone levels are; light, diet, body fat, alcohol and drugs, tobacco, touch, physical activity, and stress. These variables often do not affect the two sexes the same way. For example, increased body fat raises female testosterone and lowers male testosterone.
A women with a left-handed parent (indicating a familial tendency toward male maturational delay), that is overweight, close to 40, and smokes is in danger of giving birth to a male with strong tendencies toward maturational delay. This women already has high testosterone levels further elevated by environmental influences. Fitting the matrifocal structure profile, she is propelling her progeny even further back in evolutionary time, moving along the channel created by sexual selection. If the environmental influences are powerful enough, a child can be neurologically stationed at a point where the language centers of the brain are still wired for gestural communication, dance and song and not yet for the spoken word - a point where the two cerebral hemispheres have not begun to vary in size with a diminution of the right lobe which leads to split consciousness - a split that results in the principle dissociation, with a movement out of the mythical or dream consciousness of the early matrifocal tribal cultures.
What causes the cerebral hemispheres to diverge in size, the right side atrophying, and becoming smaller? Maturational acceleration. It is no wonder that autistic children frequently have a brain size far larger than the norm. Often both cerebral hemispheres are the same size, the right side unpruned by the effects of hormonal surges which occur in the majority of contemporary humans.
The reason that there are far fewer females than males with autism is that females actually become more maturationally accelerated as you move back in evolutionary time, as you move back into matrifocal social structures with more domineering women. These girl children also require the song, music, and dance stimulation of the maturationally delayed male, but cerebrally they are less vulnerable since hemispherically their language centers are more developed and the cerebral lobes more divergent - the effects of maturational acceleration. Since in matriarchal cultures the females are maturationally accelerated relative to females today, girls with autism have to be propelled far further back in evolutionary time to exhibit the same symptoms. Hence, far fewer females are diagnosed.
This is also the reason that there are far fewer females than males with Aspergers, a form of mild autism. A relatively slight movement in the left direction will effect a male far more than a female since the male brain has changed far more dramatically in the direction of divergent hemispheres in the last few thousand years. The female brain began that journey far earlier than the male brain did, having experienced right hemisphere pruning during matrifocal times when they were exposed to maturational acceleration.
The brains of a high percentage of autistic children dramatically accelerate in size shortly after birth, growing far faster than the usual child. It has been suggested that this is a symptom of the autistic brain’s inability to prune unneeded synapsis during early childhood. We suggest that these synapses are craving stimuli, seeking exposure to intricate patterned communications in sound, space and time. These are ‘normal’ brains growing up misunderstood in a foreign time.
We could expect that the brains of our matriarchal forbears would be larger than the brains of the last few thousand years. And, this is so. Just as autistic individuals exhibit brain sizes larger than the norm more often than statistically could be expected, humans up through 30,000 years ago, including the Neanderthal humans, exhibited brain sizes, relative to height and body mass, larger than those of recent millennia up through the 19th century.
The timing of the onset of puberty also has dramatic affects upon the ability of autistic children to join the world as we know it. Diet, percentage of body fat, food additives and physical activity are primary variables responsible for pubertal timing. There has been a drop in the age of puberty by three to four years over the last 100 years in urban cultures worldwide caused primarily by changes in diet. These dietary changes signal our bodies that increased fat, carbohydrate, and protein resources are available to sustain an increase in birth rate, accomplished by lowering the age of procreation; a naturally selected response. The fact that puberty comes several years sooner than would have occurred in the matriarchal society from which the autistic child has been severed from reduces childhood by several years giving the autistic child far less time for the brain to grow and develop. When puberty hits brain growth stops. The testosterone surges at early puberty in both sexes halts cerebral development. For the autistic child, this leaves no more time to catch up. Slower maturation plus early puberty in a world with inappropriate environmental stimulus combine to deeply inhibit these children of artistic cultures from entering the modern world. Proper diet will delay puberty and give the autistic child’s brain more time to mature.
Tracking the distribution of neurological conditions at the left end along the maturational spectrum is tracking the sequence of our genetic heritage and cultural history. At the far left end is autism representing anatomically modern humans maybe 100 M - 50 M years ago when we had bigger brains, ambidextrousness, and no dominant hemisphere. We hypothesize that responsibility for many autistic syndrome complications over and above expected developmental delays lies with the absence of constant touch, interactive music, rhythm and dance as infants, stimulus required for full functioning in a genotype as told as autism represents, coupled with a deeply inappropriate diet. Phonetic dyslexics; stutterers; many Tourette’s sufferers; many homosexuals and lesbians; many gifted athletes, mathematicians, artists, musicians, and composers; many schizophrenics; specific alcoholic types and many obese women are left spectrum, old genotype individuals who can be located along the left end of the maturational arc. We believe that the human species moves through time inside a maturational arc, its character determined by the effects of sexual selection and Lamarckian selection on the rate and timing of maturation, creating the vast skill and talent spread of contemporary culture.
