View Full Version : Racial Inbreeding


Willy
08-29-07, 04:36 PM
Scholars believe the color differences in human skins can be traced to climatic adaptation. They argue that the high levels of melanin in dark skin originally protected people living outside in hot, sunny climates, notably in Africa and South Asia, from skin cancer. Conversely, in cold climates, the low amount of melanin in light skins enabled the early humans to soak up vitamin D from a sun often hidden behind clouds.

These color differences were reinforced by millennia of inbreeding when humans lived in small groups that were geographically and socially isolated.

This inbreeding also produced variations in head and nose shapes and other facial features so that Northern Europeans look different from people from the Mediterranean area, such as Italians and, long ago, Jews. Likewise, East African faces differ from West African ones, and Chinese faces from Japanese ones. (Presumably the inbreeding and isolation also produced the DNA patterns that geneticists refer to in the latest scientific revival and redefinition of race.)


http://www.contextsmagazine.org/content_sample_v4-4.php

spidergoat
08-29-07, 04:38 PM
I would call it sexual selection, not inbreeding.

DwayneD.L.Rabon
08-29-07, 04:50 PM
Well a Polar Bears skin is black, what does that tell you.


DwayneD.L.Rabon

S.A.M.
08-29-07, 05:12 PM
FYI:


Inbreeding is breeding between close relatives, whether plant or animal. If practiced repeatedly, it often leads to a reduction in genetic diversity, and the increased gene expression of recessive traits, resulting in inbreeding depression. This may result in inbred individuals exhibiting reduced health and fitness and lower levels of fertility.

Livestock breeders often practice inbreeding to "fix" desirable characteristics within a population. However, they must then cull unfit offspring, especially when trying to establish the new and desirable trait in their stock.

Inbreeding may result in a far higher expression of deleterious recessive genes within a population than would normally be expected. As a result, first-generation inbred individuals are more likely to show physical and health defects, including:

* reduced fertility both in litter size and sperm viability
* increased genetic disorders
* fluctuating facial asymmetry
* lower birth rate
* higher infant mortality
* slower growth rate
* smaller adult size
* loss of immune system function.

Natural selection works to remove individuals who acquire the above types of traits from the gene pool. Therefore, many more individuals in the first generation of inbreeding will never live to reproduce. Over time, with isolation such as a population bottleneck caused by purposeful (assortative) breeding or natural environmental stresses, the deleterious inherited traits are culled.

Inbreeding in humans

The taboo of incest has been discussed by many social scientists. Anthropologists attest that it exists in most cultures. As inbreeding within the first generation would produce expression of recessive traits, the prohibition has been discussed as a possible functional response to the requirement of culling those born deformed, or with undesirable traits. The eugenicists used breeding techniques to promulgate their ideas of human perfection and "illness" on all humans. Some anthropologists like Charles Davenport advocated the traditional forms of assortative breeding to form "better" human stock.

[edit]


http://en.wikipedia.org/wiki/Inbreeding

spidergoat
08-29-07, 05:24 PM
Well a Polar Bears skin is black, what does that tell you.


DwayneD.L.Rabon

I don't doubt that the environment had a part in creating these differences initially, but peoples at the same latitude also look different.

Enmos
08-29-07, 06:06 PM
Scholars believe the color differences in human skins can be traced to climatic adaptation. They argue that the high levels of melanin in dark skin originally protected people living outside in hot, sunny climates, notably in Africa and South Asia, from skin cancer. Conversely, in cold climates, the low amount of melanin in light skins enabled the early humans to soak up vitamin D from a sun often hidden behind clouds.

These color differences were reinforced by millennia of inbreeding when humans lived in small groups that were geographically and socially isolated.

