Friday, August 19, 2005

Ancient faces brought to life

I'm intrigued when scientists/artists are able to recreate the faces of the past:
"It has always been Nguyen Van Viet’s dream to recreate the faces, and lives, of ancient people. After years of study abroad and hard work, Viet and his colleagues finally have a place in the sun with the recent Dong Xa excavation, which revealed a tomb with 20 2,000-year-old skeletons from three different races."

On Sex, Fertility & Motherhood

Catallaxy is blogging about an opinion article in the Sydney Morning Herald "In praise of female sexuality." It's ironic that the poster and all the commenters are male, so I thought a working mother should chime in with an opinion.

(1) Why does a woman have to choose exclusively motherhood or a career? Especially when a man is not required to make this choice? Are we that bound by biology that simply having a uterus means that if I want to procreate that I must spend 24/7 caring for my child and do nothing else? That no other caregivers will do? There's been plenty of studies about the good that daycare can do for children, the good that daddy-care can do, and the good that can come of children seeing their mothers achieve something outside of the home. It's high time that men pitch in -- and not just with supplying income. It's time that both parents forge a balance between family and career. This may mean an adjusting of society in the future. I can only hope so.

In the journal Brain and Mind (vol. 3, 2002, p. 79-100) Dr. Bruce D. Perry wrote the article "Childhood Experience and the Expression of Genetic Potential: What Childhood Neglect Tells Us About Nature and Nurture" where he says:
"For more than 90 percent of human history we have lived in bands, clans or extended families of roughly 40 persons. In the West, by 1500 the average household had decreased to 20 persons; by 1850 to ten; in the United States to less than three persons in the average American household by 2000.

"Our brain evolved over hundreds of thousands of generations in hominid and pre-hominid social groups. In these small hunter-gatherer bands a complex interactive dynamic socio-emotional environment provided the experiences for the developing child. At equilibrium in a group of fifty, there were three or more adult caregiving adults for every dependent child under age six. And there was little privacy. A dependent child grew up in the presence of the elderly, siblings, adults — related and not. There was a more continuous exposure and wider variety of socio-emotional interactions. The child in this situation had many opportunities to form relationships and, in a use-dependent way, develop the capacity to have a rich array of relationships. The genetic potential for healthy socio-emotional functioning — to be empathic, to share, to invest in the welfare of the community —is better expressed in children living in hunter-gatherer bands or extended families or close-knit communities in comparison with our compartmentalized modern world." (Read the entire article here, or read a Science News article on a similar topic here.)

Childcare has been shared for eons. The present notion of a mother being the only caregiver is not how our brains are wired.

(2) The SMH article cites prime fertility for females between the ages of 17-23. While men don't have a fertility peak, they do have a sexual peak in their early twenties and it's well-known that women don't hit their sexual peak until around 35. Certainly, it's true that while sperm quality or quantity may not wain with age in the healthy male, the ability to ejaculate does change with age and vascular deterioration. What this comes down to is that hormonally both sexes are primed for procreation in their late teens and early twenties. However, there are all sorts of other medical problems for mother and baby associated with teenage pregnancy. So, even if the ovaries are primed to procreate before age 20, other parts of a woman's body aren't ready at all and can actually be detrimental to life. This dicotomy means that biology isn't everything. Older parents are more patient and concentrate more of their time willingly to parenting because they've already experienced having a career.

Certainly having parents who want to be parents, and have the maturity and the income to support children, are advantages that outweigh any biological clock ticking.

Thursday, August 18, 2005

Geek Girl Musings

My friend Mara over at Knitting Obsession posted a link to a New York Times article called "The Male Condition" by Simon Baron-Cohen, which speaks to brain scans being used to study gender differences and how it might relate to autism. Specifically, it talks about how levels of prenatal testosterone affect fetal brains. Mara wonders if she falls into the 17% of women who have a "male brain," and I'm wondering the same thing about myself. The study broke participants down into three categories based on their score on the Systemizing vs. Empathizing spectrum -- Type E were those who tested high for empathy, Type S were for those who tested high on systemizing and Type B were those who tested equally in both areas.

