Showing posts with label natural sex. Show all posts
Showing posts with label natural sex. Show all posts

Monday, 9 January 2012

New Scientist: Fish that change sex – and back again

At  New Scientist, "Zoologger" has a post up on the transsexual abilities of the hawkfish (species Cirrhitichthys falco), which is found off Kuchino-Erabu Island in southern Japan. As the post notes, transitioning in fish occurs in many species - but this one reverses the process. (Even this ability is not unique though - see Joan Roughgarden, " Evolution's Rainbow ").


Transgender fish perform reverse sex flip

When it comes to selecting mates, hawkfish keep their options open. The flamboyantly coloured reef dwellers start life as females but can transform into males after maturing. Many marine animals do this, but these fickle fish have a rare trick up their fins: they can change back when the situation suits.

Tatsuru Kadota and colleagues from Hiroshima University in Higashi-Hiroshima, Japan, have observed reverse sex changes in wild hawkfish for the first time in the subtropical reefs around Kuchino-Erabu Island in southern Japan.

Hawkfish live in harems, with one dominant male mating with several females. Kadota's team studied 29 hawkfish and found that when it comes to sex change, the size of the harem matters.

If a male hawkfish took on many females, one of the two largest females would change sex and take over half of the harem, mating as a male. Conversely, if that new male hawkfish lost a few females to other harems and was challenged by a larger male, it reverted to mating as a female, instead of wasting precious energy fighting a losing battle. "The ability to undergo bidirectional sex change maximises an individual's reproductive value," Kadota says.

- read the full article at  Zoologger /New Scientist,06 January 2012 .

Footnote:

A reader, Mario, has shared a link to a fascinating story about a domestic hen that transitioned to a cockerel, after an injury. I've known about transitioning in fish species for years, but this is the first time I've come across an instance in birds.

Thanks, Mario.

Books:

Bagemihl, Bruce: Biological Exuberance: Animal Homosexuality and Natural Diversity

Roughgarden, Joan: Evolution's Rainbow: Diversity, Gender, and Sexuality in Nature and People,


 
Enhanced by Zemanta

New Scientist: Fish that change sex - and back again

At  New Scientist, "Zoologger" has a post up on the transsexual abilities of the hawkfish (species Cirrhitichthys falco), which is found off Kuchino-Erabu Island in southern Japan. As the post notes, transitioning in fish occurs in many species - but this one reverses the process. (Even this ability is not unique though - see Joan Roughgarden, " Evolution's Rainbow"). 

Transgender fish perform reverse sex flip

When it comes to selecting mates, hawkfish keep their options open. The flamboyantly coloured reef dwellers start life as females but can transform into males after maturing. Many marine animals do this, but these fickle fish have a rare trick up their fins: they can change back when the situation suits.
Tatsuru Kadota and colleagues from Hiroshima University in Higashi-Hiroshima, Japan, have observed reverse sex changes in wild hawkfish for the first time in the subtropical reefs around Kuchino-Erabu Island in southern Japan.
Hawkfish live in harems, with one dominant male mating with several females. Kadota's team studied 29 hawkfish and found that when it comes to sex change, the size of the harem matters.
If a male hawkfish took on many females, one of the two largest females would change sex and take over half of the harem, mating as a male. Conversely, if that new male hawkfish lost a few females to other harems and was challenged by a larger male, it reverted to mating as a female, instead of wasting precious energy fighting a losing battle. "The ability to undergo bidirectional sex change maximises an individual's reproductive value," Kadota says.
- read the full article at Zoologger /New Scientist,06 January 2012 .
Books:


Enhanced by Zemanta

Friday, 26 August 2011

Aquinas, "Nature" - and Sex.

Thomas Aquinas and Natural Law are often trotted out by the rule-book Catholics alongside the half-dozen clobber texts as a supposed justification for denying respect and equality to sexual minorities. I have absolutely no expertise in Thomist theology, but was intrigued by this observation, in a longer article ("The Other Side of the Catholic Tradition"), at the Washington Post.

