intentional out breeding [elimination] of more sexes
A comparative analysis of Mammalia shows this to be extremely doubtful, unless you think that only humans have these extra sexes. In all mammals the vast bulk of individuals can be cleanly assigned to male or female without ambiguity, and no such intentional elimination was required. [Note “outbreeding” means something else.]
You have to look at quite distantly related species before hermaphrodites show up at interesting frequencies. Certainly some fish can be hermaphrodite.
I don’t think only humans have these extra sexes. Could you direct me to the comparative analysis of Mammalian reproductive systems that discusses hermaphrodites in other species? I am sure most gonochronistic animals have cases of hermaphrodites or other genetic mutations.
You are right, outbreeding is not what I meant. That is why I split the word up, hoping to convey my point. Intentional elimination is a good way to say it. If Hermaphrodites were not so stigmatized they would not be abandoned/killed/maimed as children; if they were not on average abandoned/killed/maimed as children then there would be a decent size population of hermaphrodites able to develop a stable social station; if there were a stable hermaphrodite community their genes would spread; if there genes spread their would be more hermaphrodites. I think the intentional elimination of hermaphrodites has made a huge impact on the demographic of humanity, do you disagree?
Also I don’t think you can use the fact other gonochronistic mammals have not developed more sexes as a reason why humans would not.
Could you direct me to the comparative analysis of Mammalian reproductive systems that discusses hermaphrodites in other species?
What I meant was that we can think about other mammals ourselves, and note that no other mammal species has hermaphrodites at significant frequencies. I had no specific research in mind.
there would be a decent size population of hermaphrodites able to develop a stable social station; if there were a stable hermaphrodite community their genes would spread
This depends both on a genetic cause, and also on hermaphrodites having equal fitness to males and females.
I think the intentional elimination of hermaphrodites has made a huge impact on the demographic of humanity, do you disagree?
Yes, I disagree, for the reasons I’ve stated. Other mammals have had no “intentional elimination”, yet hermaphrodites remain at very low levels. So “intentional elimination” isn’t the reason for the very low levels.
Also I don’t think you can use the fact other gonochronistic mammals have not developed more sexes as a reason why humans would not.
Of course I can; humans aren’t particularly special, at least not in relevant ways.
Of course I can; humans aren’t particularly special, at least not in relevant ways.
Humans are incredibly special. Humans are the only single species mammal. In that sense given the diversity of human ethnicities, humans are the most specialized-unspecialized species in the world (specialized in the sense that the species allows for the vast degrees of ethnic traits to be completely compatible with any human; unspecialized in the sense that we remain neutral enough to adapt to almost any environment and have not biologically chained ourselves to a particular habitat). Humans are the only species that we know of that creates a shared reality of perception (meaning that if I point at something, you know not to look at my finger but look for what I am pointing too; we are able to see our goals, victories, and aspirations as shared with a larger social entity). Humans are the only creature with a cultural paradox (A cultural paradox is where what is prescribed by their tribe often times is detrimental to their survival, but to go against the tribe is equally if not more detrimental.).
Biological classification is useful for organizational purposes, but the categories created are often times severely lacking. In this case, I think humans are so different from most other mammals that it is not useful to use them as an insight into human nature/ the development of the human species.
Well I guess this is another flaw of classification. Species is defined as “Species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups” (Futuyma, 1998). The reproductive isolation can be genetic, or it can be simply geographical or habitual. There is no criteria that says two distinct species cannot interbreed, even though some species can and others cannot. For example dogs, wolves, and coyotes can all interbreed, but within the Felidae genus there are cat species that cannot interbreed.
What I was saying is that humans are the only living member of the Homo family. Homo sapiens exist as a single species because to some degree their is no limitation on our interbreeding. Sure there are many cultural norms and customs that have discouraged inter-racial, inter-class, inter-ethinicity breeding, but it has not stopped these things. I would argue (along with some evolutionary biologists) that the fact that homo sapiens exist in one giant gene pool is pretty unique among animals given the wide amount of territory that we populate.
