December 20, 2009

Transgender animals

The third part in a series about sex, gender and nature. In this post I look at the strange world of transgendered animals.

In her book Evolution's Rainbow (2004) Roughgarden has a separate chapter named "Multiple-Gender Families" which really took me by surprise.

I had heard the "Discovery Channel alpha male scaring the others males away" story so many times that I had come to believe that there are only two "genders" in the animal kingdom: male and female.

I need to make a little detour here. "Gender" is often understood to be the "socially constructed roles, behaviours, activities, and attributes that a given society considers appropriate for men and women." (WHO) Hence gender differences are defined by culture, sex differences by biology.

Roughgarden, however, is a biologist - not a social scientist - and in her tradition it is possible to use the word gender to denote the physical basis for the behavioral differences between males and females.

Roughgarden needs the term gender in addition to the term sex, simply because many animals have several variants for one or both of the two sexes!

This came as a total surprise to me. How is it possible than no one has ever told me this extremely important fact before? The answer, of course, is that it does not fit well with the sexual selection theory.

Gender multiplicity

So what does "multiple gendered animals" or "within-sex polymorphism" mean?

Roughgarden explains it this way:

"Males and females in a species may come in two or more sizes or colors. The morphological [pertaining to the form, structure and configuration of an organism] differences are the tip of the iceberg.

"The two morphs [i.e. gender variants of a sex] approach courtship differently, have different numbers of mates, have different arrangements of between-sex and same-sex relationships, live different life spans, prefer different types of real estate for their homes, exercise different degrees of parental care, and so on." (2004, p. 75)

Here are a few examples:

Singing fish

There are hundreds of known fish species that have two distinct types of males. The Californian singing fish (Porichthys notatus), for instance, have one large and one small type of males. The large type defend territories and guard eggs. A large male guards a big collection of eggs laid by several females. The small male defend no territories. They dart in to fertilize eggs laid in the large male's territory. (p. 77)

Male red deer or elk (Cervus elaphus) has a secondary type of males that have no antlers. They may at times be more successful at mating, according to Roughgarden (p. 78).

Three types of male

The North American bluegill sunfish (Lepomis macrochirus) has no less than three male genders, of different sizes and different colors and markings. The large males try to repel the small ones from their territories. The females spawn readily with the small males while the large male is busy with all his chasing (p. 80). The medium sized males may be schooling with the females. Roghgarden continues:
"A medium male approach the territory of a large male from above in the water and descends without agression or hesitation into the large male's territory. The two males then begin a courtship turning that continues for as long as ten minutes. In the end, the medium male joins the large male, sharing the territory that the large male originally made and defends." (p. 80)

A popular way of explaining away this strange phenomenon is to say that the medium male deceives the large one into believing he is a female.

But, as Roughgarden points out, this is the male chauvinist talking. Sunfish have great eyesight, and the medium "feminine" male may be similar to females, but they are not identical.

An alternative theory is that two males may defend the territory in a better way than one, and the females appreciate this.

Roughgarden prefers a third explanation:

"A female might wonder if she will suffer domestic violence from this male who's trying to look big and powerful...Perhaps the courtship between the large male and the medium male offers the female a chance to see how the large male behave with a feminine-looking fish who is slightly smaller than she is." (p. 84)

It gets weirder!

White-throated sparrows (Zonotrichia albicollis) of Ontario have two male and two female genders! In both males and females the white-striped individuals are more aggressive than the tan-striped individuals. Still, they can all find mates.

Not to be outdone the side-blotched lizard (Uta stansburiana) from the American Southwest has three male types and two female.

The flycatcher

Just a few kilometers from where I live now, you will find the pied flycatcher bird (Ficedula hypoleuca). Males vary from striking black and white to brown.

I have taken the liberty of reproducing a Russian drawing of the bird. Note that there is nothing here to signify that this bird violates the rule of having two genders. Indeed, the superiority of the male is displayed by the fact that there are no less than four drawings of the "normal" male, one of the female and none of the "feminine" male.



