Are racial differences obvious and important, or nonexistent?

[drkitten]

This is not something I've heard of and I am sceptical as it doesn't conform to my understanding of the mechanisms which are resposible for the inability of two species to interbreed. Do you have any idea of the name of the species concerned so I can investigate?

What, the herring gull and the lesser black-backed gull? Formally, Larus argentatus-cachinnans-fuscus, I believe. Also Larus heuglin, vegae and smithonianus as well.

Other well-documented examples are a set of Californian salamanders (Ensatina escholtzii) and the Greenish Warblers (Phylloscopus trochiloides).

The general mechanism responsible for the inability of two species to breed is, in all of these cases, simple distance. In the case of the salamanders, for example, the breeding population runs from the west, to the north, and down the east of California's central valley. There is substantial gene flow along this semi-ring, but almost none at all directly across the valley.

 

[AWPrime]

I would simply call that a further adaptation as a result of increased mobility.

Like as if that is permanent situation.

The fact is, that a lot will be lost. And everyone would look boring.

 

[Throg]

I would simply call that a further adaptation as a result of increased mobility.

Yes, an adaptation to a change in the environment in which we live. I think there's a name for that sort of adaptation.

 

[Beth]

Re: Are racial differences real or nonexistent?

Race:

A local geographic or global human population distinguished as a more or less distinct group by genetically transmitted physical characteristics.

Are there any differences between human races that are important and real, or are all the differences imaginary/constructed..... or nonexistent?

Certainly there are real differences. For example, black people have darker skin than caucasians and asians have eyes with a different appearance than non-aisans do. Given that some obvious differences exist, it seems reasonable that there would exist other, non-obvious differences.

Are those differences important? Depends on what you consider important I suppose. There are none that I consider important.

Regarding the issue of within group variation being larger than the between group variation. That is true, but doesn't imply that between group differences don't exist. For example, the variation in height is greater within each gender than it is between the two genders, but you can still say that men are, on average, taller than women.

 

[Throg]

The general mechanism responsible for the inability of two species to breed is, in all of these cases, simple distance.

You mean they can't breed because they are too far apart to mate? If that's the only reason it's pretty trivial. I had understood the claim to be that the birds that were far apart were genetically incompatible which struck me as an extraordinary claim.

Thanks for the info. by the way.

 

[Throg]

Re: Re: Are racial differences real or nonexistent?

Certainly there are real differences. For example, black people have darker skin than caucasians and asians have eyes with a different appearance than non-aisans do. Given that some obvious differences exist, it seems reasonable that there would exist other, non-obvious differences.

"Darker skin" and "different eyes" are such wooly and subjective terms as to be effectively useless. Obvious is not necessarily real.

 

[drkitten]

You mean they can't breed because they are too far apart to mate? If that's the only reason it's pretty trivial. I had understood the claim to be that the birds that were far apart were genetically incompatible which struck me as an extraordinary claim.

The birds (or whatever) at the extremes are genetically incompatible precisely because they are physically too far apart to mate. Distance has produced a (partial) reproductive isolation, which in turn has resulted in partial genetic drift at both ends, so that the ends no longer meet.

The case of dog breeds is illustrative. A chiuahua and a St. Bernard are probably no longer physically capable of mating, and although it is probably possible to fertilize a chiuahua egg with St. Bernard sperm in vitro, I would be surprised if a female chihuahua could physically carry a litter of crossbreed St. Bernard puppies to term. On the other hand, a chihuahua can successfully breed with a dachshund, which can breed with a cocker spaniel, which can, .... which can breed with a Great Dane, which can breed with a St. Bernard. So there's a continuous mix of interbreeding population groups (I believe the technical term for this is a "cline").

But imagine what would happen if a mutant St. Bernard with green, photosynthetic, fur were born. Absent human intervention, we might see a new breed (St. Patricks?), and we might also see some other new (green) cross-breeds, such as a Bernard/Great Dane mix (perhaps that's a Great Irishman?). That's not that unlikely, although not certain either. On the other hand, seeing a new breed of chiuahua verde would be much more unlikely, because the genes would need to pass through so many more handoffs, spread so much more widely, and not be selected against in so many environments.

So we can see that genetic drift among St. Bernards is not likely to make it all the way to the other end of the cline. Which, in turn, means that St. Bernards are drifting further and further away from chiuahuas, which in turn is just increasing their reproductive isolation. Who knows, perhaps in a few zillion years, they will be two separate species.