The reproductive isolation can be genetic, or it can be simply geographical or habitual.
This is probably not relevant to our point, but Futuyma (2005) Evolution p356 defines reproductive isolation as “reduction or prevention of gene flow between populations by genetically determined differences between them”—i.e. it’s not enough that they are geographically separated.
homo sapiens exist in one giant gene pool
This just seems to be a claim that the population size of our species is quite large. There are other species of mammal with large populations. Again, the relevance of any of this to sex-determination is rather doubtful.
It should be pointed out here that biological genuses, families, orders, and so on do not exist. If you discover a new continent full of organisms not previously known, there is no observation you can make to decide whether two of their species are, or are not, members of the same genus. It would be a wrong question. Every classification above the species level exists solely for the convenience of biologists talking about the organisms they are studying. Even at the species level, where we can talk about interbreeding populations, multiple definitions are possible and edge cases exist (sometimes so large as to make the very idea of a tree of descent moot).
The higher-level classifications may (but do not always) correspond to subtrees of the evolutionary history, but their ranking into genuses, orders, subfamilies, and so on in the 40-odd different levels available in current taxonomical practice is a product of human convenience, nothing more.
So the statement that some genus includes only one species is not a statement of biology. It is a statement about biologists.
It’s not clear to me why you’re presuming social effects are the primary selection pressure pushing against hermaphroditism. I don’t know the genetics / biology / embryology involved, but my prior is that deviation from normalcy decreases the chances of fertility for that individual, and possibly more importantly, their children.
[Although I am not proud of this, reflecting on your question “why you’re presuming social effects are the primary selection pressure,” the conclusion I came to was] Because it is the political position I was indoctrinated into. in undergrad anthropology we covered feminism and the idea of sex as a social construct is pretty much the big idea of third wave feminism. It was such a unique and interesting idea that I accepted it into my own ideology pretty readily. However honestly, the counter-arguement that there there are other genetic factors that are more primary is potentially acceptable.
As to your prior
that deviation from normalcy decreases the chances of fertility for that individual, and possibly more importantly, their children.
I would respond that what is normal depends on the in-group of the individual/community defining normalcy. Since people to some degree define their in-group based on the people, symbols, media, and cultures they interact with, I would argue that the process of labeling what is normal is a social construction.
It’s not clear to me why you’re presuming social effects are the primary selection pressure pushing against hermaphroditism.
Because it is the political position I was indoctrinated into.
That’s a rather startling thing to say, at least on LessWrong.
Quiet honestly it was such a unique and interesting idea that I accepted it into my own ideology pretty readily.
As is this.
However honestly, the counter-arguement that there there are other genetic factors that are more primary is potentially acceptable.
Leaving aside the particular questions of sex, gender, and normalcy, what do you, and those who have influenced you, judge to be “acceptable” forms of argument? What should, or should not, give you a reason to believe something?
That’s a rather startling thing to say, at least on LessWrong.
Is it startling to be honest? Perhaps I was not careful enough with my wording, or my tone did not come across correctly, but the statement “Quite honestly it was such a unique and interesting idea that I accepted it into my own ideology pretty readily” was confessional. I said “potentially acceptable” because I feel that the speculation here is not grounded in expertise, and I don’t want to repeat the mistakes of my youth and be just as easily indoctrinated by your flashy idea as the previous one.
I really am not too familiar with this community, but personally, I try to be as critical and reflective as possible of the discourse that encompasses my beliefs. It is somewhat embarrassing that I never thought to question the biological fitness of hermaphrodites in general, but the truth is I didn’t. It would be nice to chalk that up to youthful naiveté at the time of indoctrination, but it just as easily could have been a blind spot in my reflections.
That definition of “normal” is irrelevant to the biological effects of mutation on fertility.
Here: If the human reproductive system has evolved over millions of years in a condition where the vast majority of the population are one of either two sexes, with particular chromosomes even being present in only one of the sexes, then a mutant that somehow ends up with both sexual organs is almost certainly going to having all sorts of problems fertility-wise. That kind of mutation breaks the assumptions the reproductive systems have evolved under (assumptions such as amounts of testosterone/oestrogen/whatever other hormones in the blood, the physical arrangement of the sex organs, and probably all kinds of other stuff).