This inbreeding also produced variations in head and nose shapes and other facial features so that Northern Europeans look different from people from the Mediterranean area, such as Italians and, long ago, Jews. Likewise, East African faces differ from West African ones, and Chinese faces from Japanese ones. (Presumably the inbreeding and isolation also produced the DNA patterns that geneticists refer to in the latest scientific revival and redefinition of race.)


http://www.contextsmagazine.org/content_sample_v4-4.php

Are you deliberately being stupid ? :bugeye:

spidergoat
08-29-07, 06:10 PM
The problem is there wasn't really much geographical isolation, unless you consider islands. That's why I think the superficial differences between the "races" are a result largely of sexual selection. It comes about as a result of culture. Cultures tend to breed within themselves.

Orleander
08-29-07, 06:10 PM
I don't understand what this thread it trying to get at. ???
Wouldn't moving across the planet and having children with other cultures/races be a part of evolution?

Willy
08-29-07, 07:34 PM
I posted this thread because I got a infraction for saying:

"The more a group of being's inbreed the more they will look alike.

The less a group of being's inbreed the less they will look alike."

cosmictraveler
08-29-07, 07:39 PM
We are all from the same woman that gave birth to the first human. That means we are all inbreeding for we are all brothers and sisters.

Willy
08-29-07, 08:05 PM
Then who gave birth to that "same woman that gave birth to the first human"?

cosmictraveler
08-29-07, 08:12 PM
Then who gave birth to that "same woman that gave birth to the first human"?

A hominoid creature which because of a genetic mutation created the first human.

Willy
08-29-07, 08:17 PM
Was that human a black African?

cosmictraveler
08-29-07, 08:41 PM
More than likely from the findings of Dr. Leaky and his crew. That doesn't mean that it is the exact place, its only the place that has been located so far with bones that date back nearly 3 million years linking humans to that which evolved there.

Fraggle Rocker
08-29-07, 09:31 PM
Are you deliberately being stupid?Yes he is, and I'd say he's about three days away from being permanently banned from SciForums. This is the second time he's posted something from a racist website, which is an egregious violation of our rules.

leopold
08-29-07, 10:22 PM
willy,
interesting subjct.
so, you propose that inbreeding helped to shape a cultures traits right?
you do realize that this applies to your culture as well do you not?
also, the fact that even albinos have melenin in their skin says that ALL of us are descendants of africans. in essence willy you have black blood.
why does it suddenly smell like J.B. in here?

Willy
08-29-07, 10:29 PM
Yes he is, and I'd say he's about three days away from being permanently banned from SciForums. This is the second time he's posted something from a racist website, which is an egregious violation of our rules.Racist website?

It is from the University of California.

Exhumed
08-29-07, 10:43 PM
Yes he is, and I'd say he's about three days away from being permanently banned from SciForums. This is the second time he's posted something from a racist website, which is an egregious violation of our rules.

:scratchin:

I think you meant to say this:

Biology & Genetics is one of this website's scientific subforums. Please comport yourself like a scientist in these halls. You have not participated in this discussion so you can't fall back on the excuse that you've been trying to explain this to us knuckleheads and you just can't get through so you're expressing your frustration.

You don't jump into our discussions and just start insulting people without making a single substantive statement. That is not science, that is trolling and it is a violation of the rules. If you have something to offer, do so.

spuriousmonkey
08-30-07, 02:20 AM
Racist website?

It is from the University of California.

It published by the University of California Press. That is not the same as being from the University of California.

ASA, the american sociological association is behind it. An organization that promotes the field of sociology.

What you have quoted though is an editorial. And if you read the entire thing, well, in fact you can read the summary at the very beginning, you find out that it is not a racist piece at all:


Why does the idea of race continue to exert so much influence in the United States? Because the skin colors and other physical features used to define race were selected precisely because they mirror the country's socioeconomic pecking order.

merely it describes by racism is a popular theme in the US and why it is apparently seen as an important issue.

Of course selective quoting can turn any piece into a stinking sack of puss.

But the link is definitely not to a racist website.

Enmos
08-30-07, 06:06 AM
:scratchin:

I think you meant to say this:

Biology & Genetics is one of this website's scientific subforums. Please comport yourself like a scientist in these halls. You have not participated in this discussion so you can't fall back on the excuse that you've been trying to explain this to us knuckleheads and you just can't get through so you're expressing your frustration.

