"Slanted" Eyes in Orientals

Difference in races is nothing but difference in genetic characteristics and skin pigment.

if only in the case of humans and our sexual selection for drunks and smokers.i see what you mean, but these loud displays have been around for a long time and are not respricted to birds... many creatures participate in handicapping without detriment to their species.
*shrugs* i actually don't follow it that much.

Maybe I'm misreading you: It seems like you're saying that species with outrageous sexual structures/displays/behaviors will eventually (or are more likely to) select themselves to extinction (again, sorry if that is a misinterpretation).This flies in the face of selection - if a subset of a species became too outrageous in their sexual selection to the point survival was reduced, they should be selected against.It would seem that overinvestment in a 'sexual selection handicap' might be a detriment to adaptability in the short term - so such species might be more likely to suffer during habitat loss, climate change, novel predator introduction (esp. humans, who preferentially hunt animals with the largest sexual-attraction structures...), etc.But that is true for over-specialization in general - it's just in this case the specialization is in sexual selection instead of food or ecological niche.

I've heard possibilities for the selection of 'slanted' or 'double-lidded' eyes of Asian populations.The most plausible is that the trait developed in the North or high-elevations (Himilayas?) as protection from cold climate and/or snow/sandstorms - think Siberia/Mongolia, the Iniuts and other native peoples of the northern reaches of North America and Asia. The trait spread by migration.I did a quick search and only found:
http://www.raceandhistory.com/historicalviews/rgh.htmThe article points out that some groups in Southern
Africa have similar eyes - possibly evolved separately (sandstorms as selection?).I'd be interested to hear what others think...

"are more likely to) select themselves to extinction" because "overinvestment in a 'sexual selection handicap' might be a detriment to adaptability" as is "true for over-specialization in general"I think you get the picture. Sooner or later the overspecialization will catch them unprepared.

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

Right - I thought we'd be in agreement...I just wanted to get across my thought that sexual overspecialization isn't a detriment to species survivability any more than other forms of overspecialization.

other than that the overspecialization boundary is self imposed rather than a response to a specialized niche. it's kind of like the distinction between stupidity and willfull ignorance.

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

Maybe you could clarify that it is "self-imposed".Do female birds (of the species that follow such selection) "willfully", intelligently, decide to mate with a male - with the thought "his huge feathers are obviously cumbersome and that he survived despite them is a testament to his fitness."I believe that it is simple inherited behavior (therefore without willful choice); unless you have info to the contrary...

There have been tests with scissortail birds where the tails have been artificially modified with 4 groups(1) cut shorter
(2) left same length
(3) cut off and reglued with same length
(4) extended with glued on section (longer than normally survive)The females consistently chose the longest tails for mating with no difference between (2) and (3) (so glue did not influence the choice)Of course this also gets into the question of how much sexual choice is genetically driven ...

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

I'm not disputing that selection occurs in this way - as in your scissortail example.I think it is more a matter of language - terms like "self-imposed" and "willful ignorance" make it seem as though the individual females had the choice to choose, indeed that they had the knowledge of the handicapping nature of the trait they were selecting.It seems the true case is females (almost) always choose males with long tails - likely due to genetically defined behavior. If it is "self-imposed", it's more on the species-level than an individual level - and then I don't know that the term "self-imposed" is warranted, perhaps "genetically predisposed".

As I said, it "gets into the question of how much sexual choice is genetically driven ..."It also gets into the question of how much intelligence and choice animals have (not what we think they have).We can see choices being made, but not what is behind the choice (heck we can't always tell why people make the choices they do).A genetic version of {no free will}?

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

Right - behavior is not necessarily solely the product of genetics in this case; but I still think that talking about free will and choice in individual birds as self-directing selection is incorrect.Does a koala self-impose specialization on itself because it refuses to use anything other than eucalyptus as a food source? I don't believe that is an individual choice on the part of each koala - just as I don't believe individual birds decide if they prefer long or short tails in each case.In fact, if an anamolous female scissortail existed that selected short tails, or selected indiscriminately, I would propose an underlying genetic cause.How much sexual choice is genetically driven? Much of it, it would seem, if the results from the study you described are extremely consistent.

even in humans it goes to the question of homosexual behavior among other things: what controls attraction? genetics? hormones? environment? experience? choice?If a koala is incapable* of digesting any other food that is available to it, then yes, it is self-imposed* OOPS make that "If a koala is capable of digesting other food that is available to it, then yes, it is self-imposed (edit)This message has been edited by RAZD, 06-17-2004 09:48 PM

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

yes, but we want to know WHY those exist. it's not racist to study the differences.we know so little about it PRECISELY because of attitudes like this. because people are too scared of looking intolerant to study some of the most interesting stuff out there.This message has been edited by brennakimi, 06-17-2004 07:13 PM

I agree completely - I've attended many seminars where the researcher will discuss racial differences epidemiologically, as in "African-Americans are more likely to die from colorectal cancer", but when it comes time to analyze the human genetic data later in the seminar, refuses to split the data along race lines. I understand that much of the influence may be socioeconomic, but it is highly unlikely that there is zero genetic influence there - it is a shame that it doesn't get studied given the therapeutic implications.Like you said, it is not racist, at least until someone states that Asians are superior or inferior for having double-lidded eyes (and now that I'm writing this, I believe that someone did state that earlier in the thread...)Did you read message 34 in this thread? Since you seem interested in returning to the human topic?