Roughgarden presents a Norwegian experiment where male flycatchers who had set up territories were presented with individual caged birds to see if they could distinguish the sexes:

"A territory-holding male who hadn't already attracted a female reacted to a female by showing off the entrance to his hole and calling enticingly. When the same male was presented with a macho black-and-white male, he was not so hospitable, and jumped on the cage of the visitor, pecking at it, trying to attack, and not bothering with any welcoming calls. When a feminine brown male was presented, the male again showed off his nest hole and called invitingly." (2004, p. 93)

Note that the research Roughgarden bases this description on argues that "the female-like males gain an advantage because they are in control of when to initiate a fight because of the opponent's poor sex recognition ability." (Sætre and Slagsvold 1995) The masculine male is therefore fooled into believing the feminine male is a peaceful girl. The Norwegian researchers see, as most of their colleagues, violence and deceit, where Roughgarden sees collaboration and the division of labor.

Roughgarden does not believe the male flycatcher is fooled by the feminine male. The problem with deceit theories, she says, is that not only must some animals be implausibly dumb, but others must be remarkably devious. The masculine flycatcher cannot be that stupid, because later in the year they tend to fend the feminine ones off.

"A simpler explanation is that territorial males who have not yet attracted a female are horny and invite romance with feminine males. Once the territorial ['masculine'] males have attracted a female, they are no longer horny and no longer interested in courting a feminine male... These birds may be neighbors building a cooperative relationship based on same-sex attraction." (p. 94-95)

Moreover, it is better for a masculine male to have a feminine "gynomorphic" male as a neighbor, than a much more aggressive masculine one.

Summing up

Many biologists have done their best to ignore this strange phenomenon. But there are just too many of these cases. They require an explanation. The sexual selection theorists therefore argue that the large aggressive territory-holding male gender is "the reference male", i.e. the real thing. The other types are at best considered "alternative mating strategies" and often described as "sexual parasites". They are cheaters.

But where the traditionalists sees conflict and deceit, Roughgarden sees a practical division of labor. Roughgarden says:

"According to social selection, economic theory for the elemental one-male-one-female economic team is extended to larger teams with more 'social niches'." (2009. p. 243.)

In general feminine imagery seems to be adapted by males to reduce hostility and promote friendship (p. 99).

Roughgarden argues that the different genders represent different sectors within a kind of community economy. While some of the genders compete, others are like service providers working under contract. In return for a peaceful behavior and care for the young, they get the opportunity to mate. (p. 105)

Roughgarden argues that markings and colors on animals represents their "body English". This is how animals tell one another what their social role is, what their intentions are, and what activities they promise to perform:

"Feminine males are participating in a conversation on topics and with words used more frequently by females than by masculine males [and visa versa for the masculine females]." (2009, p. 244)

This is why they look more like females.

Now I guess you are all waiting for the punch line: trangender people are like the transgender animals. That is not given. It is definitely hard to argue that most male to female crossdreamers are feminine looking men! My main point with these posts is first and foremost to help us all think outside the box, and to demonstrate how deeply mainstream biology is anchored in traditional gender roles. Still, I will discuss the possibility of trans people being a separate gender in the final post in this series.

Up next: Gay animals!

Litterature:

Roughgarden, Joan: The Genial Gene, Berkeley 2009. Click here for Google Books excerpt.
Roughgarden, Joan: Evolution's Rainbow, Berkeley 2004. Click here for Google Books excerpt.
Susan McCarthy: The fabulous kingdom of gay animals
Nudging Darwin over the rainbow SFGate on Roughgarden

18 comments:

Robyn P said...

I think that all this discussion about transgender animals is largely pointless regarding autogynephilia. It is dangerous to take what happens in the animal kingdom and try to extrapolate to humans and human behavior.

Animals act and react on instinct. They have no choice in what they do. However, we make choices constantly throughout life. We get to think about our choices and we have the ability to make wrong choices...

Robyn

MRAutogynephilia said...