 

[drkitten]

Re: Re: Re: Are racial differences real or nonexistent?

"Darker skin" and "different eyes" are such wooly and subjective terms as to be effectively useless. Obvious is not necessarily real.

Um, I believe the genes behind epicanthic folds (and, separately, the genes that control melanin levels in the skin) have been identified.

 

[Throg]

The birds (or whatever) at the extremes are genetically incompatible precisely because they are physically too far apart to mate. Distance has produced a (partial) reproductive isolation, which in turn has resulted in partial genetic drift at both ends, so that the ends no longer meet.

The case of dog breeds is illustrative. A chiuahua and a St. Bernard are probably no longer physically capable of mating, and although it is probably possible to fertilize a chiuahua egg with St. Bernard sperm in vitro, I would be surprised if a female chihuahua could physically carry a litter of crossbreed St. Bernard puppies to term. On the other hand, a chihuahua can successfully breed with a dachshund, which can breed with a cocker spaniel, which can, .... which can breed with a Great Dane, which can breed with a St. Bernard. So there's a continuous mix of interbreeding population groups (I believe the technical term for this is a "cline").

Sorry to be dense, but is the incompatibility a matter of physiological differences (which are obviously the result of genetics) or because of a genetic incompatibility such that there gametes are incompatible in vitro or in vivo?

 

[Throg]

Re: Re: Re: Re: Are racial differences real or nonexistent?

Um, I believe the genes behind epicanthic folds (and, separately, the genes that control melanin levels in the skin) have been identified.

Epicanthic folds don't really help as their conformation varies greatly withn and acroos traditional racial groups. Similarly, the sequence of genes that control melanin may be in a huge number of different states within and across those same racial groups. In theory we could create new racial groups which were identified with specific gene sequences but these groups would be just as arbitrary (if better defined) than the onld nonsense.

None of this, of course changes the fact that "darker skin" and "different eyes" are too vague and open to interpretation to be useful.

 

[drkitten]

Sorry to be dense, but is the incompatibility a matter of physiological differences (which are obviously the result of genetics) or because of a genetic incompatibility such that there gametes are incompatible in vitro or in vivo?

Either, both, neither. Depending upon the exact species you are looking at.

Physical differences are obviously one way of preventing mating (think about the poor chihuahua again), but there is nothing physical that prevents horses and donkeys from mating. The offspring of such a union, however, is sterile and cannot itself reproduce. There are also biological incompatibilities -- if a horse is artificially impregnated with a donkey embryo, she has a substantial (something like three chances in four) of spontaneously aborting it. Other species pairs simply have incompatible gametes.

At some point in the relatively (in geologic terms) recent past, there was a single species that somehow became reproductively isolated into two groups. One group drifted to become donkeys, another to become horses. At some more recent period, there were almost certainly two groups (proto-horses and proto-donkeys) that could have interbred, but didn't (for whatever reason).

 

[phildonnia]

Re: Re: Are racial differences real or nonexistent?

Here's an idea:

Let us say that "race" exists, in the sense that there are groups of somewhat genetically isolated people. However it is erroneous to say that any individual is "of" any particular race. As a metaphor, "clouds" exist, but you cannot identify every particle of moisture with a cloud.

Certainly, some individuals may "typify" a race. "Jesse Jackson is black" means that he exhibits characteristics common within that genetically isolated group.

Tiger Woods on the other hand, cannot possibly typify an isolated group, his genes being a product of a remarkable lack of isolation. If you say that "Tiger Woods is black", you're talking about his assumed inclusion in an arbitrary social class.

The fundamental assumption of a genetically decideable race for every individula must break down. Sadly, the use of race to denote arbitrary social classes remains.

 

[Throg]

Either, both, neither. Depending upon the exact species you are looking at.

Physical differences are obviously one way of preventing mating (think about the poor chihuahua again), but there is nothing physical that prevents horses and donkeys from mating. The offspring of such a union, however, is sterile and cannot itself reproduce. There are also biological incompatibilities -- if a horse is artificially impregnated with a donkey embryo, she has a substantial (something like three chances in four) of spontaneously aborting it. Other species pairs simply have incompatible gametes.

At some point in the relatively (in geologic terms) recent past, there was a single species that somehow became reproductively isolated into two groups. One group drifted to become donkeys, another to become horses. At some more recent period, there were almost certainly two groups (proto-horses and proto-donkeys) that could have interbred, but didn't (for whatever reason).