Thomas Aquinas, who followed a century after Hildegard, wrote commentaries on 10 works by the greatest scientist of his day, Aristotle, even though the pope had forbidden Christians to study Aristotle. So controversial was Aquinas in his day that the king of France had to call out his troops to surround the convent where Aquinas lived to protect him from Christians aroused by fundamentalist clergy. For Aquinas, “revelation comes in two books—the Bible and Nature” and “a mistake about nature results in a mistake about God.” Aquinas insisted that one is always responsible to one’s conscience, more than to any other authority (emphasis added).

Thursday, 12 August 2010

Natural Law, Natural Sex, Natural Families.

A favourite argument used by the religious right against homoerotic relationships, and by the Vatican theologians against any form of sexual expression outside of marriage and not open to making babies, is that such sexual activities are "against nature", and that the "purpose" of sex is procreation. Well, the people making these claims have never considered the actual evidence from, well, you know - "Nature" itself, which shows the exact opposite.  In a famous exchange, Anita Bryant once remarked that the things that homosexuals do were so disgusting that "even barnyard animals wouldn't do it." When it was pointed out to her that actually, barnyard and other animals do "do it",  as is well known to farmers, she simply replied, "Well that still don't make it right". No, and it don't make it wrong, either.  On sexual ethics, "Nature" is morally neutral.

"Anita Bryant, Reality Denier"


Some time ago I embarked on an investigation (which still continues) into just what we can learn from "nature" about sexuality and natural sex, reading up on sexual practices as observed in the animal kingdom, and also in non-Western and pre-industrial human societies from different periods and geographic regions. The results have been truly bewildering, and the time has come to share with you some of my findings and conclusions. In particular, there is clearly no single pattern of sexuality that can possibly be described as "natural" in all societies, human or animal.  What is "natural" depends entirely on culturally determined social practices, which vary extraordinarily.

In modern Western debates about gay marriage, we often hear arguments about "traditional" marriage, as based on the Bible, or on "Judaeo-Christian values". The Biblical family was headed by a male patriarch, who controlled an assortment of wives, concubines, children and slaves, as well as his adult sons and their wives.
We commonly assume that most people are either "heterosexual" (the majority) or "homosexual" in orientation. But in many societies, men may be engage in sex with both men and women, either sequentially, at different phases of their lives, or at the same time. (In Chinese culture, there has always been powerful social expectations that men should marry and raise children - but that in no way prevents them taking male lovers as well. In a famous Chinese painting, two men are engaged in erotic play, while the wife of one watches from behind a screen. )




We assume that in a "traditional" family, the husband is male, the "wife" is female. In many traditional African cultures, numerous ethnographic studies have shown that the "husband" is the one with the wealth and the power. Where a woman was able to acquire sufficient wealth and could pay the bride-price, it was entirely acceptable for her  to marry wives, and take on the role of "husband". (In these families, procreation and child-bearing were necessarily arranged outside of the family - but were raised inside it, and recognised the female head of the family as "father". In one remarkable instance, Nzinga was a woman who came to the throne by military skill - but only men could be kings, so necessarily she was accepted as male. As king, she required a harem of wives - but as she was entirely heterosexual in orientation, she had no need of female wives, and instead kept a harem of male wives.(“Africa’s Female Kings and husbands”). Elsewhere in Africa, some wealthy men also included a male or two among their wives, valuing their strength for certain household tasks.

Nor do all cultures think only in terms of two genders. Commonly in South Asia, North America, and in some parts of Africa, societies accepted as a distinctive third gender biological males who took on female roles, or females who took on male roles (possibly but not necessarily included the corresponding sexual roles.) In the animal kingdom, especially among fish, there are many species with more than one gender, or where the physical appearances of some biologically male individual males resembles that of females or vice versa, or where individuals quite literally change biological sex, in an animal counterpart to human cross-dressers and transsexuals.