I am in favor of the fact or "theory" that human civilization is much like the animal kingdom. It depends how you want to learn about autogynephilia, if you are interested scientificlly or simplly want to know how it affects you socially. I appreciate jacks scientific studies and am interested in most of them. I try to keep my vlogs striclly about my social expierience. I wont be talking about gay or gender queer birds anytime soon.

Another thing I wanted to say is I havent metor seen pictures of too many people who claimed to be autogynephiliac. TBH most of the pictures that I see are of the individual dressed in female clothes. But I know that I dont dress like most guys. I dont wear baggy clothes and style my hair nice and try to stay in good shape. Im also very self consious about those things. In that sence I think I can relate to a "less masculine bird" that you mentioned who looks more feminine. Most AGP's probably are more stylish than most guys. Like the dam bird lol.

Susanne said...

I find discussion around animal evolution/research interesting. However, one could also argue that since humans have evolved to a level that no other animal has reached, then animal "research" would not apply to humans. Humans have factors/abilities that other animals do not have, notabily conscious free will. I've read that only humans and dolphins have sex for pleasure as opposed for procreation.

Still, findings from animal research brings up some possible explanations that might be worth exploring. Especially if there is a biological or genetic basis to all of this. Sometimes all one needs is a place to start...

Jack Molay said...

I'll be back with a more thorough analysis of the possible consequences of this new research for autogynephilia in the new year. Here are some preliminary comments.

To Robyn:
There is so much variety as regards "gay" and "transgender" behavior among animals that there is no point in trying to develop human ethics based on what -- let's say -- bonobos do with their sex life.

My point is rather that the scientists who tell's us what is normal and what is not are projecting their own prejudices onto their research.

The mere existence of transgender animals forces us to think again about what is natural and what is not, what is healthy and what is a "disorder".

For example: Same-sex sexuality is common among animals and can therefore not be labelled "unnatural" or "evolutionary dysfunctional", although you could, of course, use cultural arguments against such behavior. I will not.

The mere existence of "gay" and "transgendered" animals also indicate that homosexuality and at least some forms of transgenderism are inherited. That is: They are part of our instincts. If that is the case, it is impossible to argue that these conditions are _only_ the result of moral failure or free will. Whether autogyephilia is inherited or just a "fetish" remains to be seen.

To Susanne:

You point to those that say that humans have evolved to a level that no other animal has reached, which means that animal "research" would not apply to humans.

We seem to be the most intelligent species around (although dolphins, bonobos and parrots (!) may come close), but in most other areas there are other species that are much more advanced than us (sight, smell, speed etc. etc.)

I also believe we have a greater capacity of making conscious choices than most animals, but even my cat know when to say no. This is a matter of degree, not a radical chasm of free will vs. plain instincts. Moreover. we share 96 percent of our genes with chimps and bonobos. It seems to me that most of our decisions are as instinctual as theirs.

As you can see, I think the traditional Judeo-Christian idea that man is totally different from animals (Genesis 1) is wrong.

"I've read that only humans and dolphins have sex for pleasure as opposed for procreation." Well, that is what the old scientist would like you to believe. Roughgarden's point is that most complex animals enjoy sex so much that it has become the glue that holds their societies together. Just you wait till I tell you about the bonobos!

(And why would animals bother about sex if there was no reward?)

Robyn P said...

Jack,

Scientists cannot help but project their beliefs and prejudices on their research. That is why there are things like peer reviews to help filter out incorrect analysis of data gathered as part of research. Physical scientists should only be working with physically observable data. A scientist's definition of "normal" may be different than a non-scientist's definition...

I think you are equating natural, normal, healthy, and common as meaning the same thing. You also seem to group disorder, unnatural, and dysfunctional together. The only thing that "natural" means is "found in nature". Just because something is natural does not mean that it is healthy.

I have never heard the claim that "same-sex sexuality is common in animals". Maybe this explains the disappearance of the dinosaurs... There may be species where their sexuality is only same-sex.... but they would die within one generation.

I do not understand how the presence of gay or transgendered animals proves a) it is inherited and 2) "it is part of our instincts." There are MANY animal instincts we do not have...

I am not arguing that these conditions are only the result of moral failure or of our free will. All I am saying is that we have choices based on something other than instinct. The choices animals make are based only on their instincts.

