It seems too elegant to be true, but I’ve become enamored of the possibility.

Heterochronic theory, the study of the effects of rate and timing on maturation and development, takes the work of several late nineteenth century and early twentieth century theorists and packages that work into a sort of seamless whole. Stephen J. Gould in his Ontogeny and Phylogeny went far, codifying the various theorists’ predilections so that they made an overriding sense. I say “sort of” seamless whole because the actual endocrinological underpinnings of the dynamics were never explored.

Neoteny is the best known of the six heterochronic processes. Neoteny is the process whereby features of infants, embryos or the very young are, over the course of generations, prolonged to emerge in the adults of descendants. Acceleration is the opposite, whereby features of adult ancestors appear in the infants of descendants. For example, let’s say great great grandfather had a baritone voice, emerging at puberty. His son’s deeper voice may emerge just before puberty and his great grandson might have an unusually hoarse voice as a child. That would be an acceleration of a feature. These things normally take hundreds and thousands of generations, though they can be encouraged to occur in less than half a dozen. Wolves and foxes have been neotenized in a mere 20 years, acquiring dog-like characteristics.

Endocrinology is a new science even though we have been observing the effects of the gonadal hormones since the dawn of self awareness. That there might be an elegant correlation between specific hormones and the rate and timing of maturation has not been explored outside work done by biologists, followers of Matusa mostly, on amphibians and other nonmammal species. For over ten years, I’ve been exploring the repercussions of a theory of human evolution that considers that testosterone regulates the speed of maturation. This is a profoundly epigenetic theory, a theory that estimates that testosterone regulation occurs as a direct result of environmental factors that determine testosterone levels. Epigenetic theories are those theories that explore heredity/environment interactions that result in ontogenetic and eventually evolutionary change. It was unorthodox until recently to consider that genes are programmed to take into consideration environmental effects, and that the result of modifications will not only appear in the individual but in the individual’s descendants. So, we might see why it’s taken us a while to get to a place where testosterone could be even considered as a major force in evolution.

Chris Knight in his Blood Relations outlines the profound effect that social frames of reference have upon our ability to theorize. Thomas Kuhn alludes to the impact that shared social views have upon theorists’ frame of reference. Knight describes how hobbled we are in the West by a nonfeminist perspective. Kuhn suggests a sea change of societal perspectives would be necessary for the following to make sense.

Heterochronic theory’s changing rate and timing can be elegantly assigned to the effects of testosterone changing rates and estrogen controlling timing. Both hormones are associated with a host of related hormones, and there are circumstances where male and female hormones may transition to the other but, speaking generally, there are patterns that suggest that at a very real level, individual ontogeny, social evolution and human biological evolution are unfolding according to this very specific, two-variable dance.

Our commitment to Darwin’s theory of natural selection has made it difficult to note the effects of the environment upon evolution.

Our devotion to the idea that the behaviors of males in evolution are more important than the behaviors of females has made it almost impossible to observe that behind the scenes it has been the female controlling the timing of the process.

I wish we had a better word than “heterochronic” to describe the patterns. It would have been better if we had a name like “orchestral evolution.” Then it would make more sense when we assigned the position of conductor to a woman, she that decides the timing of the production.

There are several places where estrogen may be quietly stepping in and deciding exactly how things unfold by regulating the timing of those events. That may be occurring in no small way due to estrogen controlling the timing of testosterone’s effects.

• Fat levels at puberty, influencing estrogen levels, determine the timing of pubertal testosterone surges in both sexes. Individuals may experience delayed puberty if there is not enough fat on their bodies to propel the process.

• Estrogen levels in an infant and toddler may be influencing testosterone surges that determine cerebral synapse pruning. We don’t know what determines the timing of testosterone surges that result in the diminution of the right cerebral hemisphere. If it is a similar process to what determines the timing of testosterone surges in puberty, then estrogen levels may not only be controlling cerebral lateralization but may be heavily influencing language production, conditions such as autism and numerous other human features and conditions.

• Estrogen levels in a mother’s womb may be deciding (along with testosterone) which social structure the child will be inclined to ally with. I’ve described four social structures, two matrifocal and two patrifocal. Estrogen levels are a key determinant of social structure proclivity.

• Estrogen levels may be determining both the intensity of mate selection criteria (higher levels compelling a more determined choice) and the degree of focus on the young. Estrogen not only decides which male features get passed to the next generation but determines the likelihood of progeny survival by how much attention is directed toward the young. Consider that in female infanticide it is almost always the mother that kills the infant.

• Estrogen may offer the placating option when combat is being considered. Estrogen can control whether a battle occurs or not.

Darwin’s theory of sexual selection or female choice may be but the suggestion of a vast network of relationships determined by estrogen levels. Darwin was familiar with the work of contemporaries, Neo-Lamarckians, who focused on the orthogenetic tendency of features to evolve in particular trajectories. We can see those patterns now as part of the larger pattern of Gould’s heterochronic theory paradigm. It is possible that Darwin’s theory of natural selection and his theory of sexual selection can be allied in a heterochronic theory of evolution that places testosterone as the prime mover of rates of maturation and estrogen as the queen of timing. Interestingly enough, Darwin’s third theory, pangenesis, revealed orthogenetic insights. Darwin even hypothesized “gemmules,” or particles, that would flow through the bloodstream, carrying information regarding the environment to the places in one’s body that controlled evolutionary change.

In other words, Darwin had all the puzzle pieces. But, he was exploring these ideas in a time when society embraced only the idea that might is right, environment be damned and women control little of what occurs.