A comparative analysis of Mammalia shows this to be extremely doubtful, unless you think that only humans have these extra sexes. In all mammals the vast bulk of individuals can be cleanly assigned to male or female without ambiguity, and no such intentional elimination was required. [Note “outbreeding” means something else.]
You have to look at quite distantly related species before hermaphrodites show up at interesting frequencies. Certainly some fish can be hermaphrodite.
I don’t think only humans have these extra sexes. Could you direct me to the comparative analysis of Mammalian reproductive systems that discusses hermaphrodites in other species? I am sure most gonochronistic animals have cases of hermaphrodites or other genetic mutations.
You are right, outbreeding is not what I meant. That is why I split the word up, hoping to convey my point. Intentional elimination is a good way to say it. If Hermaphrodites were not so stigmatized they would not be abandoned/killed/maimed as children; if they were not on average abandoned/killed/maimed as children then there would be a decent size population of hermaphrodites able to develop a stable social station; if there were a stable hermaphrodite community their genes would spread; if there genes spread their would be more hermaphrodites. I think the intentional elimination of hermaphrodites has made a huge impact on the demographic of humanity, do you disagree?
Also I don’t think you can use the fact other gonochronistic mammals have not developed more sexes as a reason why humans would not.
What I meant was that we can think about other mammals ourselves, and note that no other mammal species has hermaphrodites at significant frequencies. I had no specific research in mind.
This depends both on a genetic cause, and also on hermaphrodites having equal fitness to males and females.
Yes, I disagree, for the reasons I’ve stated. Other mammals have had no “intentional elimination”, yet hermaphrodites remain at very low levels. So “intentional elimination” isn’t the reason for the very low levels.
Of course I can; humans aren’t particularly special, at least not in relevant ways.
Humans are incredibly special. Humans are the only single species mammal. In that sense given the diversity of human ethnicities, humans are the most specialized-unspecialized species in the world (specialized in the sense that the species allows for the vast degrees of ethnic traits to be completely compatible with any human; unspecialized in the sense that we remain neutral enough to adapt to almost any environment and have not biologically chained ourselves to a particular habitat). Humans are the only species that we know of that creates a shared reality of perception (meaning that if I point at something, you know not to look at my finger but look for what I am pointing too; we are able to see our goals, victories, and aspirations as shared with a larger social entity). Humans are the only creature with a cultural paradox (A cultural paradox is where what is prescribed by their tribe often times is detrimental to their survival, but to go against the tribe is equally if not more detrimental.).
Biological classification is useful for organizational purposes, but the categories created are often times severely lacking. In this case, I think humans are so different from most other mammals that it is not useful to use them as an insight into human nature/ the development of the human species.
None of the things you mention are likely to affect the sex determination system.
The only what?
Well I guess this is another flaw of classification. Species is defined as “Species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups” (Futuyma, 1998). The reproductive isolation can be genetic, or it can be simply geographical or habitual. There is no criteria that says two distinct species cannot interbreed, even though some species can and others cannot. For example dogs, wolves, and coyotes can all interbreed, but within the Felidae genus there are cat species that cannot interbreed.
What I was saying is that humans are the only living member of the Homo family. Homo sapiens exist as a single species because to some degree their is no limitation on our interbreeding. Sure there are many cultural norms and customs that have discouraged inter-racial, inter-class, inter-ethinicity breeding, but it has not stopped these things. I would argue (along with some evolutionary biologists) that the fact that homo sapiens exist in one giant gene pool is pretty unique among animals given the wide amount of territory that we populate.
So was the claim “Humans are the only single species mammal” simply a claim that humans are the only mammal with their own genus? That’s certainly not true, see http://en.wikipedia.org/wiki/Category:Monotypic_mammal_genera
This is probably not relevant to our point, but Futuyma (2005) Evolution p356 defines reproductive isolation as “reduction or prevention of gene flow between populations by genetically determined differences between them”—i.e. it’s not enough that they are geographically separated.