I disagree with your statement that our ability to make conscious choices based upon free will versus choices made by animals based on instinct "is a matter of degree". There IS "a radical chasm of free will vs. plain instincts". The fact that there may be a difference of only 4% between our genes and those of chimps and bonobos is seriously misleading. How can 4% difference in genes account for our ability to know and understand concepts such as peace, justice, beauty, love, mercy, joy, fun, happiness, etc., as well as to be creative and imaginative?

Not only do I think the traditional Judeo-Christian idea that man is different from animals (Genesis 1) is correct, it is correct NOT just because it is in the Bible but because it is something that has been observed for thousands of years. Scientific research is based on this fact and to ignore it would be trashing a huge amount of science as meaningless...

Finally, I have a huge problem with the concept that animals can enjoy anything. Satisfying an instinctive need is NOT enjoyment. What animals do things for pleasure? Or when do animals try do something that is not "natural" for them? However, we are always trying to do things that are not "natural" for us. How long has man tried to fly?

It may seem like some animals "enjoy" sex because if they didn't, their species would face extinction. If they didn't "enjoy" sex, then there wouldn't be enough of them to provide food for their predators and another species would also face extinction...

Animals bother about sex because it is hard-coded in their nature. If a male dog comes near a female dog in heat, sex is going to happen...

Finally, let's say science proves without a doubt that there is a specific gene or a specific (fill-in-the-blank) that 100% causes autogynephilia. Now what? If you know that you have this gene, what decisions would be different? Does the presence of this gene toss our free will out the window and cripple our ability to make decisions? Does this gene mean that autogynaphiliacs get the freedom to do whatever autogynaphiliacs do because they have this gene?

I guess I am wondering how you would see life different if tomorrow this gene was found or, conversely, if it was proven that there is no gene...

Anonymous said...

Robyn,

I think you are mistaken about animals not feeling pleasure. The mere existence of erogenous zones (in humans AND in animals) indicates that pleasure is biological, not something that was a result of human cultural evolution. Stimulating the "pleasure centers" of a mouse's brain can be used as positive reinforcement for any number of tasks. It's not much of a stretch to think that some animals are positively reinforced to have sex by stimulating those same pleasure centers.

Also, there is a lot of evidence that animals possess cognitive processes. Chimpanzees, for instance, are able to use tools. And some animals have passed the "mirror test," chimpanzees being one of them, which means they have some degree of self-awareness. Tool-using and self-awareness requires that they think, that they aren't simply responding to stimuli or a hard-wired drive to reproduce/survive.

ooh, I just found a two-for-one on youtube! This video describes both dolphin same-sex partnership and sex-for-pleasure: http://www.youtube.com/watch?v=b0vGamcQIYs

Anonymous

Robyn P said...

Anonymous,

What I meant about "enjoyment" is emotional enjoyment. Positive reinforcement in animals is nothing new. But this "enjoyment" is purely at a physical level. There may be "pleasure centers" but only act on purely physical sensations. Animals react to both positive and negative physical stimulation. I don't need to watch a YouTube video to understand that concept...

Okay, chimpanzees use tools. I'm not sure what this means... Did they make these tools? Are they following blueprints to make something useful or something artistic?

I stated that there is is a HUGE, fundamental difference between man and animals and this difference is not a matter of degree. The fact that chimpanzees use tools only means that their brains are a little more advanced than those of non-tool using animals. It says nothing about difference between man and animals...

Looking at something very complex as autogynephilia, (and it is complex...), I wonder if looking at the animal kingdom for similar, parallel behavior is very productive...

Anonymous said...

Robyn,

I was just trying to point out that animal behavior is not strictly determined by instinct, that there are other factors in play.

You're right that there is a huge difference between humans and the rest of the animal world, and that difference came from our cultural and technological evolution. However, no matter how much our minds evolve, our behavior will always be influenced by our biology. And no, it's not a 100% genes control you thing, there's an interplay between genes and environment. Since genes play a part in who you are, it can be useful to look at the animal world - where genes have a more direct role in determining behavior - and compare it to human society.