Like my friend, I like being female, but my interests have always leaned toward typically male interests (yes, I played with Barbies, but she stole G.I. Joe's gun and went on her own missions). Even today, I make my living designing and programming web sites. Prior to that I worked in television behind the camera. I had much more fun running cables and lugging around equipment than I ever did as on-air talent. However, like many women I have a well-developed sense of language. I have, in fact, written two novels. Though unpublished, the sheer ability to write 180,000 words coherently means an above average ability with language. So, I don't know if this ability is a mild obession with a language system (see Baron-Cohen's theory on autism and obsessions with systems), or if it's having a typical female brain with thicker connective tissue between hemispheres granting better facility with language. Or pehaps my ability to perform activities that require both sides of the brain to work together (both web design and writing involve simultaneous use of the creative and systemic thinking modes), means that I fall into the Type B category.

(On the language front, I should disclose that my grandfather spoke five languages and my father speaks two, so perhaps it's just lucky genetics.)

I do have a tendency to concentrate on one particular thing at time -- I listen to a CD and only that CD in the car until I get sick of it; I find an author that I like and read all of her novels in a row; I continually obsess about this blog. . . I don't enjoy multi-tasking, but can do it when required of me. I always chocked it up to just having a one-track mind, a simple personality quirk, but maybe it's not. Hmm. Or maybe I'm just an original.

Tuesday, August 16, 2005

Straight Talk About Gays

Gene Expression has a post titled "More Fodder for the SPLC and James Dobson" on two articles about research into the biological underpinnings of homosexuality. The Boston Globe article "What Makes People Gay?" mentioned in the blog entry does a nice job of summarizing the various studies that have been done and in the end decides that there's definitely a biological/nature factor.

The big problem with positing that homosexuality is driven by genetic factors is how is it not eliminated by Natural Selection? The author brings up baseless suppositions that homosexuality is caused by a virus, and gleans over other explanations that cite compensatory benefits.

Leonard Shlain in his book Sex, Time and Power thinks maybe the main benefit to having a homosexual male in a hunter/gatherer family is the extra meat he brings in that he doesn't have to share with a mate or children -- in that case he'd most likely share it with a sister and her children. A similar benefit with lesbianism is that without children of her own she'd be free to help her siblings with their children. Shlain says (pg. 241):
"Although poorly understood, selective pressures in the human species have ensured gay behavior in every generation and in every culture. [Homosexuality's] ubiquity suggests that it is a very old trait and was likely present at the dawn of our species. Perhaps this unique development arose from the need to enhance the survival of a primate species that had precipitously switched its diet from roots and shoots to haunches and hamhocks in order to provision burdened mothers and their children with intelligence-enhancing brain food. The insertion of [homosexuals] into the human genome was one of four adaptations that Natural Selection cleverly slipped in among the chromosomes to assist newly minted Homo sapiens hunter in his deadly competition with other species for survival. A dollop of the same mysterious formula was also ladled into Gyna sapiens chromosomal potpourri, so that lesbians would also be mixed into each generation. . . I shall call my thesis the Theory of Eights. Four unique human traits appear in any given Homo sapiens population, and each one uncannily hovers around the stable level of 8 percent of the males. The four are [homosexuality], color-blindness, left-handedness, and baldness. Eight percent roughly equals about one out of twelve men. I believe that these four traits taken together represent a constellation of genetic adaptations that enhanced the success of the original human male hunting band."

Now, Shlain isn't an evolutionary biologist (he's the chief of laparoscopic surgery at California-Pacific Medical Center in San Francisco) and I don't know how you could test this hypothesis. However, I like this theory because it provides an explanation for homosexuality without claiming that it's some kind of malformation, problem with embryonic development or some other way abnormal. I'd also like to check his 8 percent number for the occurence of color-blindness, left-handedness and baldness.