You don't jump into our discussions and just start insulting people without making a single substantive statement. That is not science, that is trolling and it is a violation of the rules. If you have something to offer, do so.

Hey its an honest question, i cant believe anyone in their right mind would belief anything that stupid. So it has to be deliberate on his part. :shrug:

Willy
08-30-07, 08:28 AM
But the link is definitely not to a racist website.Thanks for your honesty.

I can't believe how many of these "moderators" feel the need to lie as some kind of form of debate.

thatbiogeek
08-30-07, 09:51 AM
I don't really understand the point of this thread. The effect of genetic drift is strongest in small populations where inbreeding is more likely to occur (because there are fewer mates to choose from) and I am sure that genetic drift played some part in certain aspects of human evolution but I seriously doubt that it is responsible for all perceived racial differences. Inbreeding isn't really a hugely benificial thing for an organism to engage in however. This is why sexual reproduction is so common throughout the plant and animal kingdoms. Remember, flowering plants go through a LOT of trouble to have their flowers outcrossed. Also, hybrid vigor, the advantage of a hybrid between two genetically distinct groups is a well documented phenomenon.

Sex is a good thing, sex with someone unrelated to you is even better ;)

I think I really don't understand what you're trying to say. Are you asserting that inbreeding is genetically benificial in most cases?

ETA: Or are you suggesting that interbreeding between 'races' destroys the advantages that those races have built via selection - hybrid depression? This would assume first that those features are advantageous in our modern society. I would claim they are not, given we have access to sunblock and vitamin D.

Jessica = still confused

spidergoat
08-30-07, 10:23 AM
I think willy brings up a valid point. Sexual selection may have been the dominant force that created the superficial differences between races. Inbreeding is a derogatory and innaccurate term. However, people tend to marry people that look like themselves. There are evolutionary reasons for this. This could replace geological isolation as a major selection factor.

thatbiogeek
08-30-07, 10:42 AM
I'm still a bit confused here however, inbreeding does not equal sexual selection. In evolutionary genetics, inbreeding is more commonly thought of in terms of inbreeding depression, a very undesirable thing. Are you saying that he means "sexual selection" when he says "inbreeding"? That would make more sense to me.

I also don't think we know that sexual selection is responsible for many of the physical traits that differentiate the races. For instance, just because darker skin conferred a selective advantage protecting its bearers DNA from UV damage, this does not necessitate that the trait is also attractive to the opposite sex and therefore sexually selected for as well. I'm sure it's possible, but why assume that there are two selective forces acting when there need only be one? It is just as likely that some of these traits were fixed in the population as a result of genetic drift. Are there any studies that suggest skin color or other physical traits are the result of sexual selection? That would be an interesting read.

Baron Max
08-30-07, 11:59 AM
I think willy brings up a valid point. Sexual selection may have been the dominant force that created the superficial differences between races.

Agreed. But if there are superficial differences, there may well be other differences as well -- like intelligence, the propensity to do violence, laziness, bigger dicks, ...., right?

Baron Max

spidergoat
08-30-07, 12:07 PM
I can't think of a reason to prefer a dumber mate over a smarter one, or a weaker one to a stronger one, or a lazier one to a more active one... This is still common in our culture, women prefer large muscular agressive alpha male types.

thatbiogeek
08-30-07, 03:20 PM
Yes, but we're talking about racial traits here, skin color in particular. I don't think intelligence is a racial trait. I don't really think there is any reason to assume that skin color necessarily be a sexually selected trait when there is evidence that it confers a benefit with regards to basic survival. I agree that stronger men would have been sexually favored, but I don't see what that has to do with race. -- maybe I misunderstood your point?

Also, I've always gone for the geeks- my husband is a geek :D

iceaura
08-30-07, 06:16 PM
Dominant traits - like dark skin and eyes in humans - don't require sexual selection or inbreeding.

It's recessive traits - like strange eye colors, yellow hair, and translucent skin - that need things like sexual selection or inbreeding.

Inbreeding would only explain some of the white races, not any of the yellow, red, or black ones, (assuming skin color is one of your criteria for "race", which is kind of silly but fairly common).