For autogynephilia, you might be right. There may not be any valid comparisons to make. I wouldn't count it out so soon, though.

Anonymous

Jack Molay said...

Dear Robyn,
Just to make it clear:

The fact that something is found in nature does not mean that it is OK to do the same for humans. Killerwhales play with seals, using them as footballs, before killing them. Such a behavior is and should be totally unacceptable among humans, as should rape, cannibalism,infanticide and a lot of other behaviors bound in the animal kingdom.

I also believe we have a free will and a responsibility to use it for the benefit of our fellow man. We definitely have cognitive cabablilities that other animals have not, which means that we can make choices they cannot.

This means that even if we found a gene for autogynephilia, that would not it itself give us a jail free card, making it ethically defensible to give in to our passions.

So far we agree.

Where we disagree is in our view of man as something completely different from animals. I used to believe that. I do not anymore.

This is for two reasons:

1. Through psychotherapy and life itself I have come to learn and understand my own animal instincts, and all those psychic energies, compulsions and sexual drives that make me do things the conscious ego does not understand.

I have learned that straying too far away from what your inner animal wants, makes you sick.

A lot of people do, for instance, deny or suppress their sexual needs due to cultural rules or a bad upbringing, and it causes them a lot of unnecessary pain. The animal in them needs the comfort of physical friendship and sex. It is hardwired in us as it is in animals. To deny, for instance, homosexuals the right to have a love life is therefore a crime in my book.

As far as I am concerned any behavior that does not cause harm to others should be acceptable. That means that autogynephilia is in, pedophilia is out.

2. I have learned a lot from animals and they behave nothing like what you describe.

I have a cat at home -- Bingo, a big black male that has told me more about life than most philosophers.

He is no instinctual machine, that's for sure. He has his own personality, completely different from any other cat I have known. He is neutered, which means that he is denied some pleasures in life, but he make up for it with a strong bonding with his human family.

If I am resting on the sofa, he will climb up on my chest and beg me to scratch and stroke him. In return he will at least try to wash my face with his tongue.

What he does is what a lot of mammals do: They use grooming for growing closer. To me this is a kind of reciprocal love that is very close to what we human beings experience, which is why it is possible for a cat and a man to communicate. Because that is what we do: we communicate, although not with human words.

You could, of course, say that this is all about instincts. Grooming releases oxytocin in the brain, which calms the animal down and makes it less aggressive and more social. This is true. But this applies to me as well. Having him close makes my brain release oxytocin, which lowers the blood pressure and helps me relax.

You could say that there is a huge difference in that I can choose whether to allow this bonding to happen, while he is compelled to do so due to his instincts.

I am not so sure about that. It is normally he who chooses when this bonding is to happen, not me.

You say that I group disorder, unnatural, and dysfunctional together. Well, I don't, but scientists like Blanchard and Bailey do, which is why I think it is important to understand the world view underpinning their research.

Robyn P said...

1. "Psychic energies..." Interesting! Yes, of course, we all have "animal" instincts. However, because we do have intelligence and free will, we have to use them to have self-control and discipline, not only about sexual things but everything. Otherwise, if we only acted on our instincts, we would be just like animals.

Unfortunately, I have very little self-control and discipline and both my physical and mental health have been suffering. I give in way too easily to my base instincts. Unfortunately, the more I try to supress my needs, the worse I get and then become even more unhealthy.

2. I disagree with your statement that autogynephilia does not cause harm to others. How many wives who have husbands with autogynephilia think that autogynephilia is the "best thing that ever happened in our marriage"? Of course, the husband is not trying to deliberately cause any harm. But that does not mean that autogynephilia does not cause any harm....

3. I, too, am a cat owner. My cats bond to me because I provide them food, shelter, and attention when they need it. I bond with them because they provide companionship. However, I have asked them to contribute to their support and upkeep by doing the dishes every once in awhile or to clean the place up. So far, they have stubbornly refused...