We also tend to assume that same sex interactions, where they occur, apply to a minority of individuals, or to a relatively brief period in their youths, before settling down to "normal" married life. But in some New Guinea societies, "natural" sex requires that as young boys, they first go through a period whereby they act as recipient partners in sex with older boys, because it is believed that the essence of manly virtue is contained in the semen - which they need ingest in regular doses before they can become real men. As they grow older, they adopt the active role in sex with younger boys, completely avoiding heterosexual intercourse until they are strong and manly enough to withstand the "debilitating" effects of women that they will be exposed to in marriage. In one specific group, the combined period of partnership with males typically lasts about thirty years, before he marries at around forty. In this culture, homosexual sex is certainly a far greater portion of a man's life-long sexual experience than heterosexual experiences. For them, it is homosexual actions that are "natural".

The Vatican claims that homosexual "act" lead people away from God.  Many societies take the exact opposite view, believing that "homosexuals" generally, and the third gender exemplars in particular, have extraordinary spiritual gifts. Frequently, it is they who will take on the roles of religious leaders or spiritual guides. (Is it any surprise that a disproportionately high proportion of Catholic and Anglican priests are believed to be gay?) In some places, this association of spirituality and male-male sex combines with a variant of the New Guinea practice - young men become  sexual partners of religious leaders in order to ingest their spiritual wisdom.

We also often equate “masculine”, macho virtues with heterosexuality, and homosexuality with effeminacy. Among both humans and animals, this is not always so. For the ancient Greeks, the Japanese samurai, and many others, homosexuality was especially associated with the military. There have been times even in European history where “effeminate” dandyism was characteristic of rampant heterosexuality. Among bighorn sheep, most rams are exclusively homosexual in their activities, and the few that have heterosexual intercourse display remarkable submissive, behaviour – that in humans we might describe as “wimpish”.

It is also simply not true that in the natural world, even heterosexual sex is exclusively directed at procreation. Non procreative sexual activity is commonplace, including full intercourse during pregnancy, immediately after giving birth, or outside fertile periods Some primates females reaching sexual maturity, and begin sexual activities, several years before becoming fertile and capable of giving birth. Also common are  mounting behaviour without penetration or ejaculation, oral sex and masturbation (alone or with another). Some animals even make dildos and masturbation aids – or use natural objects for the purpose.

So what is the “purpose” of sex in nature?

Writing about Bonobo Chimps, Joan Roughgarden puts it neatly, in describing "at least six" situations that lead to sex :
    1. Sex facilitates sharing (for example, reducing conflicts over food supplies)
    2. Sex is used for reconciliation after a dispute
    3. Sex helps to integrate new arrivals into a group
    4. Sex helps to form coalitions
    5. Sex is candy - females sometimes barter sexual favours to obtain gifts of food from males
    6. "Oh, I almost forgot - sex is used for reproduction"
              Recognising the diversity of sexual and gender expressions in “nature” is not a licence for a code of “anything goes”. There still remains a need for a coherent system of sexual ethics, but the study of “nature” does not help us to find one. There simply is no sexual “law of nature”. To construct sexual ethics, we must look elsewhere.

              See Also:





              Gay Soldiers? Role Models, at the Foundation of Democracy.

              Gays in the Military: Japan


              Animals Use Sex Toys, Too

              Same Sex Parents, Furred and Feathered

              Natural Law, Laysan’s Albatross,  and the Question of Evidence

              The Wildlife Rainbow

              Queer Bonobos: Sex As Conflict Resolution

              Exclusive Heterosexuality Unnatural?

              Bighorn Rams: Macho Homos, Wimpish Heteros


              Books:

              Bagemihl, Bruce: Biological Exuberance: Animal Homosexuality and Natural Diversity (Stonewall Inn Editions)

              Crompton, Louis: Homosexuality and Civilization

              Naphy, William G: Born to be Gay: A History of Homosexuality (Revealing History)

              Roughgarden, Joan: Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People

              Sommer, Volker and Vasey, Paul: Homosexual Behaviour in Animals: An Evolutionary Perspective