jvkohl
09-12-2006, 08:24 PM
Citation
at
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16788900&dopt=Citation[/ur
l]
Public release date: 11-Sep-2006
Contact: Amitabh
Avasthi
axa47@psu.edu
814-865-9481
Penn State
Chemical cues from fathers may be
delaying the onset of sexual maturity in daughters, as part of an evolutionary strategy to prevent inbreeding,
according to researchers at Penn State.
"Biological fathers send out inhibitory chemical signals to their
daughters," said Robert Matchock, assistant professor of psychology at Penn State's Altoona Campus. "In the absence
of these signals, girls tend to sexually mature earlier."
The effect of chemical cues on sexual maturity is
common in the animal world, Matchock explained. If the biological father is removed from rodent families, the
daughters tend to mature faster, he said.
"Recently, experts elsewhere discovered a little-known pheromone
receptor gene in the human olfactory system, linking the role of pheromones on menarche, or the first occurrence of
menstruation," said Matchock, whose findings are published in the recent issue of the American Journal of Human
Biology.
Researchers, including Elizabeth Susman, the Jean Phillips Shibley professor of biobehavioral health
at Penn State, collected menarcheal data from 1,938 college students to explore the link between girls' social
environment and their sexual maturity. The data included information on factors such as the girls' family size,
social environment, and how long the father had been absent.
"Our results indicate that girls without fathers
matured approximately three months before girls whose fathers were present," Matchock said, adding that the data
seem to suggest a relationship between length of the father's absence and age of menarche – the earlier the
absence, the earlier the menarche.
Results from the study additionally suggest that the presence of half and
step-brothers was also linked to earlier menarche. Girls living in an urban environment also had earlier menarche
compared to girls in a rural environment, even when fathers were present for both groups, and had similar levels of
education.
Matchock speculates that urban environments provide greater opportunities to get away from
parents' inhibitory pheromones, and encounter attracting pheromones from unrelated members of the opposite
sex.
"It is possible that a stimulating urban environment can negate suppressive cues from parents," he
added.
Taken together, the Penn State researcher says the study is not a human anomaly but an explanation of
how pheromonal cues modulate sexual maturity, to enhance mating and prevent inbreeding.
"Prevention of
inbreeding is so crucial to successfully spread healthy genes that anti-inbreeding strategies such as the use of
pheromones seem to be conserved across species," he
added.
-----------------------------------------------------------
Quote from the journal article's
conclusion:
" We believe that, taken together, a more parsimonious explanation of the data is that pheromonal
cues modulate sexual maturity so as to enhance mating and prevent inbreeding (Table 2). The father absence-early
menarche finding is not just a human anomaly that can be forced into, and explained by, psychological theories. The
prevention of inbreeding is so paramount to the successful propagation of healthy genes that anti-inbreeding
behaviors and changes in reproductive physiology appear to be highly conserved across species. That is, parents
suppress reproduction of their offspring."
JVK
[url]
at
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16788900&dopt=Citation[/ur
l]
Public release date: 11-Sep-2006
Contact: Amitabh
Avasthi
axa47@psu.edu
814-865-9481
Penn State
Chemical cues from fathers may be
delaying the onset of sexual maturity in daughters, as part of an evolutionary strategy to prevent inbreeding,
according to researchers at Penn State.
"Biological fathers send out inhibitory chemical signals to their
daughters," said Robert Matchock, assistant professor of psychology at Penn State's Altoona Campus. "In the absence
of these signals, girls tend to sexually mature earlier."
The effect of chemical cues on sexual maturity is
common in the animal world, Matchock explained. If the biological father is removed from rodent families, the
daughters tend to mature faster, he said.
"Recently, experts elsewhere discovered a little-known pheromone
receptor gene in the human olfactory system, linking the role of pheromones on menarche, or the first occurrence of
menstruation," said Matchock, whose findings are published in the recent issue of the American Journal of Human
Biology.
Researchers, including Elizabeth Susman, the Jean Phillips Shibley professor of biobehavioral health
at Penn State, collected menarcheal data from 1,938 college students to explore the link between girls' social
environment and their sexual maturity. The data included information on factors such as the girls' family size,
social environment, and how long the father had been absent.
"Our results indicate that girls without fathers
matured approximately three months before girls whose fathers were present," Matchock said, adding that the data
seem to suggest a relationship between length of the father's absence and age of menarche – the earlier the
absence, the earlier the menarche.
Results from the study additionally suggest that the presence of half and
step-brothers was also linked to earlier menarche. Girls living in an urban environment also had earlier menarche
compared to girls in a rural environment, even when fathers were present for both groups, and had similar levels of
education.
Matchock speculates that urban environments provide greater opportunities to get away from
parents' inhibitory pheromones, and encounter attracting pheromones from unrelated members of the opposite
sex.
"It is possible that a stimulating urban environment can negate suppressive cues from parents," he
added.
Taken together, the Penn State researcher says the study is not a human anomaly but an explanation of
how pheromonal cues modulate sexual maturity, to enhance mating and prevent inbreeding.
"Prevention of
inbreeding is so crucial to successfully spread healthy genes that anti-inbreeding strategies such as the use of
pheromones seem to be conserved across species," he
added.
-----------------------------------------------------------
Quote from the journal article's
conclusion:
" We believe that, taken together, a more parsimonious explanation of the data is that pheromonal
cues modulate sexual maturity so as to enhance mating and prevent inbreeding (Table 2). The father absence-early
menarche finding is not just a human anomaly that can be forced into, and explained by, psychological theories. The
prevention of inbreeding is so paramount to the successful propagation of healthy genes that anti-inbreeding
behaviors and changes in reproductive physiology appear to be highly conserved across species. That is, parents
suppress reproduction of their offspring."
JVK
[url]