If something were to happen to me tomorrow, they would bond with their next owner. If something were to happen to my cats, I would miss them terribly and they would be forever in my memory...

Jasper Gregory said...

Good work! i missed this one when you published it. I did not know that Roughgarden was a proponent of Multiple Genders in biology.

Anonymous said...

People are generally prejudiced by their own experiences. Good scientists try not to be, and I think the scientific community as a whole is very open-minded.

I came to your post trying to search for species of transsexual animals, ones that spontaneously, physically change between male and female. This phenomenon exists in some plants and animals. For a transsexual species, the environment usually signals the change, but the change is only possible because that is what the DNA code is programmed to do. I think this is more significant to rethinking the role of sex chromosomes as static gender identifiers than the hive-like division of behavior described previously.

Our human brains are structured and function in basically the same way from person to person, but we have some physical differences (including DNA) and live in different environments. This mix and match makes our experiences and behaviors anywhere from a little to a lot different from person to person. Among these are what is typical or average and a range of variation.

The question then becomes what part of the range of variations is acceptable, what behaviors are desirable, and what is harmful. Now we move toward the realm of personal perspective and opinion. There are medically agreed upon behavioral illnesses, and then there are some things that are just quirky. Without some quirkiness, life would be kind of dull.

Unfortunately, sometimes a person is born with a gender that completely conflicts with most other aspects of their person, including identity. It's not typical, but it happens. When it does, it can be distressing enough that it is a disorder that needs remedied. In that case, if the person and their doctor feel that a sex change is what the person needs, then my opinion is that it should be considered a medical need and be covered by insurance.

As for gender-related variations that are not a medical issue, society needs to learn to accept that benign variations are a part of human nature – get over it. These variations should be tolerated at the very least or celebrated with the many other differences that make the world a more dynamic and interesting place.

Jack Molay said...

@anonymous

I wholeheartedly agree. But it is hard to distinguish between natural and pathological gender confusion, as the medical establishment itself has its share of prejudiced researchers. They have a tendency of labelling anything beyond the binary as "paraphilias". This is why I find Roughgarden's research so important. She forces us and them to stop and think again.

Iris said...

Hmm, I don't agree with the assertion that aggressive males can't simply be mistaking the "female-like males" for females simply because they have good eyesight or something to that extent. Males of most species are selected to be unchoosy - bluntly, they're selected to try to have sex with most anything that seems vaguely viable. In the case of the bird and the later shunning, it could have arisen because the males continued that to be unchoosy in the mating season would not pass on offspring; furthermore, it'd be interesting to see if the females go into heat at that point, or have some other distinguishing feature that may make it more obvious that the females are female.

The greater the sexual dimorphism, the greater the selection for unchoosy males and choosy females, and in both the cases of the bluegill and the birds, there's significant sexual dimorphism. It's the rare case, like humans, where the dimorphism is lower and males are actually selective. On a more personal level, Roughgarden's theories are interesting, but just not as compelling nor well supported as sexual selection, with the large body of evidence behind its canonicity.

I guess I also feel that it's dangerous to take the marginalized in science without a grain of salt. Roughgarden's theories have been widely criticized, and by some very prominent scientists, themselves established and knowledgeable in their field. The theory never gained traction, and though there may be academic politics at work, I doubt that the politics alone would leave the playing field so tilted back in favor of the sexual selection theory... Perhaps I have too much trust in the scientific community, though.

Jack Molay said...

@Iris

"Roughgarden's theories have been widely criticized, and by some very prominent scientists, themselves established and knowledgeable in their field. "

That is true, and I guess it is to be expected. After all, the established tribe see their prestige and intellectual integrity threatened and many of them will go into a defense position. Thomas Kuhn said that the previous generation had to die out before a new idea took hold. I am not so sure about that, but the fact that some well established scientists criticizes is in itself not a sign of her being wrong.

I have actually heard scientists in the field criticize Roughgarden for not being radical, in the sense that everything she says can be fitted within the existing paradigm. That probably depends on what level of the paradigm you are talking about. It is certainly true that Roghgarden's thinking fit well within the current trend towards more emphasis on collaboration, altruism and the systemic properties the social and biological context.