To seriously consider that testosterone may control the rate of evolution, estrogen the timing, we might have to go back 150 years. The answer to our origins may be in the origins of evolutionary theory.


This entry was posted on Friday, August 21st, 2009 at 7:08 am and is filed under 10-Most Commented, 10-Most Visited, Autism, Causes of Autism, Estrogen, Neoteny, Ontogeny, Sexual Selection, Testosterone & Estrogen, Theory. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
11 Comments so far

  1. Math World | Autism, estrogen and evolution : Neoteny, sexual selection, cause … on August 21, 2009 8:44 am

    […] Andrew 2009-08-21 19:08:34 Continued here:  Autism, estrogen and evolution : Neoteny, sexual selection, cause … […]

  2. sarah boardman-miller on August 21, 2009 2:31 pm

    very interesting. you are on to something. i think about all of my girlfriends, my age-39, who cannot get pregnant. i have this theory, that with the lack of progesterone in men and women-environmental, bred out of us, etc we are scaling back on reproduction. now more than ever, we are putting more things on our bodies, in our bodies and we are surrounded in the our environments by chemicals and substances that constantly alter our make-up.

  3. Liane Casten on August 21, 2009 2:54 pm

    This piece is a breakthrough. I know for certain several facts: 1. the environment is causative for breast cancer (70%) because it produces chemicals that mimic estrogens called xenoestrogens. The Estrogens out of control create the cancers. That’s in my book. 2. EPA has already given seminars at how environment factors have deeply influenced the fetus. The group of toxic chemicals are called Organochlorines and mostly come from chlorine mixed with chemicals produced in industry. Deeply toxic–like DDT, dioxins, PCBs, etc. The International Joint Commission advised the phase out of chlorine in industrial manufacturing, but both Canada and the US ignored it. 3. Pregnant Mothers eating just 2 Great Lakes fish a month are warned: their children will be born with serious brain limitations; the fish are highly contaminated from Great Lakes pollution. 4. Children born in Midland Michigan, home of Dow Chemical (dioxin, Agent Orange, etc.,) are more likely to be gay: teachers have reported as much. 5. Fertility rates and male sperm count has continued to go down world wide by 50% 6. And in the wild, female herring gulls are found trying to mate with each other while male frogs are being born with female ovaries. More evidence will be emerging, but I predict NO one will have the courage to stop the profit machines which creates these toxic pollutants and products despsite the consequences. We’ve lost our respect for human life as we pile in the money!

  4. Rod Homor on August 21, 2009 4:15 pm

    Interesting article, Andrew. Thanks for posting it. What I was curious about after reading it, is if you thought the estrogen / testosterone levels in the mother’s womb affected the child’s sexuality in any way. I don’t know if this is too much of a stretch, but something that I was curious about after reading, nonetheless. Great job, and thanks again!


  5. Tom Baker on August 21, 2009 9:43 pm

    Tom Baker here and I like this that I quote
    “..the profound effect that social frames of reference have upon our ability to theorize..”

    I call that Social Conditioning
    find that an extensive force but not seen nor
    recognized as it plods on

    For instance, I find that those of Euro and Old
    World decent look first back home, identify
    with events, history there. After all, that is from
    where they root.
    They have no other working frame of reference.
    Events outside that context get ignored, hard to
    identify with, remain periphery to what’s
    happening back in the Old World, or interpreting
    it all through the Old World point of view
    (which really lets a lot of people off the hook of
    thinking about things because their Frame of
    Reference calls politics and social problems as
    someone else’s responsibility).

    The Old World generates no real look into itself
    except to keep on doing what it does: Old World.
    It’s materialist, power oriented, tolerating of
    violence and war.
    It has no self-correct.
    It is top down through all its institutions from
    economics to social relations, politics and
    That teaching, the Social Conditioning,
    which creates Frame of Reference, begins early
    on, of course, and is supplemented by the Media
    which reinforces a Frame of Reference suiting
    its interests, not truth or inquiry, examination
    and discussion, no, but respect for authority and top down decision making.

    Maturation is a biochemical process, sure,
    but mostly it is a social one.

  6. Sybil Barker on August 24, 2009 3:20 pm

    Very impressive, Andrew. A lot of stimulating ideas.

  7. Leo Burke on September 13, 2009 7:39 pm

    Your scholarship is impressive. Two brief comments on external factors that appear to impact human hormones regulation.

    1. The Midwest uses 80,000,000 pounds of the herbicide atrazine a year. This toxin is made by Syngenta, a Swiss chemical company. (Atrazine is banned in the European Union.) It is the number one contaminant found in groundwater. And studies at the University of California have shown that it changes the sexual characteristics of frogs and fish.

    2. The SAD (Standard American Diet) is a leading cause of ever-increasing rates cancer, heart disease, diabetes, and stroke. Massive amounts of growth hormones (and antibiotics) are fed to factory-farm animals. Ronald McDonald is messing with our endocrinology!

  8. Seeking a Pathway | Neoteny, sexual selection, cause of autism, human evolution, social transformation, left organizing and internet activism - how they all connect on November 27, 2009 8:38 am

    […] Those folks reading this entry who have been more or less following along on this blog journey, please tell me in the comments below which parts of this thesis you’ve found most interesting.  What I’m thinking at this point is that a new introduction would begin with the last big piece that fell into place, the discovery that estrogen may be what manages the timing of maturation.  That seemed to communicate fairly well when I wrote people this piece. […]

  9. asperger's on November 9, 2011 9:28 am


    […]Autism, estrogen and evolution | Neoteny, sexual selection, cause of autism, human evolution, social transformation, left organizing and internet activism – how they all connect[…]…

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