Yes, these cases I understand (horses and donkeys have different numbers of chromosones I believe). It is specifically, the cases of the gulls that I am concerned with. Is it the case for them, that the gulls furthest away from each other cannot produce offspring due to physiological reasons (in which case, that's easy to understand) or due to chromosonal differences (in which case it's obviously a complicated situation if they can succesfully reproduce with other gulls nearer to them in terms of distance) or some other sort of generic compatibility which I have not considered?

 

[Throg]

Re: Re: Re: Are racial differences real or nonexistent?

Here's an idea:

Let us say that "race" exists, in the sense that there are groups of somewhat genetically isolated people. However it is erroneous to say that any individual is "of" any particular race. As a metaphor, "clouds" exist, but you cannot identify every particle of moisture with a cloud.

Certainly, some individuals may "typify" a race. "Jesse Jackson is black" means that he exhibits characteristics common within that genetically isolated group.

Tiger Woods on the other hand, cannot possibly typify an isolated group, his genes being a product of a remarkable lack of isolation. If you say that "Tiger Woods is black", you're talking about his assumed inclusion in an arbitrary social class.

The fundamental assumption of a genetically decideable race for every individula must break down. Sadly, the use of race to denote arbitrary social classes remains.

I think this makes sense. Not sure it makes "race" any more useful but it makes sense. Personally, I would rather talk about Jesse Jackson as a man and, should we have occasion to dicuss the colour of his skin, as a man with dark skin. I don't really see the value in identifying him with the colour of his skin.

 

[Beth]

Re: Re: Re: Are racial differences real or nonexistent?

"Darker skin" and "different eyes" are such wooly and subjective terms as to be effectively useless. Obvious is not necessarily real.

An obvious difference is not necessarily real? You'll have to expand on that one for me. How do you define a "real difference" such that an obvious difference is not necessarily real?

 

[Beth]

Re: Re: Re: Re: Re: Are racial differences real or nonexistent?

None of this, of course changes the fact that "darker skin" and "different eyes" are too vague and open to interpretation to be useful.

Detectives consider information about the race of an assailant to be useful even if the differences between races are vague and open to interpretation. Forensic scientists and anthropologists can make a fairly accurate guess regarding the race of a person based solely on their bones. That indicates that even if the catagorization of 'race' is subjective, it's at least consistent enough to be useful to people in those professions.

 

[Throg]

Re: Re: Re: Re: Are racial differences real or nonexistent?

An obvious difference is not necessarily real? You'll have to expand on that one for me. How do you define a "real difference" such that an obvious difference is not necessarily real?

Essentially this: things that we are brought up to believe are obvious until we are given, or find for ourselves reasons to challenge them. For much of human history it was, apparently, obvious that women were inferior to men in every way. There was no reality behind this, it was just obvious. For much of history it was obvious that the sun revolved around the Earth. There was no reality to this, it was just obvious. It was obvious because social convention said it was so.

Are there differences in skin colour from person to person? Clearly. If you stood two people next to one another I could probably say that one had darker skin than the other. That would be safe and the difference is real. I could say that one of them had dark skin and one had white skin but that would not be so safe as I would no longer be merely making a comparison between two people I would be making the value judgement that each person's skin was beyond an arbitrary (and undefined) point on a continuum of colour and hue, one way or the other. This, I am not confident is a 'real' difference, because I am now placing each of these men in an arbitrary category and reducing a continous value to a single discrete (yet paradoxically ill-defined) value - dark skinned or light skinned. Finally, I could say that one person was a member of a "white race" and the other was a member of a "black race" at which point I am fairly confident that I will not have said anything real. Not only have I arbitrarily produced two discrete categories from a continuum of values without any attempt at precise definition of my categories, I have jumped taken these categories to imply something beyond what is even contained in the very fuzzy definitions of these categories: that a dark skinned man belongs to a different group than the light skinned man.

Detectives consider information about the race of an assailant to be useful even if the differences between races are vague and open to interpretation. Forensic scientists and anthropologists can make a fairly accurate guess regarding the race of a person based solely on their bones. That indicates that even if the catagorization of 'race' is subjective, it's at least consistent enough to be useful to people in those professions

Detectives are not necessarily to be upheld as exemplars of rationality. Useful does not imply real as I have discussed in a previous post. To repeat briefly, the Aristotlean model of the solar system and the concept of Phlogisten were useful but neither were real.

 

[Roboramma]

Thanks for a fine discussion and if you do come up with any more about thos birds could you let me know, 'cause it's going to bother me.

