testosterone levels humans great apes
The Secular Trend in America ...and Elsewhere. This is What will really affect us!
"A syndrome is occurring in America and other countries, the cause of which is often attributed to one part or another of the syndrome, itself, and more often attributed to the environment or life style.  I suggest a single cause may be involved that is biological and evidence of ongoing evolution.  The cause may be increased exposure to maternal testosterone within the population with time.  This increase in testosterone produces a decline in dehydroepiandrosterone (DHEA) because testosterone interfere with steroid sulfatase.  If the precursor of DHEA, DHEAS, is not converted to DHEA, DHEA availability is reduced.  It is the reduction in DHEA that is the basis of these problems.  High DHEAS is often found with high testosterone.  A consequence of this is reduced availability of DHEA (just above) and an earlier decline in the production of DHEA during the life span.  This produces increased morbidity during life as well as earlier mortality.

It is my hypothesis that the "secular trend," the increase in size and earlier puberty occurring in children, is caused by an increase in the percentage of individuals of higher testosterone. More specifically, I suggest this is due to an increase in the percentage of mothers of higher testosterone with time within the population. This exposes more fetuses to increased maternal testosterone with time within the population. This causes permanent effects in the fetus which persist throughout the life span.  I suggest this is the cause of the parallel increases in morbidity occurring within the population, such as increased infection rates, autism, obesity, hypertension, chronic obstructive pulmonary disease (COPD), cancer, breast cancer, diabetes, the metabolic syndrome, etc., including prematurity, small for gestational age, etc., including less obvious gross effects which later contribute to "failing schools" and other adverse behavioral outcomes in children.  This includes the new (August,2011) finding of Dr. Kyung Hee Kim of The College of William and Mary that "creativity" is also declining in children.  This could also explain the increase in negative pregnancy outcomes, re: the increase in the increasing "newborn death rate" in the United States.
I have come to the conclusion that the "increase in testosterone" may partially be due to a reduction in "sex hormone binding globulin (SHBG)" as a number of phenomena explained by the secular trend may be based on changes in SHBG.   A decrease in SHBG increases free testosterone levels.  Low SHBG has been found in obese children who do not produce excessive testosterone.  A number of negative phenomena which may be caused by increased testosterone are found with low SHBG and a number of positive effects of reduced SHBG exist.
It is my hypothesis that human evolution is driven by increases in testosterone ("Androgens in Human Evolution," Rivista di Biologia / Biology Forum 2001; 94: 345-362).  This was directly supported by research in 2003; see the chart of testosterone levels in humans and related great apes, upper left at www.anthropogeny.com .  I suggest that periodically testosterone increases excessively and the exposure to excessive maternal testosterone causes negative and evolutionarily consequential changes to the human population.  We may be experiencing this effect at this time.
I suggest this increase in testosterone in the population peaks earlier with time.  This earlier peak may produce an earlier decrease in the population with aging.  A number of studies reported in the medical literature have identified low testosterone as a cause of currently increasing disorders.  Therefore, the secular trend may be causing increased morbidity and mortality as a result of excessive testosterone and low testosterone within the population.  Therefore, earlier reductions in testosterone and DHEA could be occuring simultaneously, therefore, reducing the total positive effects of these two major androgens.  This could be the explanation of the severe increase in morbidity that is occurring.  Evolution is increasing earlier reproductive capacity at the expense of post-reproductive years.  The curve of the peak of our androgens is being "skewed to the left."
As I have said before, I think women of higher testosterone drive the secular trend / human evolution.  I suggest these women produce the highest percentage of premature infants. It has been reported that "preterm boys" exhibit increased testosterone and the effects of increased testosterone compared to "full term boys" (J Clin Endocrinol Metab 2010, "Increased Activity of the Hypothalamic-Pituitary-Testicular Axis in Infancy Results in Increased Androgen Action in Premature Boys.," Kuiri-Hanninen, et al., J Clin Endocrinol Metab. 2011 Jan;96(1):98-105). What this means is that the population is increasing in women of higher testosterone and this group of women may also be increasing the percentage of men of higher testosterone simultaneously. This could explain why this "secular trend" can increase so rapidly. This mechanism could expand the percentage of these individuals within a population rapidly and drive human evolution.

