PubMed


New Explanation of Menopause
Androgens in Leigh Disease
Mitochondrial Eve, Y Chromosome Adam, Testosterone and Human Evolution
Rivista di Biologia / Biology Forum 2002; 95: 319-326
 
Human Evolution in Modern Society (from 2000) with new support
Arch Sex Behav. 1978 May;7(3):157-73.        

Plasma testosterone level and sexual behavior of couples.

Persky H, Lief HI, Strauss D, Miller WR, O'Brien CP.

Eleven couples, ages 21-31 years and married for at least 1 year, were studied intensively over a three menstrual cycle period from both an endocrine and a sexual behavioral standpoint. Each subject was interviewed individually and had a blood sample drawn twice weekly. Interviews were rated independently by two psychiatrists for degree of sexual initiation, responsivity, avoidance, couple interaction, and mood. Wives rated themselves also for degree of sexual gratification (responsivity). Plasma levels of testosterone and cortisol were determined for both husbands and wives while progesterone and estradiol levels were determined additionally for wives. Husband's initiation scores were significantly correlated with their wives responsivity (clinically rated) scores for 10 of the 11 couples; wives' initiation scores were significantly related to their husband's responsivity scores for 8 of the 11 couples. When either set of correlation coefficients was treated as a new variable and intercorrelated with the husband's average testosterone levels, a significant relationship was obtained. Intercourse frequency, while not related to either partner's average testosterone levels, was related to wives' testosterone levels at their ovulatory peaks. The wivess' self-rated gratification scores correlated significantly with their own plasma testosterone levels. Inspection of each wife's plasma testosterone profile across the three cycles indicated that a dichotomy coccurred, with some women showing a high baseline level and others showing a low baseline level. When wives were dichotomized on this basis, it was found that high baseline testosterone level was significantly related to high self-rated gratification score and to ability to form good interpersonal relationships.
 
"Myosin Isoform Mutations" and "Androgens in Human Evolution"
“Androgens...,” DHEA, Mitochondrial Gene ATP6, and Leigh's Syndrome
 
Behavioral and hormonal responses of men to brief interactions with women
 
This study tested for behavioral and hormonal reactions of young men to brief social encounters with potential mating partners. Male college students were randomly assigned to engage in a short conversation with either a young man (male condition) or a young woman (female condition). Participants provided saliva samples before and after the conversation, completed a battery of psychological measures after the interaction, and had their behavior rated by their conversation partners. Salivary testosterone (T) increased significantly over baseline levels in the female condition only, though differences between conditions were not significant. In addition, change in T was significantly correlated with the degree to which the female confederates thought the male participants were trying to impress them. These behavioral ratings, in turn, were correlated with the participants' ratings of the female confederates as potential romantic partners. Results were generally consistent with the hypothesis that human males may exhibit a behavioral and endocrine courtship response that is similar to that observed in males of many nonhuman vertebrate species.”
 
Evolution and Human Behavior 2003; 24: 365-375
“Testosterone and changes in T [testosterone] were significantly related to the timing of subsequent transition to first coitus [adolescent females] for blacks and whites.”
 
Psychosomatic Medicine 1997; 59: 161-171
“This study provides further evidence that when conception is most likely, females [women] prefer testosterone-related facial characteristics...”
 
Evolution and Human Behavior 1999;  21: 39-48
 
 
“These results extend the observation of a midcycle peak in serum testosterone [in women] to saliva ...”  [Is this why we kiss?]
 
Hormone Research 1992; 37: 132-6

“Effect of injection of testosterone derivatives to pregnant rats on the brain of their one-day offspring” B.Y.Ryzhavskii
 
“Intramuscular injection of Sustanon-250, a drug with testosterone derivatives of various action rate and duration, to rats on day 19 of gestation affected brain development in their offspring. This effect manifested in greater brain weight and neocortex thickness, smaller density of neurons in the developing cortical layer V, and larger size of these neurons and their nuclei and cytoplasm in comparison with control neonatal rats. These data attest to accelerated cerebral development in the offspring of experimental rats in comparison [to] offspring of control rats.”
 
Bulletin of Experimental Biology and Medicine 2002; 134: 509-11
 
Possible Common Mechanisms of Macroevolution and Microevolution
Mutations, Testosterone and Human Evolution
Original Theory of Human Evolution
(Extends "Androgens in Human Evolution.")
Evolution of Skin Color
Pecking Order
Hormones in Mammalian Evolution
Rivista di Biologia / Biology Forum 2001; 94: 177-184
Evolution of the Chin
Evolution of Placental Animals and Enlarged Brains
Evolution of Eukaryotes, Crossing Over and Sex
Androgens in Human Evolution. A New Explanation of Human Evolution
Rivista di Biologia / Biology Forum 2001; 94: 345-362  (If you read this publication, please examine the chart and the studies at right, which provide direct support.)  Contains explanation of early puberty in Neandertals which is reported as "new" in Nature, 2004.
Evolution