SAM had a good link to a sexual selection argument for Northern European eye colors, which are truly striking and unique among humans.

Fraggle Rocker
08-30-07, 09:49 PM
Thanks for your honesty. I can't believe how many of these "moderators" feel the need to lie as some kind of form of debate.Well I'm sorry dude. I didn't catch the UC link. I read through as much of the stuff as I could stomach and it certainly seemed like a pseudoscientific approach to racism. I removed the infraction. But as far as I'm concerned you're still skating on thin ice because virtually everything I've seen you post is a blatant attempt to establish a beachhead for racism on SciForums. It ain't gonna happen.

Willy
08-30-07, 11:12 PM
Thanks for being fair, much respect for you.

iceaura
08-30-07, 11:38 PM
This is worth repeating, in these circumstances:

Dark skinned people hold most of the genetic diversity of the human species. They are the last category of humans that could be called "inbred".

If there is any such thing as a human "race", there are several dark-skinned ones. Comparing "whites" to "blacks" would be something like comparing "terriers" to "dogs".

Willy
08-30-07, 11:47 PM
I don't really understand the point of this thread.
I posted this thread because I got a infraction for saying:

"The more a group of being's inbreed the more they will look alike.

The less a group of being's inbreed the less they will look alike."

Hercules Rockefeller
08-31-07, 12:20 AM
I posted this thread because I got a infraction for saying.....


:bugeye: You have received infractions because you are a racist troll.

You’re not fooling anyone. You racist trolls are all the same. You mix your racism and bigotry with out-of-context scientific concepts in an effort to legitimize your intolerance. The scientific validity of your musings on inbreeding aside, the only reason you are bringing it up in the first place is because your aim is to associate its negative connotations with the supposed inferiority of certain ‘races’ other than yours. This is, of course, totally bogus.

spuriousmonkey
08-31-07, 01:09 AM
The Finns are nicely inbred. Which makes them excellent study subjects to research human syndromes since most syndromes are caused by recessive alleles.

I think some American company already tried to buy a Finnish database with all this info because it is a goldmine for medical research.

fo3
08-31-07, 01:37 AM
Dominant traits - like dark skin and eyes in humans - don't require sexual selection or inbreeding.
It's recessive traits - like strange eye colors, yellow hair, and translucent skin - that need things like sexual selection or inbreeding.

Just out of curiosity - what information is there available on traits swapping from recessive to dominant? It seems logical that if a certain recessive trait is very beneficial to its bearer and it stays in the gene pool for a long time due to only sexual selection, it will eventually change to a dominant trait, to enable sexual selection concentrate on other potentially beneficial traits.

spuriousmonkey
08-31-07, 01:57 AM
You are all reading too much into the benefit of being dominant or recessive.

An allele is either dominant or recessive based on how it works. Being dominant or recessive says absolutely nothing about traits being beneficial or not.

iceaura
08-31-07, 08:18 PM
It seems logical that if a certain recessive trait is very beneficial to its bearer and it stays in the gene pool for a long time due to only sexual selection, it will eventually change to a dominant trait, to enable sexual selection concentrate on other potentially beneficial traits. I'm not following that. Why would it "change" into a form that hides its competition from selection pressure?

Genes are only "dominant" or "recessive" in relationship to each other. A dominant gene that imposes a handicap or vulnerability will be eliminated from the gene pool much more quickly than a recessive one - it's comparatively more difficult to get rid of a completely recessive gene.

spidergoat
09-01-07, 12:37 AM
Inbreeding is like what happens with the European royal families.

Baron Max
09-01-07, 06:30 AM
Inbreeding is like what happens with the European royal families.

Yep. But what does that have to do with the topic ...."Racial Inbreeding"? Note the term "racial"? How could the European royal families have done any "racial" inbreeding?