For a more detailed explanation of the interaction of testosterone and dehydroepiandrosterone (DHEA) and the importance of these androgens to the secular trend: “ DHEA, Estradiol, Testosterone, and the Relevance of Their Ratio …The Androgen Receptor …and the Secular Trend,” at: http://anthropogeny.com/Androgen%20Receptor%20and%20Secular%20Trend.htm .)

This research directly supports my explanation of human evolution.
My explanation of cancer suggests high testosterone and low DHEA are involved.  Humans have high testosterone and low DHEA, compared to other primates.  This may explain why humans have more cancer.  Also, as we age, DHEA declines.  This may explain why cancer increases in old age. 
 My explanation of:


...what it is and when and where it exists in the literature and the internet. 
I suggest the occurrence of many diseases is dependent upon the decline of DHEA which begins around 20-25 years of age and reaches very low levels in old age.  Also, it follows from my work, that many problems that are increasing with time in the United States and in the world are resulting from the "secular trend," which I suggest is due to the increase in percentages of individuals of higher testosterone and the negative effect that testosterone exerts on the availability of DHEA.  Disturbances in "dehydroepiandrosterone homeostasis" may be a significant source of morbidity and mortality.
(Copyright 2003, James Michael Howard, Fayetteville, Arkansas, U.S.A.)
it is like a wall...
it is like a snake
Copyright 1985-2014 James Michael Howard, Fayetteville, Arkansas, U.S.A.  All rights reserved.
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Modern applications extends my work to modern humans.  “Modern humans” is a very broad area since it includes Homo sapiens from our origin in Africa through today.  Human evolution is ongoing and identifiable within current populations.
New Ideas and Research contains current research of relevance to this site.  This includes applications of my work to new research.  These explanations will both extend and revise my past work.  These interpretations will be moved to the other sections below as necessary.
Physiology and Pathology is the broadest category.  This area contains many aspects of growth, development, and aging, as well as significant deviations from normal.  This concerns our individual lives or ontogeny.
Evolution  includes an examination of evolution primarily concerned with human phylogeny.  This extends from evolution of eukaryotic organisms to humans.
The Impact of Dehydroepiandrosterone (DHEA) and Testosterone on Humans
(Read "The Secular Trend" at lower right of this page! DECLINE OF SCHOOLS IS CAUSED BY THE SECULAR TREND, NOT TEACHERS)

This site is intended to disseminate information generated from ongoing work I began in 1984.  Two works were produced in 1985: Evolution of Sociopathy in Western Civilization. A Philosophical Treatise followed by A Theory of the Control of the Ontogeny and Phylogeny of Homo sapiens by the Interaction of Dehydroepiandrosterone and the Amygdala, both copyrighted.  The original focus was narrow.  The scope has rapidly broadened simultaneously with increasing awareness of the explanatory usefulness of the primary ideas.  It is my hypothesis that selection for the androgens, dehydroepiandrosterone and testosterone, is directly linked to human evolution.  Evolution consists of ontogeny and phylogeny.
The information is divided into categories variously dealing with human ontogeny and phylogeny.  Since human ontogeny, the life of the individual, and phylogeny, the life of the species, are interdependent, my divisions are also not exclusive.  These categories are intended only as different entrances to a single explanation of human biology.  There is extensive overlap.  Periodically, new research will be included and discussed below.  (Click on the appropriate category below to access the page.)
(Please do not steal my ideas.  Some universities control their students but not their professors.  If interested, here is MORE.)

Anthropogeny is the study of human ontogeny and phylogeny

I suggest the "cannabinoid receptors" and the androgen / estrogen receptors may be Dehydroepiandrosterone receptors.

A Possible Explanation of Cancer Multidrug Resistance caused by Low Dehydroepiandrosterone / High Prolactin

(Since the beginning of this work, 1984, I have had some difficulty combing some data regarding DHEA with data regarding testosterone.  I now think evolution selected these two androgens, through mammalian and human evolution, to work together in a manner which produces different effects according to their relative ratios.  For a more detailed explanation of the interaction of testosterone and dehydroepiandrosterone (DHEA) and the importance of these androgens to the secular trend: “ DHEA, Estradiol, Testosterone, and the Relevance of Their Ratio …The Androgen Receptor …and the Secular Trend,” at: http://anthropogeny.com/Androgen%20Receptor%20and%20Secular%20Trend.html  .)  Until I am able to apply this to my earlier work, the foregoing reference may apply to some of my hypotheses.)