This just seems to be a claim that the population size of our species is quite large. There are other species of mammal with large populations. Again, the relevance of any of this to sex-determination is rather doubtful.
It should be pointed out here that biological genuses, families, orders, and so on do not exist. If you discover a new continent full of organisms not previously known, there is no observation you can make to decide whether two of their species are, or are not, members of the same genus. It would be a wrong question. Every classification above the species level exists solely for the convenience of biologists talking about the organisms they are studying. Even at the species level, where we can talk about interbreeding populations, multiple definitions are possible and edge cases exist (sometimes so large as to make the very idea of a tree of descent moot).
The higher-level classifications may (but do not always) correspond to subtrees of the evolutionary history, but their ranking into genuses, orders, subfamilies, and so on in the 40-odd different levels available in current taxonomical practice is a product of human convenience, nothing more.
So the statement that some genus includes only one species is not a statement of biology. It is a statement about biologists.
Yes, this is true of course.
And whoever mentions cladistics first wins the thread. Ready, set...
Your comment inspired me to post this quote (although I still think calling humans mammals and primates is useful).
I agree that it is pretty useful, but I still like your quote.
It’s not clear to me why you’re presuming social effects are the primary selection pressure pushing against hermaphroditism. I don’t know the genetics / biology / embryology involved, but my prior is that deviation from normalcy decreases the chances of fertility for that individual, and possibly more importantly, their children.
[Although I am not proud of this, reflecting on your question “why you’re presuming social effects are the primary selection pressure,” the conclusion I came to was] Because it is the political position I was indoctrinated into. in undergrad anthropology we covered feminism and the idea of sex as a social construct is pretty much the big idea of third wave feminism. It was such a unique and interesting idea that I accepted it into my own ideology pretty readily. However honestly, the counter-arguement that there there are other genetic factors that are more primary is potentially acceptable.
As to your prior
I would respond that what is normal depends on the in-group of the individual/community defining normalcy. Since people to some degree define their in-group based on the people, symbols, media, and cultures they interact with, I would argue that the process of labeling what is normal is a social construction.
That’s a rather startling thing to say, at least on LessWrong.
As is this.
Leaving aside the particular questions of sex, gender, and normalcy, what do you, and those who have influenced you, judge to be “acceptable” forms of argument? What should, or should not, give you a reason to believe something?
Is it startling to be honest? Perhaps I was not careful enough with my wording, or my tone did not come across correctly, but the statement “Quite honestly it was such a unique and interesting idea that I accepted it into my own ideology pretty readily” was confessional. I said “potentially acceptable” because I feel that the speculation here is not grounded in expertise, and I don’t want to repeat the mistakes of my youth and be just as easily indoctrinated by your flashy idea as the previous one. I really am not too familiar with this community, but personally, I try to be as critical and reflective as possible of the discourse that encompasses my beliefs. It is somewhat embarrassing that I never thought to question the biological fitness of hermaphrodites in general, but the truth is I didn’t. It would be nice to chalk that up to youthful naiveté at the time of indoctrination, but it just as easily could have been a blind spot in my reflections.
Sorry, I had read it as being your current justification for the belief.
No problem, any fault is probably more due to my writing than your thinking.
That definition of “normal” is irrelevant to the biological effects of mutation on fertility.
Here: If the human reproductive system has evolved over millions of years in a condition where the vast majority of the population are one of either two sexes, with particular chromosomes even being present in only one of the sexes, then a mutant that somehow ends up with both sexual organs is almost certainly going to having all sorts of problems fertility-wise. That kind of mutation breaks the assumptions the reproductive systems have evolved under (assumptions such as amounts of testosterone/oestrogen/whatever other hormones in the blood, the physical arrangement of the sex organs, and probably all kinds of other stuff).
Upvoted for honesty and chasing down assumptions.
nshepperd explains well what I meant by “normalcy.”