Baron Max

Exhumed
09-01-07, 08:33 AM
I think people are getting too touchy with the term "inbreeding". I know SAM posted a definition from wikipedia, which basically defined it as incest, but it is technically applicable to any group.

sniffy
09-01-07, 08:44 AM
A member of the human race 'breeds' with another member of the human race. A baby is born. Is this news where you lot come from?

fo3
09-01-07, 09:24 AM
I'm not following that. Why would it "change" into a form that hides its competition from selection pressure?

Genes are only "dominant" or "recessive" in relationship to each other. A dominant gene that imposes a handicap or vulnerability will be eliminated from the gene pool much more quickly than a recessive one - it's comparatively more difficult to get rid of a completely recessive gene.

An allele that has a negative effect to fitness has better chances to survive if it is recessive, but in case of an allele increasing fitness relatively more than other alleles of the same gene, it would benefit the species a lot more if it was dominant instead of recessive and being expressed in the phenotype more often. That would indicate that there is a selectional pressure for "better" alleles to mutate into a dominant form while retaining its positive effect, instead of staying recessive indefinitely.

iceaura
09-01-07, 06:49 PM
but in case of an allele increasing fitness relatively more than other alleles of the same gene, it would benefit the species a lot more if it was dominant instead of recessive and being expressed in the phenotype more often. Evolution does not proceed toward benefit, but away from culling.

If there are two alleles, one of which is comparatively and definitely an inferior reproducer, the replacement of the inferior by the superior will happen much faster and more completely if the inferior is dominant compared with the superior.

If the species "benefits" by that, so much the better - that would be a side effect.

Once the inferior is culled, the remaining allele would have the gene pool to itself, with no need of "dominance".

Xylene
09-01-07, 08:52 PM
I heard that one of the reasons that the European race isn't generally dark-skinned is that when you go north of the 40th parallel, (or south for that matter) the sunlight doesn't provide enough Vitamin D if your skin is too dark. Lack of Vitamin D = rickets, which removes people from the gene pool because A) the can't hunt; B) they can't very easily even move around; C) they're extremely unlikely to be chosen as sexual partners for reasons A and B. Therefore, over the thousands of years of gradual movement into Europe by various groups--and also taking into account the atrociously damp, cold, foggy conditions that would have existed in ice-age Europe--the tendency for the dark-skinned people to have been left behind, literally and figuratively, in the sexual selection process would have been very strong.

fo3
09-02-07, 08:36 AM
Evolution does not proceed toward benefit, but away from culling.
If there are two alleles, one of which is comparatively and definitely an inferior reproducer, the replacement of the inferior by the superior will happen much faster and more completely if the inferior is dominant compared with the superior.
If the species "benefits" by that, so much the better - that would be a side effect.
Once the inferior is culled, the remaining allele would have the gene pool to itself, with no need of "dominance".

The benefit for the species wouldn't be a side effect at all, it would be a reproductive advantage over other species competing for the same resources that do not tend to get as much dominant useful alleles as fast. This should be pretty much the idea of group selection, if I am correct.

iceaura
09-02-07, 10:32 AM
The benefit for the species wouldn't be a side effect at all, it would be a reproductive advantage over other species competing for the same resources that do not tend to get as much dominant useful alleles as fast. This should be pretty much the idea of group selection, if I am correct. But it would be a reproductive disadvantage for the superior allele - selection would not be eliminating its competition as fast or as completely.

And it probably would be a disadvantage for the species as a whole, long term, carrying the burden of the inferior allele as an all but ineradicable recessive.

That is indeed a common type and line of reasoning in "group selsction" - one of the reasons "group selection" is viewed with suspicion among evolutionary theorists.

fo3
09-02-07, 12:30 PM
I guess we can conclude that there are different levels of selection to be considered, and their interaction and level of importance in any given situation is difficult to evaluate. I did not think that my view would be the correct one in this situation, but I would still argue that having a beneficial allele in dominant position would have its advantages for a species, rather than having it in a recessive position and waiting for the less useful dominant allele to be eradicated. That should be especially important in situations where there is a fierce competition between species sharing the same ecological niche, and the long term benefit might mean a short time extinction, whereas a long term disadvantage might mean a short time success, allowing the species to handle the long term effects in a less competitive environment.