Iris said...

That is true, and I guess it is to be expected. After all, the established tribe see their prestige and intellectual integrity threatened and many of them will go into a defense position.

Now this is just a bit of a cop out, and I hear this pretty often as a defense of scientific mavericks regardless of right or wrong. It's not a matter of paradigm shifts. The truth is that even without the vocal critics, her theory gained no almost traction from the academic community - that's extremely rare for anything theory with sufficient evidence.

Altruism and cooperativity generally fit well within the current paradigm, in which selection accounts for altruism and possibility of male choice. Roughgarden extends that farther than the research supports, however, when she asserts additional layers of complexities without empirical proof of the matter.

The criticisms that I've read in which it is mentioned that she's proposing anything paradigm shifting are ones that essentially say that everything proposed in her theory is not novel, because current social/altruism bents have already accounted for those things. Basically, whatever isn't ill-supported, is not novel and outside the current paradigm. The problem they have with her is not that she's not maverick enough - it is that she makes it seem as though she is when she's not.

I'm of the younger generation of scientists, and I like to think I have a relatively open mind. If I see good evidence speaking to the contrary of the current paradigms, I would definitely give it strong consideration - I'm not one to shy away from challenging paradigm and established scientists. But from what I've read, this simply isn't enough - the burden of proof is on Roughgarden's camp to provide evidence, and there really hasn't been any yet.

Also, this is a random note about something I read on the forums - that identical twins in which one is crossdreaming and the other is not rules out hormonal/genetic factors. It's not quite that simple. They may inherit the same genome, but with alternative splicing, epigenetic modifications, and simple mutations, they may, in some cases, not be wholly identical on the genetic/epigenetic level. Hormones are an even bigger thing - affected by environments, and generally feedforward in its developmental effects. Just a little more of some developmental hormones can cause effects as drastic as failed segmentation. It's interesting to see such a difference between twins, but not at all surprising on the molecular level.

Jack Molay said...

@Iris

"[Identical Twins] may inherit the same genome, but with alternative splicing, epigenetic modifications, and simple mutations, they may, in some cases, not be wholly identical on the genetic/epigenetic level."

This makes sense to me, at least on the genetic level. The pre-natal hormone exposure (the favorite explanation for transsexuality) should be the same, though, shouldn't it?

Still, since transgender conditions do not become apparent until the age of three or four at the very earliest, there should be time for other variations. I cannot help thinking that this would undermine our faith in twin research, which at the moment is essential in the nature/nurture debate (cp. Steven Pinker).

As for Roughgarden's research... I guess I do not have the same faith in the "objectivity" of scientists, including -- of course -- Roughgarden herself.

I am, of course, not in a position to make the final judgment regarding this. I guess the reason I find her critique of the sexual selection theory so interesting is that it makes so much more sense when it comes to understanding humans.

As soon as women get financial independence and trustworthy contraceptives may of them behave exactly like men.

Moreover, if there is so much variation as regards gender behavior among animals it is hard to see that it is all governed by one simple gender divided mechanism. The gender morphs presented by Roughgarden clearly tells us that there is a wide variety of approaches, even within one species.

Kristjan Birnir said...

There no fundemental diffrence between humans and other animals. Our body cells would match those of bacteria and with other none complex animals, we share one of the following: We eat, sleep, poop, pee, bread, die. Everything else realy don't matter. As for the transgender animalr argument, its not about the wish of being the other gender, I seriously cannot I think interprent Rosgarden is reaserch as solution to that problem, as the main dillema of "transexual/genders in human is the born in wrong body argument, as I don't think there is a male horse, dog, cat, sheep, lion, abe, that wise to be female horse, dog, cat, the reaserch is more to point ot that some specis can have indivuduals that have more than one gender and thats universal for all indivuduals unlike humans where trangdender pool is only small % of all human race. As for the bird there might not because of the gender hin Rosegarden is study that its lay down the guard to certain male birds, it might be down to the colors to the opposide is bird fether color rhater than the gender of that bird.
-Chris