Just as a side note, I think the point I made with the gulls (thanks new drkitten) could as easily be made with our homonid ancestors.
What I mean is this. Any definition you make of homo sapiens the species will be able to include all living human beings. It will be able to exclude whichever homonid ancestor you wish to exclude. But there will also be a time when "humans" and "non-humans" are coexisting. Some will even be members of the same family. A son might be homo sapien, when his father wasn't (or, as is seldom pointed out, the opposite could be the case). If you change the definition you can exclude all those living at that time. But then you might also exclude some living today. Certainly you can just go back to another time when the same overlap was the case.
This I think is why homonid taxonomy is such a mess. We're trying to get more detail out of it than the system is capable of.
This isn't a problem with evolution (as some creationists try to point out) it's a problem with the concept of species. The concept works pretty well today because the intermediates are all dead, we don't have to think about them, but if you do try to think about the intermediates (such as classifying extinct "species") especially if you try to do so with a high enough resolution, the problem crops up again.
What's the problem? It's the same problem that you point out with race - these "definitions" are based on gene frequencies within populations. Now, with ancestral species you can look far enough back and find a speices whose gene frequencies will not overlap with our own. For example, you might look at "Lucy"and be confident to say "she was of another species". But if you try to look forward in time and say "now, was this fossil a member of Lucy's species, or our own" you might come to some trouble. At least at some point you can no longer make that distinction.
That's because all the members of our family tree lie along a discontious continuum that leads from "undeniably species A" to "undeniably species B" but if you try to look with high resolution at the boarder between them you find it's very fuzy.

The same principle I think is true of race. It's just a lot messier. Should we throw it out? For social reasons, probably. But I'm just pointing out that the concept of race has the same problems with it as the concept of species. Just to a higher degree. Neither one is "true", but whether it is scientifically useful is another question.
On the other hand this doesn't argue that the everyday sense of race which easily pigeon-holes everyone into their separate compartment has any validity at all. You've convinced me that it hasn't.

 

[Beth]

Re: Re: Re: Re: Re: Are racial differences real or nonexistent?

Essentially this: things that we are brought up to believe are obvious until we are given, or find for ourselves reasons to challenge them. For much of human history it was, apparently, obvious that women were inferior to men in every way. There was no reality behind this, it was just obvious. For much of history it was obvious that the sun revolved around the Earth. There was no reality to this, it was just obvious. It was obvious because social convention said it was so.

No disagreement that people often believe things that are obvious but not true. However, when discussing observed differences between groups, as we are here, it's a different story. The earth-centric versus solar centric theory isn't applicable - you're not comparing two groups. The differences between men are women are not only obvious, but also undeniably real. "Inferior" was a value judgement applied to those real differences.

I think you may be confusing value judgments about differences with the differences themselves. Saying that the differences in skin tone and facial charactoristics between races are real is a different matter than making a value judgement about those charactoristics. Now, can you give an example of an obvious difference between two or more groups (not even necessarily human groups) that are not real?

 

[Throg]

Any definition you make of homo sapiens the species will be able to include all living human beings

Actually, I'm not sure this is true. I suspect that any formal definition one came up with would have to be constantly revised to include counter-examples. I think that's always the problem when you start with the conceptual category and try to work backwards to find out what qualifies the things you place in that category to be there. Whatever definition you come up with, there's a good chance that you're going to find something that you have always considered to belong to the category and which you want to keep there but which does not conform to your formal definition.

This I think is why homonid taxonomy is such a mess. We're trying to get more detail out of it than the system is capable of

Agreed.

This isn't a problem with evolution (as some creationists try to point out) it's a problem with the concept of species. The concept works pretty well today because the intermediates are all dead, we don't have to think about them, but if you do try to think about the intermediates (such as classifying extinct "species") especially if you try to do so with a high enough resolution, the problem crops up again

Also, thanks to the relative scarcity of fossils we don't get too many contemporary problem-cases.

But I'm just pointing out that the concept of race has the same problems with it as the concept of species. Just to a higher degree. Neither one is "true", but whether it is scientifically useful is another question.

Agreed to all.

On the other hand this doesn't argue that the everyday sense of race which easily pigeon-holes everyone into their separate compartment has any validity at all. You've convinced me that it hasn't.

Actually, I think all I did was argue with you. In the end it was you that decided which arguments were the fit and which were fossils. Semantics? Maybe, but I think it's worth pointing out that I made no decisions for you and did none of your reasoning for you. You looked at the arguments and came to the conclusion. I did the same somewhere along the way.